Last October, Yale lecturer Erika Christakis sent an email questioning whether university administrators should advise students on what Halloween costumes to wear. It resulted in protests on campus and a heated debate around the country.
Omega-3’s, the fatty acids, found in cold water fish, plant oils, some nuts and leafy green vegetables, are known for their health boosting properties. They’ve been linked with reduced heart disease, improved energy levels and better brain function including reduced levels of depression. It is no surprise then that sales of Omega-3 fish oil supplements are strong. But many people are confused about how much is enough, and recent research raises some new questions about overall health benefits. Please join us to discuss what Omega-3 fatty acids actually do in our bodies, how much we need, and how to best to get them.
- Dr. Thomas Sherman associate professor of pharmacology at Georgetown University Medical Center.
- Susan Allport journalist and author of "The Queen of Fats"
- Dr. Majid Fotuhi chair of the Neurology Institute for Brain Health and Fitness, and assistant professor of neurology at Johns Hopkins University School of Medicine.
- Paul Coates director of the Office of Dietary Supplements at National Institutes of Health.
Ask The Experts: Our Medical Panel Answers Audience Questions###
We received hundreds of questions and comments from listeners about the health benefits of fatty acids. Our experts include Thomas Sherman, Ph.D.,, associate professor in the Georgetown University Department of Physiology and Biophysics., Majid Fotuhi, MD, Ph.D., chair of the Neurology Institute for Brain Health and Fitness, and Paul M. Coates, Ph.D., director of the Office of Dietary Supplements at the National Institutes of Health. Some questions have been edited for space and clarity.
Q: My eye doctor told me that fish oil supplements can help with dry eyes. Is this correct? — From Facebook user Eric V.
A: Dr. Sherman: Although there is an observation from the Nurses’ Health Study that there is an association between fish oil intake and decreased risk of dry eye syndrome, there is no clinical trial evidence to support this yet. What evidence there is mostly anecdotal or from studies in which there is a clear financial conflict of interest by the researcher.
Q: I am confused. Does Algal DHA replace Omega-3 fish oil or does one take both? — From Facebook user Janice D.
A: Dr. Sherman: Algal DHA is simply an alternative source of DHA. Essentially, now both you and the fish would be getting their DHA from algae.
Dr. Fotuhi: Yes. I am in favor of Algal-DHA. There is no need to take both.
Dr. Coates: Fish oil contains DHA as well as the Omega-3 fatty acid EPA. Algal DHA contains only DHA and is a vegetarian source of this Omega-3 fatty acid. Most research, particularly for heart health, has been conducted with formulations containing both DHA and EPA; studies examining infant neurodevelopment sometime use formulations containing DHA only. If you take fish oil only, you’ll get both DHA and EPA, and if you take algal DHA only, you’ll only get DHA. Taking both algal DHA and fish oil would effectively double the dose of DHA (assuming each product contains about the same amount of DHA).
Q: Can you get Algal DHA without the fishy taste? Also, does it harm the Omega-3 fatty acid supplement to freeze it? I am concerned about the oxidation of these fatty acids given the number of double bonds. Also, freezing may help prevent the burping with the associated fishy taste. — From Facebook user Amy A.
A: Dr. Sherman: I have never tried Algal DHA (or krill oil!). It is not uncommon to store DHA gels in the freezer, both to preserve freshness and to help avoid burping for those prone to that unfortunate side effect.
Dr. Coates: Algal DHA is a vegetarian source of DHA. Nevertheless, some people still find that it has a fishy aftertaste. Whether you take fish oil or algal DHA, you can try different brands, particularly those that are manufactured to dissolve lower down in the GI tract. This may help with the fishy aftertaste and burping. As far as storage, many dietary supplements have recommended storage guidelines listed on the product label, such as “Store in a cool, dry place”. Refrigerating or freezing products may be fine for some products but not others. It’s best to follow the manufacturer’s guidelines and contact the manufacturer if you’re not sure.
Q: I became severely allergic to fish and shellfish about 15 years ago. I used to eat fish between three and five times per week. Now I can’t eat it at all or take fish oil supplements. How can I get enough Omega-3 fatty acids? I am very concerned about this missing element in my diet. I eat healthy otherwise, lots of leafy greens, olive oil, etc. — From Facebook user Dale W.
A: Dr. Sherman: You should be able to safely take an Algal-sourced DHA if you wish. I would think that any certified vegan source of DHA would be safe. On the other hand, a good diet rich in walnuts, ground flaxseed or chia seed, and your leafy greens should be good.
Dr. Fotuhi: A person who is allergic to fish may not be allergic to Algal-DHA or other forms of DHA supplements. You can check with an allergy specialist.
Dr. Coates: We would recommend talking with your healthcare provider about other options to get Omega-3 fatty acids into your diet. There are two main types of Omega-3 fatty acids – short chain and long-chain. The Omega-3 fatty acids found in seafood and fish oil (EPA and DHA) are long-chain Omega-3 fatty acids, while those in plant products such as flaxseed and walnuts (alpha-linolenic acid) are short-chain Omega-3 fatty acids. Our bodies can convert short-chain Omega-3 fatty acids into long-chain Omega-3 fatty acids. Although this conversion process isn’t very efficient, it does mean that we don’t actually have to eat the long-chain Omega-3 fatty acids. So your health care provider may suggest incorporating more plant-based foods into your diet that contain alpha-linolenic acid, the short-chain Omega-3 fatty acid. Some foods are also fortified with these fatty acids.
Q: I heard this briefly mentioned on the show, but it is true that flax, chia and hemp need to be ground in order for their nutrients to be absorbed? — From Facebook user Jenna N.
A: Dr. Sherman: Yes. Flaxseed in particular is an effective laxative when consumed whole or ineffectively chewed. Its shell is composed of lignans that gel in the presence of water: try putting a spoonful in a small glass of water. This is probably not the effect you are aiming for, however, so ground flaxseed or flaxseed meal is best. If you don’t want to grind it yourself, purchase a bag of flaxseed meal and portion it into sealable sandwich bags and store them in the freezer. Use each bag for a week or two. A careful sniff will tell you if the meal is beginning to oxidize (turn rancid).
Dr. Coates: Our bodies have to break down both foods and dietary supplements to make the nutrients available for absorption in the GI tract. If you consume whole seeds such as flax, chia and hemp, it’s likely that some of the seeds will pass through your body without being broken down. Chewing or grinding the seeds probably makes the nutrients they contain more accessible by the body, but there’s nothing wrong with consuming the seeds in whole form. They provide dietary fiber, among other things, which has many health benefits.
Q: I’ve heard that recent studies suggest that Omega-3 obtained through food may have a benefit, while Omega-3 obtained via supplements (e.g. fish oil pills) don’t carry the same benefits. I was wondering if your guests could comment on these findings. — From Facebook user Will C.
