Vegetarian Diets Linked to Lower Mortality

Adults who eat a more plant-based diet may be boosting their chance of living longer, according to a large analysis.

Research has shown that the foods you eat influence your health. Eating certain foods, such as fruits and nuts, has been associated with reduced death rates, while other foods, such as red meat and processed meat, have been linked to increased mortality. Studies comparing overall eating patterns and mortality rates, however, have had mixed results.

A research team led by Drs. Michael Orlich and Gary Fraser at Loma Linda University explored the connections between dietary patterns and death in Seventh-day Adventist men and women. The research was part of an ongoing analysis of people recruited at Seventh-day Adventist churches in the United States and Canada between 2002 and 2007. Adventists tend to have similar lifestyle habits. For instance, they typically don’t smoke or consume alcohol. However, they have a range of dietary patterns, making them an ideal group for teasing out the links between diet and the causes of death and disease.

The researchers studied more than 73,000 people ages 25 and older. The participants were categorized into dietary groups at the time of recruitment based on their reported food intake during the previous year. The study was funded in part by NIH’s National Cancer Institute (NCI), and appeared online on June 3, 2013, in JAMA Internal Medicine.

Nearly half of the participants were nonvegetarian, eating red meat, poultry, fish, milk and eggs more than once a week. Of the remaining, 8% were vegan (eating red meat, fish, poultry, dairy or eggs less than once a month); 29% were lacto-ovo vegetarians (eating eggs and/or dairy products, but red meat, fish or poultry less than once per month); 10% were pesco-vegetarians (eating fish, milk and eggs but rarely red meat or poultry); and 5% were semi-vegetarian (eating red meat, poultry and fish less than once per week).

Over about 6 years, there were 2,570 deaths among the participants. The researchers found that vegetarians (those with vegan, and lacto-ovo-, pesco-, and semi-vegetarian diets) were 12% less likely to die from all causes combined compared to nonvegetarians. The death rates for subgroups of vegans, lacto-ovo–vegetarians, and pesco-vegetarians were all significantly lower than those of nonvegetarians.

Those on a vegetarian diet tended to have a lower rate of death due to cardiovascular disease, diabetes, and renal disorders such as kidney failure. No association was detected in this study between diet and deaths due to cancer. The researchers also found that the beneficial associations between a vegetarian diet and mortality tended to be stronger in men than in women.

The researchers note several limitations to the study. Participants only reported their diet at the beginning of the study, and their eating patterns might have changed over time. In addition, they were only followed for an average of 6 years; it may take longer for dietary patterns to influence mortality.

“This research gives more support to the idea that certain vegetarian dietary patterns may be associated with reduced mortality and increased longevity. This is something that may be taken into account by those making dietary choices and by those offering dietary guidance,” says Orlich.

— by Carol Torgan, Ph.D.