AN OMEGA-3 PILL TO BANISH THE BLUES?: New animal research suggests a mechanism by which long-term omega-3 deficiency might contribute to mood disorders such as depression.
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Although most people in developed countries get plenty of calories daily, their diets are often lacking in key nutrients that their bodies have evolved to expect. Omega-3 polyunsaturated fatty acids, such as those found in fish and walnuts, are one category of crucial ingredients that the body cannot make on its own. Although these beneficial fatty acids are known to be good for heart health, researchers are just beginning to learn how omega-3s impact our brains—and by extension, our moods and behavior.
Lipids are integral to the central nervous system, and as studies of statins and diabetes drugs have shown, dropping levels of some lipids can have deleterious cognitive effects. Omega-3 deficiencies specifically have been linked to mood disorders, such as depression, but the underlying neural mechanism has been subject to debate.
New research in mice, published online January 30 in Nature Neuroscience, offers insights into just how dietary intake of these fatty acids might alter the brain's function. (Scientific American is part of Nature Publishing Group.)
"Our results can now corroborate clinical and epidemiological studies which have revealed associations between an omega-3/omega-6 imbalance and mood disorders," scientists behind the new study commented in a prepared statement.
The group, led by Mathieu Lafourcade of The French National Institute for Health and Medical Research (Inserm) Magendie Neurocenter in France, found that mice reared on an omega-3 deficient diet had lower levels of polyunsaturated fatty acids, such as docosahexaenoic acid (DHA), in their brains as well as higher overall levels of the more harmful omega-6. These mice also went on to exhibit a range of depressive symptoms in behavioral tests. The deficient animals, for example, gave up more easily in a classic forced swimming test, were less inclined to explore, and were more inclined to stay near the wall of a cage, "a widely accepted index of anxiety," the researchers noted in their study.
More specifically, the team found that a diet lacking ample omega-3 decreased the function of presynaptic cannabinoid receptors, part of the brain's signaling network that is thought to be involved in pain and appetite regulation. By getting down to synaptic levels in the brain—even if only in mice—the researchers seem to have taken a step toward explaining why omega-3 trials in humans have shown some success in treating mood disorders.
Others who have been following the links between nutrition and neuroscience are excited about the findings. "I think it's an important paper," says Gregory Asnis, a professor of psychiatry at the Albert Einstein College of Medicine in the New York City and who was not involved in the new study. "This raises concern [about] the true effect of omega-3 on behavior in human beings."
Omega-3 has already been used to treat depression in adults as well as children, but as Asnis points out, "not every [depressed] patient has omega-3 deficiencies." And although clinical data has shown it to be effective in some patients, "it's not a knock-your-head-over kind of data," he says.
Researchers can now measure a person's omega-3 levels relatively accurately via a blood test. Now that this test is available, "this research is really going to blossom," Asnis says. He suggests that screening might soon become routine for people with depression as well as other key populations, such as pregnant women.
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16 Comments
Add CommentGood article. I was hoping there would be a link to a site for dosage, but realized that's beyond the scope of the article. So I found and read an apparently objective piece (http://www.supplementquality.com/efficacy/fishoil_flaxoil.html) comparing fish oil to flaxseed oil, and am now motivated to switch from flaxseed to fish oil for depression and diabetes. Thanks, SA, for the nudge to explore further.
Reply | Report Abuse | Link to thisI wonder if the researchers took into account the effect of vitamin D? A good source of omega-3's is fish oil and, depending on the source, can contain a large amount of vitamin D (DRI). Vitamin D is involved in reducing seasonal depression, because our brains and minds slow down with lack of sunlight, which is our normal source of vitamin D. This is why the FDA has been adding it to our milk for decades.
Reply | Report Abuse | Link to thisIf the researchers fed the mice cod liver oil or any other product that contains livers, then you would have a muddied results.
hate to bust your bubble stew, but that ain't quite correct. Lovaza is a prescription O-3 that the FDA and others would have you believe is a "drug" because the drug company wanted it to be, hence the insurance companies would have to pay for it. Some idiots have referred to it as a drug which is garbage, it is fish oil. As to dose, depends. 3 grams per day is minimum, if you eat a lot of packaged goods (DONUTS,ETC) you may want to take more. You may also need to fill your tank if you are really deficient. It blows that doc's need to think it is a drug before they are bright enough to recommend it to their pt's, but they are probably saving more lives now than they ever did before (probably helping arthritis and a bunch of other inflammatory conditions as well).
Reply | Report Abuse | Link to thisDietary supplements are arguable. I'm old and I know I eat a crappy diet. So I take an Omega3 fish oil supplement, my Dr. thinks i'm wasting my money. But I would never recommend that others do as I do, and I would never take my medical advice from other internet comments. As for Omega6..... i've read some material which indicates it would not be good for me, so I skip that one. But again this is the comment section of an internet blog...so use your own best judgement. It's your money and your body.
Reply | Report Abuse | Link to thisI understand that, unlike OTC dietary supplement Omega-3 products, Lovaza is regulated by the FDA and monitored for quality. It is processed to eliminate mercury and other impurities that are a risk in OTC fish products. It is also specifically formulated to reduce triglycerides. I can't assess any value of that level of quality control A generic version may be available this year.
Reply | Report Abuse | Link to thisI happened to be prescribed Lovaza following an extended regimen of chemo that induced severe anemia. Within a week I noticed that my intellectual abilities had dramatically improved. I had at that time only been taking 1 gram daily.
