|Women’s Health Study Finds Vitamin
E Does not Protect Women from Heart Attack, Stroke,
Vitamin E supplements do not protect healthy women
against heart attacks and stroke, according to new results
from the Women’s Health Study, a long-term clinical
trial of the effect of vitamin E and aspirin on both
the prevention of cardiovascular disease and of cancer.
The vitamin E results of the Women’s Health Study
are published in the July 6 issue of the Journal
of the American Medical Association. In addition
to the cardiovascular disease findings, the study authors
report that there was no effect of vitamin E on total
cancer or on the most common cancers in women — breast,
lung, and colon cancers. The Women’s Health Study was
funded by the National Heart, Lung, and Blood Institute
(NHLBI) and the National Cancer Institute of the National
Institutes of Health.
“This landmark trial has given women and their physicians
important health information. We can now say that despite
their initial promise, vitamin E supplements do not
prevent heart attack and stroke. Instead, women should
focus on well proven means of heart disease prevention,
including leading a healthy lifestyle and controlling
risk factors such as high blood pressure and high cholesterol,” said
NHLBI Director Elizabeth G. Nabel, M.D.
The Women’s Health Study was conducted between 1992
and 2004. The participants were 39,876 healthy women
age 45 years and older who were randomly assigned to
receive 600 IU of Vitamin E or placebo and low-dose
aspirin or placebo on alternate days. The participants
were followed for an average of 10.1 years. The aspirin
results published last March found no benefit of aspirin
(100 mg every other day) in preventing first heart attacks
or death from cardiovascular causes in women but did
find a reduced risk of stroke overall, as well as reduced
risk of both stroke and heart attack in women aged 65
In recent years, there has been a great deal of public
and scientific interest in the potential of antioxidant
vitamins like vitamin E to reduce the risk of cardiovascular
disease. Laboratory and animal research suggested that
vitamin E might prevent the accumulation of fatty deposits
inside arteries, which would reduce the chance of clogged
and blocked arteries. Other large observational studies
have also suggested that people who eat foods high in
vitamin E or take supplements have a lower risk of coronary
heart disease. Although several clinical trials conducted
prior to the Women’s Health study found little cardiovascular
benefit from vitamin E, these trials were shorter and
primarily studied individuals with cardiovascular disease
or CVD risk factors. The intent of the Women’s Health
Study was to provide a long-term look at the effects
of vitamin E supplementation among healthy women.
Participants in the Women’s Health Study were monitored
for major cardiovascular “events” — a combination
of nonfatal heart attack, nonfatal stroke, or cardiovascular
death. By the end of the study, participants in the
vitamin E group had 482 such events compared to 517
in the placebo group. However, this difference was not
For the individual cardiovascular events, the study
- Non fatal heart attacks: 184 in the vitamin E group
versus 181 in the placebo group — not a statistically
- Non fatal strokes: 220 in the vitamin E group versus
222 in the placebo group — not statistically
Study investigators also found no significant effect
of vitamin E on total deaths (deaths from all causes).
By the end of the study, there were 636 deaths in the
vitamin E group compared to 615 in the placebo group.
Although total deaths were unaffected by vitamin E,
there was a significant 24 percent reduction in cardiovascular
deaths among all women taking the vitamin (106 deaths
in the vitamin E group versus 140 in the placebo group).
In another positive finding, women 65 and older taking
vitamin E had a 26 percent decrease in heart attacks
and cardiovascular deaths, but not strokes.
“These intriguing findings deserve further study.
But they were not part of the primary aim of the study — to
look at the effect of vitamin E on overall cardiovascular
disease, which includes heart attack, stroke, and cardiovascular
death. Additionally, previous studies of vitamin E in
patients with heart disease have not shown any benefit
for cardiovascular deaths. At present, we cannot recommend
vitamin E for prevention against cardiovascular disease
or cancer,” said lead investigator I-Min Lee, MBBS,
ScD of Brigham and Women’s Hospital.
The study finding of a decrease in major cardiovascular
events among women age 65 years and older is relatively
unique, added Dr. Lee. “Almost all previous trials have
not reported findings by age. If other current trials
provide age-related results, these additional data will
help clarify the Women’s Health Study results of benefit
among the women aged 65 years and older,” she said.
Overall, the results were not affected by a study
participant’s menopausal status, use of hormone therapy,
body mass index, alcohol intake, or physical activity.
The study found no significant side effects among women
taking vitamin E except for an increase in nosebleeds,
which was likely due to chance, as there was no increase
in risk of other types of bleeding, including hemorrhagic
According to the 1999-2000 National Health and Nutrition
Examination Survey, an estimated 13.5 percent of women
in the U.S. take vitamin E supplements, although it
is not known how many are taking the vitamin to prevent
heart disease and stroke.
NHLBI’s Dr. Nabel encouraged women to learn more about
proven ways to prevent heart disease, the number one
killer of women. The Heart Truth (www.hearttruth.gov),
NHLBI’s program to increase women’s awareness of the
dangers of heart disease, offers resources and information
on leading a healthy lifestyle.
NHLBI is part of the National Institutes of Health
(NIH), the Federal Government’s primary agency for
biomedical and behavioral research. NIH is a component
of the U.S. Department of Health and Human Services.
NHLBI press releases and other materials including
information about high blood pressure and heart disease
are available online at www.nhlbi.nih.gov.
The National Institutes of Health (NIH) The
Nation's Medical Research Agency is comprised
of 27 Institutes and Centers and is a component of the
U. S. Department of Health and Human Services. It is the
primary Federal agency for conducting and supporting basic,
clinical, and translational medical research, and investigates
the causes, treatments, and cures for both common and
rare diseases. For more information about NIH and its
programs, visit www.nih.gov.