In recent decades, the concept of food has evolved from merely satisfying hunger to playing a crucial role in preventing disease and promoting optimal health. The term functional foods refers to foods that provide benefits beyond basic nutrition, owing to the presence of bioactive compounds such as antioxidants, probiotics, phytochemicals, and omega-3 fatty acids (Diplock et al., 1999). These foods, whether naturally occurring or fortified, are increasingly being studied and consumed for their potential health-enhancing properties.
1.0 Definition and Classification
Functional foods can be defined as “foods that have a potentially positive effect on health beyond basic nutrition” (Shahidi, 2009). This concept bridges the gap between nutrition and medicine by offering dietary options that contribute to the prevention of chronic diseases or the improvement of physiological functions.
Functional foods are typically classified into two broad categories:
1.1 Naturally Functional Foods
These are foods that inherently contain components with health-promoting properties without any added ingredients. For instance:
- Oats: Rich in beta-glucans, a type of soluble fibre known to lower LDL cholesterol levels and improve heart health (Anderson et al., 2009).
- Fatty fish: Such as salmon and sardines, naturally high in omega-3 fatty acids which are linked to reduced inflammation and improved cardiovascular function (Kris-Etherton et al., 2002).
- Berries: Including blueberries and strawberries, which contain antioxidants like anthocyanins that may protect against oxidative stress and cognitive decline (Spencer, 2010).
- Garlic: Contains allicin, associated with immune support and reduced blood pressure (Shahidi, 2009).
1.2 Modified or Fortified Functional Foods
These foods have been enhanced with bioactive components not originally present or present in insufficient amounts:
- Probiotic yoghurt: Fermented milk products enriched with live cultures (e.g. Lactobacillus and Bifidobacterium) to support gut microbiota and digestive health (Sanders, 2008).
- Vitamin D-fortified milk: Aimed at improving calcium absorption for bone health, particularly in populations at risk of deficiency (Weaver et al., 2016).
- Plant sterol-enriched margarine: Designed to lower cholesterol absorption and improve cardiovascular health (Mensink et al., 2015).
- Folic acid-fortified cereals: Important in preventing neural tube defects during pregnancy and supporting cell growth (Slavin, 2013).
1.3 Medical or Special-Diet Functional Foods
These are designed to meet specific dietary needs, often for individuals with medical conditions:
- Gluten-free bread and pasta: For individuals with coeliac disease or gluten sensitivity.
- Low-GI snacks: Targeted at those managing blood glucose, such as individuals with type 2 diabetes.
- Lactose-free dairy: Aimed at consumers with lactose intolerance.
This classification illustrates that functional foods span both whole and processed food categories, reflecting the wide scope of their use in modern dietary patterns.
2.0 Health Benefits of Functional Foods
Functional foods can positively affect several areas of health, though the magnitude of benefit depends on factors such as regular consumption, overall diet, and individual health status.
- Heart health: Foods high in omega-3s, soluble fibre, and plant sterols—such as oily fish, oats, and sterol-fortified spreads—may reduce cardiovascular risk by lowering LDL cholesterol and improving vascular function (Kris-Etherton et al., 2002; Anderson et al., 2009).
- Digestive health: Probiotics (e.g. in yoghurt, kefir) and prebiotics (e.g. in bananas, onions) support the gut microbiota, contributing to digestive comfort and immune modulation (Gibson & Roberfroid, 1995).
- Immune and bone support: Foods containing vitamins C, D, and minerals like zinc and calcium—such as citrus fruits, dairy products, and fortified cereals—can strengthen immune responses and maintain bone density (Carr & Maggini, 2017; Weaver et al., 2016).
Functional foods are not curative in isolation but contribute significantly to overall health when integrated into a balanced diet.
3.0 Safety, Regulation, and Consumer Perception
While functional foods offer promising benefits, their safety and effectiveness must be underpinned by scientific evidence. In the UK and EU, any health claim on packaging must comply with EU Regulation No 1924/2006, which ensures that claims are evidence-based and not misleading (European Commission, 2021).
Despite growing consumer interest, confusion can arise due to ambiguous labelling or exaggerated marketing claims. A 2013 study by Lähteenmäki indicated that while consumers are willing to try functional foods, they often lack understanding about their ingredients or mechanisms of action. This highlights the need for clear, transparent labelling and public education. Furthermore, it is important to consider individual health needs and consult healthcare professionals before relying on functional foods for managing health conditions.
Functional foods represent a valuable innovation in nutritional science, providing health-enhancing benefits that go beyond basic sustenance. From naturally occurring foods like berries and oily fish to fortified products like probiotic yoghurt and sterol-enriched spreads, they support various aspects of health including cardiovascular function, digestion, immunity, and bone health.
However, these benefits are best realised when functional foods are consumed as part of a well-rounded, balanced diet. As the market for such products grows, continued research, regulation, and public awareness are crucial to ensure both safety and efficacy.
References
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Carr, A.C. and Maggini, S., 2017. Vitamin C and immune function. Nutrients, 9(11), p.1211.
Diplock, A.T., Aggett, P.J., Ashwell, M., Bornet, F., Fern, E.B. and Roberfroid, M.B., 1999. Scientific concepts of functional foods in Europe: Consensus document. British Journal of Nutrition, 81(S1), pp.S1–S27.
European Commission, 2021. EU Register on nutrition and health claims. [online] Available at: https://ec.europa.eu/food/safety/labelling_nutrition/claims/register/public/ [Accessed 20 July 2025].
Gibson, G.R. and Roberfroid, M.B., 1995. Dietary modulation of the human colonic microbiota: Introducing the concept of prebiotics. The Journal of Nutrition, 125(6), pp.1401–1412.
Kris-Etherton, P.M., Harris, W.S. and Appel, L.J., 2002. Fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease. Circulation, 106(21), pp.2747–2757.
Lähteenmäki, L., 2013. Claiming health in food products. Food Quality and Preference, 27(2), pp.196–201.
Mensink, R.P., Ebbing, S., Lindhout, M., Plat, J. and van Heugten, M.M., 2015. Plant sterol-enriched functional foods and coronary heart disease. European Journal of Lipid Science and Technology, 117(4), pp.524–532.
Sanders, M.E., 2008. Probiotics: Definition, sources, selection, and uses. Clinical Infectious Diseases, 46(Supplement_2), pp.S58–S61.
Shahidi, F., 2009. Nutraceuticals and functional foods: Whole versus processed foods. Trends in Food Science & Technology, 20(9), pp.376–387.
Slavin, J.L., 2013. Fibre and prebiotics: Mechanisms and health benefits. Nutrients, 5(4), pp.1417–1435.
Spencer, J.P.E., 2010. The impact of flavonoids on memory: Physiological and molecular considerations. Chemical Society Reviews, 39(6), pp.2393–2407.
Weaver, C.M. et al., 2016. The National Osteoporosis Foundation’s position statement on peak bone mass development and lifestyle factors. Osteoporosis International, 27(4), pp.1281–1386.
