Seth’s blog

Susan Allport, having written The Queen of Fats, unsurprisingly eats a diet high in omega-3 and low in omega-6. For one month, however, she ate a diet with more omega-6 and less omega-3 and wrote about it– like Supersize Me, except far more realistic.

O magazine commissioned a story about it but didn’t run it. “My weight gain was only 0.5 pounds and they thought their readers wouldn’t see the importance of that,” says Allport. Her draft is here. There were three striking changes over the month: the omega-6/omega-3 ratio in her blood doubled (implying that this ratio is controlled by diet rather than by stored fat); her belly fat noticeably increased; and the elasticity of her arteries decreased by 20%. This supports Allport’s belief (and mine) that omega-6 is dangerous when consumed in large amounts, as it is if you eat a lot of food cooked in vegetable oil.

The American Heart Association recommends that Americans eat more omega-6. The justification of this recommendation says nothing about the Israeli Paradox, which to me is the best reason to avoid a diet high in omega-6. Allport’s experience is another reason.
Allport is also the author of Explorers of the Black Box, about neuroscience research.

A few years ago I learned that flaxseed oil improved my gums and other people’s — especially Tyler Cowen’s. A few months ago I went to Beijing for two months. Toward the end of the visit my gums would bleed when I’d use a toothpick. Yet I was drinking 3 tablespoons of flaxseed oil every day, just like in Berkeley. (more…)

• “ant tribes” near Beijing
• What exactly is umami?
• Is omega-3 an antidepressant?  “Initial analyses failed to clearly demonstrate the effectiveness of Omega-3 for all patients taking part in the study. Other analyses, however, revealed that Omega-3 improved depression symptoms in patients diagnosed with depression unaccompanied by an anxiety disorder.” Are they fooling themselves? Maybe not. My research suggests that morning faces can reduce only depression but also anxiety disorders. So if you have depression without an anxiety disorder it may indeed have a different cause.

Thanks to Anne Weiss.

Rereading an old post, I found this:

Today I had my teeth cleaned and was told my gums were in excellent shape, better than ever before [due to flaxseed oil]. They were less inflamed than usual. “What causes inflammation?” I asked. “Tartar,” I was told.

I believe that reddish gums are a great sign (so easy to see) that overall your body has too much inflammation, putting you at higher risk for many common diseases. (Perhaps due to too little omega-3, which the body uses to make an anti-inflammation hormone.) Every day my dentist measured, or at least saw, a great correlate of health (the redness of his patients’ gums) and failed to notice. It’s like failing to notice an oil field under your property. If dentists became experts in measuring gum redness and helped their patients lower overall inflammation, the public health contribution would be great. (Writing this makes me wonder why I haven’t become skilled at measuring the redness of my gums.)
Experimental psychologists are in a similar position. I believe brain health is closely correlated with health of the rest of the body. In other words, the foods that make the brain work better make the rest of the body work better. I discovered the anti-inflammatory effects of flaxseed oil because it improved my balance. The brain is much easier to study (via behavior) than the rest of the body — it’s a model system for the rest of the body. Experimental psychologists are as unaware of their good fortune as dentists. By using their skills to figure out how to have the healthiest possible brain, they could make a great contribution to human welfare.

A problem with much nutritional epidemiology, as I blogged earlier, is “the narrow range of intakes within a given population”. For this reason Ernst Wynder thought it better to make between-country comparisons. Of course different countries differ in many ways other than the ones you care about. A solution to both problems is to study an unusual country — a country with a wide range of intakes of the nutrient you care about — in depth.

This is what a new paper about omega-3 has done. The researchers measured the blood of about 400 Eskimos, who had a much larger range of omega-3 levels in their blood than Americans or Europeans. The results aren’t easy to sum up because there were plenty of non-linear associations. Here’s what I think is their most interesting result:

Associations of EPA and DHA with C-reactive protein were inverse and nonlinear: for EPA, the association appeared stronger at concentrations >3% of total fatty acids; for DHA, it was observed only at concentrations >7% of total fatty acids.

C-reactive protein is a marker of inflammation. Notice that, due to the details, the combination of (a) high intakes and (b) a wide range of intakes makes this correlation much easier to see. This result suggests that EPA and DHA (or something correlated with them) indeed reduce inflammation, as is often proposed. Perfectly consistent with my dentist’s observation that my gums looked a lot better (less inflamed) right after I started drinking 4 T/day flaxseed oil. Plus a reader’s observation that his sports injuries healed much faster after he started drinking 4 T/day flaxseed oil. (And here.)

Previous epidemiology had had a hard time detecting the anti-inflammatory correlation of omega-3s. My self-experimentation plus other people’s observations made it obvious there was something to it (and provided experimental evidence for causality: more omega-3, less inflammation). Better epidemiology has now supported this.

Thanks to Dave Lull.