A: Dr. Sherman: I am unfamiliar with these studies and would be surprised if they were anything more than anecdotal reports. It is not clear to me who would fund such a study other than a supplement manufacturer, and their results would surely not denigrate their own product! On the other hand, fish and other foods rich in Omega-3 and DHA are more than simply oil; they contain iodine, fat soluble vitamins, protein, etc. So there is no reason to assume fish oil supplements and fish are the same either.
Dr. Fotuhi: I believe that the Omega-3 fatty acid molecules have the same benefits, whether they are from food or from supplements.
Dr. Coates: It’s always preferable to get nutrients from food first because foods contain other compounds such as fiber and phytochemicals that also have health benefits. The Dietary Guidelines for Americans states that consuming about 8 ounces per week of a variety of seafood (providing about 250 mg per day of DHA and EPA) is associated with reduced cardiac deaths.
However, a lot of research has also been conducted on fish oil supplements providing both DHA and EPA. The FDA has approved a qualified health claim for both foods and dietary supplements that contain DHA and EPA, stating that “Supportive but not conclusive research shows that consumption of EPA and DHA Omega-3 fatty acids may reduce the risk of coronary heart disease.” Our fact sheet on Omega-3 fatty acids summarizes some of the research on these fatty acids.
Q: If we take a supplement of DHA and also eat organic free-range Omega-3 rich eggs, do we need to be worried about too much DHA? (For a nursing mother as well as young children.) — From Facebook user Amanda V.
A: Dr. Sherman: No. And you are doing a great service to your growing little one. Breast milk derives its DHA and other long-chain polyunsaturated fats from your diet, so the more, the better.
Dr. Fotuhi: The amount of Omega-3 in eggs is very small, and so taking it with a DHA supplement cannot become toxic. Taking DHA 900 mg/day has been shown to improve memory in one double-blind placebo-controlled study. Doses up to 1,500 mg are quite safe.
Dr. Coates: DHA itself does not have an established upper limit, but the Institute of Medicine of the National Academies states that it’s acceptable to consume between 0.6 – 1.2 grams per day of the short-chain Omega-3 fatty acid alpha-linolenic acid. If you are following the manufacturer’s recommended serving for the DHA supplement and eating a reasonable amount of Omega-3 rich eggs, there’s probably nothing to worry about. In most cases, people get into trouble when taking doses of supplements that are higher than the recommended amount listed on the label. This is true for most nutrients, including vitamins and minerals.
Q: What does the panel recommend for pregnant women? — From Twitter user @SilviaRdz
A: Dr. Sherman: this is certainly a conversation to have with your physician, but most recommendations include frequent fish intake. The biggest concern, of course, is the heavy metals and other contaminates of fish, which is why many pregnant and nursing mothers opt for pure fish oil supplements. On the other hand, cultivating a taste for small fishes offers enormous benefits and will serve you well for the rest of your life. Sardines, anchovies, smelt, wild-caught pacific salmon, trout, etc., are safe and tasty choices. Personally, I love canned sardines on toast or sardines or anchovies on a sandwich or in a salad. I cannot get my wife or kids to join me, however.
Dr. Fotuhi: I am in favor taking DHA for pregnant women. DHA is highly important for developing brain.
Dr. Coates: Consuming moderate amounts of seafood, largely due to its Omega-3 fatty acid content, may have a variety of health benefits including improved infant health outcomes. Therefore, the Dietary Guidelines for Americans recommends that pregnant and breastfeeding women eat 8-12 ounces of a variety of seafood per week from choices that are lower in methyl mercury. Women who are pregnant or breastfeeding should not eat four types of fish because they are high in methyl mercury. These are tilefish, shark, swordfish, and king mackerel. All types of tuna, including white (albacore) and light canned tuna are fine, but white tuna should be limited to 6 ounces per week because it is higher in methyl mercury.
Q: With daily Omega-3 fish oil supplements I get tinnitus and have heard similar reports, but no information on why. If the dose is reduced, ringing is too. Why? — From Twitter user @brrrrgrr
A: Dr. Sherman: I have also heard this, but have encountered both sides of this issue, with those who take fish oil to treat tinnitus and those who stop taking it because fish oil seemingly caused tinnitus. I have never heard of anyone saying that eating fish caused tinnitus, however. I should look into this, for it is commonly reported.
Q: What are the effects of DHA and Omega-3 from birth versus taking them up later in life? Do children benefit in ways adults cannot recover later? — From Twitter user @clayheaton
A: Dr. Sherman: There is a very nice paper published in 2005 from the EPIC-elderly prospective cohort study (BMJ 330: 991) that enrolled almost 75,000 men and women, aged 60 or more, across Europe. They were asked to adhere to a modified Mediterranean diet and the extent to which they adhered was scored on a 10-point scale. Those who increased their diet score, meaning that they changed their diets to better adhere to the Mediterranean diet, had a lower overall mortality. It is never too late to start.
Dr. Fotuhi: DHA is an important factor for growth and neuroplasticity in the brain. Children’s brains are in a constant state of rapid development and so it is possible that DHA may be particularly beneficial for kids. However, new research shows neuroplasticity and growth of new synapses continues in adults as well and so it is never too late to start taking DHA.
Q: What is the bioavailability of Omega-3’s from supplements? How much actually makes it into our systems without breaking down? — From Twitter user @trianglman
A: Dr. Sherman: unless you have some sort of fat malabsorptive condition, which is typically associated with many chronic GI ailments such as Crohn’s or Celiac disease, sufficient uptake of Omega-3 fatty acids is not a concern.
Q: My daughter and I are vegan and we get our Omega-3 from supplements from algae, flax seeds and chia seeds. Are these as effective as those sourced from fish oil? Also talk about the mercury problems with fish sources. — From Sara G. via Website
A: Dr. Sherman: Algae oil is very rich in DHA, but all other plants, including flax and chia seeds and walnuts, contain the precursor to DHA called ALA (alpha-linolenic acid). ALA is the dietary “essential Omega-3 fatty acid” for making the longer, more unsaturated, Omega-3 fatty acids, such as DHA (and EPA) that are so important. The problem is that we convert ALA to DHA ineffectively: on the order of 1–4% conversion in men and 8–10% in women (the enzymes that conduct this conversion are estrogen regulated). The other problem is that these enzymes are also responsible for converting the Omega-6 essential fatty acid, LA (linoleic acid) to its longer form (arachidonic acid). If your diet is very rich in LA, as most American diets are given our dependence on corn, this will impede the conversion of ALA to DHA. Eating or taking DHA directly from algal or fish sources obviates this concern.
