Lycopene is an extremely powerful carotenoid antioxidant found in certain red and pink foods such as tomatoes. Consumption of lycopene-rich foods is associated with lower levels of cancer, cardiovascular disease, and other health problems. However, because lycopene-rich foods contain a number of other beneficial phytonutrients, it is difficult to determine what proportion of their health-protective effects are attributable to lycopene.
Research into Lycopene’s Health Benefits
A study of elderly subjects in the U.S. found that those consuming more tomatoes were 50% less likely to die from all cancers. Also, in a review of 72 epidemiological studies, 57 found that tomato consumption or lycopene levels were inversely correlated with certain cancers (these results were statistically significant in 35 of the studies). In addition, a study involving subjects from 10 European countries found that those with higher lycopene levels were less likely to die of coronary artery disease.
Unfortunately, there has not been sufficient research into the connection between lycopene and disease prevention to definitively prove the benefits of this phytonutrient. There is evidence that lycopene may be beneficial for the following conditions, though more research is required to confirm this:
- Breast cancer
- Cardiovascular disease
- Gingivitis
- High blood pressure
- Increasing HDL (good) cholesterol
- Male infertility (increasing sperm counts)
- Ovarian cancer
- Pre-eclampsia (pregnancy-associated high blood pressure)
- Reducing LDL (bad) cholesterol
Lycopene has also been shown to provide some degree of sunburn protection (in combination with vitamins C and E, selenium, beta-carotene, and proanthocyanidins), and it is possible that it may help to reduce the risk of skin cancer. However, research is required to explore this possibility.
Studies into lycopene’s health-protective effects for the following conditions have yielded mixed results thus far, with some supporting lycopene’s benefits and others finding no effect:
- Atherosclerosis
- Cervical cancer
- Cancers of the digestive tract (oral, pharyngeal, esophageal, gastric, colon, and rectal)
- Exercise-induced asthma
- Lung cancer
- Prostate cancer
A recent well-publicized study suggested that lycopene provides no benefits for prostate cancer, but the study’s claims have been criticized for a number of reasons. Overall, while variable study results certainly don’t rule out the possibility that lycopene may help to prevent prostate cancer and other diseases, more studies are needed to definitively confirm or disprove such effects.
There is little scientific evidence supporting lycopene’s benefits for the following conditions:
- Eye disorders such as cataracts and age-related macular degeneration
- Diabetes
- Immune system boosting
- Kidney disease
- Post-exercise lung function
Natural Sources of Lycopene
Getting lycopene through a healthy diet is recommended, as lycopene-rich foods contain many other health-promoting phytonutrients, some of which may have synergistic effects. Natural sources of lycopene include:
- Tomatoes and tomato products (sauces, ketchup, etc.)
- Apricots
- Pink grapefruits
- Pink guavas
- Watermelons
Tomato products such as tomato sauce and paste are particularly good sources of lycopene, as the body is better able to access the lycopene due to the cooking process. As for raw tomatoes, vine-ripened are higher in lycopene than those that are picked early. Also, taking lycopene with beta-carotene (found in orange and yellow vegetables) and a small amount of added fat (i.e., olive oil) increases its bioavailability.
Diet and Lifestyle Factors
Those who smoke or drink regularly may have depleted levels of beneficial phytonutrients. In addition, smoking can cause lycopene to become oxidized in the body. As a result, those who smoke and take carotenoid supplements are actually more likely to develop lung cancer and cardiovascular disease than smokers who don’t take supplements.
While evidence suggests that lycopene does have some health-protective effects, maximum health benefits can be achieved through eating a varied diet that is rich in brightly coloured vegetables and fruits, whole grains, and legumes, and low in saturated and hydrogenated fats. Because it is difficult to determine which elements in various foods provide health benefits, and because many phytonutrients work in tandem with other phytonutrients, obtaining lycopene from natural sources whenever possible is recommended.
Safety
No studies have shown increased rates of illness with high tomato consumption or high lycopene levels in non-smokers. Natural sources of lycopene are safe as long as the individual isn’t allergic to those particular foods (though eating an enormous amount of tomatoes can cause the skin to take on an orange hue).
Lycopene supplements are usually well-tolerated. However, they have caused digestive disturbances such as nausea and vomiting or diarrhea in a small number of people. Those who are interested in taking supplements should consult a health care practitioner to establish a safe dose before proceeding.
For more food articles, see the main Food and Nutrition page. For more health articles, see the main Mind/Body Health page.
References:
- American Cancer Society. (2007). “Lycopene.” Cancer.org.
- CBC News. (18 May 2007). “Study Disputes Benefits of Lycopene for Preventing Prostate Cancer.” CBC.ca.
- Edmonton Journal. (29 September 2008). “Don’t Abandon Tomatoes Just Yet.” Canada.com.
- George Mateljan Foundation. (2008). “Lycopene.” The World’s Healthiest Foods, WHFoods.com.
- Mayo Foundation for Medical Education and Research. (2008). “Lycopene.” Drugs & Supplements, MayoClinic.com.