As a consumer, it is easy to give into fancy marketing with big claims. You walk into your local supplement store and see “Antioxidant supplement. Clears your skin and detoxifies your body!”.
You may immediately want to drop all of your money on this new and exciting product, in hopes of seeing the results it promotes. Before giving into supplements with claims that may seem too good to be true, it’s always best to do some research and understand the truth behind the claim.
Let’s take a look at what antioxidants are and how they may play a role in an individual’s health.
What are antioxidants?
Antioxidants are molecules that inhibit or quench free radical reactions (3,5). Antioxidants may be attributed to delaying or inhibiting cellular damage, oxidative rancidity, and chronic diseases attributed to oxidative stress (3). They are split into categories of being enzymatic and non enzymatic (3).
Non enzymatic antioxidants act by interrupting free radical reactions, they may also fall into a subcategory of synthetic or natural.
Natural antioxidants are those such as vitamin C, vitamin E, flavonoids, bioflavonoids, polyphenols, and plant sources found in fruits and veggies.
The most commonly used synthetic antioxidants are BHA and BHT. Synthetic antioxidants are mostly used for the purpose of preventing rancidity in food and other goods, such as cosmetics and pharmaceuticals (4).
Enzymatic antioxidants are those such as superoxide dismutase (SOD), catalase, and glutathione (6). Enzymatic antioxidants act by breaking down and removing free radicals. Each antioxidant (there are many more than the few I have listed) has its own biological properties and effects on the body (5). However, while each antioxidant may have its own effects, they are widely known for neutralizing free radicals which may be attributed to several other health benefits (5).
What is oxidative stress and oxidative rancidity?
Oxidative stress, induced by reactive oxygen species (ROS), results in an accumulation of free radicals in the body (3). The accumulation of free radicals may be involved in the progression of many chronic illnesses, such as cardiovascular disease, cancer, cognitive disorders, and aging (1,3,4,5,7).
Oxidative stress may also play a role in the modification of lipids, protein and nucleic acids (1). The modification of lipids may cause LDL (bad cholesterol) to have a higher chance of being trapped in the artery wall, this can lead to atherosclerosis (5,1). The modifications caused by oxidative stress may also cause cell damage (1).
Antioxidants neutralize, or inhibit, the free radicals which may possibly aid in reducing the damage they can cause (6).
Oxidative rancidity of certain goods is a result of the oxidative deterioration of the fats and oils in a product (4). Oxidative rancidity can decrease the nutritional quality of certain products and even alter the flavor or color. Adding antioxidants to products can aid in preventing deterioration. Synthetic antioxidants such as the aforementioned BHA and BHT, are most commonly used for this purpose however, the use of natural antioxidants is becoming more popular (4).
What are the benefits of antioxidants?
Let’s go more into detail about what research has to say about antioxidants.
There is a lot of research about antioxidants, but most of it is considered inconclusive due to a high number of limitations (5). Those limitations are the short duration of most studies done, and a lack of inclusivity of people with the diseases associated with free radicals.
Most research has had the same findings about antioxidants: they may reduce illness associated with free radicals, however the benefits may also be little to none (1).
Data found in an early animal study showed that antioxidants found in dietary sources, such as from fruits and veggies, may reduce the progression of atherosclerosis (1). Another early human study showed that antioxidants from dietary sources may reduce the risk of cardiovascular disease (1).
However, several other studies have data showing that antioxidants may have little to no benefit of preventing illness associated with oxidative stress (1,5). While most studies are inconclusive, natural antioxidants are still promoted as being helpful in preventing diseases associated with oxidative stress (7).
As far as antioxidants go for food preservation, synthetic antioxidants have been used and studied the most. The most common synthetic antioxidants are BHA and BHT. Antioxidants can help prevent oxidative rancidity in food products and other goods by preventing deterioration (2).
As an interest in the safety of synthetic antioxidants increases, natural antioxidants such as tocopherols and flavonoids are being more commonly used as food preservers (7).
The inconclusive results of most antioxidant research has led to more studies being worked on, and has inspired researchers to try different designs to study antioxidants (1).
Natural sources of antioxidants
There are many natural sources of antioxidants, much more than I will list off today. They all have different biological properties and have different effects. While each antioxidant has its own individual purpose, they all play a role in the neutralization of free radicals and inhibiting or delaying oxidative stress and rancidity.
Some natural (4) sources of antioxidants are:
- Vitamin C: broccoli, brussel sprouts, cauliflower, strawberries, kiwi fruit, bell pepper,ginger.
- Vitamin E: avocado, almonds, leafy greens, sunflower seeds, peanuts.
- Carotenoids (beta carotene and lycopene): apricots, asparagus, beets, carrots, kale, mangos, peaches, pumpking.
- Selenium: brazil nuts, shellfish, beef, brown rice, barley.
- Zinc: beef, poultry, shrimp, chickpeas, lentils, cashews, fortified cereals.
- Phenolic compounds: red wine, cocoa, berries.
- Flavonoids: onions, kale, grapes, red wine, tea, peaches, tomatoes.
Are antioxidant supplements worth it?
Back to the conversation about fancy marketing we talked about earlier. Should you be supplementing with antioxidants and purchasing products claiming to be “high in antioxidants, superfood products!”?
According to the Harvard School of Public Health, most companies market antioxidant supplements and hype the benefits of them only to make money. Additionally, most of the data that is used by supplement companies to promote their product is distorted data to make their product look good (5).
