Vitamin E has also been linked to a lower risk of prostate cancer. Other studies have not shown a link between lycopene and prostate cancer. A study from England found no association between lycopene and prostate cancer risk, but report that beta-carotene is protective. These conflicting reports support the notion that the carotenes work both synergistically and in ways we don't understand. It has also been shown that different combinations of carotenoids provide different degrees of protection against free radicals.
Vitamin E appears to be very important in enabling the carotenes biological actions.
Lycopene, in turn, can be adversely affected by inadequate supplies of vitamin C and sulfur molecules such as N-acetylcysteine. Cholesterol-lowering drugs deplete lycopene Lipids, too, play a role in whether the carotenes are effective. The carotenes are lipid soluble-they must have fat to be absorbed. Drugs that lower cholesterol can drastically interfere with the carotenes. It took one to two years for levels of lycopene and beta-carotene to return to normal after Probucol.