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December
2001
Nothing
Light About 'Light' Cigarettes
A report recently issued by the National Cancer Institute proves what
many people have suspected all along: "light" cigarettes are
more a marketing ploy, than an attempt to make smoking safer.
Light and ultralight cigarettes produce lower amounts of tar and nicotine
than regular cigarettes when smoked by testing machines. However, this
is not the case when a person uses them. This is due to the smoker's
desire to get as much of the harmful chemicals as possible, and from
the design of the cigarette. Because smokers are addicted to nicotine,
not the act of smoking, they usually inhale harder on light cigarettes
or simply smoke more of them to get their fix. And the way the cigarettes
are designed- with ventilation holes placed where smokers' fingers or
lips easily block them - means smokers are often inhaling harder than
necessary, regardless of whether or not they are craving more nicotine.
In the 1960s and '70s, studies on light cigarettes showed promising results.
Smokers using the reduced strength cigarettes had lower risk of lung
cancer risk than those using the full-strength tobacco products. The
increasing use of light products was expected to further decrease smoking-related
diseases. Unfortunately, this has not come to pass. Lung cancer rates
rose until the early 90s. And it was a decrease in smoking in general—not
tobacco light—that has caused the decline seen since then.
December 2001 Update
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Shapely
Sperm and Fertility
The shape of a man's sperm is the best gauge of fertility,
according to a recent study in The New England Journal of Medicine.
Researchers from the National Cooperative Reproductive Medicine Network
have found the best sperm structure is an oval head and long straight
tail. Unusually shaped sperm — those with very large or small heads,
or tails with twists and coils — were not able to fertilize the
egg. The World Health Organization (WHO) publishes standards of normal
semen measurements, but the guidelines on the quantity of quality semen
indicative of fertility have varied throughout the years and have not
proved themselves in thorough testing.
The men in the study were more likely to be infertile if fewer than 9
percent of their sperm were well shaped, while they were most likely
to be fertile if more than 12 percent of their sperm looked normal.
While there is no surefire way to diagnose fertility, these findings
on well-shaped sperm could help standardize the WHO's criteria.
December 2001 Update
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High-Normal
Blood Pressure Bad for the Heart
People with high-normal blood pressure are more likely to suffer a heart
attack, stroke, or heart failure than those with lower blood pressure,
according to recent findings from the Framingham Heart Study.
The researchers followed the cardiovascular events of 6,859 participants
of the famed study, which has been monitoring subjects from the Boston
suburb for more than 50 years. A third of participants had normal blood
pressure (120–129 over 80-84 mm HG), a quarter had high-normal (130–139
over 85–89 mm Hg), and the remainder had optimal blood pressure
(less than 120 over less than 80 mm HG). People with high blood pressure
were excluded from the study.
Of those in the optimal category, 81 had cardiac events, over a ten-year
time period, compared to 136 people in the normal blood pressure category
and 180 in high-normal category. In all, people with high-normal blood
pressure were two to three times more likely to suffer a heart attack,
stroke, or heart failure than those with lower blood pressure. This held
true in both men and women, and was consistent in both age groups (35
to 64 and 65 and over), even after researchers adjusted for other cardiovascular
risk factors such as smoking and obesity. Indeed, the study found risk
increases in a stepwise fashion as blood pressure increases.
Blood pressure reflects how hard your heart is working and what conditions
your arteries are in. Risk factors include heavy drinking, smoking, eating
a diet high in salt, obesity, and family history. Doctors generally get
alarmed only if systolic blood pressure is above 140 mm Hg or if diastolic
blood pressure is above 90 mm Hg. However, this study calls for further
research to be done to see if patients in the high-normal group benefit
from lowering their blood pressure.
December 2001 Update
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Salt
Restriction More Potent Than Exercise
Physicians often give patients with hypertension a daunting list of lifestyle
changes to help lower their blood pressure: lose weight, exercise more,
eat less salt, drink less alcohol, eat more foods rich in calcium, potassium,
and magnesium. Of course, these changes do work — people who follow
them can reduce their need for medications or even do without blood pressure-lowering
drugs. But which of these lifestyle changes gives you the biggest bang
for your buck?
University of Colorado researchers recently compared the impact of exercise
or moderate salt restriction in 35 healthy older women with high-normal
blood pressure or mild hypertension (systolic blood pressure 130–159
mm Hg), none of whom were using drugs to lower their blood pressure.
Half the women exercised for three months — starting at 30 minutes
a day three or four times a week and working up to 45 minutes a day every
day, if possible. The other half tried to reduce their daily salt intake
to less than 2.4 grams of sodium (the amount in a level teaspoon of table
salt) without otherwise changing their diets. All were asked to try to
avoid gaining or losing weight.
The clear winner, reported in the American Journal of Cardiology,
was sodium restriction. Among the women who ate less salt, average systolic
blood pressures fell 16 mm Hg, compared with a still-respectable 5 mm
Hg in the exercise group. By the study's end of the study, systolic blood
pressure was lower in 88% of the women who ate less salt and in 55% of
the exercisers.
So if you're trying to lower your blood pressure, should you just forget
about exercise and work harder at eating less salt? No. Exercise has
other benefits besides lowering blood pressure — it can help control
weight, improve the cholesterol profile, stave off diabetes, and keep
bones strong. The real message from this study is that everyone should
exercise, but that people who are trying to control blood pressure should
lower their sodium intake, too.
December 2001 Update
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