CDTA supporters of stimulating the natural production of antioxidants claim that natural antioxidants provide better protection against the damaging effects of free radicals than do antioxidant supplements. One concern this group has is that the triggering mechanisms for the production of natural antioxidants can be desensitized by the over use of antioxidant supplements. The belief here is that a continuous production of natural antioxidants brought on by very mild activation of the Nrf2 protein is the healthiest possible state for human body. Anything that disrupts this does more harm than good. They also claim that the natural antioxidant production may be disrupted by taking too much of known Nrf2 activators such as curcumin or resveratrol. Some supporters in this group believe that current antioxidant over-supplementation has already created serious health issues.

The main proponents of CDTA support the idea of taking significant amounts of readily available external antioxidants such as vitamin C, E, and other supplements. Many of them recommend taking one or more grams of Vitamin C daily. They believe this can safely reduce the amount of cellular damage free radicals generate. The good news is that some research actually does support this claim. The not so good news is that the concerns of the pro natural antioxidant camp are not being taken seriously. It is also true that, by focusing on a few well known antioxidants, too little attention is being paid to the role antioxidants play in the body.

Humans utilize numerous (1000s) types of antioxidants and their variants. Each antioxidant's biochemical reactions with different kinds of free radicals are unique. A few antioxidants, such as Vitamin A, C, and E are popular and are well known. Most others such as Uric acid, best known for its association with gout, are much less well known but are equally important. Using this antioxidant as an example, Uric acid, which in humans happens to have the largest blood concentration of all antioxidants, is responsible for over half of the antioxidant capacity of human blood serum.  Uric acid can reduce oxidative stress caused by high-altitude hypoxia. Another such antioxidant is Glutathione (GSH). It has been called "the mother of all antioxidants", and considered by many to be the body's most essential antioxidant. It is produced and  found within all human cells and is essential for proper functioning of the immune system. GSH levels in the blood fall with poor health and increasing age.  As a biomarker, GHS blood levels, have been associated with longevity. Glutathione works synergistically with many antioxidants and GSH levels in the body  can be raised by  Vitamin C and Selenium. A great many antioxidants that counteract free radicals also inhibit viruses and bacteria. Most of this CDTA related antioxidant research is only reported in technical journals but the research itself suggests that lots of interesting anti-aging tidbits being put on the shelf for future study or are under reported.

The human body has several enzyme systems that fight free radicals by using antioxidants (vitamins A, C, E, and the mineral selenium) we can only get through our diets and/or by supplements. Vitamins A, C, and E are also essential nutrients. Dietary deficiencies of these antioxidants can cause specific diseases and possibly lead to other chronic and/or degenerative health problems. A Beta-carotene (vitamin A) deficiency can cause night blindness. Vitamin C deficiency can cause scurvy. Vitamin E deficiency can causes nerve conduction problems. In the U.S. a diet rich enough in fruits and vegetables (6 to 8 daily servings) can prevent such deficiencies and is highly recommended. In reality such an ideal diet may be difficult to maintain. This presents a strong argument for supporting the use of at least a few antioxidant supplements but the possible negative long term effects of using large amounts of such supplements are not yet well known. So far general studies on this do report some negative effects but also seem to be inconclusive (Antioxidant Overuse) (Too Many Antioxidants).

Bickering amongst advocates of CDTA has left us with several pressing unanswered questions.
Should we rely on naturally produced antioxidants and limit our use of external antioxidant supplements?
What are the correct antioxidant supplement dosages you need to slow down the aging process?

There are no agreed upon standards to go by. CDTA tells us cellular damage is cumulative. This may mean the real answers are relative; i.e. they will vary depending on how old you are. It is a well established fact that the efficiency of many of the body's homeostatic mechanisms declines with age. If you are getting older, say over 60 years of age, your natural antioxidant defenses are slowly weakening. How long can you rely on them to adequately protect you? The efficiency of the body's digestive absorption of many foods, including the trace minerals that the natural antioxidant systems require, slowly decreases with age. At a certain point in life an increase in antioxidant supplements and/or supplemental digestive enzymes may really be helpful. Several of the antioxidants produced in our body are becoming available in the supplement market.
 
The current interpretation of CDTA's vague approach to anti-aging is that to slow down the rate at which cellular damage accumulates you should increase your daily intake of dietary antioxidants (fruits and vegetables) and perhaps take some unspecified amount of various vitamins and anti-aging supplements. With increasing age you may need to increase your intake of vitamins and antioxidant supplements. Until the experts agree on supplement dosages you will have to diligently research any supplement you are interested in.

There are hundreds of health supplements available on market. Many scientific studies on the benefits of any given health supplement are at odds with each other. Some claim taking supplements has benefits while others claim there are few or no benefits, or that supplements may even be harmful. The vitamin and anti-aging supplement business has become a 23 billion dollar industry that is not very well regulated. This has allowed the market to become full of overpriced products that may have few real benefits. You need to be careful.