Lycopene Helps Fight Prostate Cancer
Tomato compound is strongly linked to a decreased risk of this disease
ho would ever have thought that a healthy man's best friend might be the tomato? It's a startling idea, isn't it? But there's more than a kernel of truth in this seemingly preposterous notion. Sure, the tomato is a much appreciated culinary treat and an essential ingredient for many popular dishes, including salsa, salads, pasta, and pizza. But who would have thought that something like pizza, of all things, might play an important role in reducing the risk of prostate cancer?
OK, you're right - pizza will never be nominated as Health Food of the Year. But there are some health benefits buried in all that cheese. Specifically, the processed tomatoes in the pizza sauce appear to reduce the risk of prostate cancer. That is the conclusion of a Harvard University Medical School study that involved 47,894 men, aged 40-75.1 When the eating habits of these men were dissected, it turned out that tomato sauce, tomatoes, and pizza were associated with a decreased risk of prostate cancer. In fact, those who ate 10 or more servings of tomato products per week were 35% less likely to develop prostate cancer than those who ate fewer than 1.5 servings per week.
LYCOPENE PUTS THE RED IN TOMATOES
What's in tomatoes that makes them so good for your prostate? The answer is lycopene, a carotenoid related to beta-carotene (carotenoids are pigments found in many plants). Just as beta-carotene is responsible for the orange color of carrots and pumpkins, lycopene imparts the deep red hue to ripe tomatoes. And, as it turns out, there is more lycopene in cooked tomatoes than in raw tomatoes. For some reason that researchers don't yet understand, the heating and processing of tomatoes increases the amount of lycopene present in tomato sauce. Furthermore, the oil added to tomato sauce for purposes of pizza appears to help your body take up lycopene more efficiently - as does the cheese - because lycopene is much more soluble in fat than in water. So, here's to pizza! And to your healthy prostate!
LYCOPENE DECREASES THE GROWTH OF PROSTATE CANCER
It's one thing to realize that tomatoes play an important role in protecting against prostate cancer, and quite another to demonstrate that a single compound in tomatoes, such as lycopene, is the protective agent. An international group of researchers with this goal in mind recruited a group of 26 men with prostate cancer, aged 51-71, who were scheduled to undergo radical prostatectomy (surgical removal of the prostate gland).2 The patients were divided into two groups: one group received 30 mg of lycopene per day for three weeks prior to surgery, while the other group served as a control and received no lycopene supplementation.*
*The control group received no placebo either, because the outcome of the trial relied on measurements that were presumed to be independent of psychological influence. Hence the measurements would accurately reflect the effects of the lycopene treatment, and the treatment group would not be subject to a placebo effect that would need to be taken into account.
The cancer patients who received the lycopene supplement had a decrease in prostate-specific antigen (PSA), a molecule that serves as a marker for prostate cancer (higher PSA levels generally indicate a higher risk for this cancer). In addition, cancerous cells were less likely to be found outside the prostate tissue (i.e., in other tissues of the body) in those patients who received lycopene (4 of 15, or 27%) than in those who did not (9 of 11, or 82%). The researchers concluded that lycopene may be an antitumor agent and may serve a role in protecting against prostate cancer.
Because this was a small trial (only 15 patients received lycopene), it is wise to be cautious in interpreting the above information. However, given that lycopene supplementation lasted only three weeks and yielded positive results in men with diagnosed prostate cancer, there is good reason to believe that it may be especially beneficial in preventing prostate cancer in susceptible individuals when taken for longer periods.
HOW DOES LYCOPENE WORK?
