10 Medical Studies That Prove We Should All Eat a Plant-based Diet

Photography by John Kuczala

Photography by John Kuczala

A juicy hamburger . . . lip-smacking barbecued ribs . . . saucy chicken cutlets . . . savory pork chops. Sound tasty?  But meats like these are off-limits for a growing number of people – purely by choice. Interest in plant-based diets, which center on vegetables, fruits, whole grains, nuts and beans, has virtually exploded in recent years.

Viver Health Your Guide to a Plant-based Diet Photo.jpg

Your Guide to a Plant-based Diet: 5 Simple Steps to Reduce Your Risk of Chronic Disease

Those eschewing meat go beyond the 6% of Americans who are vegans – avoiding all animal-based products, including fish and dairy – and 7% classified as vegetarians, who might consume fish, eggs and milk but skip anything containing meat. Recent research indicates an additional one-third of American consumers prefer dairy milk alternatives and use meat alternatives – meaning more of their diets are plant-based, according to the website Food Navigator.

This major nutritional shift isn’t just due to concerns over animal cruelty, but the dawning realization that a plant-based diet includes far fewer saturated fats and other components that may spell bad news for health. Scientists are learning that even cutting back on meat and other animal products – the goal of so-called “flexitarians,” whose diets are dominated by plant-based foods – can yield significant health benefits.

 Here are 10 medical studies that drive home why shifting to a plant-based diet is better for our health:

1. Promotes longevity     

Research tracking more than 70,000 people showed vegetarians may live longer than meat-eaters. Published in JAMA Internal Medicine in 2013, the study split participants into 5 groups, including non-vegetarian, semi-vegetarian, pesco-vegetarian (includes seafood), lacto-ovo-vegetarian (includes dairy and egg products) and vegan. The all-cause death rate for all vegetarians compared to non-vegetarians was 12% lower over an average follow-up time of nearly 6 years. 

2. Lessens cancer risk    

Midlife adults who eat diets rich in animal proteins are 4 times more likely to die of cancer than a peer who consumes low-protein fare – a risk comparable to smoking, a 2014 study in the journal Cell Metabolism suggests. Following more than 6,000 people ages 50 and older for 18 years, researchers defined a high-protein diet as including at least 20% of calories from protein that’s both plant-based and animal-based. Moderate protein intake was defined as 10% to 19% of calories from protein, while a low-protein diet was defined as less than 10% protein. Middle-age adults who consumed foods rich in animal proteins — including meat, milk and cheese — were also found to be 75% more likely to die of any cause than peers who ate a low-protein diet during the study. 

3. Aids weight management  

Vegetarian diets may be more nutritious overall and more optimal for weight management than those including meat, a 2011 study in the Journal of the Academy of Nutrition and Dietetics found. Analyzing more than 13,000 adults, scientists learned vegetarians were slimmer than meat-eaters and also consumed more potassium, iron, thiamin, riboflavin, folate and vitamins, along with less total fat. 

4. Hinders diabetes    

Plant-based diets may hold the upper hand in preventing and managing diabetes. A 2009 study involving more than 60,000 women and men in the journal Diabetes Care indicated that those on a vegan diet had a 2.9% incidence of type 2 diabetes, compared to 7.6% of the non-vegetarians. Scientists believe a low-fat, plant-based diet that includes little or no meat may improve the body’s insulin sensitivity and decrease insulin resistance. 

Viver Health Your Guide to a Plant-based Diet photo.jpg

Your Guide to a Plant-based Diet: 5 Simple Steps to Reduce Your Risk of Chronic Disease

5. It’s heart-healthy  

It’s long been understood that a Mediterranean diet – which emphasizes eating primarily plant-based foods and limiting red meat – is a heart-healthy path. The Lyon Diet Heart Study, published in 1999, drove this point home, finding a “striking protective effect” after a first heart attack for those on the Mediterranean plan. These participants experienced a 73% drop in coronary events and a 70% decrease in dying of any cause over follow-up period of more than 2 years. 

6. Hampers high blood pressure  

Vegetarians had a 34% lower risk of high blood pressure compared to non-vegetarians in a large 2016 study published in the Journal of Hypertension. Matching each vegetarian participant with 5 non-vegetarians and analyzing more than 4,100 nonsmokers in all, researchers believe vegetarian diets protect against high blood pressure by lessening the degree of obesity, inflammation and insulin resistance. 

7. Slashes stroke risk   

Reviewing 20 prior studies on stroke incidence in relation to fruit and vegetable consumption, scientists found that the more fruits and vegetables people ate, the lower the risk of a potentially deadly “brain attack.” The 2014 meta-analysis in the journal Stroke also suggested that citrus fruits, apples, pears and leafy vegetables might contribute to the protective effects against stroke. The findings showed the risk of stroke dropped by 32% and 11% for every 200 grams per day (about 0.4 pound) increase in fruit and vegetable intake, respectively. 

8. Improves gut bacteria  

With “gut microbiota” or gut bacteria increasingly linked to a healthy immune system and other health advantages, 2014 research in the journal Nutrients showed that vegans’ particular array of gut bacteria are very different from omnivores – people who eat all types of food – but not as distinct from vegetarians. Vegans’ “gut profile” had fewer disease-causing organisms that promote systemic inflammation. 

9. Cuts cholesterol  

Plant-based vegetarian diets, and especially vegan diets, were linked with lower cholesterol levels in a wide-ranging 2017 review of 49 prior studies published in Nutrition Reviews. The findings indicated a plant-based vegetarian diet is associated with total cholesterol levels of 29.2 mg/dL in less-rigorous observational studies, and a 12.5 mg/dL drop in total cholesterol in more rigorous clinical trials. Study authors noted that high cholesterol levels often go undiagnosed and untreated, but a 10% increase in treatment prevalence could prevent 8,000 deaths every year. 

10. Boosts brain health    

Brain volume – a signal of robust brain health – was better retained among older people following a Mediterranean diet, which emphasizes consumption of vegetables, fruits, olive oil, beans and cereal grains, a 2017 study found. Published in the journal Neurology, the research gathered information on 967 Scottish people around age 70 without dementia. It showed that those following the Mediterranean plan retained more brain volume over a three-year span than peers who didn’t eat as many of those foods. 

Maureen Salamon is a widely published health and medical writer who has written for The New York Times, The Atlantic, CNN.com, HealthDay, The Dallas Morning News and other major publications.