The Big Benefit of Eating Veggies That You Didn’t Know About
Three new studies have linked plant protein intake to a longer, healthier (disease-free!) life.
It seems like practically every day, there’s a new headline out about the “best diet trend for your health.” From the keto diet to the Mediterranean diet to the vegan diet, it’s tough to know where to begin if you want to make a healthy change.
One thing that hasn’t ever gone out of fashion? The benefits of eating more plants. Whether you choose to give up animal products entirely, or just to incorporate more veggies into your current diet, you can’t go wrong by adding more nutrient-dense whole foods to your plate. The science supports this, too—a new study in JAMA Internal Medicine found that a greater consumption of plant protein (versus animal protein) plays a role in supporting a longer, healthier life.
“Our data provides evidence supporting a favorable role for plant-based diets in the prevention of cardiovascular disease mortality,” says Demetrius Albanes, M.D., study co-author and senior investigator with the National Cancer Institute’s Division of Cancer Epidemiology and Genetics in Rockville, Maryland. The results also “suggest that modifications in choices of protein sources may influence health outcomes and longevity.”
The takeaway here: Swapping out your usual beef stew for a bean-based version might help you ward off disease and live longer. Veggie chili, anyone?
What Is Protein, Really?
When you think of protein, the first foods that probably come to mind are meat, eggs, and tofu. These are the typical “proteins” you might order on top of a restaurant salad or bowl. But vegetables themselves are also great sources of protein–especially legumes, nuts, and seeds. “Protein is not a food, it’s a nutrient,” explains Christopher Gardner, Ph.D., professor of medicine at Stanford School of Medicine in Stanford, California. More specifically, it’s a macronutrient, made up of building blocks called amino acids that play a role in your body’s day-to-day functions.
A common misconception is that animal products are the only way to get adequate protein in your diet. But, Gardner notes, this isn’t true at all. Plants contain all 20 of the amino acids that make up a complete protein. They just don’t have quite the same proportions that animal products do. “For the most part, they’re pretty similar,” he says, noting that variety is key to ensuring you get the optimal nutrients your body needs.
Findings from This New Study
For the JAMA study on protein, researchers looked at data from a group of almost 500,000 elderly Americans spanning 16 years. Participants detailed their dietary choices in a questionnaire, noting what percentage of their protein intake came from plants, and how much came from animals. The researchers then looked to see which of these participants lived longer than others, with lower incidences of chronic cardiovascular disease.
Their results revealed a significant difference in lifespan between those who got more protein from plants versus animals. “Based on data from 237,036 men and 179,068 women, with nearly 78,000 deaths within the follow up period, we found that greater intake of plant protein was associated with significantly lower overall and cardiovascular disease mortality, independent of several other health risk factors,” explains Jiaqi Huang, Ph.D., postdoctoral fellow with the National Cancer Institute’s Division of Cancer Epidemiology and Genetics, who also coauthored the study. And living longer didn’t necessarily correlate to eating a 100% vegan diet. “Replacing 3% dietary energy from animal protein sources with plant protein was associated with 10% lower overall mortality in both sexes,” Huang says – so even making a few tiny switches throughout the week can help promote better long-term health.
The research team adjusted for a variety of other potential factors that could have skewed the results, including age, body mass index, alcohol consumption, smoking status, physical activity, diabetes, and other dietary factors. The breadth of this study makes its results particularly strong, Huang notes. “The large cohort sample size … and the long-term follow-up together afforded substantial power to detect moderate associations between plant protein intake and mortality risk.”
This joins a growing body of research identifying the benefits of plant-based diets, including two additional studies out this summer. The first, in Public Health Nutrition, looked at a group of 3,349 Greek men and women to find that participants who ate a lot of plants were more likely to stay active and fit as they aged. The second study, in BMJ, studied a cohort of 715,128 participants and determined that replacing animal protein with plant protein can help contribute to longevity.
The Surprising Takeaway
The most important conclusion to draw from these studies might have nothing to do with protein at all. Gardner explains that most Americans eat much more protein than the National Institute of Health’s recommended dietary allowance (RDA), which is 0.8 grams of protein per kilogram of body weight. “Most Americans get double the RDA,” Gardner says, and that’s simply by eating enough daily calories. The U.S. Department of Health and Human Services 2015-2020 Dietary Guidelines state that more than half the population is meeting or exceeding their protein needs, while three-fourths of the population is not eating enough fruits and vegetables every day.
