Health Briefs: Eat Your Broccoli!

July 16, 2004

NEW CHOLESTEROL GUIDELINES (Circulation): Based upon previous research, the National Cholesterol Education Program (NCEP) recommended, in 2001, that patients with elevated risk factors for cardiovascular disease should attempt to lower their blood LDL (the “bad” cholesterol) levels below 100 mg/dL. Since 2001, multiple research trials have evaluated the health impact of cholesterol-lowering medications, and the statin class of drugs in particular. Several of these studies have shown that lowering LDL and total cholesterol levels below previously established target levels result, in turn, in an additional reduction in the risk of heart attacks. Based upon the results of these recent clinical studies, several modifications to 2001 NCEP recommendations have just been added. These include a reduction in the target LDL level (from <100 mg/dL to <70 mg/dL) in patients considered to be at very high risk for heart disease and heart attacks, a reduction in the LDL target level for moderately-high risk patients (from <130 mg/dL to <100 mg/dL), and the inclusion of diabetes as a “high risk category” factor. As always, the NCEP strongly urges lifestyle changes as the initial strategy for LDL reduction. Such lifestyle changes should include a nutritious low-fat high-fiber diet, plenty of exercise, reduction of excessive weight, and control of elevated blood sugars.

DOCTORS WHO DON’T WASH (Annals of Internal Medicine): Mom knew what she was talking about whenever she told you to wash your hands after playing outside, or before eating. We know that the most effective (and simplest) way to prevent the transmission of infectious diseases from one person to another is to wash your hands thoroughly with soap and water. One would think, therefore, that physicians and other healthcare providers would lead by example by frequently washing their hands before and after contact with their patients. Sadly, this has been shown, time and time again, not to be the case. A new study evaluated 163 physicians in a large university hospital. On the average, only about 57% of the doctors were observed to regularly wash their hands before or after patient contact. (Not surprisingly, one of the most powerful factors that predicted physician hand-washing was the awareness that they were being observed by the study’s research team!) Other factors associated with good hand-washing habits included a sense of being a role model for others, a positive attitude towards hand-washing following patient contact, and easy access to hand-washing soap or hand disinfectant. Factors associated with poor hand-washing habits included a heavy patient workload, activities associated with (ironically) a high risk of disease transmission, and certain medical specialties. Ironically, not only were anesthesiologists, ER doctors and ICU doctors more prone to omit hand-washing than other specialists, but surgeons also fared badly as well! In view of the rising morbidity and mortality caused by hospital-acquired infections around the world, and the emergence of resistant strains of disease-causing bacteria and fungi in even our best medical centers, the findings of this little study are cause for continued concern. Clearly, as supported by this study and previous studies, healthcare workers, including doctors, have to be better trained (and monitored) regarding the absolute importance of frequent hand-washing between patient contacts.

DIET & BENIGN BREAST DISEASE (Cancer Epidemiology Biomarkers & Prevention): A number of recent studies have looked at the impact of diet on the risk of developing breast cancer, with some evidence for a slight increase in risk associated with high fat diets and increased alcohol consumption. However, there has been little study of the impact of dietary habits on the risk of developing benign breast disorders that are, themselves, linked with an increased risk of developing breast cancer. This study used data from the huge Nurses’ Health Study II to assess the impact of specific dietary factors on the development of the so-called “non-proliferative” and “proliferative” benign breast diseases, including atypical hyperplasia (AH), which has previously been associated with a 14-25% risk of having or developing breast cancer. The dietary factors studied included the dietary intake of fat, fiber, multi-vitamin supplements and caffeine. Overall fat and fiber intake was not associated with an increase in the risk of benign breast diseases, although increased vegetable fat intake was associated with a decrease in the incidence of benign proliferative breast changes without atypia (i.e., ductal and lobular hyperplasia, without atypia). High caffeine consumption was, however, associated with a 146% increase in the relative risk of developing AH, while the use of multi-vitamin supplements was associated with a 43% reduction in the relative risk of developing AH. (These findings support our clinical advice to women with severe fibrocystic breast changes, which are part of the spectrum of benign breast diseases, to decrease caffeine intake and to take supplemental vitamin E.)

Eat Your Broccoli! (Cancer Epidemiology Biomarkers & Prevention): Previous studies have suggested that the so-called cruciferous vegetables might contain substances with anticancer effects. This class of vegetables, unfortunately, includes some of the less popular members of the vegetable family, including broccoli, cauliflower, Brussels sprouts, bok choy, radishes, cabbage, chard, collard and mustard greens, arugula, kohlrabi, turnips, watercress, kale and rutabagas. This new study looked at the effects of pretreatment of colorectal cancer cells with extracts from mixed cruciferous vegetables and bean sprouts, followed by treatment of the cells with DNA-damaging hydrogen peroxide. After incubation of the cultured cancer cells in the vegetable extract for 24 hours, the cells were then treated with hydrogen peroxide, which causes DNA damage through the generation of oxygen free radicals. Tests were then performed to measure the degree of genetic damage caused by the hydrogen peroxide. This experiment revealed that the cells pretreated with the mixed vegetable extract sustained significantly less DNA damage than did the control cells that were not pretreated before exposure to hydrogen peroxide. Based upon these results, the researchers then fed 113 grams of supplemental cruciferous vegetables and bean sprouts to healthy young volunteers each day for 14 days. After 14 days, the white blood cells of the volunteers who had consumed the vegetable supplements, once again, showed evidence of reduced DNA damage when compared to the control group of volunteers who did not receive the vegetable supplements. This is an intriguing little study that adds to previous data suggesting that cruciferous vegetables and bean sprouts may possess anticancer qualities, and provides a possible mechanism for this protective effect. Millions of moms around the world have been vindicated by this study!

