Q: What kind of diet or supplements are recommended for stroke prevention?
A: Currently, there is no direct evidence of dietary intervention associated with stroke prevention. However, evidence-based medicine suggests that the Mediterranean-style diet is the most promising. This diet offers heart-healthy yet delicious food. It is characterized by high intake of olive oil, fruits, nuts, vegetables and cereals; moderate intake of fish and poultry; low intake of dairy products, red meats, processed meat and sweets; and wine in moderation with meals.
A large trial in people at high risk of cardiovascular disease found a benefit of the Mediterranean dietary intervention. Compared to a low-fat diet, a Mediterranean diet plus tree nuts (≥ 3 serving/week) or extra-virgin olive oil (≥ 4tbsp/day) reduced the risk of stroke by 42% and reduced the risk of heart attack, stroke, or death from cardiovascular disease by 30%
All of these contribute to lowering bad cholesterol, blood pressure, and inflammatory as well as oxidative stress markers. They help improve insulin sensitivity, enhance the endothelial function, and antithrombotic function. It is very likely that bioactive ingredients such as polyphenols, monounsaturated and polyunsaturated fatty acids, or fibers produce this effect.
The second highly recommended diet is the vegetarian diet including vegan, pesco vegetarian, and lacto-ovo-vegetarian diets. However, there is high prevalence of vitamin B12 deficiency in lacto-ovo-vegetarian and vegan diets. Vitamin B12 deficiency increases the risk of stroke and therefore, vitamin B12 supplement is needed with these diets.
When choosing vitamin B12 supplement, use methylcobalamin or oxocobalamin— the preferred vitamin B12 supplements, instead of cyanocobalamin— which is a man-made form of vitamin B12. Researchers reported that high levels of vitamin B12 (likely from cyanocobalamin supplement) increase the cardiovascular risk in elderly people (aged ≥ 85 years).
Two foods that should be avoided by elderly people are red meat and egg yolks. Both foods contain toxic metabolites that are associated with atherosclerosis, which involves the buildup of fats, cholesterol and other substances in and on your artery walls (plaque), that can restrict blood flow.
The only supplement that has moderate certainty of evidence for stroke prevention is folic acid supplementation (0.5-5 mg) with or without low-dose vitamin B12 (50 micrograms /day) for people who live in regions without folic acid fortification. Vitamin D, Vitamin B3, or Omega-3 fatty acids have no effect on stroke prevention.
For more information about the Mediterranean-style diet, please visit:
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Spence JD. Harm With High Levels of Serum B12 in Elderly Persons. J Gerontol A Biol Sci Med Sci. 2019 Jan 1;74(1):137.
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