Brain health » The Thinking Meat Project

DHA and brains

Brain health, General, Human origins and evolution Comments Off

Jun 102010

The more I learn about fish oil, the happier I am that salmon tastes so good. Fish is an excellent source of docosahexaenoic acid (DHA), which is an essential part of the human brain and appears to be vital for healthy brain function.

In fact, it’s possible that an expanded diet that included fish and other aquatic creatures was a necessary part of the process by which our brains grew to their relatively large size. A recent paper in the Proceedings of the National Academy of Sciences examines fossils from a site in Kenya that indicate that pre-Homo hominins had added aquatic animals to their diet about 1.95 million years ago, before the emergence of Homo erectus and other ancestor species to our own. Perhaps the addition of these protein-rich and DHA-rich creatures to the hominin diet provided the energy and nutrients needed to support bigger brains. This story from Wired has more information, and the paper is:
Early hominin diet included diverse terrestrial and aquatic animals 1.95 Ma in East Turkana, Kenya, David R. Braun, John W. K. Harris, Naomi E. Levin, Jack T. McCoy, Andy I. R. Herries, Marion K. Bamford, Laura C. Bishop, Brian G. Richmond, and Mzalendo Kibunjia. Proceedings of the National Academy of Sciences, Vol. 107 No. 22, June 2, 2010.

The Economist has written this article about a recent “Celebration of DHA” in London. The article briefly describes the importance of DHA for not just the emergence of large human brains, but perhaps the emergence of nervous systems in the first place. It also talks about the current human diet in many industrialized countries, which tends to substitute omega-6 fats for omega-3 fats, and goes into some of the detrimental effects of this switch. Eat your fish!

Your brain on smog

Brain health 2 Responses »

Nov 152009

I love being in the heart of a neighborhood near the IU campus and being able to walk everywhere. However, I live half a block from a major street, and the air I breathe is probably laced with various pollutants from the traffic on that street. (Back when I had a day job, I stood every day on the corner of a big intersection waiting to cross the street. While I waited, I sometimes contemplated what was happening to my lungs as I spent probably 10 or 15 minutes a day in close proximity to all those cars and buses; they are probably not as healthy and pink as they were when I started out.) Maybe I should have been worrying more about my brain.

Some recent research, reported by Scientific American, shows that airborne pollutants have a negative effect on the developing brains of unborn babies (lower IQ scores at age 5) and on the cognitive abilities of adults (reduced memory and attentional capacity and slower reaction times). Pending the development of greener alternative energy sources and greater energy efficiency, if you live in an urban environment you can reduce your exposure by choosing less-traveled streets for running and walking, and avoiding or ramping down activity on days when the smog is particularly bad.

Mediterranean diet and depression

Brain health, Psychology Comments Off

Oct 142009

A recent study of nearly 11,000 people indicates that following the so-called Mediterranean diet, which is high in monounsaturated fatty acids, fish, and plants (e.g., veggies, fruits, whole grains), can lower the risk of developing depression. Those who most closely followed the eating patterns of this diet were 30% less likely to develop depression over a 4.4-year period. This press release from EurekAlert gives the details. It’s not clear in any detail why this diet should have this effect. It could well be a synergistic effect of the combination of all the different components of the diet, rather than arising from the presence of any particular nutrient or food. And of course there are plenty of other health benefits of the Mediterranean diet.

While I’m on the soapbox here, I will mention that I’ve been reading about omega-3 and omega-6 fatty acids and health. The typical American diet contains far more omega-6 than omega-3 fatty acids, and the evidence so far suggests that this is deleterious to health in a number of ways. In particular, a more balanced intake of omega-3 and omega-6 might be useful in treating depression. If you’re curious, you can check out the Linus Pauling Institute’s Essential Fatty Acids page for more information. Also, several good books about omega-3 fatty acids and health are available, many with recipes; check your local library. [I'm reading The Ultimate Omega-3 Diet: Maximize the Power of Omega-3s to Supercharge Your Health, Battle Inflammation, and Keep Your Mind Sharp by Evelyn Tribole (very clearly written, includes recipes and suggestions for modifying existing recipes). Next on my list is The Queen of Fats: Why Omega-3s Were Removed from the Western Diet and What We Can Do to Replace Them by Susan Allport, which provides more historical context as well as dietary suggestions.]

Make a joyful noise

Being human, Brain health, Psychology 5 Responses »

Nov 112008

Or listen to a joyful noise, anyway. Recent research suggests that listening to music that makes you happy may be good cardiovascular hygiene, with a positive effect on not only mood but also the endothelium, the lining of the blood vessels. Following up on an earlier study that found that laughter was linked to blood vessel dilation (a cardiovascular plus), researchers examined the effects of listening to various types of music. They found that when participants listened to music that they said made them feel joyful, their brachial arteries increased in diameter, indicating better blood flow. Music that made the participants feel anxious had a milder effect in the opposite direction, slightly constricting the artery.

