Functional Foods: Definitions, Development, and Benefits

Functional foods are a fascinating and growing area of nutrition, offering benefits beyond basic sustenance. Originally coined in Japan in the 1980s, the term refers to processed foods containing ingredients that aid specific body functions in addition to being nutritious. This guide will delve into their definitions, the factors driving their development, and the numerous benefits they offer.

What are Functional Foods: Definitions and Core Concepts

The term functional food first emerged in Japan in the 1980s, leading to the creation of Foods for Specified Health Use (FOSHU) with a regulatory approval process for products with specific healthful effects. While a universal statutory definition is still lacking, the general consensus describes functional food as any healthy food resembling conventional foods, consumed as part of a regular diet, and claimed to offer physiological benefits like health-promoting or disease-preventing properties beyond merely supplying nutrients.

Various organizations and researchers have proposed definitions, consistently highlighting the role of these foods in improving health or reducing disease risk for healthy individuals, rather than treating existing illnesses. They focus on improving functions like growth, metabolism, defense against oxidative species, cardiovascular health, gastrointestinal function, and even psychological well-being.

Understanding Related Terms in Functional Food Science

It's common to encounter several terms that are often linked with or interchanged with functional foods:

• Bioactive compounds: Naturally occurring chemical compounds from plant, animal, or marine sources that provide desired health or wellness benefits.
• Dietary supplements: Products that supplement the diet, containing active ingredients in pills, powders, or liquids, and do not replace complete meals.
• Functional ingredients: Standardized preparations or extracts of bioactive compounds used by manufacturers in foods.
• Medical foods: Formulated for consumption under physician supervision for the dietary management of specific diseases or conditions with distinctive nutritional requirements.
• Natural health products (NHP): Include homeopathic preparations, traditional medicines, vitamins, minerals, amino acids, essential fatty acids, or other botanical, animal, or microorganism-derived substances. They are often sold in medicinal forms to diagnose, treat, prevent disease, or promote health, and include nutraceuticals.
• Nutraceutical: Any substance, food or part of a food, that provides medical or health benefits, including disease prevention and treatment. They are derived from foods and can be consumed in various forms like pills or liquids.

Driving Forces Behind Functional Food Development

The development of functional foods has been propelled by a convergence of global trends and scientific advancements. Key factors include:

• Transitional health: Shifting health priorities in populations.
• Urbanization and its effects: Changes in lifestyle and dietary patterns.
• Changing demography: An aging global population seeking to maintain health.
• Food security: Ensuring access to nutritious and health-optimizing foods.
• Loss of traditional food culture: A move away from traditional, often healthier, diets.
• Busy lifestyles and poor convenience food choices: Leading to a demand for healthier, convenient options.
• Competitive food market: Driving innovation to offer added value.
• Insufficient exercise: Increasing the need for diet-based health support.
• Increased incidence of self-medication: Consumers taking more control over their health through diet.
• Increased information from health authorities and media: Heightened awareness of nutrition and the link between diet and health.
• Scientific developments in nutrition research: Uncovering new health benefits of food components.

Classification of Functional Foods for Students

Functional foods can be classified based on their origin or how they are modified to enhance health benefits:

• Fortified foods: Products enriched with ingredients known to positively influence diseases and health. Examples include calcium-fortified bread, omega-3 fortified breads, or phytosterol-fortified spreads.
• Foods liberated from anti-nutritional compounds: Foods processed to counteract or remove harmful compounds produced during processing, such as toxic compounds or allergens.
• Improved food raw materials: Raw foods enhanced by increasing specific beneficial components, often through altered animal feeding (e.g., eggs or meats high in omega-3 fatty acids, beef high in conjugated linoleic acid) or postharvest treatments (e.g., functional grapes with higher antioxidants developed by UV irradiation).
• Novel foods: Products with improved health benefits created through genetic manipulation or the selection of new varieties not traditionally consumed, such as rice with high iron content, vitamin-rich vegetables, or canola oil high in carotenoids.
• Prebiotic and probiotic foods: Foods containing live microorganisms (probiotics) that confer health benefits or non-digestible food ingredients (prebiotics) that stimulate the growth and/or activity of beneficial bacteria in the colon. Probiotic yogurts and prebiotic bread are common examples.
• Immune system enhancing foods: Products specifically designed to boost immune function.

