Antioxidants have long been praised for their potential health benefits and their ability to combat oxidative stress and free radicals in the body. Consequently, the food industry has embraced the incorporation of antioxidants into various food products to enhance their perceived healthfulness. However, recent scientific studies and emerging research have prompted a reexamination of the health implications associated with the addition of large amounts of antioxidants to foods.
Antioxidants play a vital role in food formulation by providing numerous benefits related to food quality, stability, and human health. These compounds help protect food products from oxidative damage caused by free radicals, which can lead to deterioration, off-flavors, and nutrient loss. Oxidation is a chemical process that occurs in food when it is exposed to oxygen, light, heat, or enzymes. This process can lead to the formation of free radicals, which are highly reactive molecules that can cause damage to lipids, proteins, and DNA. Antioxidants act as scavengers, neutralizing these free radicals and preventing or slowing down the oxidation process. The presence of antioxidants in food formulations helps extend the shelf life of products by inhibiting or delaying the oxidation of fats, oils, and other susceptible components. By protecting against oxidative deterioration, antioxidants help maintain the sensory qualities of food products, such as color, flavor, and texture, thus increasing their overall quality and consumer acceptability.
Antioxidants also contribute to the preservation of essential nutrients in food products. Certain vitamins, such as vitamin C and vitamin E, exhibit antioxidant properties and help prevent the degradation of other sensitive nutrients, including vitamins, minerals, and phytochemicals. By preserving the nutritional value of food, antioxidants contribute to the overall nutritional quality of the diet. In addition to their protective role, some antioxidants can contribute to the flavor and aroma of food products. For example, natural antioxidants derived from herbs, spices, and fruits can provide unique and desirable flavors, enhancing the overall sensory experience. These antioxidants not only contribute to food quality but also offer opportunities for flavor innovation and consumer preference.
Antioxidants can enhance the stability of food products during processing, storage, and distribution. They help protect against oxidation that can occur during food processing steps, such as milling, frying, and baking. By maintaining product stability, antioxidants contribute to the production of high-quality and safe food products. Antioxidants can be derived from natural sources, such as plant extracts, herbs, and spices, as well as synthetically produced compounds. Natural antioxidants, including vitamin C, vitamin E, carotenoids, and polyphenols, are often preferred by consumers due to their perceived health benefits and clean label appeal. However, synthetic antioxidants such as butylated hydroxytoluene and butylated hydroxyanisole also are commonly used in food formulations and have been approved for safe consumption.
Vitamin A, C, E, carotenoids such as beta-carotene and lycopene, flavonoids, phenols, omega-3, omega-6, and trace minerals such as selenium and zinc are the most common naturally occurring dietary antioxidants and are the nutrients of interest in the food industry when it comes to antioxidant fortification. These antioxidants have been associated with various health benefits due to their ability to combat oxidative stress and reduce the risk of chronic diseases. Consumption of foods rich in antioxidants, such as fruits, vegetables, nuts, and whole grains, has been linked to a lower risk of cardiovascular diseases, certain cancers, age-related macular degeneration, and neurodegenerative disorders such as Parkinson’s disease, Alzheimer’s disease, dementia, and cognitive decline.
Studies have also shown that vitamins E, C, and zinc play an important role in cognitive function and mental health, and vitamins A, C, and E can play a role in cancer prevention. Selenium, a powerful antioxidant, can protect the thyroid gland against oxidative damage and prevent thyroid-related diseases such as Hashimoto’s thyroiditis. Omega-3 and omega-6 are essential fatty acids required to protect brain cells and tissues against oxidative damage. Flavonoids and phenols are both anti-inflammatory compounds that function as antioxidants. Antioxidants may also play a role in supporting the immune system and overall well-being.
