Peter Spero has sent me the following abstract from a paper published in 2003 in the Journal of Alzheimer’s Disease:

It has been suggested that the dietary intake of omega-3 polyunsaturated fatty acids could be inversely related to the risk of dementia and cognitive decline. This analysis examined the association between plasma concentration of omega-3 polyunsaturated fatty acids and prevalence and incidence of cognitive impairment and dementia. Data are reported on subjects 65 years or older who had a complete clinical evaluation at the first two waves (1991-1992 and 1996-1997) of the Canadian Study of Health and Aging. Main outcome measures were cognitive impairment and dementia by mean relative plasma concentrations of fatty acids in the phospholipid fraction at baseline. Results were adjusted for age, sex, education, smoking, alcohol intake, body mass index, history of cardiovascular disease, and apolipoprotein E e4 genotype. In the cross-sectional analysis, no significant difference in omega-3
polyunsaturated fatty acid concentrations was observed between controls and both prevalent cases of cognitive impairment and dementia. In the prospective analysis, a higher eicosapentaenoic acid (p < 0.01) concentration was found in cognitively impaired cases compared to controls while higher docosahexaenoic acid (p < 0.07), omega-3 (p < 0.04) and total polyunsaturated fatty acid (p < 0.03) concentrations were found in dementia cases. These findings do not support the hypothesis that omega-3 polyunsaturated fatty acids play a protective role in cognitive function and dementia.

The people with worse-functioning brains had more omega-3 in their blood than everyone else. Which is opposite to one of the two studies I described yesterday.

I’d love to have seen what reviewers made of this.

Two papers in the latest issue of the American Journal of Clinical Nutrition provide more support for the idea that omega-3s improve brain function.

The first was a cross-sectional study involving about 2000 persons 70-74 years old in Norway. Their fish consumption was measured and they took a battery of cognitive tests. The more fish you ate, the better your score on every test, even after adjustment for several things.

The second used data collected as part of a 3-year experiment about something else (the effect of folic acid) with 800 persons aged 50-70. They measured the omega-3 concentrations in the blood of their subjects. Would these predict anything? Their results were more ambiguous:

Higher plasma n–3 PUFA proportions predicted less decline in sensorimotor speed . . . and complex speed . . . over 3 y. Plasma n–3 PUFA proportions did not predict 3-y changes in memory, information-processing speed, or word fluency. The cross-sectional analyses showed no association between plasma n–3 PUFA proportions and performance in any of the 5 cognitive domains.

Cross-sectional correlations between a measure of omega-3 (fish consumption) and cognitive performance are exactly what the first study did find.

The November 2007 issue of Acres USA, a magazine about organic/sustainable farming, has an article (not online) about using omega-3s to cure farm-animal problems. Here are the best parts:

One family reported that their dog had failed obedience training three times. Our therapy of cod liver oil (Nordic Naturals), Fasttrack probiotic, and a homeopathic prescription enabled him to pass on the next attempt. . . . Dogs experience panic attacks for a variety of reasons. One frantic German shepard dog jumped through a plate glass window to escape the house and get near his owner. The solution to his panic and anxiety attacks proved to be cod liver oil, the correct homeopathic medicine, and a whole-food diet rich in omega-3 oils and quality live probiotics.

The obedience-training story resembles my story of taking flaxseed oil capsules and the next morning being able to easily put on my shoes standing up. With the difference that I’d had trouble several hundred times in a row, not just three.

Thanks to Joshua Schrier.

Anonymous wrote again:

I started taking the flaxseed oil when I saw your post about Tyler Cowen not having to get gum surgery because he was taking it. I have had bleeding gums etc for most of my adult life, and nothing has ever made them better so I tried flaxseed oil. Worked great.

Tyler’s experience. My experience. Joyce Cohen’s. Tim Beneke’s.

A reader who wishes to be anonymous wrote:

I compete in MMA (mixed martial arts/ultimate fighting)–amateur of course, but I train with professionals. As you can imagine, full contact fighting leads to all kinds of sprains, strains, dislocations, etc. Ever since I started taking flaxseed oil–in caplet form, equivalent of 2 tablespoons a day–I have noticed a serious reduction in the number of small, inflammation-type injuries, and a reduction in recovery time for those injuries.

I asked what he meant by “inflammation-type injuries”.

That would be any injury where inflammation is the key component of the damage, for example:

-sprain
-strain
-bruise

This is opposed to injuries where the key component of damage is
something more significant, for example:

-break
-dislocation
-tear

Another way to put it would be that I don’t seem to get as many small injuries, and when I get them, they seem to heal quicker. I used to have to take like four Advil every day before I went to class, simply because I was so sore from the things we had done the previous days . Now, I don’t take any–and I haven’t changed anything else other than the flaxseed caplets.

Tissue inflammation is a huge part of most sports injuries. You ever watch Sportscenter, and see the post game interviews in the locker rooms? Notice how the athletes–especially pitchers–always have ice wrapped on their arms or knees or whatever? That is to reduce the tissue inflammation that occurs with high stress use. The general acronym for treating a minor sports injury is RICE (Rest, Ice, Compression, Elevation). Each of those are primarily designed to reduce tissue inflammation in the damaged areas, because once that is reduced, the body can heal itself much faster (I am simplifying this, but you get the point).

If high levels of omega-3’s really do reduce this sort of sports injury inflammation, it would be a HUGE discovery in sports medicine.

It makes sense. Injuries heal faster when the body’s “natural response” is reduced? Apparently the “natural response” is excessive.

Julia Powell, the inspired Julia/Julia blogger (the first blog to be made into a movie), wrote in the Washington Post she was “almost 95 percent sure that Seth Roberts, author of THE SHANGRI-LA DIET: The No Hunger, Eat Anything Weight-Loss Plan (Putnam, $19.95), is a snake-oil salesman.” Almost 95%?

How about 100%? Snake oil, it turns out, is high in omega-3.

Recently in Japan, a group of scientists at the Japanese National Food Research Institute led by Nobuya Shirai turned their attention to snake oil . . . Shirai and his team evaluated the effects of Erabu sea-snake oil on a number of outcomes in mice, including maze-learning ability and swimming endurance. In both cases, snake oil significantly improved the ability of the mice in comparison with those fed lard. . . .The original Chinese purveyors of snake oil offered something that probably did exactly what they claimed it would do: help fellow workers relieve the pain of their labors.

Thanks to Tucker Max.

Here is a very important omega-3 paper, titled “High Omega-3 Essential Fatty Acid Status in Nigerians and Low Status in Minnesotans,” that a reader named Melissa linked to in the comments. It shows you can have much more omega-3 in your blood than Americans even if you don’t eat fish.

Rural and urban Nigerians had similar omega-3 levels. Here’s what they eat:

The major carbohydrate-rich staples are the starchy tubers such as yams, cocoa-yams and cassava, the cereals rice and maize, and minor foods such as plantains and bananas. The major protein staples include legumes such as beans and pulses, seeds, nuts, cereal proteins and leaf proteins, some of which are rich in 18:3w3. Animal protein sources such as milk and eggs are virtually nil for rural communities, and are very limited for the urban population. Meats and fish . . . are in limited supply. Crayfish and dried fish are important but cost constraints limit intake.

The effect:

Nigerians have more than twice as much essential w3 EFA in their plasma lipids as do Minnesotans.

There was a negative correlation between blood levels of omega-3 and blood levels of omega-6. Perhaps raising omega-6 levels lowers omega-3 levels, even when the amount of omega-3 in the diet is constant. The theoretical mechanism is competition for the same enzyme. I haven’t yet studied this via self-experimentation; I will.

Thanks, Melissa.