The study, published in the American Journal of Clinical Nutrition, observed multivitamin use to be inversely associated with myocardial infarction in women with no history of cardiovascular disease. The researchers noted that the association grew stronger with long-term use, and was not affected by how often supplements were taken.
“From a public health point of view, it is important to evaluate whether multivitamins should be recommended to prevent myocardial infarction,” stated the researchers, led by Dr Susanne Rautiainen, from the Divisions of Nutritional Epidemiology at the Karolinska Institutet, Sweden.
The new research shows correlation and not causation, however, and the researchers noted that further research must be completed in order to confirm or refute their findings. If such findings supported this study’s observation then it would be important to “clarify what composition of multivitamins (doses and ingredients included) and duration of use is needed to observe beneficial effects on myocardial infarction,” wrote Dr Rautiainen and her co-workers.
Multivitamin and mineral supplements are the most frequently used supplements in industrialised countries, where there is a common belief is that they ensure an adequate nutrient intake, which can help to prevent coronary heart disease
Most multivitamins contain a wide spectrum of nutrients, including antioxidant vitamins, B vitamins, and minerals such as magnesium and selenium – all of which have been inversely related to heart disease by previous research.
Despite the widespread use of multivitamins, the authors noted the limited data available on the relationship between multivitamin use and coronary heart disease incidence, with only one previously published randomized controlled trial on low-dose multivitamin supplements and heart disease incidence, which showed no significant effects.
However, some observational studies have associated multivitamin use with statistically significant effects on the risk of myocardial infarction, with a Dutch study finding a 51 percent lower risk of incidence in a prospective cohort study (American Journal of Clinical Nutrition, Vol. 69, No. 2 ). Additionally, an American study observed combined use of multivitamins and supplements of vitamin A, C, or E to be associated with a 25 percent lower risk of coronary heart disease mortality.
The new study prospectively investigated the association between multivitamin use and myocardial infarction in a population of over 30,000 Swedish women between 49 and 83 years old.
In women with no history of cardiovascular disease, the researchers observed that use of multivitamins alone – compared with no use of supplements – was associated with a 27 percent lower risk of myocardial infarction.
They found women using multivitamins together with other supplements had a 30 percent lower risk of myocardial infarction; however the use of supplements other than multivitamins was not significantly associated with such effects.
Researchers noted that the observed associations were similar among regular and occasional users of multivitamin supplements.
On the other hand, multivitamin use, alone or in combination with other supplements, was not statistically significantly associated with myocardial infarction in women with a history of cardiovascular disease.
The association between multivitamin use and myocardial infarction was seen to be stronger among women using multivitamins for more than five years.
Researchers suggested the potentially protective effects of multivitamins on myocardial infarctions may the due to antioxidant vitamins – such as vitamin C and vitamin E –, and B vitamins and minerals included.
“Even if multivitamins contain low amounts of antioxidant vitamins […] they may be involved in mitigating the atherosclerotic process by scavenging free radicals,” suggested the authors.
Source: American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.3945/ajcn.2010.29371
“Multivitamin use and the risk of myocardial infarction: a population-based cohort of Swedish women”
Authors: S. Rautiainen, A. Åkesson, E.B. Levitan, R. Morgenstern, M.A Mittlemanand A. Wolk