So, if free radicals cause this damage, why can’t we stop it with antioxidants? We do. But not the antioxidants that we take in supplement form–those don’t make their way into the interior of the mitochondria where the damage takes place. Nature has endowed us with our own antioxidant system located within the mitochondria where, so to speak, the rubber meets the road in terms of free radical damage. The antioxidants produced require sulfur, which comes from the sulfur-containing amino acids, i.e. methionine. There are certain substances contained in particular foods that stimulate the enzymatic machinery that increases the production of these intramitochondrial antioxidants. Sulforaphane, for instance, a substance found in broccoli sprouts greatly stimulates a particular enzymatic pathway within the mitochondria, resulting in an increased production of antioxidants where they need to be. Sulforaphane has been shown to prevent cancer, vascular damage, and a host of other disorders thought to result from excess free radical damage.
Our defense against free radicals, then, really comes in two forms. First, the production of antioxidants within the mitochondria, and, second, by making the fats in the mitochondrial membrane less prone to damage. How can we do that? By making them more saturated.
Saturated fats aren’t prone to free radical attack–only unsaturated fats can be damaged by free radicals. Fats that have double carbon-carbon bonds, i.e. unsaturated fats, are the only fats susceptible to free radical damage. If the fats in the mitochondrial membrane are more saturated, then the membrane is less prone to free radical damage.