Lycopene is a relative newcomer on the supplement scene, and the mechanism behind its benefit has not been completely established. Researchers have determined that lycopene is an antioxidant (a beneficial compound that scavenges and inactivates potentially dangerous free radicals), but it is not clear that this particular function is what makes it such a potent anticancer compound. Lycopene performs a number of other functions by which it may reduce the risk of prostate cancer. For example, it may:
1. Regulate cancer-cell growth by modulating the cell cycle. Lycopene interferes with the progression of the cell cycle in some cancerous cells and thus prevents them from proliferating. In fact, lycopene is a much more effective growth inhibitor of select cancer-cell types than either alpha-carotene or beta-carotene.3
2. Increase the level of the tumor-suppressor protein Cx43. Certain proteins, called tumor suppressors, can prevent cells from becoming cancerous. A protein called Cx43 is believed to be one such tumor suppressor; it helps cells communicate with their neighbors, a feature that is linked to minimizing the proliferation of precancerous cells. In cell-culture studies, carotenoids such as lycopene increase the level of Cx43 and may thus prevent cells from becoming cancerous.4
3. Regulate the oxidation status of cancer cells. Some transcription factors (molecules that lead to the expression of specific genes and that may make cells cancerous) are sensitive to the oxidation status of cells.
4. Decrease the extent of oxidative damage. Some researchers have noted that protein oxidation is higher than normal in patients with prostate cancer and that lycopene levels are significantly lower than normal. They suggest that higher lycopene levels may prevent protein oxidation, thus reducing the risk of cancer-inducing events in the cells.5
5. Increase the activity of carcinogen-metabolizing enzymes. Some carotenoids, such as lycopene, increase the liver's ability to produce enzymes that inactivate cancer-causing compounds.
ENLARGED PROSTATE CAN LEAD TO WORSE THINGS
The majority of men will eventually encounter problems with their prostate gland, and all men will, if they live long enough - it's a statistical certainty. Most of these problems, fortunately, are not related to cancer. They stem, rather, from a condition called benign prostatic hyperplasia (BPH) - enlargement of the prostate caused by growth in the number of its constituent cells. BPH can also mean benign prostatic hypertrophy, which is less common and also noncancerous. This version of BPH means enlargement of the prostate caused by growth in the size of the cells that are already there. The two conditions are obviously not the same, although their defining symptom - enlargement of the prostate - is.
Enlargement of the prostate for whatever reason occurs in more than 60% of men over the age of 60.6 The condition usually begins, however, in the mid-40s. Fortunately, there are nutritional supplements - notably saw palmetto - that are effective in preventing and relieving this condition (see the sidebar). The most common symptoms of enlarged prostate are:
- The need to urinate frequently
- Delay in starting urination
- Diminished force and volume of the urinary stream
- The sensation of having an incompletely emptied bladder even after urination
- Awakening at night - several times, perhaps - because of the need to urinate
- Stubbing your toe - OW! - on the way to the bathroom in the middle of the night (OK, that's technically not a symptom, but it might as well be)
|A Plethora of Prostate BenefitsIn addition to lycopene, there are quite a few natural supplements that are believed to be beneficial for prostate health. Probably the best known of these is saw palmetto, a dwarf palm native to the American Southeast and the Caribbean region. The ability of saw palmetto extract to counteract prostate enlargement is widely acknowledged - evidence of its effectiveness can be found in the medical literature as far back as the 1800s. |
In April 2000, the United States Pharmacopeia openly supported the use of saw palmetto to treat the symptoms of benign prostatic hyperplasia (BPH) in older men.1 They based this recommendation on the strong results obtained with saw palmetto in clinical trials. Specifically, they noted that this product decreases the urgency and frequency of urination, including the urge for nighttime urination (nocturia), and it improves urinary flow.
The extract of the dried red berries of saw palmetto includes a number of active ingredients. One of these is believed to inhibit the action of an enzyme called 5-alpha-reductase, which catalyzes the formation of dihydroxytestosterone, a male sex hormone that is implicated in prostate enlargement. A 5-alpha-reductase inhibitor, therefore, is a good thing for prostate health.
Among the other natural supplements that are believed to be beneficial for prostate health are:
Zinc. This essential element is also a 5-alpha-reductase inhibitor and has long been known to reduce enlarged prostate glands.
Vitamin D. Deficiencies in this important "sunlight" vitamin have been linked to prostate cancer and high levels of prostate-specific antigen (PSA).
Vitamin E. Supplementation with vitamin E - which is actually a family of eight similar molecules, including alpha-tocopherol - has been linked to large reductions in prostate cancer rates and deaths due to prostate cancer.