Dr. Coates: There are two main types of Omega-3 fatty acids – short chain and long-chain. The Omega-3 fatty acids found in seafood and fish oil (EPA and DHA) are long-chain Omega-3 fatty acids, while those in plant foods (alpha-linolenic acid) such as flaxseed and walnuts are short-chain Omega-3 fatty acids. Algal DHA is another source of the long-chain Omega-3 fatty acid DHA. Research indicates that long-chain Omega-3 fatty acids have somewhat greater health benefits (particularly for heart health) than short-chain Omega-3 fatty acids. Our bodies can convert short-chain Omega-3 fatty acids into long-chain Omega-3 fatty acids, but the process isn’t very efficient, so consuming long-chain Omega-3 fatty acids directly is a more effective way of getting them into your body.
Some forms of seafood are higher in methyl mercury than others, but research indicates that the health benefits of consuming a moderate amount of seafood outweigh the possible detrimental effects of the methyl mercury. The Dietary Guidelines for Americans recommends consuming at least 8 ounces per week of a variety of seafood (less for young children). Even women who are pregnant or breastfeeding should consume 8-12 ounces per week of seafood, though they should choose varieties that are lower in methyl mercury and should not eat tilefish, shark, swordfish, and king mackerel because they are high in methyl mercury. All types of tuna, including white (albacore) and light canned tuna are fine for pregnant or breastfeeding women, but white tuna should be limited to 6 ounces per week because it is higher in methyl mercury.
Q: Is there a difference in Omega-3 from wild salmon versus farmed salmon? And if so, does the benefit from the Omega-3 from farmed salmon outweigh the chemicals in the fish? — From Jan via Website
A: Dr. Sherman: No, there is no significant difference in the chemical forms of Omega-3 fatty acids, but there can be in their amounts. Farmed fish is very dependent on the food source, and if they are fed good sources of DHA, they will be an excellent source of DHA for those who eat them. The problem is that many farmed fish are fed the fish meal byproducts of fish oil production. Not only are these sources already somewhat depleted of the essential oils, but often they are sourced from big fish rich in toxins. This “reverse-food chain” or “reverse protein factory” as Francis Moore Lappé (“Diet for a Small Planet”) referred to it, is creating a very unsafe product. So no, the DHA does not outweigh the chemicals. Find clean sources of fish or fish oil.
Q: In fresh or canned salmon, is there more Omega-3 in the skin than in the flesh? Most people don’t eat the skin. Should they? — From lynnlc via Website
A: Dr. Sherman: Omega-3’s are in the fat, whether it is the fat in the flesh or in the skin. If prepared properly – if that is the goal – fish skin can be just as tasty as the crispy chicken skin many are more accustomed to. I am not sure that we “need” to eat the skin, however. Trout is an example of a fish where I typically eat the skin; both because the skin of trout is thinner and more palatable, and because trout is not as fatty as other fish and its skin offers a bit more fat.
Q: What brand of supplements do you recommend for Omega-3, fish oil and DHA? — From bneupane via Website
A: Dr. Fotuhi: DHA from all supplements are equally effective. You need to read the label and make sure to get about 900-1000 mg of DHA/day. If you prefer a vegetarian form, you can take Algal-DHA. You can watch my interview with Dr. Oz for more information.
Q: I have a question about DHA and its use for a child who has had a brain injury at birth. Can DHA improve his brain function? He has cognitive, language and motor delays. Also, what would be a recommended amount? He also has apraxia of speech and some parents are using it for that. Is there a danger of giving a child too much DHA? What would that amount be? — From Sara M. via Email
A: Dr. Fotuhi: There is no scientific evidence that DHA can reverse the effect of brain injury at birth. However, DHA is critical for brain development and has no side effects. In a recent placebo-controlled clinical trial, children given 600 mg Algal-DHA improved their reading skills.
Q: Is whole fish-based DHA superior to algae based-DHA for health benefits (i.e., Does the DHA have more beneficial properties when obtained from eating whole fish as compared to taking algae-based supplements?) — From Susan E. via Email
A: Dr. Sherman: Remember, fish get their DHA from algae. Remember also, however, that fish are more than their DHA, and are a great food, perhaps the perfect food. Given a choice, I would rather eat fish than algae.
Dr. Fotuhi: DHA has the same benefits, whether it is from eating fish or from taking algal-based supplements.
Dr. Coates: Seafood and fish oil contain both DHA and EPA, while most algal-based products contain only DHA. DHA is the same compound whether sourced from fish or algae. Much of the Omega-3 fatty acid research has been conducted with formulations containing both EPA and DHA, so it is very difficult to separate the health effects of each.
Q: I am curious about how diet affects meat and milk. I have heard that if cows eat grass their meat has a better balance of Omega-3 and Omega-6. Is this true? Does it apply to milk also? Also, do walnuts rival salmon for content of beneficial fatty acids? — From JoAnn N. via Email
A: Dr. Sherman: It is definitely true that wild animals and grass fed animals have significantly more Omega-3 fatty acids in their meat and milk than do grain fed animals. That being said, they still do not represent a significant source of Omega-3 fatty acids, but it is much better than grain-fed meat. Personally, I think that feeding corn to cows is one of the worst things we have ever developed.
I love walnuts, but as I mentioned earlier, walnuts and salmon deliver very different kinds of Omega-3 fatty acids. Salmon has pre-formed DHA, whereas walnuts have the precursor to DHA, alpha-linolenic acid (ALA). The effectiveness of ALA is completely dependent on our ability to convert it to DHA, which is dependent on many other factors.
Dr. Coates: Just like humans, the foods that cows and other animals eat affects the levels of nutrients in their bodies and their milk. Chickens who eat feed high in Omega-3 fatty acids for example, lay eggs that are higher in Omega-3 fatty acids.
The Omega-3 fatty acids found in seafood like salmon and fish oil (EPA and DHA) are long-chain Omega-3 fatty acids, while those in plant products such as walnuts are short-chain Omega-3 fatty acids.Our bodies can convert short-chain Omega-3 fatty acids into long-chain Omega-3 fatty acids, but the process isn’t very efficient, so consuming long-chain Omega-3 fatty acids directly is a more effective way of getting them into your body.
Q: Is there a blood study, urine study, etc., that can be done to monitor Omega levels in the cells? I understand that it is very easy to get the ratio of Omega-3 and 6 thrown off with diet, resulting in too much Omega-6. Is it possible to have too much Omega-3? — From Cynthia via Email
A: Dr. Sherman: There are blood analyses that can measure red blood cell composition of Omega-3 fatty acids, that offer some sort of indirect measure of the level of Omega-3 fatty acids in our diet. I understand that these tests cost about $100 to $150. And yes, it is easy to have a lot of Omega-6 in our diets, but the consequences of a lot (too much) of Omega-3 are unclear.
