For some, a decision to become a vegetarian, or to adopt a reduced-meat diet, can be met with a degree of friction from family, friends or peers. It's rare, for example, to meet a vegetarian who hasn't been quizzed on their source of protein, or hasn't been asked to present an explanation for their diet. One bit of fodder for that conversation could be longevity, according to a study published in JAMA Internal Medicine, with research conducted by Loma Linda University, a Seventh-day Adventist college in California.
According to the study, "Some evidence suggests vegetarian dietary patterns may be associated with reduced mortality, but the relationship is not well established."
The method of research surveyed mortality rates among 73,308 Seventh-Day Adventist individuals, both men and women. And between 2002 and 2007, researchers looked to five dietary patterns as variables: non-vegetarian, semi-vegetarian, pesco-vegetarian, lacto-ovo-vegetarian, and vegan. According to the Huffington Post, the results of the endeavor found that mortality rates during the study's timeframe were 12% lower for vegetarians, compared to non-vegetarians, whereas vegans saw an even lower mortality rate during the timeframe, or a 15% reduced risk of death.
Pesco-vegetarian, or vegetarians who make the exception to include fish in their diets, saw a 19% lower mortality rate as compared to non-vegetarians, according to the study, whereas lacto-ovo-vegetarians (vegetarians who eat eggs and non-vegetarian dairy products) saw a 9% lower mortality rate than non-vegetarians. And compared to meat-eaters, semi-vegetarians had an 8% lower risk of death during the study's timeframe.
Certain foods have been tied to lower mortality rates, according to the study, among them fruit, nuts, green salad, a Mediterranean diet, plant-based diets and vegetarian diets, whereas other certain foods, such as meat, eggs and animal-based low carbohydrate diets, may prove to have the inverse effect.
And according to Time, vegetarians diets can help support low blood pressure, better moods, reduced heart disease, reduced rates of cancer, reduced risk of diabetes and a lesser chance of being overweight.
Though the results are promising for vegetarians who believe in the long-term health benefits of their diets, as with many scientific studies, it's important to remember that correlation doesn't imply causation.
"We can't tell from this current paper with certainty, but one of the most plausible potential reasons contributing to this beneficial association is perhaps the absence or reduction of meat intake," said Dr. Michael J. Orlich, Loma Linda University's program director of the preventative-medicine residency, Time reported.
"It could also be that consumption of various plant foods may be beneficially associated with reduced mortality, so we definitely want to look at those things on the food level in the future."
For those interested in digging into the weeds on what scientists and academics have to say about how plant-based diets can affect human health, here's some highly-recommended reading: The China Study.