Health Briefs

May 3, 2002

TEA DRINKERS AND THE RISK OF DEATH FOLLOWING HEART ATTACK
Tea, and green tea in particular, is loaded with antioxidant compounds that may partially block the cell damage caused by certain byproducts of cellular metabolism.

Previous studies have shown an apparent reduction in the risk of cardiovascular disease among healthy people who drink tea on a regular basis. The journal Circulation has just published an interesting study of the effects of tea drinking on 1,900 patients who had already experienced a heart attack (between 1989 and 1994).

The average follow-up of this large group of patients, after their heart attacks, was almost 4 years. Compared with non-drinkers, moderate tea drinkers (defined as less than 14 cups per week) experienced a 31% reduction in death rates during the study period, while heavy tea drinkers (defined as more than 14 cups per week) experienced an apparent 39% reduction in the risk of mortality.

These reduced mortality rates were maintained when the researchers looked at death due to cardiovascular causes or death due to any cause. Moreover, when multivariate analysis of socioeconomic and other non-cardiac health factors were considered, the tea-related improvements in survival also persisted.

These findings add to the growing evidence that naturally occurring antioxidants-and possibly other compounds as well-in tea may exert a significantly beneficial effect on both healthy and diseased hearts. However, before you think about adding substantial amounts of tea to your diet, please pass it by your family doctor to make sure that any preexisting health problems or medications might not be adversely affected by frequent tea consumption.

DURATION OF BREASTFEEDING & ADULT INTELLIGENCE
A somewhat provocative study in this week's Journal of the American Medical Association has made a correlation between the duration of breastfeeding and babies' subsequent intelligence level as adults. This Danish study prospectively evaluated babies born between 1959 and 1961, and divided them into 5 groups based upon the length of time that they were breastfed.

A history of breastfeeding duration was collected prospectively at the time of the infants' one-year check-up, and intelligence was then later measured in these same volunteers, during early adulthood, using standardized intelligence tests. In an effort to eliminate other likely causes for variable outcomes in IQ, the researchers also evaluated parental social status and educational levels, mother's marital status, number of pregnancies, estimated infant maturity at birth, birth weight and length, and history of pregnancy or delivery complications.

The authors determined that progressively longer periods of infant breastfeeding were associated with improved scores on standardized measures of intelligence in early adulthood. It is known that breastfeeding improves immune function in otherwise healthy babies, and nearly eliminates the risk of food-related allergies. However, the precise mechanism(s) whereby breastfeeding may enhance the overall health of infants and, it would appear, their subsequent intellectual function as adults, is not altogether clear at this time. Indeed, more than just nutritional and immunologic benefits are likely to result from regular breastfeeding.

The close emotional and physical bond that develops between mother and baby during breastfeeding also exerts a very powerful influence on the baby's emotional and physical well-being. However, it is not clear to me that this new study adequately controlled for some of these less tangible aspects of breastfeeding. While there are perfectly good reasons why some moms may choose not to breastfeed, and while most babies who are raised on the formulas available today do just fine, this study was conducted on infants born in the late 1950s.

Cultural values were very different in the 1950s than they are today, and our knowledge of nutrition was rather limited then as well. Studies performed during the 1960s, using rhesus monkey infants, clearly showed that loss of regular contact with the babies' mothers resulted in profound retardation of emotional and cognitive development, even when the infants were allowed to cuddle with a cloth-covered model of a mother monkey. In this current study, there could have been some undetected differences in the overall "nurturing environment" between the babies who were breastfed for longer periods of time and the babies who were breastfed for a briefer duration. Also, the nutritional differences between the diets of bottle-fed babies in the 1950s and babies who are bottle-fed today are enormous.

This is an interesting study, but it is far from clear that there is a purely nutritional basis that explains this study's findings. Unquestionably, breast milk is almost always best for a new baby. However, mothers who, for various reasons, are compelled to bottle-feed their babies should not feel that they are somehow harming their babies based upon this particular study's conclusions. Also, it should be noted that the differences in measured adult IQ between the various groups of breast-fed infants in this study was very small, ranging from a "minimum" of 99.4 to a "maximum" of 104.0.

While this study's conclusions are intriguing, more research needs to be done in this area to confirm these rather provocative findings.

ABDOMINAL AORTIC ANEURYSMS: SURGERY OR OBSERVATION?
Abdominal aortic aneurysms (AAA) occur when the main artery that carries blood from the heart to the rest of the body enlarges like a balloon. Generally thought to result from the same degenerative changes that affect the heart's arteries in patients with cardiovascular disease, AAA can be a potentially life-threatening condition when the aneurysm enlarges to the point where the arterial wall becomes so thin that the artery is in danger of rupturing.

When AAA rupture occurs outside of the hospital, more than half of such patients will die. The diameter at which an asymptomatic AAA should be surgically repaired has been debated for many years. Two new studies in this week's New England Journal of Medicine strongly suggest that patients with asymptomatic AAA less than 5.5 centimeters in diameter, or just over 2 inches, can probably be safely observed instead of undergoing elective surgery. While death related to AAA occurred among both patients who were observed and patients who underwent elective surgery, the overall risk of death due to AAA was similar in both groups as long as the AAA was not larger than 5.5 cm. When I was a surgical resident in the early 1990s, most vascular surgeons were recommending elective surgical repair of asymptomatic AAA when the aorta reached 4 to 5 centimeters in diameter (a bit less than 2 inches).

These two new studies appear to add considerable weight to a more conservative approach to managing AAA disease. However, patients with symptomatic or rapidly expanding AAA, or those with AAA diameter exceeding 5.5 centimeters, should probably undergo elective surgical repair of the aorta if their overall health will allow them to tolerate the surgery with an acceptable risk of complications.

Dr. Robert A. Wascher