Dr. Fotuhi: There are now commercially available blood tests to measure the amount and ratio of Omega-3 and Omega-6 fatty acids. At the doses of 500 mg to 1,500 mg, Omega-3 fatty acids are safe (except for people who take blood thinner medications such as Coumadin/Warfarin).
Q: The labels on most of the Omega-3 and fish oil supplements I see in the drugstore show the total amount of oils along with the amounts specifically of EPA and DHA. For example, the daily supplement I have been taking contains 1200 mg of fish body oils (marine lipid concentrate), with 400 mg of EPA and 200 mg of DHA. What should I be looking for by way of an adequate daily dose for an adult? — From Charles G. via Email
A: Dr. Fotuhi: My usual recommendation to my patients is 900-1000 mg of DHA per day.
Dr. Coates: Recommended dietary allowances (RDAs) have not been established for EPA or DHA because they are not “essential” nutrients (our bodies can make them from alpha-linolenic acid, the short-chain Omega-3 fatty acid). The RDA for alpha-linolenic acid is 1.1 – 1.6 grams per day for adults depending on age, gender and whether pregnant or breastfeeding. The American Heart association makes the following recommendations, but these are not government-issued recommendations: “The American Heart Association recommends that people without documented coronary heart disease (CHD) eat a variety of fish, preferably oily fish (salmon, tuna, mackerel, herring and trout), at least twice a week. People with documented CHD are advised to consume about one gram of EPA and DHA (eicosapentaenoic and docosahexaenoic acids, EPA and DHA) per day, preferably from oily fish, although EPA+DHA supplements could be considered in consultation with a physician. People who have elevated triglycerides may need two to four grams of EPA and DHA per day provided as capsules under a physician’s care.”
Q: You didn’t answer the caller’s question about Omega-3’s in dairy sources. Please address. — From Jennifer K. via Email
A: Dr. Sherman: Dairy is a poor source of Omega-3 fatty acids, but it is a source. Some types of milk are supplemented with DHA, which makes is a better source. Although the amounts are trivial compared to eating fish, I still recommend it.
Dr. Coates: Some foods, including some dairy products, are fortified with Omega-3 fatty acids.
MS. DIANE REHMThanks for joining us. I'm Diane Rehm. Omega-3 fatty acids are linked with any number of health benefits: lowered blood pressure, reduced inflammation and increased mental acuity. But it's hard to know how much is enough. And recent studies pose new questions about health benefits. Joining me to talk about what omega-3s may or may not do for us: Dr. Majid Fotuhi of the Neurology Institute for Brain Health and Fitness, Paul Coates of the Office of Dietary Supplements at the National Institutes of Health and Thomas Sherman of the Georgetown University Medical Center.
MS. DIANE REHMI invite you to be part of the program. Call us on 800-433-8850. Send your email to firstname.lastname@example.org. Follow us on Facebook or Twitter. Good morning, gentlemen. Thanks for joining us.
DR. MAJID FOTUHIGood morning.
MR. PAUL COATESGood morning, Diane.
PROF. THOMAS SHERMANGood morning.
FOTUHIDr. Fotuhi, I'll start with you. You've said that omega-3s are the building blocks of the brain. Explain what they are and exactly how they operate within the brain.
FOTUHII, first, want to thank you for having me on your show. I am very much interested in omega-3 fatty acids and have done research in this area and have found very strong benefits of omega-3 fatty acids for brain function, among other things. So I have looked into what they actually do, and I just summarize it for you. Omega-3 fatty acids are these chains of molecules which are anywhere between 16 or 22 carbon molecules attached together in a chain, and that's what we call omega-3 fatty acids.
FOTUHIAnd the three or six refer to the structure of double bonds which is a minor issue anyway. But these compounds in the brain do three things: number one, they reduce inflammation, number two, they increase blood flow, and, number three, they are very important for the structure of the membranes which are the surroundings of cells and make those things and are important for reduction of proteins associated with Alzheimer's disease. So the three things are: increase blood flow, reduce inflammation and structure of the membranes which are important for integrity of the brain cells.
REHMI gather you get these omega-3s primarily in food. But if not in food, some people take supplements for them.
FOTUHIThat's right. Just like many other vitamins, there are molecules that our bodies cannot make, and omega-3 fatty acids are examples of such molecules. An excellent source of omega-3 fatty acids, such as DHA, is fish, and the fish get it from algae. There are other sources, but they're not as good sources. Now, these include meat or egg or flax seed, walnuts. But the best sources are really algae and fish and some specific type of fish, such as salmon.
REHMDr. Majid Fotuhi, he's chair of the Neurology Institute for Brain Health and Fitness, assistant professor of neurology at Johns Hopkins University School of Medicine. And turning to you, Paul Coates, at the National Institutes of Health, I gather there have been some recent studies that raise questions about some of these benefits. Talk about that research.
COATESThe research, I think, you're referring to is a series of what are called systematic reviews with meta-analyses that have tried to understand the full body of evidence relating these omega-3 fatty acids to putative health benefits. And I think what you're referring to is that they raised questions about whether or not omega-3 fatty acids really do have the benefits that had been seen in smaller studies in ecologic sort of epidemiologic studies. And they do give us a pause to think about what it is we are looking at here.
COATESAre -- is it the omega-3s themselves that are providing benefits in certain kinds of studies? Are there confounding factors in those studies that make it seem as though we're losing the benefit of omega-3 fatty acids? We don't necessarily do studies the same way now as we did maybe 10 or 15 years ago. Our office actually sponsored a series of these systematic reviews about 10 years ago and discovered that for most of the putative health benefits, really, the data were not there.
COATESThere were some promising leads, but that the data were not there. Well, that doesn't mean that there isn't an effect. What it meant to me was that more research needed to be done. And so we've tried to enhance that research effort at the NIH.
REHMYou know, it's interesting. I gather it is -- it arises out of this question of why the Eskimos seem to be without heart disease and tend to eat lots of salmon and other fatty fishes.
COATESThis was a very exciting discovery and something that we really paid a lot of attention to. That was the whole research community, and there definitely had been studies that have indicated that there are benefits, cardiovascular disease benefits associated with increased omega-3 fatty acid intake usually from fish. Is it only the omega-3s from fish? Or is it something -- is it the broader array of things that are associated with eating fish that afford the benefit? And, to be honest with you, I don't think we know all of those answers yet.
REHMPaul Coates, he is director of the Office of Dietary Supplements at the National Institutes of Health. Tom Sherman, as associate professor of pharmacology at Georgetown University, you've said that these studies raise some red flags for you. Tell me about that.
SHERMANYou know, these studies seemingly contradict a lot of earlier studies that were seemingly very, very positive, and I think it just highlights a lot of changes that have happened in the American diet and in the way we administer health care for cardiovascular disease in the last 20 or 30 years. You know, when these studies were originally done back in -- started in the '60s and up through the '90s, our diets were different than they are today. You know, it's not just the fact that we're eating less fish oil.
