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Health Briefs
May
3, 2002
by Robert A. Wascher, M.D., F.A.C.S.
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
Dr. Robert A. Wascher is
a senior research fellow in molecular & surgical oncology at the John Wayne
Cancer Institute in Santa Monica, CA
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