Mixed tocopherols/tocotrienols. These substances contain a specific form of vitamin E - gamma-tocopherol - that limits the growth of human prostate cancer cells in the laboratory.
Vitamin B2 (riboflavin). Also a 5-alpha-reductase inhibitor, high levels of this important B vitamin appear to decrease the risk of prostate cancer.
Pygeum. Extracts of this evergreen tree from southern Africa reduce the clinical symptoms of enlarged prostate and have been used in Europe for decades.
Stinging nettle. When combined with pygeum extract, stinging nettle (the European version, Urtica dioica, not the American version) is effective in reducing the symptoms of enlarged prostate.
Green tea. Extract of green tea contains a polyphenolic compound, epigallocatechin gallate (EGCG), that kills human prostate cancer cells in the laboratory and is believed to be the most effective natural anticancer agent there is.
Resveratrol. A powerful antioxidant present in red wine, this polyphenolic compound not only reduces the risk of cardiovascular disease but also inhibits the growth of prostate cells in the laboratory.
Selenomethionine. A combination of mineral (selenium) and amino acid (methionine), selenomethionine is required for normal prostate function and also acts as an inhibitor of the growth of cancerous prostate cells.
Boron. An epidemiological study shows that men with the highest intake of this vital trace element have the lowest risk of prostate cancer.
- USPDI. Saw Palmetto. United States Pharmacopeia, Inc., Rockville, MD, April 28, 2000. www.usp.org.
There can also be posturination dribble and even outright incontinence. Although most of these symptoms are tolerable (though certainly annoying), you should not disregard them, because they can progress to more serious disorders, such as kidney and bladder infections. Furthermore, they can be a prelude to prostate cancer or a symptom of it.
PROSTATE CANCER IS THE MOST COMMON
Men who have prostate cancer, in which cells of the prostate gland grow uncontrollably, exhibit symptoms similar to those described for BPH, but usually not until the disease is fairly advanced. Routine screening for prostate cancer, therefore - even in men who do not exhibit these symptoms - is advised beginning at the age of about 45.
It is important to realize that prostate cancer is the most common cancer in American males, accounting for 29% of all cases. The incidence of this disease increases with age, and more than 75% of all cases are diagnosed in men over the age of 65. Finally, a sobering truth is that only lung cancer accounts for more cancer deaths in men.7
A SUPPLEMENT BETTER THAN PIZZA
If you're concerned about your prostate function but don't want to pack on the calories by eating pizza every day, order a pizza every now and then and live it up, but for day-to-day maintenance of your one-and-only prostate gland, the best approach may be to avail yourself of a cornucopia of nutrients.
- Giovannucci EL, Ascherio A, Rimm EB, Stampfer MJ, Colditz GA, Willett WC. Intake of carotenoids and retinol in relationship to risk of prostate cancer. J Natl Cancer Inst 1995;87:1767-76.
- Kucuk, O, Sarkar FH, Sakr W, et al. Phase II randomized clinical trial of lycopene supplementation before radical prostatectomy. Cancer Epidem Biomarkers Prev 2001;20:861-8.
- Levy J, Bosin E, Feldman B, et al. Lycopene is a more potent inhibitor of human cancer cell proliferation than either alpha-carotene or beta-carotene. Nutr Cancer 1995;24:257-66.
- Bertram JS, Pung A, Churley M, et al. Diverse carotenoids protect against chemically induced neoplastic transformation. Carcinogenesis (Lond.)1991;12:671-8.
- Rao AV, Fleshner N, Agarwal S. Serum and tissue lycopene and biomarkers of oxidation of prostate cancer patients: a case-control study. Nutr Cancer 1999;33:159-64.
- Carson CC. Update on benign prostatic hyperplasia. The Clinical Advisory for Nurse Practitioners 1998;1:57-65.
- Heuther SE, McCance KL. Understanding Pathophysiology, 2nd ed., pp. 888-93. Mosby, Inc., St. Louis, MO, 2000.