Dear Dietitian,

I enjoyed your column last week on functional foods and heart health. I eat healthy and exercise regularly. I’ve also read about functional foods that are good for your brain. What is your opinion?

Ken

Dear Ken,

The concept of functional foods began in Eastern cultures, where many believe food and medicine come from the same source. These societies have used herbal remedies for years to treat certain illnesses and maintain health.

While there is no legal definition of functional food, the Academy of Nutrition and Dietetics (AND) defines them as “whole foods along with fortified, enriched, or enhanced foods that have a potentially beneficial effect on health when consumed as part of a varied diet regularly at effective levels.” (1)

Functional foods have gained popularity in Western cultures due to scientific discoveries that connect certain dietary factors to disease. For example, there is a link between a diet high in saturated fat and heart disease. Conversely, when saturated fats are replaced with unsaturated in a diet that is also low in cholesterol, the risk of heart disease goes down.

Many of the same foods that aid in heart health are also good brain food. Listed in the table below are foods that may help prevent mental decline.

Functional Food: Green, leafy vegetables    

Examples: Kale, spinach, broccoli, turnip greens

Claim: Antioxidants lutein, folate, and beta carotene protect the brain from free radicals, thereby possibly slowing mental decline (2).

Functional Food: Walnuts

Examples: All nuts are a good source of monounsaturated fat.

Claim: Walnuts contain an omega-3 fatty acid called alphalinolenic acid, which lowers blood pressure. This action helps the heart and brain (3).

Functional Food: Flavonoids

Examples: Dark chocolate, red wine, green tea

Claim: Improvement in cognitive function of the elderly (4).

Functional Food: Choline

Examples: Egg yolks, chicken, veal

Claim: May slow mental decline (5)

Functional Food: Fatty fish

Examples: Salmon, mackerel, trout, sardines

Claim: The omega-3s may slow cognitive decline (6).

Functional Food: Mushrooms

Examples: Shitake, golden, oyster, white button mushrooms

Claim: May slow mild cognitive decline (7).

Functional Food: Coffee

Examples: Both caffeinated and decaffeinated coffee

Claim: Caffeine may improve mood by increasing serotonin levels. Improves concentration. Caffeinated and decaf coffee contain antioxidants (8).

It is important to note that studies on functional foods are limited. Much of the research has been conducted on rodents or in a laboratory. These studies are considered pre-clinical, and the same results cannot be predicted in humans.

Human nutrition studies are often expensive and difficult to perform. Many studies rely on volunteers’ recording of their food intake. These food recalls are sometimes inaccurate. It is costly to conduct nutrition research in a hospital setting where the amounts and types of foods eaten are controlled.

That said, the foods listed above are healthy as they provide fiber, vitamins, minerals, and other important nutrients. Remember to limit coffee to four cups per day, as too much of a good thing is not a good thing. Up to 400 mg of caffeine each day is generally considered safe for healthy adults.

Stay tuned for next week’s column on fermented functional foods. Until then, be healthy!

Dear Dietitian

References

1. Crowe K, Francis C. Position of the Academy of Nutrition and Dietetics: Functional Foods. J of the Academy of Nutrition and Dietetics. 2013; 113 (8): 1096-1103.

2,3. Foods linked to better brainpower. Harvard Health Publishing. Retrieved from https://www.health.harvard.edu/mind-and-mood/foods-linked-to-better-brainpower.

4. Letenneur L, Proust-Lima C, Le Gouge A, Dartigues JF, Barberger-Gateau P. Flavonoid Intake and cognitive decline over a 10-year period. Am J Epidemiol. 2007;165:1364-1371.

5. McCann JC, Hudes M, Ames BN. An overview of evidence for a causal relationship between dietary availability of choline during development and cognitive function in offspring. Neurosci Biobehav Rev. 2006;30:696-712.

6. Van Gelder BM, Tijhuis M, Kalmijn S, Kromhout D. Fish consumption, n-3 fatty acids, and subsequent 5-y decline in elderly men: the Zutphen Elderly Stud. Am J Clin Nutr. 2007;85:1142-1147.

7. Lei Feng, Irwin Kee-Mun Cheah, Maisie Mei-Xi Ng, Jialiang Li, Sue Mei Chan, Su Lin Lim, Rathi Mahendran, Ee-Heok Kua, Barry Halliwill. The association between mushroom Consumption and Mild Cognitive Impairment: a community-based cross-sectional study in Singapore. Journal of Alzheimer’s Disease, 2019;1. DOI: 10.3233/JAD-180959.

8. Ruxton, CHS, The impact of caffeine on mood, cognitive function, performance and hydration: a review of benefits and risks. Feb 2013. Retrieved from https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1467-3010.2007.00665.

LEANNE MCCRATE, RDN, LD, CNSC, is based in St. Louis, Missouri. Her mission is to educate consumers on sound, scientifically-based nutrition. Do you have a nutrition question? Email her today at deardietitian411@gmail.com. Dear Dietitian does not endorse any products, health programs, or diet plans.

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