The fat intake provided by the 1,800 and 2,000 calorie diets, as described in Chapter 12, amounts to around 20 per cent of the total calorie intake, which is well in line with targets set by expert nutritionists such as Dr Elmer Cranton, whose work on free radicals was quoted in previous chapters. This relatively reduced fat intake, compared with 'normal' diets, relates very much to the tendency for fats to oxidize (peroxidize), a process which triggers a vast amount of free radical activity. The pattern of eating in a calorie restriction diet also reduces free radical activity, as does the inclusion of large amounts of vitamin and mineral-rich raw and unprocessed food.
Additional antioxidant help can be gained by judicious supplementation using the army of antioxidant nutrients now available. Many of these substances literally sacrifice themselves when confronted by a free radical, combining with them to deactivate the damaging chain reaction. The resulting combination of free radical and antioxidant is then easily eliminated.
The main antioxidant nutrients include: vitamins A (or its precursor beta carotene), C, E, B', B3, B5, B6, B12 the mineral selenium and the amino acid compound glutathione. To go into detail on why each of these is needed would take a great deal of space, so suffice it to say that ample evidence exists for their use; and further reading on the subject is readily available. I do, however, include a brief resume of the value and indications of some of the more important of them in the dosage suggestions which follow.
Vitamin A (or beta carotene)
Vitamin A is a fat soluble nutrient, excessive amounts of which can be toxic, which is why the recommendation for supplementation is to use its precursor, beta carotene, instead, as this is totally non-toxic. The ability of vitamin A to act as an antioxidant is strongest in the linings of tissues, where it protects the mucous membranes of the lung, intestinal tract and bladder, as well as the skin. It has been shown experimentally to prevent cancer formation in such tissues. It is also a vital factor in protecting the thymus gland, one of the immune system's most important organs
Beta carotene not only turns into vitamin A in the body but is itself a quencher of that most powerful of free radicals, singlet oxygen, which it deactivates without damage to itself. While not toxic, too much beta carotene will turn you slightly yellow, and so a reasonable amount only should be supplemented, especially if you are also eating large amounts of yellow/orange and dark green vegetables which are rich in it.
The suggested dosage of beta carotene is between 15 and 50 milligrams daily. If vitamin A is taken it is suggested that no more than 15,000iu of this is supplemented daily. This is a perfectly safe dose for anyone.
We do not know the real human requirement for vitamin C, partly because it varies from person to person (biochemical individuality) and partly because the research still has not been done to prove all of vitamin C's functions. All the evidence to hand points to a far greater need than that provided by the current RDA, which is well under 100 milligrams per day for an adult. Most life extension experts seem to suggest a range of intake of between 5 and 15 grams daily.
Vitamin C is almost totally non-toxic (mild diarrhoea is the worst to expect if you overdose) and is one of the most important protective substances we have. It has anti-tumour, anti-viral and anti-bacterial potentials; it stimulates immune function and increases the strength and integrity of collagen the tissue which literally holds us together. Its antioxidant function is strongest when combined with the amino acid cysteine (found in garlic).