Nuts For Brain Health!

August 25th, 2010 by Karen Merzenich

Many people think that eating nuts is good for your brain. This is true, but not all nuts are created equally. There is great variation in the health benefits to be found in different types of nuts, especially from a brain health perspective.

  • Walnuts are the top nut for brain health. They have a significantly high concentration of DHA, a type of Omega-3 fatty acid. Among other things, DHA has been shown to protect brain health in newborns, improve cognitive performance in adults, and prevent or ameliorate age-related cognitive decline. One study even shows that mothers who get enough DHA have smarter kids. Just a quarter cup of walnuts provides nearly 100% of the recommended daily intake of DHA.
  • Almonds and Hazelnuts are two of the most concentrated sources of vitamin E available, and vitamin E intake is generally associated with less age-related cognitive decline. In one study, participants who received vitamin E improved statistically and clinically in some memory and verbal measures, while participants who received a placebo did not. 1/4 cup of almonds or hazelnuts packs in nearly 50% of the RDA for vitamin E.
  • Peanuts have not been extensively studied as a brain healthy food, but there is good reason to believe that they offer brain benefits. Peanuts are high in niacin (1/2 cup of peanuts offers about 50% of the RDA for niacin.) Studies have correlated niacin deficiencies with a higher incidence of cognitive decline and Alzheimer’s. There has also been preliminary research that suggests that eating peanuts may help stave off Parkinson’s.

Other nuts like pecans, chestnuts, and cashews are often mentioned as having brain health benefits. However, there are little or no published scientific studies to back up those claims, so we’ll have to wait on further research to be sure.

Of course, nuts are high in calories. Many worry that the proven health benefits of eating nuts will be outweighed by the increase in caloric intake and potential weight gain. Interestingly, studies have shown that people who regularly eat nuts actually weigh less than their nut-free counterparts. This is a correlation, not a cause and effect, so I’m not suggesting that adding nuts to your diet will help you lose weight. However, I have found that when I’m hungry between meals, grabbing 6-10 roasted almonds helps stave off hunger better than most other snacks I’ve tried, and gives me those brain benefits at the same time.

UPDATE: After posting this article, new research came out showing that people with walnuts and walnut oil in their diets have lower resting blood pressure as well as lower blood pressure responses to stress in the laboratory. Read the article here.

REFERENCES

Here are links to the PubMed abstracts of studies referenced in this article:

  1. Maternal docosahexaenoic acid-enriched diet prevents neonatal brain injury.
  2. Omega-3 polyunsaturated fatty acids and depression: a review of the evidence.
  3. Serum phospholipid docosahexaenonic acid is associated with cognitive functioning during middle adulthood.
  4. Maternal supplementation with very-long-chain n-3 fatty acids during pregnancy and lactation augments children’s IQ at 4 years of age.
  5. Essential fatty acids and the brain.
  6. Grape juice, berries, and walnuts affect brain aging and behavior.
  7. Vitamin E use is associated with improved survival in an Alzheimer’s disease cohort.
  8. A vitamin/nutriceutical formulation improves memory and cognitive performance in community- dwelling adults without dementia.
  9. Better cognitive performance in elderly taking antioxidantvitamins E and C supplements in combination with nonsteroidal anti-inflammatory drugs: the Cache County Study.
  10. Dietary niacin and the risk of incident Alzheimer’s disease and of cognitive decline.
  11. Follow-up study of early-life protective and risk factors in Parkinson’s disease.
  12. Nut Consumption and Weight Gain in a Mediterranean Cohort: The SUN Study.

18 thoughts on “Nuts For Brain Health!

  1. Karen MerzenichKaren Merzenich Post author

    Hi Edith, I agree! Macadamias are so tasty. There is not good evidence that macadamias are good for your brain, but the silver lining there is that they have been shown to be good at lowering LDL (bad cholesterol) and raising HDL (good cholesterol) – much like other great sources of monounsaturated fats like olive oil and avocados. So while we don’t know if they benefit the brain, they do have other health benefits for the body.

  2. Charles Preston

    While walnuts are one of the fairly rare sources for any Omega-3 fatty acids, don’t they have a high content of Omega-6s as well? One of the nutrition problems cited by others is that many American diets have too high a ratio of Omega-6s to Omega-3s, contributing to inflammation. Chronic inflammation is a possible contributor to brain disfunction.
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC263865/
    http://www.lef.org/protocols/prtcl-146b.shtml

    Thank you.
    Charles Preston

  3. Pingback: Nuts Known to Improve Cognition - NextBrain! Daily tips to improve brain fitness and cognitive performance - Your Next Brain!

  4. Karen MerzenichKaren Merzenich Post author

    @Charles – good point to bring up Omega-3/Omega-6 balance. That is indeed an important point and I believe it warrants a full follow-up blog post! Foods that contain Omega-3′s tend to contain Omega-6 as well, and walnuts actually have a reasonably low ratio of 6 to 3 compared to other foods (about 4:1). Of course the idea is to cut out processed foods that are high in Omega-6 and replace those with a handful of walnuts, not add walnuts to an already unhealthy diet.

    Thanks for the comment as I think this is an important piece of the puzzle that requires more investigation and explanation!!

  5. Karen MerzenichKaren Merzenich Post author

    @Louise: I can find no evidence of difference between different types of commonly consumed walnuts.

    @Doug: I think you may have that reversed… macadamia nuts are about 10% protein, & about 75% fat. Still, they have been recommended in moderation as part of a heart-healthy diet because they are mostly “good” monounsaturated fat (like olive oil.)

  6. Doug Johnson

    Sorry, Karen, I was a victim of the hype. I live in a household of fat-haters, and as you know memory is selective. I subscribe to a number of health blogs and what I really remembered was that macadamia nuts come highly recommended. I extrapolated from that that their macronutrient content must be mostly protein–you are right, it is not. I usually break fast with 28 grams of lightly salted macadamia nuts which according to the label is 210 KCalories. That allows my blood glucose to return to around 100 in two hours. Sorry for the mistake.

  7. Don Torluemke

    Hi Karen. I teach brain fitness here at South Bay Adult School (using PositScience software as part of our course). We do a lot on brain nutrition education and this is really helpful. I would only add that Brazil Nuts are a great source of Selenium, a powerful antioxidant, although they should only be enjoyed along with mixed nuts because too much selenium can be toxic.

  8. Jim Thielman

    A year ago I my blood test showed low hdl–the good cholesterol (the level was 39). I read about pecans being good for this. I began eating a breakfast of pecans, flaxseed, fruit, yogurt and milk, plus cinnamon. Within six months I tested at 44 for HDL. This year I tested at 51 HDL. I also added red yeast rice to lower ldl levels and I take extra niacin. The nuts are responsible for the improved HDL, because that was the one change in my diet. Now I mix in walnuts and cashews at breakfast along with pecans. Good fats seem to be good for me. Glad to hear they might also help my brain, which needs all the help it can get!

  9. lindard

    a handful of nuts packs a really good amount of calories. i usualy eat whole bags of nuts when watching tv. althought its high in fat in calories it is still helpful for the body if consumed right and very tasty to. thanks for your informative post, i really appreciate it.

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