It’s been a few years since antioxidants exploded in popularity and swamped the “health-food” supplement market. Sure, antioxidants can inhibit oxidation and thereby lower the production of free radicals (which can harm our cells).
However, the main thing influencing oxidation and the production of free radicals is your diet, your environment (pollution) and amount of exercise. As for diet, the biggest offender is carbohydrate metabolism.

When we produce energy from carbohydrates, carbohydrates and oxygen transforms into carbon dioxide and water. This process also produces toxic oxygen radicals which must be decomposed immediately, as they would otherwise cause damage to cells.
This simply means that if you consume carbohydrates, your need for antioxidants increases. If you eat several times a day, it increases with each meal. In other words, consuming carbohydrates, eating the traditional 5 to 8 meals a day while exercising a lot will contribute to premature aging – both on the outside and inside – and a reduced lifespan like nothing else.
Even if you consume foods rich in antioxidants, the bioavailability is very low, so most of it will not be utilized in the body. Instead, it will act as an antinutrient and some of it will turn into oxalates, which calcify our blood vessels, our joints and our kidneys (kidney stones) – as seen with vitamin C. Actually, supplements are even worse. Most studies on the vast majority of antioxidant supplements has only shown promise in test tubes, not when administered to people – simply because the bioavailability is miniscule, there is no ‘food synergy’ and therefore they end up hurting us instead.

On the opposite side of the spectrum, if you only, or mostly, consume protein and fats (and you are in ketosis most of the day), only eat 1 to 3 meals a day, and mainly exercise for keeping fit and strong, your oxidation and demand for antioxidants will be minimal. The amount found in muscle meat is enough for most people, and if you consume some organ meats or raw dairy, you’ll be good even in more harsh conditions.
Also, the strongest and most abundant antioxidant in the human body is uric acid, something that our body produces from endogenous, and to a lesser degree, from exogenous purines.
In other words, if you follow our natural animal-based diet, your body will be able to keep up with oxidation in most scenarios. It’s nothing to worry about.
And if you exercise a lot, simply add in a little bit more organ meats to get some extra vitamin A, C, and CoQ10, and you’ll be fine.