Stress & Blood Pressure Variations (Circulation): There has been some previous evidence that people without chronic high blood pressure, but who experience large increases in their blood pressure during periods of stress, may be at increased risk of developing chronic hypertension later in life. The results of a 13-year study of more than 4,000 adult men and women, ages 18 to 30 years, are now being reported, and seem to confirm this hypothesis. Serial blood pressure measurements of all study volunteers were taken in response to 3 psychological challenges over the course of the study. The study found that the greater the rise in blood pressure during these psychologically stressful tasks, the higher the risk was of developing chronic high blood pressure later in life. Moreover, those volunteers who experienced the most dramatic blood pressure elevations during stressful tasks were also at high risk of an earlier onset of chronic high blood pressure when compared to subjects with minimal blood pressure elevations while stressed. Therefore, this study suggests that blood pressure “lability” during early adulthood, particularly in response to stressful tasks and events, may be an early marker for the subsequent development of hypertension. Additional research will be necessary to evaluate the benefits, if any, of initiating early antihypertensive therapy to patients who are currently “normotensive,” but who have significant stress-induce blood pressure lability, and who are, as this study suggests, at high risk for early-onset hypertension.

Hernia Surgery & Chronic Pain (Archives of Surgery): The repair of inguinal (groin) hernias is one of the most common surgical procedures performed by general surgeons. There are several approaches to the repair of these hernias, although most surgeons have switched to the use of an implantable mesh panel that is tacked or sutured to the weakened area of the deep tissues in the groin. These mesh repairs can be performed though a 3-inch skin incision in the groin, or through the use of several smaller incisions and a laparoscopic video camera. There are enthusiastic proponents of both techniques, although the majority of all inguinal hernia repairs are still performed through the “open” technique of making a single incision in the groin, dissecting out the site of the hernia (a weakening in the support layers of the abdominal wall that allows internal abdominal organs and structures to “herniate” out of the abdomen), and suturing or tacking the mesh panel in through the skin incision. For most patients, recovery from a groin hernia repair occurs fairly rapidly, and the vast majority of all such patients will make a complete recovery. However, 15-20% of patients will experience at least occasional but mild discomfort at the repair site one or more years after surgery, and 2-3% will experience chronic and severe postoperative pain. As there are several sensory nerves that transit the typical areas where groin hernias occur, it is not too surprising that the surgical manipulation of these nerves during the course of a mesh hernia repair may predispose them to injury. Moreover, the mesh panels are eventually overgrown with inflexible and tough scar tissue, and may therefore entrap sensory nerves during the healing process. Some surgeons have, therefore, advocated the routine excision of at least one of these three nerves, the ilioinguinal nerve. This nerve passes right through the areas where most groin hernias occur, and where the surgeon performs most of the steps necessary to repair these hernias. The data on this practice has been rather contradictory so far, with some studies suggesting a reduced incidence of postoperative pain (though, not surprisingly, an increased incidence of permanent numbness in the groin), while other studies have shown no benefit from cutting this nerve. This Italian study, a prospective, double-blind, randomized trial, enrolled 813 patients with inguinal hernias over a 5-year period. The patients were randomly assigned to have their hernias repaired using the open technique, either with or without excision of their ilioinguinal nerve. Unfortunately, in this study, the patients who underwent resection of this sensory nerve did not experience any significant reduction in the incidence of postoperative pain syndromes, although they did, of course, experience a far greater incidence of reduced or absent sensation in the groin. My criticism of this study is that it only addressed resection of one of three known sensory nerves that supply sensation to the groin area. Indeed, in patients with debilitating postoperative pain following inguinal hernia repair, the reoperative resection of all three nerves in the groin is often very successful in relieving their pain, albeit at the cost of permanent numbness in this area (fortunately, however, the sensory nerves that supply the male and female genital organs originate outside of the sites of groin hernias…).

Obesity and Prostate Cancer Outcomes (Journal of Urology): Previous studies have suggested that severely obese men (BMI > 35 kg/square meter) who undergo surgery for prostate cancer have a higher likelihood of positive surgical margins (i.e., incomplete removal of their prostate tumors), and a higher incidence of prostate cancer recurrence, than non-obese men. What has not been clear, however, is the relationship, if any, between these two adverse factors. A new study looked at the role of obesity alone as a risk factor for recurrence of prostate cancer following radical prostate surgery. A total of 1,250 men who had undergone radical prostatectomy were evaluated retrospectively, 731 of whom had completely negative surgical margins and tumors that were confined within the prostate gland. Despite complete surgical removal of their tumors (i.e., with negative surgical margins), the obese men with negative surgical margins and tumors confined to their prostate glands still experienced a 4-fold increase in the risk of cancer recurrence when compared to non-obese men with identical stages of cancer. Thus, this study concluded that severely obese men (BMI > 35 kg/square meter) were at significantly higher risk of developing prostate cancer recurrence than non-obese men, despite having tumors that had not yet invaded the tissues outside of the prostate gland, and despite complete surgical removal of their prostate gland tumors. These findings suggest two important conclusions. First, difficulty in obtaining a negative surgical margin due to severe obesity is not the only obesity-related factor that is correlated with a higher risk of cancer recurrence. Secondly, and in view of the previous conclusion, severe obesity appears to be associated with a more aggressive biological prostate cancer behavior. Prostate cancer is the most common cancer in men. More than 230,000 new cases of prostate cancer, and 30,000 deaths, are expected to be diagnosed during 2004. Clearly, as the US struggles with an unprecedented prevalence and level of obesity among all age groups, the public health impact of this obesity epidemic will be felt at many levels. The apparently worse prognosis experienced by prostate cancer patients who are also severely obese is just one among a growing list of diseases that are adversely associated with obesity.

Dr. Robert A. Wascher