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science. medicine. health.

I Say Tomato, You Say Cancer Prevention


A saucy new medicine

Shalin Shah

Fall 2005


tomato cancer prevention lycopene   Pizza’s reputation as an unhealthy vice may soon be reformed by biomedical researchers; new research suggests that the primer of every good pizza, tomato sauce, contains an important antioxidant known as lycopene, which may have cancer-preventative properties.

    Lycopene has recently been correlated with the prevention of many degenerative disorders and has thus attracted the meticulous scrutiny of the biomedical research community. Its effects are believed to target the hazardous byproducts of routine metabolic processes: free-radicals. Free radicals have one or more free electrons and are thus unstable and highly reactive. In an attempt to stabilize their own electron configuration, free radicals may beget even more free radicals by stealing neighboring electrons. “No process is perfect,” asserts Bruce Ames, PhD, graduate professor of molecular biology at the University of California, Berkeley (UC Berkeley). “The mitochondria, which are the power plants of cells, pull electrons from fats and carbohydrates, forming radical oxygen,” he explains. These compounds are extremely reactive and tend to bump into cellular components, such as DNA, leading to cell damage.
 
    This process, better known as oxidative stress, is ultimately responsible for the accumulation of free-radicals in the body. Many phytochemicals, including lycopene, that are found in fruits and vegetables act as antioxidants to relieve the oxidative stress exerted on cells. “They help destroy radicals, reducing their numbers in the body,” says Dr. Ames, thereby helping the body avert many harmful disorders.

    Raw tomatoes contain an inactive form of lycopene. Once tomatoes are processed, heated, and mixed with oils, the lycopene molecules undergo a conformational change known as a cis-trans isomerization. Steven Pedersen, PhD, a professor of organic chemistry at UC Berkeley, stresses that “lycopene processing can make it much more potent for humans.” The modification of lycopene during tomato processing increases the bioavailability of the substance upon ingestion. The modified lycopene in foods like tomato sauce and tomato juice is in a form more readily utilized by the body.

    Other antioxidants are readily available for consumption, but what sets lycopene apart is its distinct cancer-preventing quality. An observational study conducted in 2004 by Arnon Blum, MD, of the Cardiology Branch National Heart, Lung, and Blood Institute in Bethesda, Israel, found that people living in and around the Mediterranean region, who had diets rich in foods containing processed tomatoes appeared to have a lowered rate of various cancers. Maria Stacewicz-Sapuntzakis, PhD, at the University of Illinois, Chicago remarks, “In some epidemiological studies, high tomato consumption [or high levels of lycopene in the blood] was associated with [a] decreased risk of lung, stomach, colorectal, pancreatic, oral and pharyngeal, bladder, breast, cervical and ovarian cancer.” The high amount of modified tomato food products consumed in the region contributed to the lower rates of these cancers.

    In another experiment conducted by Dr. Blum and his colleagues, 32 patients with acute prostate carcinoma ate tomato sauce-based pasta dishes for three weeks prior to a radical prostatectomy, while the control group ate a diet with comparatively fewer servings of the tomato sauce-containing meals. Prostate tissue was obtained from each patient at the start of the tomato sauce regimen and once again just before their prostatectomy. The experimental group showed a statistically significant decrease in cancer tissue cells. Furthermore, the men who eventually developed prostate cancer were all deficient in lycopene.


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