Functional foods are recognized for offering additional health benefits that extend past their fundamental nutritional value. They reflect a growing public interest in how diet can contribute to overall wellness beyond basic sustenance.
What Makes a Food Functional?
A functional food is a conventional food consumed as part of a regular diet that provides proven health benefits exceeding its basic nutritional content. These foods can naturally contain health-promoting substances or have beneficial components added during processing. The term “functional food” originated in Japan in the 1980s, where a government approval process called “Foods for Specified Health Use” (FOSHU) was established.
Functional foods differ from fortified foods and dietary supplements. Fortified foods have added nutrients, such as milk fortified with Vitamin D or cereals with added B vitamins, primarily to prevent deficiencies or enhance their nutritional profile. In contrast, functional foods theoretically contain sufficient amounts of a component to offer a specific health benefit.
Dietary supplements are typically presented in pill, capsule, or liquid form and contain isolated active ingredients. While supplements aim to augment health, they are regulated differently than foods. Functional foods are consumed as part of a regular diet and resemble conventional food, unlike supplements.
Prominent Functional Food Categories and Their Benefits
Probiotics
Probiotics are beneficial live microorganisms, often bacteria or yeasts, that contribute to the gut microbiome when consumed. These microbes can improve digestion and immune response, potentially preventing conditions like periodontal disease and constipation, and easing symptoms of irritable bowel syndrome (IBS). Probiotics also support hormonal balance, enhance nervous system function, and help reduce inflammatory processes. Specific strains like Lactobacillus and Bifidobacterium have shown benefits for mental health, potentially mitigating effects of depression and anxiety. Common sources include yogurt, kefir, sauerkraut, kimchi, and kombucha.
Prebiotics
Prebiotics are specialized plant fibers that are not digested by the human body but instead feed beneficial gut microbes. When these fibers are fermented, they produce short-chain fatty acids (SCFAs) that provide energy to colon cells, aid in mucus production, and support inflammation reduction and immunity. Prebiotics also regulate bowel movements, improve calcium absorption, and may help regulate blood sugar and insulin resistance. Examples of prebiotic-rich foods include onions, garlic, leeks, asparagus, bananas, oats, and resistant starches found in cooked and chilled potatoes.
Omega-3 Fatty Acids
Omega-3 fatty acids are healthy fats that the body cannot produce and must be obtained from external sources. These polyunsaturated fatty acids are highly concentrated in the cells of the eyes and brain, supporting their proper function. Omega-3s are recognized for reducing triglyceride levels, a type of fat in the blood that, when elevated, increases the risk of heart disease and stroke. They may also help raise HDL (“good”) cholesterol, lower blood pressure, and reduce inflammation. Fatty fish like salmon, mackerel, and sardines are rich sources of EPA and DHA, while flaxseed, chia seeds, and walnuts provide ALA.
Antioxidants
Antioxidants are compounds that may help delay or prevent cell damage by neutralizing harmful free radicals. When free radicals accumulate, they can cause oxidative stress, which increases the risk of chronic conditions such as heart disease, certain cancers, and age-related macular degeneration. These compounds are abundant in plant-based foods, including vitamins A, C, and E, as well as phytochemicals like anthocyanins, lycopene, and lutein. Berries, dark chocolate, green tea, red cabbage, and spinach are examples of foods rich in antioxidants.
Plant Sterols/Stanols
Plant sterols and stanols are natural substances found in plants that have a chemical structure similar to cholesterol. When consumed, they compete with cholesterol for absorption in the intestines, leading to less cholesterol being absorbed into the bloodstream. This mechanism can reduce LDL (“bad”) cholesterol levels without affecting HDL cholesterol or triglycerides. While naturally present in small amounts in vegetable oils, nuts, seeds, and whole grains, fortified foods like certain margarines, juices, and yogurts are often necessary to achieve the recommended intake for cholesterol reduction.
Incorporating Functional Foods into Daily Eating
Integrating functional foods into a daily diet involves making intentional choices to enhance overall well-being. These foods should be viewed as part of a balanced eating pattern rather than a standalone solution for health concerns. Prioritizing whole, unprocessed foods like fruits, vegetables, and whole grains naturally increases the intake of beneficial compounds.
Variety is important to ensure a broad spectrum of nutrients and bioactive compounds. For instance, adding berries to oatmeal or yogurt provides antioxidants, while incorporating fermented vegetables like kimchi or sauerkraut with meals boosts probiotic intake. Swapping processed snacks for nuts and seeds offers healthy fats and fiber, and cooking with olive oil can add anti-inflammatory compounds. Reading food labels can help identify fortified products that offer additional vitamins, minerals, or other functional ingredients.