A little research indicated that Omega-3 is thought to enable repair of the fatty myelin sheaths insulating the dendrites linking neurons. I guess that my health issues had damaged the dendrite insulation, diminishing electrical signal strength, improving neuron performance.
I doubt that anyone without that damage would have experience the improvement I saw. I also suspect that the myelin sheath repair was completed not long after treatment begun, at which time it could have been discontinued as long as I could maintain some reasonable (non-anemic) level of nutrition.
I'd recommend a brief 'experimental' treatment with Lovaza for anyone suffering from anemia, especially chemo induced. Fish oil gives you gas, but I haven't had many other problems. Consult your doctor...
In reply to @grandpa
Reply | Report Abuse | Link to thisIt is true that the ratio of omega3 to omega6 is something that everyone should bear in mind. As we tend to eat more of omega6s in our diets, it is not recommended to supply too much omega6 from supplements, but good high quality, purified omega 3 supplements should be considered, especially when it comes to patients with depression (as previously research indicated benefits for alleviating depression symptoms). There are many products available on the market, I can recommend Vegepa (available in UK, US and many other countries!)
I certainly didn't intend to be in anyway providing a commercial endorsement for Lovaza, but I did at least provide anecdotal evidence of my positive results.
Reply | Report Abuse | Link to thisYou bring up another issue: on what basis can you recommend a OTC Omega-3 product? How is anyone to evaluate them? I doubt that any indicate any mercury content on their label, for example, and I don't know that anyone requires or ensures that they do not contain it.
jt...the IFOS sets standards for fish oil. Anyone buying OTC fish oil should ensure that it is IFOS approved. IFOS approved products are as safe as Lovaza.
Reply | Report Abuse | Link to thisAssuming one has a healthy liver, the human body can easily metabolize low amounts of mercury. If it couldn't, the tuna industry would be out of business.
http://www.ifosprogram.com/IFOS/default.aspx
I'm a poster child for high doses of Omega Three. I'm bipolar and for the past 7 years I've added 10 standard fish oil caps, which gives you 1200mg EPA and 1800mg of DHA, to augment my regular medication. I buy the caps from Costco. If I don't take them for a couple of days, I find an edginess coming on. Most Fish Oil research even beyond depression, heart health for example, are using dosages at this level for positive therapeutic effects Here's a link to a compilation of fish oil/depression studies:
Reply | Report Abuse | Link to thishttp://www.psycheducation.org/depression/meds/Omega-3.htm
FYI - I was prescribed 4000mg of Lovaza daily for lowering triglycerides... I've reduced that to 2 grams daily, which I've been taking for nearly 3 years. Formulations of Omega-3 products are not identical, but I suspect you're not approaching dangerous dosage levels.
Reply | Report Abuse | Link to thisThanks - it's good that there is some self regulation of Omega-3 product manufacturers. As far as I know IFOS approved products might be more (or less) safe than FDA approved Lovaza. Lovaza is expensive, but I understand that generic prescription products should be available soon. Being a prescription medication, insurance coverage may apply...
Reply | Report Abuse | Link to thisRegarding mercury ingestion, I have to take a potassium depleting loop diuretic to address heart failure symptoms, so I also have to take an oral potassium chloride supplement. However, since excess potassium levels are fatal, I have to have blood tests to monitor it on a regular basis.
Reply | Report Abuse | Link to thisI do occasionally eat tuna, but I'm not sure its safe for people to obtain most of their nutrition from eating tuna these days, especially since some may unknowingly have liver damage. Likewise, self-treatment of medical conditions by ingestion of self determined dosages OTC dietary supplements that may contain some unknown quantity of mercury may be dangerous unless critical mercury levels are monitored.
I don't think it completely safe to dismiss mercury as a concern for anyone regularly ingesting substances that may contain it. I can't assess that risk either, but it should remain a concern...
I'm wondering how reliable your website reference is because when I wanted to know which is a better source of Omega-3 I picked up a bottle of fish oil and a bottle of flax seed oil and the flax seed oil was substantially better than the fish oil. Since Omega-6 absorbs before Omega-3 you need the best ratio you can get. Most fish oils have quite a bit more Omega-6 than Omega-3 whereas Flax seed oil has an even ratio. I checked across multiple brands and it was the same every time. I also did a bit of research across different brands for quality control and a couple of brands have good processes but most don't.
Reply | Report Abuse | Link to thisFor the basics of Omega-6/3 ratio benefits check with a medical information source that isn't out to make money off of you by selling something such as the USA NIH (link to Omega fats info provided below). Since most people get far more Omega-6 than is healthy, it is important to take an oil with as flat a ratio as possible and to avoid processed foods.
I forgot to include the NIH link.
Reply | Report Abuse | Link to thishttp://www.ncbi.nlm.nih.gov/pubmed/12442909
Good point about the mercury and the same applies to other environmental contaminants as well. This is why I switched to flax seed oil. It has no mercury and has a much better ratio of Omega-6 to Omega-3. As far as I have been able to determine the flax grows well with only minimal chemical intervention by the farmer. Never the less, history has shown that self regulation is next to meaningless so until a reliable governmental agency sets and imposes standards, I'll continue to not trust any of the producers. My blood profile is significantly better on the flax seed oil than it was on the fish oil but what works for one may not work for another.
Reply | Report Abuse | Link to thisIn reply to jtdwyer
Reply | Report Abuse | Link to thisI can recommend certain product, as I know from experience (and heard it from many people as well) that it might be helpful. I am careful when it comes to checking the product quality and wouldn't advice anyone something I don't trust myself. In doubts, it is always advised to check if the product meets international standards. Checking opinions of other people who tried specific products is also helpful.