If you don’t eat meat, how many times have you heard the question: Where do you get your protein? Everyone is an expert on nutrition when you tell them you don’t eat meat; and they can often expect you to wither away into a weakling in poor health.
Is it a disadvantage to obtain protein (really, just amino acids) from plant foods rather than from steak, chicken, pork, egg whites, or turkey? New data confirms that it is an advantage, not disadvantage, to eat your beans rather than beef for your protein requirements.
What Is Protein, Anyway?
Protein is considered a macronutrient along with carbohydrate and fat. Proteins are made of amino acids and are an essential part of the diet used to build, repair, and maintain the body’s structures. We need all 22 types of amino acids for optimal health. There are 9 amino acids that the human body cannot make. These are called the “essential” amino acids. The 9 essential amino acids can be sourced from either plant foods like tofu or quinoa, or from animal foods like beef or chicken.
Does It Make a Difference Where You Get Your Protein?
New Data from Greece: Plant Protein and Aging
To examine if consuming plant-based sources of protein differed from animal-based sources, researchers in Greece analyzed the diets of 3,349 men and women over age 50. They scientists calculated a successful aging (SAI) score and related the diet to this index. They found that participants with a high plant protein diet had a higher SAI score than those that had a low plant protein intake. They concluded that eating a protein-rich diet from plant sources seemed to be a beneficial nutritional choice that should be promoted and encouraged to older people. They commented that a plant diet may benefit both your health and prolong successful aging.
Plant Protein and Lifespan: Part 1
Although “successful aging” is an important goal, other researches have looked at lifespan and protein intake. Drs. Morgan Levine, Valter Longo, and others, examined protein intake in a nutrition database of 6,381 men and women over age 50 in the USA. Participants between the age of 50-65 who reported high protein intake had a 75% increase in overall mortality and a 4-fold increase in cancer death risk during the following 18 years. These associations were either abolished or attenuated if the proteins were plant derived. The investigators concluded that high protein intake was linked to increased cancer, diabetes, and overall mortality (except for older adults). In all age groups, plant proteins were associated with a lower mortality risk than animal derived proteins.
Plant Protein and Lifespan: Part 2
Harvard researchers along with Longo, extended studies on protein intake and mortality by studying 131, 342 participants in the Nurses’ Health Study and Health Professionals Follow-Up Study. The main measure was the risk of death during follow-up that extended over 30 years. Higher intake of animal-derived protein was linked to a higher risk of dying of cardiovascular disease (CVD). A higher intake of plant-derived protein was associated with lower all-cause mortality and heart mortality. These associations were confined to participants with at least one unhealthy lifestyle factor based on smoking, heavy alcohol intake, overweight or obesity, and physical inactivity. Replacing animal protein of various origins with plant protein was associated with lower mortality. The researchers concluded that substitution of plant protein for animal protein, especially that from processed red meat, was associated with lower mortality.
Plant Protein and Lifespan: Part 3
The most recent large study to examine plant vs animal protein and health was performed in Japan and involved 70,696 participants. Intake of plant protein was associated with lower total mortality. Furthermore, plant protein intake was linked to lower death rates from CVD. Substituting plant protein for red meat protein was associated with lower total, cancer-related, and CVD-related mortality.
So, Where Should You Get Your Protein?
The new study of Greek citizens builds on impressive prior data that obtaining protein from plant sources, like legumes, whole grains, vegetables, and even fruit, is preferable to relying on animal-derived protein. When you swap beans in place of beef, tempeh in place of bacon, and tofu in place of chicken, you have upgraded your health, as well as contributed to a smaller carbon footprint and less suffering for animals. The next time you are asked “where do you get your protein?” you can confidently answer “from the best source on the planet: plants.”
Dr. Joel Kahn is Professor of Cardiology, Summa cum Laude grad, Kahn Center for Longevity and GreenSpace & Go, author, “The Plant Based Solution.” www.drjoelkahn.com @drjkahn.
