Jewish World Review May 31, 2002 / 20 Sivan, 5762

Broccoli kills cancer-causing stomach bug

By Robert A. Wascher, M.D., F.A.C.S. | Broccoli, along with cauliflower, Brussels sprouts and cabbage, is a member of the so-called cruciferous vegetable group. Several previous studies have found apparent anti-cancer substances in these relatively unpopular vegetables.

The current issue of the Proceedings of the National Academy of Science, however, elevates the lowly broccoli to an even more impressive pedestal with the finding that broccoli contains a potent antibiotic against a nasty bug that has been firmly linked to stomach cancer. Helicobacter pylori (H. pylori) is a stubborn bacterium that is now thought to cause most cases of stomach and duodenal ulcers, and is also believed to significantly increase the risk of developing stomach cancer.

H. pylori has proven itself a very formidable pathologic foe, and is very difficult to eradicate in humans. Sulforaphane, a chemical present in broccoli, and in especially high concentrations in young broccoli sprouts, effectively killed 90% of H. pylori bacteria, including those bacteria that were known to be resistant to standard antibiotic regimens. Moreover, this same study revealed that sulforaphane also appears to protect mice from developing stomach tumors after exposure to the carcinogen benzo-[a]-pyrene (a potent inducer of stomach cancer in mice, and a byproduct of cooking or grilling meat at high temperatures).

These results, taken together, suggest a potentially important role for broccoli-derived sulforaphane in the prevention and treatment of H. pylori stomach infections and, possibly, for the prevention of at least some stomach cancers as well. If these results hold up following human studies, this finding could be a major breakthrough in disease prevention.


I have previously reported on the disappointing results of research into the hormone leptin. Leptin was originally linked to obesity in mice, but attempts at manipulating leptin levels in the blood of humans have not proved to be clinically useful. This week's New England Journal of Medicine presents new research on another hormone that has been linked to obesity in the past.

Ghrelin is a hormone that appears to stimulate appetite and feeding in both mice and humans, and is produced primarily in the stomach. In an intriguing study, blood levels of ghrelin were measured in 13 obese volunteers, both before and after they embarked on a weight loss program. Five of these 13 patients were also matched up against 5 additional obese patients undergoing partial removal of the stomach as treatment for their obesity (the surgery patients also had their ghrelin levels measured before and after surgery). In the dieting patients, successful weight loss was accompanied by significantly increased levels of ghrelin in the blood compared to their pre-diet levels. In comparison, the patients who underwent partial removal of their stomachs also lost a significant amount of weight, however their blood levels of ghrelin were actually significantly decreased following postsurgical weight loss.

The authors noted that ghrelin blood levels appear to rise prior to meals, and drop after eating. They hypothesize that ghrelin may stimulate appetite and feeding in obese patients with intact stomachs, and that the levels of ghrelin in the blood are stimulated by dieting and weight loss. This may explain the well-known tendency of most dieters to eventually regain most or all of the weight that they have lost by dieting. It appears that partial removal of the stomach reduces ghrelin blood levels, and may play a role in the more durable weight loss seen in patients who have undergone surgical treatment for morbid obesity.

More investigation into the physiologic effects of ghrelin needs to be undertaken, and other factors that might modulate ghrelin secretion (such as exercise, diet, smoking, and various medications) should also be explored. A note of caution: the disappointing outcome of leptin research in humans following heavily hyped results in rodent studies should serve as a cautionary tale when interpreting the results of this new study.


Following recent studies that suggested an increased risk of heart attack among people taking the COX-2-specific inhibitors Vioxx and Celebrex, particularly when compared to people who were taking the nonspecific anti-inflammatory drug naproxen, much confusion has abounded. The association of COX-2 specific inhibitors with an apparent increase in the incidence of heart attack is thought to arise from their lack of inhibition of the COX-1 enzyme.

The COX-1 enzyme affects the blood's clotting system, and the platelets in particular, in ways that can increase the likelihood of a blood clot being formed within a coronary artery that has already been narrowed by cholesterol plaque formation. Thus, it is not thought that Vioxx or Celebrex actively cause an increased risk of heart attack. Rather, it is their lack of heart-protective COX-1 enzyme inhibition that probably accounts for the increased incidence of heart attacks when compared to nonspecific anti-inflammatory drugs like naproxen and aspirin, and which inhibit both COX-1 and COX-2.

Two studies in the current Annals of Internal Medicine looked specifically at the effects of naproxen (Naprosyn) and other so-called "nonsteroidal anti-inflammatory drugs" (NSAIDs) on the incidence of heart attack (aspirin, which is also a nonspecific NSAID, and is known to reduce the risk of heart attack, was not evaluated in these studies) . Both studies retrospectively reviewed patient databases to identify patients who were taking anti-inflammatory drugs and those who were not. Patients in each category were then matched according to age, gender, race, cardiac risk factors, other medication use, and underlying health problems.

When the two groups of patients were compared and analyzed, only the use of naproxen appeared to significantly reduce the incidence of heart attack. In the first study, there was a 16% reduction in the risk of heart attack among patients who had taken naproxen within the previous 6 months, while the second study found a 17% reduction in heart attack with naproxen use. The authors theorize that naproxen probably protects the heart better than other nonspecific NSAIDs because its anti-clotting effects are known to be more powerful than most of the other NSAIDs.

Please remember, however, that the use of NSAIDs can be associated with bleeding in the gastrointestinal tract and kidney injury in some people. NSAIDs can also thin the blood so that it does not clot normally (even NSAIDs other than naproxen), which can be a serious problem in patients who are taking other medications or dietary supplements that also thin the blood. If you are contemplating adding aspirin or naproxen to your list of medications, please see your primary care physician first to help you evaluate both the risks and benefits of NSAID therapy in your particular case.

