Jewish World Review Jan. 11, 2002 / 27 Teves, 5762




Heart attack: sex and survival

By Robert A. Wascher, M.D., F.A.C.S.

http://www.NewsAndOpinion.com -- A number of studies have identified a poorer survival rate for women experiencing a heart attack when compared to men of the same age. A study in this week's Journal of the American Medical Association (JAMA) evaluated 502 women and 1435 men who had sustained an acute myocardial infarction (heart attack).

All patients were provided comparably aggressive treatment irrespective of gender, and were followed for at least a year. Survival rates were then compared. Contrary to previous studies, this study found no significant difference in survival at 1-year between the sexes. As the women involved in this study were, on the average, older than the men, the authors then statistically matched male and female study patients based upon age. When matched to the men by age, women were actually about 35% less likely than the men to die within the first year following their heart attacks!

ESTROGEN LEVELS IN THE BLOOD & BREAST CANCER RISK

In another study published in JAMA this week, further evidence of a link between chronically high levels of the female hormone estrogen in the blood and breast cancer is presented. It has long been observed that the risk of developing breast cancer increases in women who begin their menstrual periods early, or who go through menopause later.

The use of estrogen hormone replacement medications after menopause is also known to increase the risk of breast cancer over time. It is thought that the cumulative lifetime degree of exposure to estrogen increases the risk of breast cancer development by way of estrogen's stimulatory effects on breast duct cells.

The authors studied 7,290 postmenopausal women who had participated in a clinical trial using an estrogen-blocking drug, raloxifene (a drug very similar to Tamoxifen), in a breast cancer prevention study. None of the study patients had a history of breast cancer or hormone replacement therapy, and all patients underwent measurement of their blood estrogen levels upon entry into the raloxifene study.

A total of 4,483 women received raloxifene and 2,447 women received a placebo ("sugar pill") for 4 years. The women were closely observed, and the incidence of breast cancer versus blood estrogen levels was then studied.

Among the women taking the placebo pill, there was a 6-7-fold higher incidence of breast cancer in patients having high estrogen levels in their blood when compared to women with low estrogen levels. Among the women taking raloxifene (which blocks the stimulatory effect of estrogen on breast cells), the women with the high estrogen levels experienced a 76% lower incidence of breast cancer when compared to their high-estrogen counterparts taking the placebo pill. The group of women with the low blood estrogen levels in both the raloxifene and placebo groups, however, had similar rates of breast cancer.

The authors of this study calculated that raloxifene would have prevented 47% of the breast cancer cases that developed in the placebo-group women with high estrogen levels during the 4-year study period. This adds powerful evidence to support the hypothesis that cumulative exposure to estrogen, particularly at higher blood levels, increases the risk of developing breast cancer. It also suggests that high blood levels of estrogen should be considered as a risk factor for breast cancer, and that women with naturally-occurring high estrogen levels should at least be considered for breast cancer prevention therapy (e.g., with Tamoxifen or raloxifene).

DANGEROUS LETTUCE INVADERS

A Rutgers university team has made a rather startling finding, as reported in the journal Applied & Environmental Microbiology (and reviewed in this week's journal, Nature Science).

Despite public health authorities' recommendations that all vegetables be thoroughly washed before consumption, outbreaks of bacterial food poisoning still regularly occur in the United States. While most disease-causing bacteria are relatively harmless to healthy individuals, a few, including the O157:H7 strain of E. coli, can cause serious disease, or even death. Following an outbreak of O157:H7 E. coli food poisoning in people eating prewashed lettuce, the study's authors planted lettuce in animal manure spiked with the O157:H7 strain of E. coli. They harvested the lettuce and sterilized the surfaces of the lettuce leaves with bleach.

Careful analysis of the washed leaves revealed O157:H7 E. coli bacteria within the "veins" of the lettuce leaves. This study's findings suggest that potentially harmful bacteria, present within fertilizer or irrigation water, may be capable of penetrating the interior of lettuce leaves through the plants' root systems.

A similar study in the United Kingdom, from the University of Nottingham, showed that O157:H7 E. coli and Listeria bacteria also accumulated within the interior of the leaves of spinach plants following absorption of the bacteria from contaminated irrigation water.

Although these findings are based upon the artificial experimental conditions present in the laboratory they, at least, point to a possible mechanism whereby disease-causing bacteria can enter vegetables in such a way that they are impervious to even the most thorough washing. The Rutgers scientists are currently evaluating farm-grown salad greens to see if this same phenomenon occurs naturally in the produce that we eat.

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.

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© 2002, Dr. Robert A. Wascher