The effects of funny videos and audiotapes designed to encourage relaxation were also examined; the former was also linked to blood vessel dilation, although effect was not as big as in the case of the joyful music. The relaxation tapes had no statistically significant effect. I was curious about the tapes, because over the years I’ve listened to so many relaxation tapes when I was stressed out that by now, by association, they tend to give me the heebie-jeebies.

The study looked at ten people; many of them chose country music as their “joyful” music and heavy metal for the “anxious” music. There’s obviously a whole lot more to be explored in terms of genres and the effects of personal history and experience, but this is a very interesting link between the mind and body. (Coincidentally, I happened to be listening to the jubilant final movement of Brahms’s first symphony as I wrote this, which certainly raised my spirits and I hope did my heart good.) The research is described in this press release on EurekAlert, and was presented today at the American Heart Association’s meeting.

Feed your brain well

Brain health 2 Responses »

Jul 192008

A neurophysiologist at UCLA has done a meta-analysis of more than 160 studies of how food affects the brain. The results were recently published in Nature Reviews Neuroscience and are summarized in a press release on EurekAlert. There’s quite a lot in the EurekAlert story about omega-3 fatty acids (a so-called “good fat” found in salmon, flax seed, walnuts, and other foods), and also some information about transfats (distinctly bad, for the brain as well as your cardiovascular system), folic acid (good), and curcumin (an ingredient in the curry spice turmeric; also good and perhaps responsible for the low rate of Alzheimer’s in India). Also, it turns out that excessive caloric intake can be bad for your brain, and, interestingly, perhaps for the brains of your descendants as well.

Napping 101

Brain and mind, Brain health 3 Responses »

Jun 172008

This spring I had a three-month leave from my day job, and one of the things I liked the most about it was that I was freer to follow the schedule my body wanted to follow. In particular, when I got sleepy in the late afternoon, I was often able to take a nap. In the end, that made me more productive and certainly happier than trying to soldier on through intense drowsiness. I’m a big believer in the mental and physical benefits of napping, so I was delighted to find this guide to napping from the Boston Globe. In a poster-like format, it summarizes some recent research into how naps improve mental performance and reduce stress, and provides concrete and useful tips for napping intelligently, taking into account the brain’s sleep cycles and your own circadian rhythms. If I print this out and post it outside my cube at work, do you think I could get away with an afternoon siesta now and then?

Eat those blueberries!

Brain health 2 Responses »

Apr 112008

You all know by now that flavonoid-rich foods like many fresh fruits and vegetables have a number of benefits, including anti-oxidant properties that can help protect your body from age-related damage. In a recent study, researchers found that adding blueberries to the diet can also improve spatial memory, reversing age-related decline. The researchers identified the specific mechanism in the hippocampus by which the flavonoids had their memory-enhancing effect. This story from Science Daily has more details, although it doesn’t mention how many blueberries the people in the study ate. I’m really intrigued by the idea of a nutritional approach to not only enhancing memory but reversing decline. The next step in the research will be to study how flavonoid-rich diets affect people with Alzheimer’s and other forms of cognitive impairment.

Brain food

Brain health Comments Off

Nov 122007

A recent study relating diet and Alzheimer’s disease and other dementias turned up yet more evidence that your mother was right when she said to eat your fruits and vegetables and fish. The eating habits of more than 8,000 men and women over the age of 65 were tracked for four years; none of them had been diagnosed with dementia at the beginning of the study, but some developed it over the course of the study. This press release on EurekAlert says that the results are not ready to be turned into dietary advice just yet, but the study did turn up some interesting things. It turned out that consuming oils rich in omega-3 fatty acids (these include canola, walnut, and flaxseed oils) was related to a significantly lower incidence of dementia. Eating fruits and vegetables daily also helped, and weekly fish consumption helped in most cases (the exception was people who carried a gene that increases the chance of getting Alzheimer’s, apolipoprotein E4, or ApoE4). On the other hand, a diet high in oils rich in omega-6 fatty acids (these include sunflower and grape seed oil) and low in the omega-3 rich kind was associated with a higher incidence of dementia in people lacking the ApoE4 gene.

Another press release on EurekAlert describes the results of a longer study of beta carotene supplementation in men. Men who regularly took beta carotene for 15 years or longer did significantly better on some cognitive tests than those who took placebo. Before you go out and buy yourself a bottle of beta carotene, though, check out the caveats in the last paragraph of the press release and the editorial at the bottom. It sounds like the jury is still out on what anti-oxidants like beta carotene can do for the normal brain.

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