JWR contributor Dr. Robert A. Wascher is a senior research fellow in molecular & surgical oncology at the John Wayne Cancer Institute in Santa Monica, CA. Comment by clicking here.


05/24/02: Molecular detection of tumor cells in the blood & prognosis; Cox-2 & breast/lung cancers; BRCA2 gene mutations & the risk of breast cancer; breast density & the risk of breast cancer

05/19/02: Moderate alcohol intake and blood sugar levels; more good news for tea drinkers; blood potassium levels & the risk of cardiovascular disease; ethnic differences in diabetic complications

05/10/02: Tea drinkers and the risk of death following heart attack; duration of breastfeeding & adult intelligence; abdominal aortic aneurysms: surgery or observation?

05/03/02: Risk of adverse drug reactions from newly released medications; preoperative beta-blockers may reduce heart bypass deaths; shape-shifting plastics may alter surgical practice; weight loss supplement may cause liver damage
04/26/02: Angry young men & risk of premature cardiovascular disease; stay-at-home dads & risk of cardiovascular disease; more on the effects of statins; dairy consumption and the risk of pre-diabetes; smallpox vaccine: good to the last drop?
04/19/02: Change your sex by drinking water?; Anti-inflammatory RXs may reduce growth of breast cancer cells; radiation treatment reduces repeat narrowing of bypass grafts
04/05/02: Fish & Omega-3 fatty acid consumption and cardiac health; news briefs
04/05/02: Can coffee reduce your risk of tooth decay?; exercise & blood pressure; a single high-fat meal reduces coronary artery function
04/01/02: Pre-diabetes: a newly defined category of health risk; teen television viewing and subsequent aggressive behavior; the benefits of strength training in the elderly; more ...
03/22/02: Bacteria, antibiotics & heart disease; mammograms: the debate continues; calcium & the risk of colon cancer ... and more
03/15/02: Mammography debate continues; statins & fracture risk; physical fitness & the risk of death; other intriguing findings
03/08/02: Blows to the chest & sudden cardiac death; air quality & the risk of lung cancer; tomatoes and your prostate
03/01/02: Diet & the risk of ovarian cancer; lifetime risk of developing high blood pressure; Osteoporosis prevention with a once-a-year injection?
02/26/02: The continuing controversy regarding screening mammography
02/22/02: Lowering body temperature after heart attack improves outcome; A silver lining for the chronically sleep-deprived?
02/15/02: Hormone replacement therapy & the risk of breast cancer; use it or lose it: Alzheimer's disease & cognitive stimulation; stress, divorce & death; child daycare, infections & parental guilt
02/08/02: Possible breakthrough in early cancer diagnosis; mammography: the controversy continues; CPR techniques revisited
02/01/02: Antibiotics in livestock feed & human disease; genetic detection of early colon cancer in the stool; genetic analysis of breast cancers may help decide treatment
01/25/02: Drug increases lifespan (if you're a fly...); workplace attitudes and smoking cessation; effects of inadequate sleep on surgeons
01/18/02: Lifelong effects of premature birth; smokers under the knife; aspirin and cardiovascular health
01/11/02: Estrogen levels in the blood & breast cancer risk; Heart attack: sex and survival; dangerous lettuce invaders
01/09/02: Cancer & aging: Two sides of the same coin?
01/04/02: Vitamin a & the risk of hip fracture in postmenopausal women; ovarian cancer risk and oral contraceptives
12/28/01: Magnetic Resonance Imaging (MRI) detects coronary artery disease; new development in obesity research; adverse childhood experiences & the risk of suicide attempts
12/21/01: Vaccination of children controls hepatitis a in the community; a possible cure for sickle cell disease; leptin and the risk of heart attacks
12/14/01: Chernobyl and the Risk of Thyroid Cancer in hildren; children & obesity; gastroesophageal reflux disease update
12/07/01: Update on school shootings; new implantable heart-assist device approved for further evaluation; prevention of fungal infections in pre-term babies
11/30/01: Flu vaccination in asthmatics; low-tar cigarettes are not less harmful; beans and your heart
11/21/01: Modified smallpox vaccine may reduce risk of cervical cancer; New approach to breast cancer diagnosis; New non-invasive prenatal diagnostic test for down's syndrome
11/16/01: Cholesterol-lowering drugs reduce risk of heart attack; supplemental radiation therapy reduces risk of breast cancer recurrence; brains of women may answer age-old questions
11/09/01: Bio-warfare (redux); my gray matter is bigger than yours; mad elk disease?
11/02/01: Making sense of bio-warfare
10/26/01: The impact of mammography on deaths due to breast cancer; diet & exercise may slow cancer cell growth; antidepressants and the risk of heart disease
10/19/01: New insights into autism; the wiley appendix
10/12/01: More bad news about obesity links to other diseases…Hey dad, can I borrow the car keys?
10/05/01: California leads nation in reduction of tobacco-related disease; exercise as an antidepressant?
09/25/01: Advances in the detection of breast cancer; primary care physician awareness of peripheral arterial disease; arsenic in the water
09/17/01: In perspective
09/12/01: Genes may hold secret to long life; men and women: cognitive function in the elderly; physical activity, obesity and the risk of pancreatic cancer
09/05/01: English milk cows prefer Beethoven and Simon & Garfunkel over Bananarama; new prostate cancer prevention study: looking for a few good men; exercise & diet can help prevent diabetes
08/28/01: Arthritis drugs may be linked with increased risk of heart disease; errors in blood clotting tests can be fatal; infant soy formula not associated with reproductive side effects

© 2002, Dr. Robert A. Wascher