It's important to note that natural traditional products, like cranberry juice consumed as such for urinary tract infections, are not considered functional foods unless their health-contributing ingredient is isolated and added to another food to enhance its health properties.

Functional Ingredients and Their Health Benefits

Many functional ingredients offer specific health benefits. Here's an overview by food source:

Dairy-based Functional Foods

Milk is a rich source of calcium, vital for preventing osteoporosis and potentially colon cancer. Beyond basic nutrients, milk contains bioactive elements like immunoglobulins, hormones, and peptides. Bioactive peptides, derived from milk proteins, can lower blood pressure, combat cardiovascular diseases, and enhance immunity.

Examples of commercial dairy-based functional foods:

• Calpis (Japan): Sour milk with blood pressure-lowering ingredients (Valine-Proline-Proline and Isoleucine-Proline-Proline).
• BioZate (USA): Hydrolyzed whey protein isolate with β-lactoglobulin fragments for blood pressure control.
• BioPure-GMP (USA): Whey protein isolate with glycomacropeptide for blood pressure, dental caries, and infection control.
• C12 and Cysteine peptide (The Netherlands): Hydrolysates with milk protein-derived peptides for blood pressure reduction and energy boost, respectively.
• Clarinol (International): Delivers conjugated linoleic acid (CLA) from yogurt to reduce body weight.

Probiotic dairy products, often containing prebiotics, are a major segment, with examples including Actimel, Activia, Jovita Probiotisch, ProViva, Rela Yogurts, Revital Active Yogurt, Yakult, Vitality Yogurt, and Vifit.

Cereal-based Functional Foods

Cereals are abundant in dietary fibers, both insoluble (roughage) and water-soluble (e.g., β-glucan, arabinoxylan). Oligosaccharides like galacto- and fructo-oligosaccharides promote beneficial physiological effects and stimulate the growth of lactobacilli and bifidobacteria, acting as prebiotics. Barley and oats are rich in β-glucan, known for lowering cholesterol and glycemic index.

Examples of commercial cereal-based functional foods:

• β-glucan ingredients: Incorporated into nutrition bars, chews, breakfast cereals, beverages, baked products, yogurt, ice cream, pasta, and dietary supplements by companies like Nutraceuticals Inc., Ceapro Inc., and Parrheim Inc. (Canada).
• Magiform (Sweden): Develops muesli, biscuits, pasta, and crackers with specially processed cereals for individuals with chronic gastrointestinal tract diseases.

Cereals also provide tocopherols, phenolics, phytosterols, and insoluble fibers, contributing to heart health and cancer risk reduction. Wheat aleurone-rich foods can decrease fasting homocysteine and LDL-cholesterol.

Flaxseed-based Functional Foods

Flaxseed (linseed) is a versatile nutritional ingredient, rich in proteins, dietary fiber, polysaccharides, polyphenolics, and essential fatty acids, particularly α-linolenic acid (ALA). ALA helps inhibit cardiovascular disease, inflammation, high blood pressure, cancer, skin diseases, and immune disorders.

Examples of commercial flaxseed functional foods:

• Incorporated into breads, cereals, pastas, and muffins by companies like Oroweat Foods (USA) and Dimpflmeier Bakery Ltd. (Canada).
• Linola™: A flax variety low in linolenic acid, used as an oil source for cooking, salads, and margarine.

Flaxseed's phytoestrogens have been linked to benefits for menopausal symptoms and osteoporosis. The US FDA granted flaxseed a Generally Recognized As Safe (GRAS) status in 1998.

Tea-based Functional Foods

Tea, especially green tea, is a major source of polyphenols, primarily catechins (epicatechins, epicatechin gallate, epigallocatechin, epigallocatechin gallate). These compounds offer antioxidant, anticarcinogenic, antibacterial, antiviral, anti-inflammatory, and weight loss benefits by increasing basal metabolism.

Examples of commercial tea-based functional foods:

• Sunphenon (Japan): A series of purified polyphenols rich in natural green tea catechins from Taiyo.
• Mega-T (USA): Green tea-based weight loss supplements by CCA Industries, Inc.

