Harvard Health Blog
Eat more plants, fewer animals
Science has shown us over and over again that the more meat we eat, the higher our risk of diabetes, heart disease, and strokes. Conversely, the more fruits and vegetables we eat, the lower our risk for these diseases, and the lower our body mass index.
Why is eating meat bad? High-quality research shows that red meats (like beef, lamb, pork) and processed meats (bacon, sausage, deli meats) are metabolized to toxins that cause damage to our blood vessels and other organs. This toxic process has been linked to heart disease and diabetes. (Want to know more? Read about how these animal proteins harm the body here and here).
Should we all become vegetarian or vegan?
Not necessarily. One can be 100% perfectly vegetarian or vegan and still have an unhealthy diet. Many foods that aren't made with animals are still unhealthy. Think candy, soda, and pasta, and baked goods made with refined flour. Sugar-sweetened beverages and refined grains are also toxic to the body and associated with significant health risks.
A better approach is a plant-based diet. This means consuming mostly fruits and vegetables, including beans and legumes, nuts and seeds, and whole grains. A plant-based diet is well associated with a lower risk of diabetes, high blood pressure, heart disease, stroke, and death from any cause.
An estimated 90% of the population of the United States is omnivorous, and the vast majority of people aren't going to give up meat. The good news is, they don't need to. A 2017 study published in JAMA showed that consuming just 3% less animal protein and replacing it with plant protein was associated with up to a 19% lower risk of death from any cause.
Not only that, but a plant-based diet can protect us when we do occasionally eat meat. Fruits and vegetables contain special plant nutrients that neutralize toxins. These are antioxidants, and they are really good for us. But they cannot be isolated and packed into a capsule or pill — supplements don't work. A balanced diet that includes a wide variety of colorful fruits and vegetables is what works. Just eat more plants that anything else, and minimize the meats, and you'll be doing your body a huge favor.
Where will I get my protein?
Protein does not have to mean meat. As a matter of fact, many plant foods are excellent sources of protein. And no, it doesn't have to be tofu. Think beans, lentils, peas, and edamame! Nuts and nut butters, seeds and seed butter! Whole grains contain a fair amount of protein as well.
Having trouble envisioning meals without meat? You can enjoy the same classic meals, just substitute in plant protein. For example:
If you love tacos, replace the meat filling with spiced lentils. (Try my Easy Spiced Lentil Taco Filling recipe below.)
If you love shepherd's pie, use finely diced mushrooms instead of ground meat.
If you love fajitas, switch out the steak or chicken for portabella mushrooms.
Classics like minestrone soup, chili, spaghetti, and lasagna are easily converted into healthier, animal-free meals. Use whole grain pasta where pasta is called for, and add extra veggies. Even if you prepare any of these dishes using animal protein, add extra veggies and you will be benefiting.
Going to a plant-based diet doesn't have to mean eating plants exclusively. Just aiming to eat more healthful plant foods, focusing on overall nutrition, decreases health risks significantly. Even a little improvement can have big results.
A Plant-Based Diet, Atherogenesis, and Coronary Artery Disease Prevention. The Permanente Journal, Winter 2015.
Healthy Dietary Patterns for Preventing Cardiometabolic Disease: The Role of Plant-Based Foods and Animal Products. Current Developments in Nutrition, December 2017.
Association Between Dietary Factors and Mortality From Heart Disease, Stroke, and Type 2 Diabetes in the United States. JAMA, March 7, 2017.
Animal and plant protein intake and all-cause and cause-specific mortality: results from two prospective US cohort studies. JAMA Internal Medicine, October 2016.
Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosis. Nature Medicine, April 7, 2013.
Intestinal Microbial Metabolism of Phosphatidylcholine and Cardiovascular Risk. New England Journal of Medicine, April 25, 2013.
Easy Spiced Lentil Tacos
This dish cooks up fast, faster than meat. Red lentils are cheap; I always keep several bags in our pantry for soups and taco filling. This hearty, satisfying, high-protein meal can be made from scratch in under 30 minutes.
1 tablespoon olive oil
1 small yellow onion, grated or finely diced
3 cloves garlic, finely diced or pressed (or, 1 teaspoon of garlic paste from a tube)
2 cups of red lentils, dry
5 cups of water
4 tablespoons of taco/fajita seasoning (buy it ready-made, or make your own — see recipe below)
8 corn tortillas
1 jar low-sodium salsa (less than 90 mg sodium per 2 tablespoon serving; examples include Newman's Own, Green Mountain Gringo)
Chopped lettuce, lime slices, chopped green onions, plain Greek yogurt and/or red pepper flakes for serving, if desired
Homemade Taco/Fajita Seasoning:
3 tablespoons chili powder
3 tablespoons ground cumin
1 teaspoon garlic powder
1/2 teaspoon black pepper
1/2 teaspoon salt
1/4 teaspoon cayenne (or to taste)
Easy Spiced Lentil Taco Filling
Pour the lentils into a colander and rinse under cool water, swishing around. This removes any debris that may be mixed in. Classically, red lentils are known to have debris mixed in, and so people often call for washing them prior to cooking. You can choose whether or not to rinse the lentils in a colander first. I'll admit I often skip this step, and haven't come across any rocks yet.
Heat a large sauté pan or medium saucepan (that has a cover) over medium-high heat. Add the oil and swish around for a couple of seconds. Add the onion and sauté until soft. Add the garlic and sauté until fragrant.
Add the lentils and water, and bring the water to just boiling, then turn down to a simmer. Simmer for five minutes, then add the fajita seasoning and stir. Cover the pan and turn off the heat. The lentils will absorb the rest of the water while you prep the rest of your meal.
Put the meal together
Wrap the tortillas in a clean towel or paper towel and microwave for thirty seconds to heat.
Chop some lettuce (romaine is a good choice here), slice a lime, and set out plain Greek yogurt and the salsa. Let people put together their own tacos. Enjoy!
About the Author
Monique Tello, MD, MPH, Contributor
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