Nutraceuticals or functional foods are any food or food ingredients that may provide beneficial health effects beyond the traditional nutrients they contain. Nutraceuticals are also known as medical food, nutritional supplements, and dietary supplements. Nutraceuticals range from isolated nutrients, dietary supplements, genetically engineered “designer” foods, herbal products, and processed products such as cereals and soups. Functional foods are “foods or dietary components that may provide a health benefit beyond basic nutrition”.
Regular and plentiful consumption of fruits and vegetables as well as marine foods have been evidenced to be beneficial for human health and in the prevention of diseases, according to different epidemiological studies. An aging population and general health trends are factors which have influenced the growth of the nutraceutical and functional food market. Globally, average life expectancy has been on the rise. However, as a result, the number of age related diseases are also on the rise as populations live longer. Obesity, heart diseases, cancers, osteoporosis and arthritis are highly prevalent in our world today. Sedentary lifestyles along with the stress and pollution in day to day life are the major reasons for the enhancement of free radical generation in our body. Reactive oxygen species and free radicals fasten the aging process, and can only be mitigated through the action of antioxidants. Further, as we age, the efficiency to remove these free radicals by the antioxidant defense systems in our body decreases. Consumption of antioxidant rich foods (fruits, vegetables, etc.) balance the free radical and antioxidant status and, thus, reduces the oxidative stress in our body.
Prevention strategies are preferred and should be acceptable among people in order to minimize the suffering in a patient’s life. Dietary modification is one such strategy to deal with oxidative stress.
Cancer: Cancer is one of the most prevalent diseases across the globe. It has been reported that a majority of patients suffering from prostate cancer undergo some kind of alternative therapy. Chemopreventive effect of lycopene (tomato) on the development and progression of prostate cancer is well studied. Other nutraceutical sources include green tea (Epigallocatechine-3-gallate; EGCG), cruciferous vegetables (isothiocyanates), nuts and vegetable oils (tocopherols) and soybean (isoflavones). Furthermore, the compounds which are known to be anticancer antioxidants are Vitamin-C (citrus, red algae, brown algae), Vitamin-E (green algae, brown algae), carotene (red, green, brown algae, cyanobacteria), curcumin (turmeric), and lycopene (tomato, gac, watermelon, papaya).
Ocular health: In human diets, significant amounts of yellow carotenoids, zeaxanthin and lutein are reported to be found in egg yolks, yellow peppers, and yellow corn. Leafy greens are rich in lutein but do not typically retain high zeaxanthin levels. Apart from carotenoids, omega-6 and omega-3 fatty acids are also known to be beneficial in ocular health.
Sleep Problem: A good night’s sleep is essential for maintaining good health in general. Sleep deprivation is increasingly prevalent among people today, and poses serious risks for our health. Proteins rich in tryptophan help in dealing with sleep problems. Melatonin (tart cherries, banana, grape) rich foods are also beneficial in this regard.
Cardiovascular diseases (CVD): CVD is one of the leading causes of mortality worldwide. Compounds helpful in the prevention of coronary heart diseases include cinnamaldehyde (cinnamon), sulphoraphane (broccoli), resveratrol (grapes), luteolin (celery, green peppers, carrots, oregano), quercetin (tea, apples, onion), and omega-3-fatty acids (walnuts, chia, flaxseed, salmon, sardines).
Neurodegenerative disorders: Dementia is caused due to physical changes in the brain. Alzheimer’s disease is the most common type of dementia, although there are other types of dementia. Vitamin B12, Vitamin-D (mushrooms, salmon, fish oil, sardines, milk, orange, tuna), folic acid, and Vitamin-A are found to be very beneficial and useful for preventive action. Parkinson’s disease is another important neurodegenerative disorder. Nutraceuticals rich in EGCG (green tea), quercetin, resveratrol, rosmarinic acid (rosemary), carnosic acid, and melatonin (tart cherries, banana, grapes) are helpful in the prevention of the disease.
Fruits and vegetables are a rich source of a multitude of nutraceuticals and other bioactive natural products. Such value-added products not only provide essential nutrients but also enhance the ability of the body to fight, cure and prevent diseases through anti-oxidant, anti-carcinogenic, anti-inflammatory, anti-bacterial, anti-proliferative and other properties. Plant-derived antioxidants are particularly important because they are believed to protect the body against free radicals, the harmful molecules that can cause heart disease, premature aging, Alzheimer’s disease, blindness and a variety of cancers. These are known to scavenge superoxide and hydroxy radicals to prevent lipid peroxidation and undue oxidation of other biological substrates. Since perishable vegetable and fruit commodities rich in light-sensitive nutraceuticals have a specific shelf life, these run the risk of getting spoilt beyond a specific time. Excessive quantities of such materials must, therefore, be processed and converted into value added fortified products with improved shelf life and nutrition value.
A number of technologies have been developed at ICAR-Indian Agricultural Research Institute, New Delhi on the extraction of nutraceuticals from different fruits and vegetables. Some of these are:
o Anthocyanins from fruits and vegetables: Bench scale know-how has been developed for the extraction of anthocyanin from black carrot, black rice, purple corn, purple cabbage, rose petals.
o Lycopene from tomato: Technical know-how has been standardized for the extraction of lycopene from tomato.
o Capsanthin and capsaicinoids from chili: Bench scale know-how has been developed for the extraction of biocolorant and pungent principle from chili.
o Steviol glycosides from Stevia sp: For the separation of natural sweetener, bench scale know-how has been developed.
o Phycocyanin from Spirulina: Technical information for the extraction of phycocyanin from spirulina has been standerdised.
The majority of nutraceuticals mentioned here are available in fruits, vegetables and animal sources. A person who consumes a healthy balanced diet is most likely obtaining adequate amounts of these nutraceuticals to receive the said benefits. However, if diets lack key nutritional/nutraceutical components, supplementation may be of benefit.
Principal Scientist*, Division of Agricultural Chemicals, ICAR-Indian Agricultural Research Institute