Plant-based diets are tied to a lower risk of health problems like heart disease, diabetes, obesity and certain cancers - and pretty much anyone can eat this way, according to a leading group of nutritionists.
Vegetarian and vegan diets are appropriate for all stages of life, including during infancy, pregnancy, childhood, adolescence and old age, the authors write in a position statement from the Academy of Nutrition and Dietetics.
That's because people who adopt a plant-based diet tend to consume more fruits and vegetables, fewer sweets and salty snacks, and smaller amounts of total and saturated fats, the statement, published in the Journal of the Academy of Nutrition and Dietetics, asserts.
The trick is to make sure these diets are well planned out and well balanced, said Vandana Sheth, a registered dietitian nutritionist and spokesperson for the Academy of Nutrition and Dietetics.
"Any diet that is not well planned and balanced can have negative side effects," Sheth said by email.
"Just because foods are plant based doesn't automatically make them healthy," Sheth added. "For instance, pastries, cookies, fried and salty foods may be vegan but don't really provide much in terms of nutritional value."
For younger vegetarians and vegans in particular, it's important to plan meals that include enough iron, zinc, vitamin B-12, and for some, calcium and vitamin D, Sheth said.
"Well-planned vegetarian and vegan diets containing vegetables, fruits, whole grains, legumes, nuts and seeds can be nutritionally adequate and may provide health benefits for the prevention and treatment of some chronic diseases," Sheth noted.
Approximately 3.3 percent of American adults are vegetarian or vegan, meaning they never eat meat, poultry or fish, according to the guidelines. This way of eating is much more common among younger adults than elderly people.
Among the health benefits noted in the guidelines, people who eat a plant-based diet are less likely to be overweight or obese than adults who consume meat.
Vegan diets in particular, which exclude meats as well as animal products like milk, eggs and honey, are associated with a lower risk of heart disease than other ways of eating, the statement also points out.
According to the authors, people who adopt a vegan diet reduce the risk of diabetes by 62 percent, the risk of prostate cancer by 35 percent, the chance of being hospitalized for a heart attack by 33 percent, the risk of heart disease by 29 percent and the risk of all forms of cancer by 18 percent.
"People who adopt vegetarian diets have a lower body mass index, better control of blood pressure and blood glucose, less inflammation and lower cholesterol levels compared with non-vegetarians," Sheth said.
Just because a diet is vegetarian or vegan, however, doesn't necessarily mean it's healthy, cautioned Dr. Dariush Mozaffarian, dean of the Tufts Friedman School of Nutrition Science and Policy in Boston.
"For instance, fries and a coke are vegan," Mozaffarian, who wasn't involved in the position statement, said by email.
"Indeed, much of the harmful stuff in the food supply is vegetarian or vegan: refined grains, starches, added sugars, sweets, trans fats, salt, etc," Mozaffarian added. "People can have a vegetarian or vegan diet that is healthy or terrible; and a non-vegetarian or non-vegan diet that is healthy or terrible."
A healthy diet is rich in minimally processed foods, especially from plants, but also from animals, Mozaffarian said.
"I recommend a high-fat Mediterranean-style diet, rich in fruits, non-starchy veggies, nuts, beans, fish, whole grains, and vegetable oils; and including yogurt, cheese, poultry, and occasional half serving a week of fresh, unprocessed red meat," Mozaffarian said.