SHERMANWe're eating less and fewer fruits and vegetables. We're eating way more carbohydrates. We're eating a lot more processed sugars. And I think other components of our diet are affecting the impact maybe, as Paul says, that these fish oils would be having on our health.
REHMCould it also possibly be that the foods themselves are changing the amounts of fish oil, for example, within salmon, the amount of omega-3 within walnuts? Could it be that something in the environment itself is changing?
SHERMANCertainly, the levels would be changing, and we learned that in the early days of fish farming that, you know, just like industry is trying to raise a population on corn in this country, we tried to raise populations of fish when we started fish farming on corn and realized that they will not survive. And fish, probably surprising to many people, don't make their own omega-3 fatty acids but derive them, as Dr. Fotuhi said, from algae, from marine dinoflagellates, which are shockingly rich in omega-3 fatty acids.
SHERMANBut -- and so we had to start feeding them these essential fats in order for them to survive. And certainly, many farm-raised fished, depending on where they're made, are very poor in omega-3 fatty acids. Tilapia, which is the chicken of the seafood realm right now, is very poor in omega-3 fatty acids, and that's what most Americans like to eat: a bland, white fish.
REHMSo do we have to take food supplements in order to achieve a healthy body balance of omega-3s, Dr. Fotuhi?
FOTUHIThe answer is yes. And I appreciate that Paul and Tom raised the issue of doing a systematic review and really figure out what is going on with this. Some people say it's good, sometimes not good. It's like vitamin E, you know, for a few years, it's good. In a few years, it's not so good. So what is the consumer to think of these things? And this is something that I read every day. And I keep up with the literature, so let me give you the bottom line. The problem is, as Paul mentioned, there are different outcomes that people measure.
FOTUHIIn one study, for example, people measure memory. In another study, people measure executive function. So how do you compare that? In one study, they put 300 milligram. In the other study, put 600 milligram. In one study, they have mostly African Americans, and the other study are mostly white people from Scandinavia, for example. So what have you got to do with this, and how are you going to make sense of these things? Well, I'll tell you.
FOTUHII published a paper, a systematic review of literature in Nature Clinical Practice Medicine along with a professor of neurology and psychiatry in UCSF, Dr. Yaffe, and we concluded that, overall, there seems to be a strong association with taking this DHA at about 900 milligram or 1,000 milligram and reduced risk for Alzheimer's disease.
REHMIn pill form.
FOTUHIYes. Many of them suggest that whether it's from pill or whether it's from strong diet with a lot of fish in it, that seems to be the amount. But that's an association, and that association does not mean causal. So then a study was published called MIDAS, which was a study, a double-blind, placebo-controlled. That's the gold standard of the studies.
FOTUHII mean, in that study, they took people which were 55 -- who were 55 years and older. And one group received placebo, and the other group received 900 milligrams of algal DHA, the very pure form of DHA from algae. And they found out that people who took that performed better in memory tests as if they were three to seven years younger.
REHMInteresting, all of it very interesting. I hope our listeners will join us with their own questions, comments. Stay with us.
REHMAnd welcome back. We're talking about omega-3 that we get from both foods and food supplements. There have been some recent studies that have raised questions in people's minds. This most recent study, I gather, included -- incorporated some 70,000 people which, in and of itself, could contain a huge variability. But I want to ask you specifically, Dr. Fotuhi, and then get the others to chime in. What about this relationship between omega-3s and Alzheimer's?
FOTUHIThere seems to be an association between taking omega-3 fatty acids and a reduced risk for Alzheimer's. But you need to keep in mind that Alzheimer's is a complex disease that has many different factors. So it's really difficult to say that any one factor would significantly abolish the risk for Alzheimer's.
REHMSo there's no way of proving that taking supplements or eating foods containing omega-3s is actually going to mitigate or indeed reduce the incidence of Alzheimer's? Paul Coates.
COATESYes, there are ways to do it. But what we've discovered in trying to do them is that they are difficult studies to do.
REHMWhy? Tell me why.
COATESThere are a lot of confounding factors that we don't always take account of. Background diet in people who are enrolled in these clinical trials can be quite variable. You referred to that when you mentioned 70,000 people in the systematic review of cardiovascular disease. And that can be confounding issue. We also don't know very much about the individuals who are included in these clinical trials.
COATESLet me give you a hypothetical: supposed we knew at the beginning that there were people who were responsive and then people who are not responsive, then maybe we would -- instead of seeing an average effect, we'd be able to articulate the effect in people whom we believe were responsive. Sounds really good, but it's very difficult to identify people who could -- to enroll in a trial like that.
REHMOf course, the other issue becomes we now seem to be able to at least begin to identify people who are susceptible or who might develop Alzheimer's disease. So if you've got that as something that's in your family history, would you, as individuals who've been studying this, recommend to those individuals that they take omega-3 supplements and increase the fatty acids in their diet? Tom Sherman.
SHERMANI would definitely recommend a diet or a Mediterranean-style diet that was rich in polyunsaturated fats and low on carbohydrate. But I wouldn't necessarily recommend supplements for fish oil because, I think, the associations, while sometimes there, are actually much stronger with staying lean, staying active, staying mentally fit, eating low, you know, keeping sugar levels low. Those associations and risks with Alzheimer's disease, I think, are stronger than the results that have been observed with fish oils. But it's certainly, certainly part of a really good diet.
REHMPaul Coates, a number of people have asked about the difference between omega-3s and omega-6s? Can you help us understand that?
COATESI can try, and I'm sure the others have opportunity to weigh in as well. Both omega-3 fatty acids and omega-6 fatty acids are classes. There's not a single one of either kind. They're all essential. They are not made by most individuals, and so we do need them. Omega-6s have tended to be looked at as the bad guys, and omega-3s...
COATESBecause they end up being the starting point for synthesis of fatty -- of factors that maybe problematic later on.
REHMTo put it simply, weight gain?
SHERMANProbably more inflammation.
COATESYeah. So our -- but they are both very important. Is the ratio between them as important? We don't really -- I don't really know that. But there is certainly plenty of evidence to suggest that omega-3s are less important or less seen in our diets now than are omega-6s.
REHMAll right. And joining us now by phone from Westchester County, N.Y., Susan Allport, she is the author of a book titled "The Queen of Fats: Why Omega-3s Were Removed from the Western Diet and What We Can Do to Replace Them." Good morning to, Susan. Thanks for joining us.
MS. SUSAN ALLPORTThank you, Diane.
REHMTalk about how omega-3s were removed from our diets and nutritional thinking. How did that happen?
