Functional foods do more than provide nutritional value. They contain naturally-occurring chemicals that are thought to do something special (when consumed as part of a balanced diet).

Unlike the mythical superfoods, there are reams of scientific evidence to support the claims being made about functional foods. Nonetheless, you need to know that most of the science is theoretical, with conclusions based on associations rather than proof of causation. But it’s unlikely that we will ever find a way to test these theories on humans because the body’s systems are all interconnected and extraordinarily complex.

It is impossible to isolate the effects of one specific nutrient in the midst of an estimated 37 thousand-billion-billion chemical reactions per second in a healthy human body. However, we have discovered elements within certain foods that have the potential to provide health benefits above and beyond the food’s obvious nutritional value.

Here are a few examples:

• Polyphenols have antioxidant capabilities which may reduce the risk of developing cardiovascular disease and type 2 diabetes; the catechins and tannins in tea, cocoa; hesperidin in citrus fruit; quercetin in tea, apples, onions; phenolic acids in coffee, anthocyanins in berries, grapes, eggplant and red cabbage; oleocanthal in the unripe green olives used to make cold-pressed extra virgin olive oil.
• Omega-3 fatty acids (EPA, DHA, ALA) have an anti-inflammatory effect which can reduce pain, improve circulation, and enhance neural pathways. The best source of EPA/DHA is oily fish (salmon, mackerel, tuna, sardines, anchovies), some shellfish (oysters, mussels, prawns), oysters, shellfish), and fish oil supplements. ALA is found in flaxseeds, avocados, walnuts, some vegetable oils, cruciferous vegetables (such as broccolini, broccoli, silver beet, kale, Brussels sprouts, cauliflower), and some herbs and spices (such as basil, mint, oregano, cloves, marjoram).

• Potassium-rich foods such as leafy greens, bananas, mushrooms, celery, yoghurt, potatoes, sweet potatoes, lentils and beans (lima, pinto, kidney) may help reduce the risk of high blood pressure and stroke by assisting kidney function.
• Dietary inulin and fructo-oligo-saccharides (FOS) from whole grains, beetroot, onions, garlic, honey, leeks, asparagus and chicory may help with magnesium and calcium absorption.
• Pectin in berries, apples and other fruit might help reduce the LDL cholesterol produced by the liver.
• Rolled oats contain more than 20 unique avenanthramides (polyphenols) and beta-glucans (soluble fibre) that may help your body evacuate excess cholesterol.
• Lycopene in tomatoes might reduce the risk of prostate cancer in some men.
• Isoflavones (a type of polyphenol) are found in legumes such as soybeans (tofu), chickpeas, fava beans, pistachios and peanuts, all common in Asian cultures which have lower rates of cardiovascular disease and some types of cancer.
• Prebiotics and probiotics help to promote the growth of beneficial gut bacteria which supports the gut/brain axis of communication – controlling appetite, reducing inflammation, and combating depression. This is leading edge science. Many vegetables, legumes, fruit, nuts and grains are prebiotic foods. Many naturally fermented foods are probiotic.

So which functional foods should you include in a well-balanced diet? Here are a few suggestions:

• oily fish (tuna, salmon, sardines, mackerel), shellfish and seaweed/nori,
• European and Asian cruciferous vegetables (e.g. broccolini, broccoli, kale, silverbeet, cauliflower, turnips, Brussels sprouts, bok choy, cabbage, radishes and herbs),
• soybean products (soy milk, tofu),
• berries,
• tomatoes,
• rolled oats,
• unsalted nuts and seeds (walnuts, linseed),
• black or green tea,
• dark chocolate,
• natural full-fat Greek style yoghurt.

REFERENCES

• Caballero, B., Finglas, P. M., & Toldrá, F. (2016). Encyclopedia of food and health. Elsevier Science.
• Crowe, T. (2018). Deakin University, Superfoods or Supermyths alumni seminar, Brisbane.
• Kovatcheva-Datchary, P., & Arora, T. (2013). Nutrition, the gut microbiome and the metabolic syndrome. Best Practice and Research: Clinical Gastroenterology, 27(1), 59–72.
• Park, C., Brietzke, E., Rosenblat, J. D., Musial, N., Zuckerman, H., Ragguett, R.-M., … McIntyre, R. S. (2018). Probiotics for the treatment of depressive symptoms: An anti-inflammatory mechanism? Brain, Behavior, and Immunity, 73, 115–124.
• Williamson, G. (2017). The role of polyphenols in modern nutrition. Nutrition Bulletin, 42(3), 226–235.