Consumers are increasingly seeking out foods with perceived health benefits, including those enriched with antioxidants. The availability of antioxidant-fortified products can satisfy consumer demand, enhance product appeal, and contribute to market competitiveness. Antioxidants, with their potential to combat oxidative stress and reduce the risk of chronic diseases, align with the health-conscious mindset of consumers. They are seen as natural compounds that can contribute to maintaining optimal health and preventing illness.
More specifically, consumers are increasingly drawn to nutrient-dense and functional foods that offer additional health benefits beyond basic nutrition. Antioxidants, which are found in fruits, vegetables, nuts, and whole grains, are associated with these desirable attributes. Foods and beverages that are rich in antioxidants are often marketed as "superfoods," or as having functional properties, appealing to consumers who prioritize health and are willing to pay a premium for products that offer added value.
Additionally, the association between antioxidants and anti-aging benefits has captured consumer attention. Antioxidants are perceived as agents that can help fight the signs of aging, such as wrinkles and skin damage caused by oxidative stress. This perception has led to the popularity of beauty and skincare products containing antioxidants and the inclusion of antioxidants in functional foods and beverages targeting skin health and beauty.
Natural and clean label products are becoming increasingly popular because consumers believe they are safer and healthier alternatives. Antioxidants derived from natural sources, such as fruits, vegetables, and herbs, align with this preference. Food products that highlight the presence of natural antioxidants on their labels are often seen as more trustworthy and appealing to consumers who are concerned about synthetic additives or chemicals.
The popularity of functional beverages and dietary supplements also has contributed to the demand for antioxidants. Consumers are seeking convenient and easy ways to incorporate antioxidants into their daily routines. Functional beverages, such as antioxidant-infused waters, teas, and smoothies, as well as dietary supplements containing concentrated antioxidants, provide consumers with convenient options to enhance their antioxidant intake.
Consumer perception of antioxidants is influenced by the availability of information and education on their benefits. Scientific studies, media coverage, and health professionals play a significant role in shaping consumer perceptions and understanding of antioxidants. Increased research and positive media attention on the potential health benefits of antioxidants have further fueled consumer interest and demand for products containing these compounds.
While antioxidants have shown promise in laboratory and epidemiological studies, recent research suggests that the indiscriminate addition of large amounts of antioxidants to foods may not necessarily translate into improved health outcomes. Several key considerations warrant a closer examination of the health implications:
Optimal dosage and safety. The health benefits of antioxidants are dose-dependent, and excessive intake may not provide additional benefits. Not only can supplementing with too much of a nutrient be ineffective, but it can also have a deleterious effect on health. A study conducted in the late 1990s was terminated prematurely because the researchers found that supplementation of beta-carotene and retinol in high doses (30 mg and 25,000 IU, respectively) led to an increase in the occurrence of lung cancer, other types of cancers, and even death—and not a reduction (Omenn et al. 1996). The doses of beta carotene and retinol given in this study were far higher than the suggested daily intake and Recommended Daily Allowance (RDA), which are 6–15 mg for beta-carotene and 23,333,000 IU for retinol.
The results of this study were further supported by another large-scale trial in which beta-carotene was again found to increase the occurrence of lung cancer (Alpha-Tocopherol Beta Carotene Cancer Prevention Study Group 1994). Therefore, it is safe to say that supplementing foods with doses that are within the RDA might be the optimal and safe dosage for supplementation when it comes to the general population. Doses that are exceedingly higher than the RDA are warranted only in certain populations with diseases or deficiencies. Vitamins such as A, D, E, and K are fat-soluble and cannot be eliminated by the body like water-soluble vitamins. As a result, they tend to accumulate in the body and can be toxic when consumed in excess.
Bioavailability. The bioavailability and absorption of antioxidants can vary among individuals and food matrices, influencing their efficacy. Antioxidants may interact with other nutrients and compounds in food, altering their bioavailability and overall effects. It is possible that supplementation with high doses of synthetic individual antioxidant supplements may not offer the same health benefits as those found in combination in whole foods, working synergistically with other bioactive compounds such as polyphenols to prevent and protect against various diseases.