ALLPORTWell, omega-3s and omega-6s are both the central fats, as was pointed out, but they compete with each other for positions in our cell membranes, such that if you have a diet that's very, very rich in the omega-6s, your membranes are going to be full of those fats even if you eat large amounts of fish. You have to eat very large amounts of fish or take large amounts of fish oils in order to counteract a diet that's very rich in those omega-6s. So...
REHMAnd what are the foods that contain these omega-6s that are problematic?
ALLPORTWell, seed oils tend to be very much richer in omega-6s than omega-3. So as we replace the butter and lard in our diet with these seed oils from corn and from soy, we very much increase the amount of 6s in our diet.
REHMThat's very interesting. And I gather that you experimented to see what changed when you tried to alter the balance between the omega-3s and omega-6s in your own body. What did you do?
ALLPORTI did do that. But a little a background is that we store omega-6s in our fat cells, whereas we don't store very much omega-3s. We either use them in our membranes, or we, you know, metabolize them. So we don't have large amounts of stored 6s hanging around. So when a person who -- on the normal American diet, has plenty of extra fat around, let's say, 20 pounds, a huge amount of that is going to be these omega-6s.
ALLPORTAnd when they go on fish oil, you're not going to see that fish oil showing up in their membranes for a long time because it's competing with those stored omega-6s. So I thought to myself, well, here I've been on a high-omega-3 diet for -- since 2004, since then, when I started researching this book, and I have fairly good levels of omega-3s in my body. Let me see if I go on what's recommended, to have fish twice a week but I'm going to change just the oils in my diet to be those oils that are very rich in omega-6. So I had a very healthy diet by most people's standards.
ALLPORTBut instead of my peanut butter with flax oil, which has a good balance of these 3s and the 6s, I switched to just peanut butter instead of my usual salad dressing of olive oil and canola, which happens to be a seed that has some omega-3s in it. I switched to salad dressings made with safflower or sunflower and corn oil. And I just made that change for a month, and the omega-3s in my tissues dropped by half. The DHA, which is so vital for brain function, also dropped by about a half.
REHMAnd what happened to your weight?
ALLPORTAnd I thought my weight -- I felt really heavy after this. But my weight went up just half a pound and not very much and -- which was the reason this article had been commissioned by Oprah Magazine. But they didn't run it because they thought, well, half a pound of weight after a month, who's going to think there's anything significant about that? But my resting metabolic rate also dropped, and that could've accounted for that gain in weight.
REHMAll right. And finally, you write that when it comes to diet trends, the public usually focuses on just one bad guy or a good guy at a time. What's to say that the current fixation with omega-3s isn't just another in a long line of fixations?
ALLPORTIf that's question for me, it's because there are all these clear biological mechanisms linking omega-3s to better health, and chief among those are the reduced inflammation, the increased blood flow and the better structure of membranes because those omega-3s are faster fats, and they get in there and create membranes where enzymes can do their jobs much more readily.
REHMSusan Allport, she's the author of "The Queen of Fats: Why Omega-3s Were Removed from the Western Diet and What We Can Do to Replace Them." Thank you so much for joining us.
REHMGood luck with your eating habits.
ALLPORTThank you very much.
REHMAll right. We've got lots of callers waiting. I'm going to open the phones now. Our listeners are always a very important part of the program. Let's hear their questions. First, we'll go to Indianapolis and to Dan. Good morning to you.
DANGood morning, ma'am. I have been a vegetarian since the age of 18, and as I've progressed, I'm now practicing medical doctor psychiatrist and searched for sort of vegetarian options of omega-3s as most foods that are supplemented include fish oil, and a lot of flaxseed pills are in gel caps. And that has led me to looking at various things like, for instance, milk. And I was wanting to know if your guests could comment on the content of omega-3s in milk and sort of the effects of the fat-free dairy movement and the removal of the omega-3s via that process.
REHMInteresting. Dr. Fotuhi.
FOTUHIYes. The amount of omega-3 fatty acids -- and I must specify is that DHA, that's the most critical. As Paul mentions, omega-3 fatty acids are a group of compounds, not just one. There are probably 10 of them. And the most important one and the one that seems to be most critical for brain function, for brain development, for prevention of cognitive impairment with aging seems to be DHA.
FOTUHISo let's focus on the amount of DHA in various foods that we can -- we eat. So salmon, let's say, has anywhere between 700 milligram or 1,000 milligram, whereas meat or poultry or walnut or all of these other ones have in the magnitude of one or two milligrams per serving. So there's a huge difference in the amounts that we get from, let's say, salmon versus other sources.
REHMNow, I have in front of me a Wall Street Journal report on this study that was recently done, which says that a serving of salmon can contain anywhere from 1,200 to 2,400 milligrams per 4-ounce serving. And that's a salmon steak I'm looking at, which tends to be the fattier portion of salmon. And then a look at walnuts would indicate that you get 2,300 milligrams from a quarter of a cup of walnuts. That puts them pretty much on the same level, doesn't it?
FOTUHIWell, I need to look at the sources before...
SHERMANThey're probably not making a distinction between DHA and alpha-linolenic acid...
REHMOh, my goodness.
SHERMAN...which is the essential fatty acid that we need.
SHERMANIt's actually a very interesting difference. I mean, all plants, leafy green vegetables, walnuts, things like that can be very rich sources of omega-3s, but it's the essential fatty acid that we then process and extend to make DHA. And that -- we do that slowly, but we do do that.
REHMAnd you're listening to "The Diane Rehm Show." I want to go back to our caller who talked about her own experiment, Susan Allport. From a physician's perspective, Majid, what is your thought on her experiment with trying to change the balance between the omega-3s and the omega-6s?
FOTUHII think she was absolutely right. One way to think of the omega-3 and omega-6 fatty acids is to compare them to LDL and HDL. We know that LDL is a bad cholesterol, HDL is a good cholesterol. So, same way, omega-3 fatty acids and, again, DHA seems to be the good omega-3 fatty acid, the good guy, and omega-6 fatty acid seems to be the one that are not so good, and they're associated with increased risk of inflammation.
REHMYou're smiling, Tom Sherman.
SHERMANI mean, it's true. I mean, it is true. It's just that this competition between omega-3s and omega-6s is very seductive biochemically because we know that these two pathways compete for enzymes that take these essential fatty acids and make them into arachidonic acid or DHA. It's very seductive, but we've actually never seen good studies that have confirmed that. And so we -- it makes sense.
SHERMANIt seems like it should be that way, but the studies have never actually been particularly strong in that regard. And so I'm always sort of waiting to see who's going to design the experiment that sort of decides this question.
REHMSo you're saying it's going to be awfully hard to do.
SHERMANIt is hard. You know, Susan is right, and Dr. Majid is right, too, I mean, that omega-6s have dominated our diet and omega-3s are more rare. And it's -- and we really can't implicate it or associate it with all of these things. It's just that it's an association, and...
