This is the last article in a series about preventing Alzheimer’s, based on Dr. Neal Barnard’s evidence-based book “Power Foods for the Brain.” Other physicians have websites and have written books on this subject, but many of these books are not based on good science, and many of the authors are biased because they sell supplements. The last article discussed how metals such as copper, zinc, iron and possibly aluminum can adversely affect the brain, especially in combination with animal products.
Dr. Barnard is founding president of the respected PCRM (Physician Committee for Responsible Medicine). His book has a chapter about “foods that build your vitamin shield.” Vitamin E and three B vitamins—B6, B12 and folic acid– protect against cognitive impairment when ingested in a plant-based diet. However, studies using these vitamins in supplement form indicate they are not beneficial, and can even cause harm:
- Vitamin E pills in doses over 400 units a day increase the risk of heart disease.
- Vitamin A pills in smokers increase the risk of lung cancer.
- Folate is found in many vegetables. Folic acid, present in many vitamin pills and in fortified food is made artificially and is not exactly the same as natural folate. There is evidence that folic acid increases cancer risk.
We evolved to get vitamins, minerals and other micronutrients through the food we eat. Sudden, huge doses of vitamins in pill or liquid form are not natural, and can cause harm such as oxidation and inflammation, that contribute to several maladies including heart disease, cancer and dementia.
According to Dr. Barnard, here’s how you can get brain-healthy vitamins through what you eat:
- Traces of vitamin E are present in broccoli, spinach, sweet potatoes, mangoes and avocados. Larger amounts are found in nuts and seeds– particularly almonds, walnuts, hazelnuts, pine nuts, pecans, pistachios, sunflower seeds, sesame seeds and flaxseed. Dr. Barnard mentions a study that showed that “every 5 mg. of vitamin E in a person’s diet reduced the risk of developing Alzheimer’s disease by 26 percent.”
- Best sources of B6 are whole grains, green vegetables, beans, sweet potatoes, bananas and nuts.
- Sources of folate are broccoli, green leafy vegetables, beans, peas, citrus fruits, and cantaloupe.
- The caveat is that there is one supplement we should take, particularly if we are vegan– vitamin B12, which is made by bacteria in dirt. B12 is found in meat, fortified cereals, fortified soy milk and nutritional yeast. With treated water and pre-washed produce, most of us don’t eat much dirt these days. Vegans should take a 1000 mg. B12 supplement daily, and Dr. Barnard argues that even meat-eaters should take a daily 2.5 mg. supplement, particularly if over age 50 (older people don’t absorb B12 from their diet as well).
Previous articles have discussed how Alzheimer’s may prove to be a vascular disease. While that hasn’t been proven yet, we do know that Alzheimer’s patients have clogged arteries in their brains, and that the risk factors for heart disease (such as hypertension, high cholesterol, smoking, diabetes) are also risk factors for Alzheimer’s. Therefore, what’s good for the heart is good for the brain. Avoid or at least cut back on meat; dairy; eggs; processed food; added oil, salt and sugar. Eat mostly, or ideally exclusively, vegetables, fruit, whole grains, nuts and seeds.
In a recent video on his website nutritionfacts.org, Dr. Michael Greger talked about the marked increase in Alzheimer’s in Japan over the past few decades, as meat, dairy and egg consumption increased by 500 percent. We know what we need to do to ensure healthy brains as we age. Why is it so difficult, then, for so many Americans to modify their lifestyle? Next week’s column will be about food cravings.