For example, lycopene is a very powerful antioxidant with various health benefits ranging from promoting cardiovascular health to reducing the risk of cancer. But when lycopene supplementation (Lyc-O-Mato) with doses higher than the RDA was compared with tomato and tomato products (such as tomato juice, tomato sauce, tomato soup, tomato paste, ketchup, tomato puree), to determine its effect on cardiovascular risk factors such as oxidative stress and inflammation, it was found that tomato and tomato products yielded much more favorable results compared to lycopene supplementation (Burton-Freeman and Sesso 2014). The main reason for this could be that the lycopene from tomato and tomato products was more bioavailable than the lycopene from supplements. Therefore, it is possible that products that are naturally rich in antioxidants may be more bioavailable.
Contextual role of oxidative stress and prooxidant effects of antioxidants. Oxidative stress, while generally implicated in the development of chronic diseases, also plays essential roles in cellular signaling and normal physiological processes. Periodic oxidative stress such as that developed during exercise is, in fact, beneficial and important for cell repair and growth. Over-supplementation with antioxidants may disrupt these delicate signaling pathways and interfere with the body's natural defense mechanisms. These interactions can be complex and may affect the balance of the body’s oxidant-antioxidant defense system. Some studies have suggested that high levels of certain antioxidants such as phenolics, vitamin C, beta-carotene, flavonoids, and vitamin E can exhibit prooxidant properties under specific conditions. This prooxidant activity may negate their intended benefits and potentially contribute to oxidative damage.
Fortification of products is becoming a common practice in the food industry. Some commonly fortified products are dairy products, cereals, fruit juices, energy drinks, teas, etc. For example, Kellogg’s Smart Start Original Antioxidants breakfast cereal provides 10% RDA (per serving) of vitamins C and E. Fairlife milk (10% RDA of vitamin A) and Nestlé Boost Balanced Nutrition Drink (50% RDA of vitamins C and E and 20% RDA of vitamin A) are some examples of fortified dairy products. There are several antioxidant-infused drinks such as Bai Antioxidant Infusion and Supertea (15% RDA of vitamin C), BodyArmor Lyte (70% RDA of vitamins A, C, and E) and Vitaminwater (250% RDA of vitamin C and 25% RDA of vitamins A and E).
In addition to the products that are fortified with vitamins, several natural products, including dark chocolate, nuts and seeds trail mixes, berry smoothies, açai bowls, cold-pressed juices, and fruit and vegetable powders, also are marketed as naturally rich in antioxidants. These natural antioxidant-rich products might be more appealing to health-conscious consumers.
Antioxidants from whole foods and natural food ingredients might be more bioavailable and are better absorbed than their synthetic counterparts. They also occur in combination with other vitamins, minerals, dietary fiber, and substances that aid in their absorption. For example, fat-soluble vitamins such as vitamins A and E are better absorbed when they are consumed along with fats. So, they are not absorbed completely by the body when they are consumed with water-based drinks such as energy drinks or teas or fat-free or low-fat milk. Therefore, consumers may benefit more from naturally occurring antioxidant sources such as fruits and vegetables than from food products that have been fortified.
Overall, antioxidants encompass a diverse group of compounds with varying chemical structures and mechanisms of action. Generalizing the health effects of all antioxidants may oversimplify the complexities associated with different compounds and their interactions in the body. While antioxidants have shown potential health benefits, the addition of large amounts of antioxidants to foods warrants careful consideration. The current understanding suggests that a balanced and moderate approach to antioxidant intake is essential, taking into account optimal dosages, bioavailability, and interactions with other nutrients.
Future research should focus on elucidating the complex mechanisms and exploring personalized approaches to antioxidant intake, considering individual variations and genetic factors. Ultimately, a well-informed and evidence-based approach is necessary to navigate the potential risks and benefits of antioxidant-fortified foods, ensuring that they contribute positively to overall health without unintended consequences.ft