REHMPaul, what do you think?
COATESYeah. And I mentioned a little earlier that these studies need doing. They are not easy to design, but I think we are obliged to be able to do them. If we're going to be able to say that A causes B, then we have to figure out a way to go beyond just association between the potential intervention and the health effect. We need to show that, and it has not been easy to do that.
FOTUHIYes. So I think that what we need are double-blind, placebo-controlled studies, and more of them are getting published these days. One was just published recently and showed that children ages 7 and 9 who took DHA performed better in the reading versus children who received placebo. It was a placebo-controlled study. The MIDAS study in which people took 900 milligram of algal DHA was a placebo-controlled study.
REHMSo it's also indicated that omega-3s may help with ADHD in some children?
FOTUHIYes. And, again, as Paul and Tom mentioned, it's really difficult to have good outcomes that everybody agrees on and uses the same thing. So the challenge is doing the right studies.
REHMDr. Majid Fotuhi, he's chair of the Neurology Institute for Brain Health and Fitness. Short break here. We'll be right back.
REHMAnd welcome back. We're talking about omega-3s. Some have raised questions about some recent studies involving some 70,000 people to try to determine exactly what the benefits are and what the benefits may not be from either eating omega-3-filled foods or taking omega-3 supplements. Here's an email from Linda, who says, "Does canned salmon have the same benefit as wild salmon? Also, is fish oil better than cod liver oil?" Tom Sherman.
SHERMANCanned foods -- so, actually, back -- actually, Susan Allport could have answered this question well, too, that the reason omega-3s many times are removed from processed foods is that they shorten shelf life, that it's when they oxidize, they contribute to the rancidity of food. So if canned salmon is rancid, then not only is it not edible, but its levels of omega-3 are going to be lower. But if it's edible and it's good, then it's going to simply reflect the amount of omega-3s in that fish when it was canned. The second question was?
REHMWell, the second question was in terms of fish oil and cod liver oil.
SHERMANOh, so fatty fishes: the mackerels, the sardines, the salmons, they're fatty fishes because the fat is in their flesh where lean fishes keep the fat in their livers. And so it seems like a good idea to eat cod liver oil because that is where all the oils are, and they do have lots of omega-3s. But they also have very high levels of vitamin A, which can be problematic for people who take too high levels of vitamin A in terms of bone health, in terms of some cancer risks, so...
REHMSo you would say that fish oil is better than cod liver oil?
SHERMANOh, definitely. Definitely.
REHMDefinitely. OK. Here is an email from Gloria, who says, "I was taking fish oil supplements until my doctor recommended krill oil as a better option. What's the difference? And is it really better?" Paul Coates.
COATESI think krill is one of those microorganisms.
SHERMANIt's the little crustacean.
COATESIt's the little -- oh, it is. So it's not...
SHERMANIt's the -- it's -- I mean, it's a good source of omega-3s, but, yeah.
COATESBut is it -- it's not the vegetarian source that you might think algae are.
SHERMANYou know, that's a good question.
COATESYou know, they are little micro-crustaceans.
REHMI love the fact that doctors themselves are not quite, quite sure.
COATESYou know, the point there, though, is that the lower you get into the food chain, the cleaner your omega-3 fatty acids are going to be, and so the lower...
REHMThe lower you get in the food chain.
COATESAnd so as you eat -- so as you go from dinoflagellates and algae and krill, to anchovies and sardines up to salmon, the bigger the fish, the more fat they store, but the more that they accumulate these toxins, heavy metals...
COATES...pesticides in the water. So...
REHMYeah. Well -- and you've got these warnings, for example, about swordfish and mercury. So how do you balance? Is swordfish not one of the fish that you gentlemen would recommend?
SHERMANSwordfish doesn't -- is not a big source of omega-3 fatty acids to my knowledge.
SHERMANBut in the -- just so you know, when fish oil supplements are manufactured, very often, the manufacturing process itself eliminates a lot of those toxins. That's not guarantee that they're not there, but they're considerably less in supplements, ironically, than there might have been in some of the native fish.
REHMOK. I do want our listeners to know, because I realize that there are great many people online with questions, that our three doctors have agreed to be online to respond to your questions. After the program, they'll do it by virtue of answering questions that come in on the Web. I hope I'm saying that correctly. If I'm not, somebody's going to call me and say, Diane, you didn't say that right. OK. Let's take a caller in Gainesville, Fla. Good morning, Bill. You're on the air.
BILLGood morning. Yeah. I take Lovaza because my doctor says I would not get enough of the omegas I need from fish and flaxseed and walnuts for my purposes. Can you speak to any research showing that omegas help with depression? And is there any harm in taking Lovaza? I'd -- I haven't had any side effects. Thank you.
COATESI'd be happy to try to answer that. Lovaza -- or is the prescription drug version of omega-3 fatty acids. And it has a fairly specific clinical indication, and that's to reduce the level of triglycerides in blood. I'm not aware -- maybe one of my colleagues is -- about the use of this drug for depression or other...
FOTUHIYes. To my knowledge, this study -- this drug has not been tested in clinical trials for depression, though I'm not -- I wouldn't be surprised if there are ongoing clinical trials.
FOTUHII think the best source, in my opinion, is to take algal DHA. As Tom mentioned, algal is the most pure form, and algal DHA is a supplement that people can take. And a clinical trial that was done was done with algal DHA 900 milligrams. So that's makes it easy for me. That's what I take myself. And, you know, we're talking about children with ADHD. I do -- I give it to my two daughters, who are five and seven. It's like a desert after dinner. We have our little DHA supplement. They have smaller amounts, obviously, than I do.
REHMInteresting. Seven and nine.
FOTUHIFive and seven, yeah.
REHMFive and seven. All right. Here's an email from Michelle: "If algae is the source of the omega-3s in fish, can we just eat seaweed to get the same benefits? I realize this might not be a popular suggestion, but it sure would be cheaper." Any comment?
COATESI mean, yes, you can do that. It actually be -- the seaweed is typically commercially available, isn't particularly rich in omega-3 fatty acids. But probably, more importantly, when somebody eats seaweed, they actually don't eat very much seaweed. And so -- I mean, yes, it would be part of a good diet and -- but it is -- it wouldn't necessarily be a replacement.
REHMAll right. To San Antonio, Texas. Good morning, Philip.
PHILIPGood morning. Yes, I'm a forager, and a lot of people don't realize in this country that we don't market purslane very well in this country. It's a wild succulent that just grows in my yard, in anybody's yard. And you could probably buy it at Home Depot potted in a plant, and that's the only way we market it in this country. We do not real -- it's higher in omegas than spinach, and nobody even realizes it.
COATESYou're right. And sometimes we have these unexpected treasures even in our own backyards.
FOTUHIYeah. It isn't the best tasting we've known, but...
