Lycopene is a carotenoid that has been found to be an antioxidant. A previous study showed that lycopene has strong antioxidant activity, being able to combine oxygen better than alpha-carotene, beta-carotene, lutein, and alpha-tocopherol.
Beta-carotene has been studied the most of the carotenoids but it has failed to show anticancer effects. In some high-risk patients, beta-carotene seems to increase cancer risk. One study showed that people on beta-carotene had an increased risk of fatal heart attacks but showed no effect on nonfatal heart attack risk.
Lycopene is believed by the authors to prevent prostate cancer and cardiovascular disease in humans.
Tomatoes are the most common source of lycopene in the diet in the U.S. Tomatoes are a rich source of beta-carotene, vitamin A, folate, potassium, and vitamin C. Lycopene seems to absorb best from tomatoes when they have been heated and are consumed with fats.
Cigarette smoking causes an increase in atherosclerosis, perhaps due to low-density lipoprotein (LDL) oxidation by the free radicals from smoking because LDL is very susceptible to oxidation. Antioxidants can protect the LDL from this oxidation. Smokers generally have lower levels of carotene antioxidants. Serum levels of lycopene are not definitely reduced by smoking.
The effect of lycopene is not believed to be due to antioxidant activity. Lycopene and beta-carotene are carried inside the particles of LDL. Lycopene may inhibit cholesterol synthesis and increase LDL degradation.
A group of men were given 60 mg. of lycopene daily for 6 months. This was about equivalent to 1 kg. of tomatoes per day. The results showed an average of 14% reduction of LDL cholesterol and no change in HDL. This would calculate to be a 30-40% reduction of risk of myocardial infarction.
People with higher levels of tissue lycopene have reduced thickness of blood vessel walls and reduced risk of heart attacks. This effect is especially significant in nonsmokers. This leads researchers to believe that lycopene works by some mechanism other than as an antioxidant since antioxidants would, in theory, be most effective in smokers.
CONCLUSION: The authors suggest specific clinical trials be done to see if lycopene truly does reduce the risk of myocardial infarctions. Lycopene seems to protect from myocardial infarction, perhaps by some mechanism other than as an antioxidant.
NOTE: Passionflower fruit is an excellent source of lycopene.