Black tea, through the oxidation of catechins into theaflavins and thearubigins, also possesses antioxidant, antimicrobial, anti-inflammatory, and anticancer activities.

Fruits and Vegetables-based Functional Foods

Fruits and vegetables are rich in diverse phytochemicals with numerous benefits. Berry fruits, high in polyphenols like anthocyanins and flavonoids, act as powerful antioxidants, preventing cardiovascular diseases, cancer, diabetes, and premature aging. Red grapes and red wine contain resveratrol, known for cardioprotective, anticancer, and anti-inflammatory effects.

Examples of fruit and vegetable functional foods:

• Resveratrol-enriched table grapes: Developed through UV irradiation by the Center of Edafology and Applied Biology of Murcia, Spain.
• Lycopene-rich products: Tomatoes and tomato products provide lycopene, an antioxidant with protective effects against oxidative stress, hypertension, atherosclerosis, and certain cancers (prostate, lung, stomach). Lycopene is being fortified into sausages, oils, and snacks.
• Soy products: Soybeans are concentrated sources of isoflavones (genistein, daidzein), which may protect against hormone-dependent cancers (breast, prostate) and benefit cardiovascular health, osteoporosis, and menopausal symptoms. Soy protein is GRAS and can reduce total and LDL-cholesterol.
• Black carrots: Rich in water-soluble phenolic compounds, acting as strong radical scavengers and preventing cancer and cardiovascular disease.
• Garlic, onion, and broccoli: Contain compounds that decrease blood pressure.
• Plant sterols and stanols: Reduce total and LDL-cholesterol, lowering coronary heart disease risk, found in products like Bayer Heart Health Advantage™, Benecol® spreads, and Centrum Cardio®.
• Nuts: Walnuts, pecans, and other nuts are high in soluble free phenolic and flavonoid compounds, demonstrating significant antioxidant activity and reducing heart disease risk.

Seafood-based Functional Foods

Seafood is an excellent source of omega-3 fatty acids, antioxidants, and high-quality protein. Marine algae, particularly their oil (rich in DHA) and polysaccharides (dietary fiber), provide natural functional ingredients with benefits such as preventing CVD, and acting as antihypertensive, antioxidant, antiviral, and anticancer agents.

Examples of seafood functional foods:

• Pasta incorporating edible Japanese seaweed, wakame (Undaria pinnatifida).
• Functional fish: Developed through farming to have elevated polyunsaturated fatty acids. Fish oils are also incorporated into animal feed to enrich eggs and beef with DHA and EPA.
• Chitin and chitosan: Derived from crustacean exoskeletons, these act as dietary fiber, antimicrobial preservatives, and possess antitumor, immune-potentiating, hypocholesterolemic, and antihypertensive properties.

Meat-based Functional Foods

Meat provides essential nutrients like taurine, L-carnitine, creatine, conjugated linoleic acid (CLA), and endogenous antioxidants. Meat can be made more functional through modifications.

Examples of meat functional foods:

• CLA-enriched meat: Adding 1% CLA to animal feed can reduce the risk and severity of atherosclerosis and type 2 diabetes.
• Functional meat products with nuts: Developed to reduce CVD risk.
• Modified meat with fish oil, vegetables, fiber, soy, natural antioxidants, and reduced sodium chloride.
• Chondroitin sulfate (CS) and glycosamine: Isolated from bovine skin, these are attempted as functional ingredients for joint health.

Egg-based Functional Foods

Eggs can be enriched to become functional foods, primarily with omega-3 polyunsaturated fatty acids, crucial for preventing heart disease, atherosclerosis, thrombosis, and managing blood pressure. They can also be enriched with antioxidants, vitamins D, E, B12, folic acid, carotenoids, and selenium.

Examples of egg functional foods:

• Columbus eggs (Belovo, Belgium): Enriched with omega-3 and vitamin E.
• VITA eggs (Freshlay Foods, UK): Another brand of enriched eggs.
• IgY-eggs: Eggs containing high quantities of immunoglobulins (antibodies) can act as an oral vaccine for consumers.