REHMWell, it do sound that way.
FOTUHI...Susan Allport tells a good story in her book, "The Queen of Fats," about how free-range chickens will eat purslane and insects and that the high levels of omega-3 in those plants lead to eggs that are just so rich in omega-3s that they compete with many fish and are delicious.
REHMAll right. Here is an email from Kate, who says, "This topic is great. Could your guests go out on a limb to help an overwhelmed mother and prescribe a source of omegas for my family: one husband, almost 40, 6-year-old boy, 4-year-old girl, 18-month-old boy and me, a 35-year-old woman. In case it matters, I am white, and I live in Ontario." Majid.
FOTUHIYes. I'll tell you what I take. I'm actually on the same age group as what's mentioned. And my wife and myself and our daughters are the same age. So I usually take 900 milligram of algal DHA and my wife does the same. And our daughters take 100 milligram each.
REHMSo a different milligram counts depending on the age. How do you feel about that, Paul?
COATESI'm not quite as excited about that possibility. I would very much like to see people consider taking omega-3 fatty acids. But if they're taking them in relatively high amounts -- and I'm not saying that 100 milligrams is high for a child -- I would probably be a little more comfortable if I saw this being done under the supervision of a health care professional.
REHMOf a physician. And what do you say, Tom Sherman?
SHERMANWell, I'm the proud father of three beautiful daughters, including a 2-year-old and 4 1/2-year old, and we take more of a dietary approach. And we -- our daughters have grown up eating fish, eating green vegetables, eating nuts and my granola. And I think developing these kinds of eating habits is going to serve them well for their whole lives.
REHMOf course, I adore walnuts, so I'm with you. Let's go to Boston, Mass. Good morning, Heather.
HEATHERHi. Thank you for having me on the show.
HEATHERI wanted to bring up the idea of chia seeds which are antioxidant rich, so they don't spoil and then rich in omegas. And then also after that, coconut milk as a DHA alternative as I'm raising a vegan son.
SHERMANWell, chia seeds are very rich in DHA which -- I mean, in alpha-linolenic acid. It's, you know, given my growing up with Chia Pets, I've always thought that was entertaining. I don't think there is DHA in coconuts, but they are a very rich source of short-chain fatty acids which have their own benefits. But, yeah, chia seeds, they're small, so they really have to be ground. Our teeth are really designed for grinding those really small seeds.
REHMAll right. To Detroit, Mich. Hi there, Chuck.
CHUCKYes. I just wanted to provide an endorsement of fish oil and the omega-3s. I lost my health insurance about in the mid-'90s and started taking a nutritional regimen and -- including, you know, lots of supplements, including large quantities of fish oil. And I discovered some of my other ailments, such as Crohn's disease, reversed. My depression went away. And I was taking fairly large quantities, and I still do.
REHMInteresting. Dr. Fotuhi.
FOTUHIYes. I think that 1,000 milligram -- roughly 1,000 milligrams seems to be a good dose, but sometimes people take 2,000 or 3,000 milligram a day. And I think when you get to that range, then, if you're taking Coumadin or some blood thinners, you may be at risk for harmful issues. But at the range of 1,000-plus or minus, you know, 500, I think, people are safe. And again, the distinction is between fish oil, omega-3 fatty acids and DHA. DHA is a form of omega-3 fatty acids, and fish oil have a lot more than omega-3 fatty acids.
FOTUHISo I personally prefer DHA because DHA has been associated with reduced blood pressure, better HDL, better brain function. And I have seen in some studies that I feel there is plenty compelling evidence that I would take it myself.
REHMI have the feeling there is going to be a run on this across the country. Are you, Paul Coates, comfortable with what Majid Fotuhi is saying without talking with your own physician?
REHMYou are not?
COATESThat's the easy answer.
COATESBut there's a lot behind it. And the fact is that associations are really very important in helping us to discover whether something will have a benefit in a particular setting. Since I make decisions that are intended to effect the public health rather than the clinical decision making that goes on between a patient and the health care provider, I have to worry about things like, are there side effects that we don't know about? They have not been completely studied.
COATESI'm not saying that omega-3s have a dangerous safety profile. They certainly do not. But there are some things that we don't know. And if I'm going to be making recommendations across a population, I feel I need to have a higher bar for evidence.
REHMPaul Coates is director of the Office of Dietary Supplements at the National Institutes of Health, and you're listening to "The Diane Rehm Show." Let's go to Crystal Lake, Ill. Good morning, Yvonne.
YVONNEGood morning. Thanks for taking my call.
YVONNEI'm a physician, and I've done quite a bit of research in the last year on how to best help my patients. And I've been recommending fish oil capsules. And my question is, because I've been researching the krill oil also and I know someone else called with this question, the difference that they market for the krill oil is that it's in the phospholipid form so it's supposed to be better absorbed.
YVONNEHowever, the dosage of the DHA that's in each capsule of krill oil is only 62.5 milligrams, whereas, you know, I use a omega-3 that has 200 milligrams per capsule. And I know you can get the higher DHA capsules that have much more. But I wonder if there's any comment from the people on your show today regarding whether the phospholipid form is that much better absorbed to warrant the much lower dose in the krill oil capsule.
SHERMANNo, I don't believe so. I mean, fats -- unless you have a malabsorption disorder, fats are going to be well-absorbed no matter what.
REHMAnd here is a tweet: "So many vendors are offering vitamin supplements, particularly for omega-3-type supplements, what is the pertinent criteria when choosing?"
SHERMANActually, Paul could probably answer that one best.
COATESJust to distinguish, vitamins are not the same as omega-3s, but they are all in the category of dietary supplements. And I think the overarching issue that we should be concerned about is the quality of the products that are made and be able to identify reasonably well that the contents are what they say they are on the label.
FOTUHIYes, I agree. But also, just following up the conversation we had just before this question is, why doesn't NIH support the recommendation of the DHA for use for brain health? There are double-blind, placebo-controlled studies. Another one is published. How much more do we need to say that it is at least good?
COATESDo all of the studies that you're aware of point to -- in the same direction?
COATESI'm not aware that they all point in the same direction. And that's probably where the tension lies, that there may well be some evidence of benefit. And that usually should be a good clue for moving forward with research.
REHMPaul Coates, he is director of the Office of Dietary Supplements at NIH. Dr. Majid Fotuhi, he is an assistant professor of neurology at Johns Hopkins University School of Medicine. Tom Sherman is associate professor of pharmacology at Georgetown University Medical Center.
REHMWe know we can't get to all of your questions, could not get to all your questions during this segment, so, please, submit your questions for this panel via email, Facebook or Twitter. We'll post as many answers as we can on our website, drshow.org, by tomorrow. Thank you, all. And thanks for listening. I'm Diane Rehm.
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