Plant-based diets are becoming increasingly popular in the United States. A 2017 report estimated that 6% of U.S. consumers eat a vegan diet, up from just 1% in 2014.
There are many reasons why people choose to adopt a vegan diet, including avoiding harm to animals and mitigating the environmental impact of intensive farming.
A plant-based diet also provides health benefits. This diet is higher in fiber and lower in cholesterol and fat than an omnivorous diet, and it scores higher on the Healthy Eating Index.
A new review of the evidence on plant-based diets suggests that they may also protect against type 2 diabetes and heart disease and could reduce cardiometabolic-related deaths in the U.S.
The Physicians Committee for Responsible Medicine (PCRM) in Washington, DC, led the review, which features in the Journal of the American College of Nutrition.
The review focuses on health in the context of aging, an important topic given that the world’s population is rapidly getting older.
“The global population of adults 60 years old or older is expected to double from 841 million to 2 billion by 2050, presenting clear challenges for our healthcare system,” explains first author Hana Kahleova, M.D., Ph.D., director of clinical research for the PCRM.
Dr. Kahleova and her team reviewed both clinical trials — which researchers perform under controlled conditions, usually to test the effect of a specific intervention on a particular outcome — and epidemiological studies, which follow people over time under normal conditions.
They found evidence that a plant-based diet reduces the risk of obesity, type 2 diabetes, and coronary heart disease.
Specifically, they found that plant-based diets could halve the risk of metabolic syndrome, which increases a person’s risk of developing cardiovascular disease and type 2 diabetes. Eating a plant-based diet could also halve the risk of type 2 diabetes itself, as well as reducing the risk of coronary heart disease events, such as a heart attack, by 40%.
People who eat plant-based diets may also live longer. The authors refer to so-called Blue Zones, where people live longer than the average. Examples include Loma Linda, CA, where people live up to 10 years longer than other people in California, and Okinawa, Japan, which has one of the highest life expectancy rates in the world.
As well as not smoking and engaging in moderate physical activity, people in Blue Zones tend to have a mostly plant-based diet. In Okinawa, for example, people consume a diet high in sweet potatoes, green leafy vegetables, and soy products.
As well as living longer, people who eat a plant-based diet may also remain cognitively healthy for longer.
The authors found one study which showed that the MIND diet — which is rich in fruits, vegetables, grains, nuts, and seeds but does not exclude animal products — reduced the risk of developing Alzheimer’s disease. The team found that the DASH diet, which is similar to the MIND diet, and the Mediterranean diet were also associated with a reduced risk of developing Alzheimer’s disease.
Although aging is inevitable, the authors say that adopting a healthful, plant-based diet could help delay the aging process and reduce the risk of age-associated diseases. It could also increase a person’s life expectancy.
“[S]imple diet changes can go a long way in helping populations lead longer, healthier lives.”
Dr. Hana Kahleova, Ph.D.
This conclusion is in line with the findings of the Global Burden of Disease Study 2017, which showed that a low intake of fruits, vegetables, and whole grains and a high intake of red and processed meats are major risk factors for disease.
The authors say that as well as offering significant benefits for health, plant-based diets could reduce healthcare costs in the U.S., which are close to $3.5 trillion each year. They suggest that a healthful diet is a cost effective approach to preventing disease and recommend incorporating it into everyday life.