Herb-based Functional Foods

Herbs are sources of various functional ingredients. Curcumin, the yellow pigment in turmeric, shows therapeutic potential against numerous conditions including Alzheimer's, Parkinson's, cardiovascular diseases, cancer, and diabetes. Its antioxidant properties are significant, and it has GRAS status for addition to various foods.

Examples of herb functional foods:

• Cinnamon: Contains methylhydroxy chalcone, a polyphenol aiding glucose and lipid metabolism, used in water-soluble extracts (e.g., by Integrity Neutraceuticals International).
• Fenugreek seeds: Source of galactomannan, a soluble dietary fiber for controlling blood sugar.
• Ginger: Contains gingerols and flavonoids with antioxidant activity. Barley-wheat-fenugreek-ginger bread can help maintain postprandial blood glucose.
• Chicory: Its inulin-type fructans act as prebiotic dietary fiber, low-glycemic, low-calorie sugar substitutes, and fat replacers.
• Rosemary: Source of antioxidant and antimicrobial compounds.

Other botanicals like ginkgo, St. John's wort, ginseng, and echinacea also contain bioactive compounds. However, their incorporation into foods requires careful study regarding dosage, precautions, and longitudinal studies to confirm safety and efficacy.

Vitamin-based Functional Foods

Vitamins B6, B12, D, and K are known to reduce the risk of CVD and osteoporosis, while vitamins C and E may help prevent colorectal carcinoma. Major producers like Roche Vitamins and BASF AG introduce bioactive vitamin ingredients into the market, which are then used to fortify functional foods such as yogurt and milk with calcium, omega-3 fatty acids, folic acid, and various vitamins.

The Global Market for Functional Foods

The global interest in and acceptance of functional foods have led to a dynamic and rapidly expanding market. It was estimated to reach at least 90.5 billion US$ by 2013, with major markets in the U.S., Japan, and Europe contributing over 90% of total sales.

• Japan: A leader in functional food innovation, with over 1,700 products launched between 1988 and 1998, reaching 17 billion US$ in 2005. FOSHU products, like Econa cooking oil and Healthia green tea, have high recognition rates.
• North America: Saw a significant increase in functional food introductions, from 200 in 2006 to over 800 in 2008. Canada has shown strong growth with companies like Harmonium International Inc. (probiotics) and Ocean Nutrition Canada Ltd. (omega-3 fatty acids).
• Europe: Germany, France, the UK, and the Netherlands are key markets. New regulations requiring scientific evidence for health claims have impacted product launches but the market remains strong, especially for functional dairy and cereal products.
• India: The market is growing at 12-15%, with strong growth in probiotics and nutraceuticals. Pharmaceutical players like GlaxoSmithKline and Abbott are investing, and the government is developing guidelines for probiotic products.

The success of functional foods hinges on factors like a focus on general well-being, addressing common health complaints, mass distribution, effective communication of health benefits, brand extension, and competitive pricing, taste, and convenience. Consumers need to be well-informed about active ingredients and their benefits.

FAQ: Common Questions About Functional Foods

What is the primary difference between functional foods and traditional foods?

The primary difference is that functional foods are either naturally rich in or fortified with specific ingredients that are scientifically shown to provide health benefits beyond basic nutrition, such as disease prevention or improved physiological functions. Traditional foods, while nutritious, don't necessarily make such specific health claims or undergo modifications for this purpose.

Why did functional foods become so popular in Japan first?

Japan was the first country to establish a specific regulatory framework for functional foods in the 1980s, coining the term Foods for Specified Health Use (FOSHU). This governmental recognition and approval process helped build consumer trust and encouraged widespread development and adoption of these products in the Japanese market.

Are there any risks associated with consuming functional foods?

While generally safe, functional foods, especially those with isolated or concentrated ingredients, should be consumed responsibly. Excessive intake of certain components, like iron or folic acid, can lead to imbalances or mask deficiencies. Many countries lack framed rules for proving health claims through longitudinal studies, highlighting the importance of verified scientific evidence and adhering to recommended dosages.

How are functional food benefits scientifically proven?

Scientific evidence for functional food benefits often comes from various studies, including in vitro (laboratory), clinical (human trials), and epidemiological (population-level) research. These studies evaluate the effects of food ingredients on target functions in the body, such as lowering cholesterol, reducing blood pressure, or enhancing immunity, to substantiate health claims.