Rather than obsessing over your protein intake, Gardner suggests focusing on eating whole plant-based foods and replacing animal protein with plants when you can. “I feel like [these studies] are masking a deeper message,” he says. “I’m worried that it perpetuates this obsession with protein, when all these studies are really just a marker for a more plant-based, less animal-based diet.”
If you head to the store after reading this and pick up three huge containers of soy protein, Gardner says you’re missing the bigger point of these findings. Real food, full of fiber and vitamins and minerals, will fuel your body without exposing you to harmful additives or cutting out crucial nutrients from the foods themselves. (Not that protein powder is inherently bad for you – it’s not! Just use it in moderation and don’t rely on it as a substitute for other plant-based sources of food.) Just eat more plants!
Best Sources of Plant Protein
Since we are talking protein here, you should know how it breaks down in your diet. Most plant-based foods contain at least some amount of protein, and certain foods contain quite a lot. To start working these into your diet, try eating one plant-based meal per day – like oatmeal with nut butter instead of eggs and sausage for breakfast. Then see how you feel and work up from there.
Beans: Beans are one of the best sources of plant-based protein out there, Gardner notes. Coincidentally, beans are also a food eaten frequently in the cultures labeled as the “blue zones” – the five regions in the world where author Dan Buettner and his research team identified an unusually high number of people living past age 100. (You can learn more about this longevity research in Buettner’s 2008 book The Blue Zones.) “The single diet thing that’s consistent is that they eat a lot of beans,” Gardner says: everything from pinto beans to hummus to edamame.
Tofu and tempeh: Tofu is made from soybeans, so it technically still falls into the “beans” category, but many people think of it as its own entity. Tempeh is also made from fermented soybeans. They both pack a protein-filled punch and contain a hefty number of vitamins. The major caveat here: these options won’t work for someone with a soy allergy or sensitivity. Check with your doctor if you’re concerned.
Nuts: Good news for peanut butter lovers out there: nuts and seeds are an awesome source of plant-based protein and fat. They do pack on the calories, though, so if you’re trying to watch your weight, just be careful not to overdo them.
Whole grains: We’re not talking about a slice of white bread! Make room for whole grains like oatmeal, quinoa, wild rice, and buckwheat in your diet. These grains help fill you up and give you energy from complex carbohydrates, and they also contain a moderate amount of protein.
Vegetables: Yes, veggies have protein, too! Broccoli, brussels sprouts, and asparagus are some of the highest-protein options. Try to buy them fresh when you can and work them into your meals as much as possible to reap the nutrient-dense benefits.
At the end of the day, it’s all about eating high-quality foods from mostly plant-based sources. Your body and mind will thank you–especially as you age.
Plant-Based Protein and Mortality Study: JAMA Internal Medicine. (2020.) “Association Between Plant and Animal Protein Intake and Overall and Cause-Specific Mortality.” jamanetwork.com/journals/jamainternalmedicine/article-abstract/2768358
Greek Study on Plant Protein: Public Health Nutrition. (2020.) “The association of animal and plant protein with successful ageing: a combined analysis of MEDIS and ATTICA epidemiological studies.” pubmed.ncbi.nlm.nih.gov/32434609/
Protein Sources and All-Cause Mortality Study: BMJ. (2020.) “Dietary intake of total, animal, and plant proteins and risk of all cause, cardiovascular, and cancer mortality: systematic review and dose-response meta-analysis of prospective cohort studies.” bmj.com/content/370/bmj.m2412
Recommended Daily Protein Intake: National Institutes of Health. “Nutrient Recommendations: Dietary Reference Intakes.” (n.d.) ods.od.nih.gov/Health_Information/Dietary_Reference_Intakes.aspx
Dietary Guidelines: U.S. Department of Health & Human Services. (2015.) “Current Eating Patterns in the United States.” health.gov/our-work/food-nutrition/2015-2020-dietary-guidelines/guidelines/chapter-2/current-eating-patterns-in-the-united-states/
Plant Protein Sources: Harvard School of Public Health. (n.d.) “Protein.” hsph.harvard.edu/nutritionsource/what-should-you-eat/protein/