(CNN) Eating more plants and less meat has been tied to a longer life and a reduced risk of cardiovascular disease in a new study.
Sticking to an overall plant-based diet or a diet that includes more plant foods than animal foods could be associated with a 16% lower risk of cardiovascular disease and up to 25% lower risk of early death, according to the study published in the Journal of the American Heart Association this week.
The new study adds to "the substantial body of literature" suggesting that consuming a plant-based diet is associated with better heart health and lower risk of death, said Casey Rebholz, an assistant professor at the Johns Hopkins Bloomberg School of Public Health in Baltimore and senior author of the study.
"Plant-based diets emphasize higher intakes of plant foods and lower intakes of animal foods. Foods derived from plants include fruits, vegetables, whole grains, nuts, and legumes," Rebholz said.
"Animal foods include meat, eggs, dairy, and fish or seafood," she said. "In this study, we did not define plant-based diets on the basis of complete exclusion of animal foods from the diet ... but rather ranked individuals according to their relative frequency of intake of these foods."
The study involved data on 12,168 middle-aged adults in the United States, which came from the National Heart, Lung, and Blood Institute's Atherosclerosis Risk in Communities study.
The adults, who were followed up from 1987 through 2016, did not have cardiovascular disease at the start of the study.
The researchers took a close look at each adult's usual diet and their heart health later in life, including whether they were diagnosed with stroke, heart failure or other events related to cardiovascular disease.
After analyzing the data, the researchers found that the adults who adhered to diets with mostly plant-based foods, compared with those who had the lowest adherence, had a 16% lower risk of cardiovascular disease; about 32% lower risk of dying from a cardiovascular disease; and 18% to 25% lower risk of early death from any cause.
The study had some limitations, including that the data on dietary intakes were based on people self-reporting their eating habits, which poses a risk of measurement error.
More research is needed to determine if a causal relationship exists, and to determine how the modern food supply might influence outcomes, as the data in the study came from years' past.
Cardiovascular diseases, disorders of the heart and blood vessels such as heart disease, are the No. 1 cause of death globally, according to the World Health Organization.
The new study's findings are "important," said Dr. Michelle McMacken, director of the plant-based lifestyle medicine program at NYC Health + Hospitals/Bellevue and an assistant professor of medicine at NYU School of Medicine in New York, who was not involved in the study.
"They strongly suggest that in a general US population who don't necessarily identify as vegetarian, the higher the proportion of plant foods in the diet, the lower the risk of cardiovascular events and death from any cause," McMacken said, adding that plant-based diets can promote heart health by multiple mechanisms.
"First, they are higher in beneficial nutrients such as fiber, plant fats, potassium, and antioxidants, and lower in potentially harmful nutrients such as animal-based iron, animal fats and nitrite preservatives," she said.
"Second, plant-based diets are also linked to healthier body weights, lower inflammation, lower risk of type 2 diabetes, better blood pressure and blood vessel function, and beneficial gut bacterial metabolites," she said. "All of these factors translate into a lower cardiovascular risk."