March 23, 2005
Ontario, Canada-
Cultural tendencies and animal model studies believe vitamins
are beneficial to all people and illnesses, but a recent study
by Eva Lonn, MD et al, from the Health Research Institute and
McMaster University in Ontario, Canada published an article in
the March 16, 2005 issue of JAMA showing that vitamin E had no
beneficial effect on heart disease or cancer. In fact, this
study showed that in patients with vascular disease or diabetes
mellitus, long term Vitamin E supplementation does not only lack
preventative mechanisms for cancer and major cardiovascular
events, it increases the risk for heart failure.
The predominant and active form of Vitamin E is a-Tocopherol
which is a major antioxidant in lipid phases. The Heart Outcomes
Prevention Evaluation (HOPE) and HOPE-The Ongoing Outcomes
(HOPE-TOO) designed a randomized, double-blind,
placebo-controlled international trial to evaluate whether
long-term supplementation with vitamin E decreases the risk of
cancer and major cardiovascular events. The patients were at
least 55 years old with vascular disease or diabetes mellitus
and participated in the study spanning from 1993 to 2003. In the
HOPE study, patients were given ramipril vs. placebo and vitamin
E vs. placebo. In the HOPE-TOO study participants continued to
take daily vitamin E (400 IU) or matching placebo.
Among all HOPE patients, there were no significant differences
in the primary analysis. For cancer incidence, there was a RR
0.94; 95% confidence interval, 0.84-1.06; p=0.3. For cancer
deaths, RR, .88; 95% CI 0.71-1.09; p=.24. For major
cardiovascular events, 1022 (21%) patients in the vitamin E
group vs. 985 (20.6%) patients in the placebo group (RR, 1.04,
95% CI, 0.96-1.14; p=.34). Patients in the vitamin E group had a
higher risk of heart failure (RR, 1.21; 95% CI,1.0-1.47;
1.01-1.26; p=0.03) and higher hospitalization for heart failure
(RR, 1.21; 95% CI, 1.00-1.47; p=0.045). Similarly, among
patients enrolled at the centers participating in the HOPE-TOO
trial, there is no difference in cancer incidence, cancer
deaths, and major cardiovascular events. In the HOPE-TOO
analysis of study patients with longest duration of treatment
and observation, the increase in risk was 19% in heart failure
events (p=0.007) and 40% increase in the risk of hospital
admission for heart failure (p= 0.002).
The major finding for the HOPE and HOPE-TOO trial is the lack of
benefit for vitamin E in preventing cancer or major
cardiovascular events after prolonged period of treatment and
observation. Furthermore, there may be a higher risk of heart
failure with prolonged use of vitamin E. The mechanism for the
deleterious effect of vitamin E is not clear but the study
suggested vitamin E’s potential to become pro-oxidant and
depress myocardial function or the reduction of HDL cholesterol
with vitamin E.
Thus, this study indicates that in conjunction with its lack of
efficacy, the potential for harm suggests that vitamin E
supplements should not be used in patients with vascular disease
or diabetes mellitus.
Co-authors: Jackie Bosch, MSc, Salim Yusef, MBBS, Dphil, Patrick
Sheridan, MSc, Janice Poque, MSc, J. Malcom O. Arnold, MD,
Andrew Arnold, MBBS, Peter Sleight, MD, DM, Jeffrey Probstfield,
MD and Gilles R. Dagenais MD.
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