Role of antioxidants in the prevention of chronic diseases

What are free radicals, oxidation and oxidative stress?

To date, the term antioxidant is not clearly defined, but it can be associated with a compound that inhibits oxidation. To understand what an antioxidant is, we must first understand what oxidation is and how it is generated.

In our body, oxidation is a chemical reaction that corresponds to the attack of a cell or a compound by free radicals of an oxygenated species. Free radicals attack the components of the cell, such as proteins and DNA. They are unstable and highly reactive molecules. They are generated naturally by the body, but also in reaction to certain environmental factors, such as smoking, alcohol or exposure to the sun. It is not free radicals (or oxidation) as such that are dangerous, as they are essential for normal physiological functioning, but their presence in excess: having a balance in their production is fundamental. To achieve this balance, cells are naturally endowed with antioxidant defenses that will regulate the level of free radicals by restoring their stability. These antioxidants can be enzymes or non-enzymatic metabolic compounds (lipoic acid, glutathione, uric acid, bilirubin).

However, these antioxidant defenses can be depleted, free radicals become excessively present in cells and tissues and we speak of oxidative stress. Oxidative stress is a threat to our body, it is a factor of inflammation, it reduces the ability of our body to eliminate free radicals, it can trigger inflammatory phenomena and can be the cause of the development of chronic diseases or metabolic disorders.

What are the different types of antioxidants?

There are multiple antioxidants, which can be divided into two groups:

• Endogenous antioxidants, naturally produced by our body. For example, glutathione helps prevent cell aging and the development of chronic diseases (especially cardiovascular). From the age of 45, its production decreases and the risk of developing diseases increases, so it becomes important to provide it through diet. Since glutathione does not literally exist in food, it is necessary to target its precursors, i.e. the amino acids that constitute it: glycine, cysteine and glutamate.
• Exogenous antioxidants, which must be provided by our diet. We can mention vitamin E, vitamin C, selenium, carotenoids or omega-3. They can be provided by various foods, including fruits and vegetables, but also spices, cocoa, tea, coffee …
• The action of endogenous antioxidants can be improved with the addition of exogenous antioxidants.

Finally, there are synthetic antioxidants, but these are not recommended because they are associated with undesirable effects (carcinogenic, endocrine disruptors …).

They are mainly used in the food industry for the preservation of products. We can mention here BHA, BHT, E-310 or TBHQ.

The health benefits of antioxidants and their role in disease prevention

Some benefits have been demonstrated by science, we can cite the following examples.

• They play a preventive role in the development of eye diseases, particularly cataracts and AMD.
• They help protect the brain and cognitive abilities, which is an area particularly prone to oxidative stress. Recent studies have also shown that certain antioxidants reduce the risk of depression (green tea polyphenols, phytoestrogens).
• They are known for their role in skin health.
• A diet rich in antioxidants has been correlated with a lower risk of type 2 diabetes.
• They influence the prevalence of good bacteria in the intestinal microbiota.
• They reduce the risk of developing cardiovascular disease (e.g. selenium and CoQ10 reduce cardiovascular mortality).

Antioxidants are all different, they do not have the same form, they do not act in the same way and are not necessarily associated with the same benefits. To date, it remains complicated to determine a recommended dose and to understand the real impact of their intake. This is why understanding the physiological effects of antioxidants is a topic of current interest.

Antioxidants and Disease Prevention: A Promising Future

The anti-aging potential of antioxidants is on the rise: in the scientific sphere, there is also a focus on the role of antioxidants in “aging well. While life expectancy has increased, the prevalence of chronic diseases and the number of years spent in “poor” health have also increased. Finding solutions for healthy aging is therefore a crucial issue. This is why the focus is on research into compounds with antioxidant properties, including polyphenols and carotenoids. A study has shown that some natural antioxidant molecules contribute to increase telomerase (telomerase allows to maintain the size of telomeres division after division) and thus to decrease our cellular age. In humans, it is only active in stem cells and those at the origin of spermatozoa and eggs). These molecules could potentially be integrated into treatments for age-related diseases. New studies related to this topic can be expected to emerge.

Recent studies are also investigating the anticancer and anti-thyroid potential of antioxidants.

The Dietary Antioxidant Market and Consumer Trends

The antioxidants market is growing globally (CAGR 2022-2031 9.2%), with growth driven in part by the anti-aging trend.

For food antioxidants, the beverage and dry goods markets are dominant (although antioxidants to extend the shelf life of food products are included).

In terms of consumers, North America has the largest market share, while the United Kingdom dominates the European market. However, while the term antioxidant is familiar to consumers, it is not necessarily their presence that will drive market growth, but rather the health claims of products.

Innovations around antioxidants are emerging. For example, a coffee enriched with green tea antioxidants and marketed as anti-aging has recently emerged. Major ingredient companies have also positioned themselves and are innovating in the antioxidant sector.

Consumer demand for naturalness is a key trend, and there has been a shift from synthetic to natural antioxidants, which are safer for health, better metabolized by the body and more environmentally friendly.

The latest studies and trends suggest that the prevention of chronic diseases through nutrition is on the rise. Alcimed follows closely the developments in this field and we are ready to accompany you in your projects related to food and health. Do not hesitate to contact our team!

About the author

Elise, Consultant in the Life Sciences team of Alcimed in France