In this study, Harvard researchers followed more than 4,000 men who were given either 50 mg of
beta carotene every other day or a placebo pill.
Three new tomato breeding lines from ARS hold 10 to 25 times more
beta carotene than typical tomatoes.
In one study, researchers examined how vitamin E, vitamin C, and carotenoids such as
beta carotene collaborate to get rid of free radicals, whose harmful effects arise from their readiness to grab an electron from another molecule.
"Antioxidant nutrients such as
Beta Carotene and Vitamins C and E help protect against harmful cell damage," claimed an ad by vitamin giant Hoffmann-LaRoche.
That's because these are among the richest sources of
beta carotene, a nutrient believed to protect against cancer and cataracts.
government has sobering news for devotees of
beta carotene. The dietary supplement doesn't prevent heart disease or cancer, and it may even increase a smoker's risk of lung cancer.
They contain an average of 58 milligrams per gram of fresh weight of
beta carotene compared to about 1.5 milligrams per gram in normal tomatoes.
The most recent studies on a particular carotenoid,
beta carotene, taken in supplement form, did not report such protection (see p.
Rothman explains that
beta carotene must be converted into vitamin A in the body and that "the body regulates the amount of
beta carotene it converts."
The three treatment groups received either
beta carotene alone, vitamins C and E, or
beta carotene plus vitamins C and E.
The vitamin combos included the vitamin A precursor known as
beta carotene, two B vitamins, vitamin C, vitamin E, or other nutrients thought to provide a shield against cancer.
Then the researchers randomly assigned the study participants to nine months of maintenance therapy with either a low dose of 13-cis-retinoic acid or
beta carotene, a natural vitamin A precursor found in many orange fruits and vegetables.