Superfoods are considered foods with a high antioxidant content (5). The United States Department of Agriculture created the oxygen radical capacity (ORAC) database to measure antioxidant capacity in different antioxidant rich foods (5,8). Cocoa, berries, spices, legumes, and blueberries were some of the foods ranking the highest ORAC score. Therefore, while supplement companies hype up their high antioxidant product; you could be intaking those antioxidants through natural sources such as fruits and veggies.
Like I’ve talked about before in many of my posts, consuming the whole food versus a portion of the food (aka antioxidant supplements) will give you so many more benefits. Like actually enjoying a meal or snack, or getting in some fiber.
Can antioxidants be pro-oxidants?
Well, that superfood antioxidant potion you were hoping to ingest? It may harm rather than heal. Antioxidants have prooxidants properties when the environment is just right in the body, and certain metal ions are present (9).
Prooxidants are chemicals that instead induce oxidative stress (11).
For example, vitamin C at doses <100mg/kg had antioxidant effects, while doses 1000mg/kg and above showed a prooxidant effect in the body (10).
If you think about the role of an antioxidant, it donates an electron to an unstable cell that is lacking an electron. This donation, in turn, can make an antioxidant a pro-oxidant. This strengthens the point that antioxidants should be taken as a whole part of your diet, and perhaps not as one individual supplement. If you do want to supplement, consider taking your antioxidants with a meal.
Personal opinion
While much data about antioxidants is inconclusive, consuming antioxidants may still be attributed to better health and better preservation of food products and other goods.
I believe that if your diet is rich in a variety of nutrient dense foods such as the sources listed above, and if you consume plenty of fresh fruits and veggies, antioxidant supplements may not be something you have to spend your money on.
I write a lot about supplements on this website, and I think they can be fun things to add to your already health conscious meals. If you do decide to supplement, be sure to read the labels, and choose a company with the GMP (good manufacturing Practice) label. Always check with your doctor if you are living with health conditions or taking medication to ensure it’s safe.
If you believe you need supplementation because you aren’t getting enough antioxidants through your diet, make an appointment with a registered dietitian who has the expertise to help you create a well-rounded meal plan, and work with you to determine if supplement use would benefit you and your lifestyle.
To summarize
Antioxidants are a molecule that neutralizes free radicals caused by normal metabolic processes or external things such as x-rays, air pollution and cigarette smoke (6). By neutralizing free radicals, antioxidants play a role in inhibiting or delaying oxidative stress and rancidity (1,2,3,4,5,7).
Oxidative stress is associated with many conditions like inflammatory conditions, cardiovascular disease, cancer, and aging (6). It may also affect the structure of lipids and damage cells (6). While research is inconclusive, antioxidants are promoted as possibly reducing the progression of the illnesses mentioned above and preventing or slowing down oxidative rancidity (5).
There are many sources of antioxidants, both natural and synthetic. While superfood/antioxidant supplements are growing in popularity, a diet rich in nutrient dense foods may serve the same purpose.
References:
- Yoshihara, Daisaku, et al. “Antioxidants: Benefits and Risks for Long-Term Health.” Maturitas, vol. 67, no. 2, 2010, pp. 103–107., doi:10.1016/j.maturitas.2010.05.001.
- Shahidi, F. (2000), Antioxidants in food and food antioxidants. Nahrung, 44: 158-163. https://doi.org/10.1002/1521-3803(20000501)44:3<158::AID-FOOD158>3.0.CO;2-L
- Nimse, Satish Balasaheb, and Dilipkumar Pal. “Free Radicals, Natural Antioxidants, and Their Reaction Mechanisms.” RSC Advances, vol. 5, no. 35, 2015, pp. 27986–28006., doi:10.1039/c4ra13315c.
- Moure, Andrés, et al. “Natural Antioxidants from Residual Sources.” Food Chemistry, vol. 72, no. 2, 2001, pp. 145–171., doi:10.1016/s0308-8146(00)00223-5.
- “Antioxidants.” The Nutrition Source, Harvard School of Public Health, 3 Mar. 2021, www.hsph.harvard.edu/nutritionsource/antioxidants/.
- Lobo, V, et al. “Free Radicals, Antioxidants and FUNCTIONAL Foods: Impact on Human Health.” Pharmacognosy Reviews, 1 Jan. 1970, dx.doi.org/10.4103%2F0973-7847.70902.
- Valenzuela B, Alfonso, et al. “Natural Antioxidants in Functional Foods: From Food Safety to Health Benefits.” Grasas y Aceites, vol. 54, no. 3, 2003, doi:10.3989/gya.2003.v54.i3.245.
- David, Haytowitz, and Bhagwat Seema. “USDA Database for the Oxygen Radical Capacity (ORAC) of Selected Foods.” Publication : Usda ARS, 10 May 2010, www.ars.usda.gov/research/publications/publication/?seqNo115=251105.
- Sotler, Robert, et al. “Prooxidant activities of antioxidants and their impact on health.” Acta Clinica Croatica 58.4 (2019): 726.
- Seo, Min-Young, and Sun-Mee Lee. “Protective effect of low dose of ascorbic acid on hepatobiliary function in hepatic ischemia/reperfusion in rats.” Journal of hepatology 36.1 (2002): 72-77.
- Rahal, Anu, et al. “Oxidative stress, prooxidants, and antioxidants: the interplay.” BioMed research international 2014 (2014).
