Proteins are essential building blocks for muscles, internal organs, blood cells, hormones, enzymes and disease-fighting antibodies. Weight-loss diets packed with protein are touted just about everywhere, and they really can help you shed pounds. But a new report that you shouldn't ignore uncovers long-term risks of eating a diet loaded with animal protein: Eating even what's a moderate amount (for many of you) of beef, pork and lunch meats quadruples your odds for fatal cancer.
University of Southern California researchers recently announced that the folks who were at highest risk for deadly cancers were eating 100 grams (3.5 ounces) or more of meat protein daily on a 2,000-calorie-per-day diet. And a heavy meat habit in middle age boosts cancer risk just as much as smoking. In fact, it increases the odds for an earlier death by 74 percent.
These findings join a wave of new science suggesting that the type of protein and amount of protein that you choose to eat can be a health bomb or a healthy boost.
So here are the best ways to put tasty, satisfying protein on your plate, worry-free.
Right-size it. Stick with the Institute of Medicine's guidelines: 46 grams of protein a day for women, 56 for men. It will help control appetite. (Some government surveys estimate that the average American adult eats 69-113 grams of protein a day, and you can bet it mostly comes from meat!) On a daily basis, you want to aim for the amount of protein found in a 4-ounce salmon fillet; an ounce of nuts, especially walnuts, the only nuts with omega-3's; 8 ounces of skim milk; two tablespoons of pure peanut butter; and a little bit in whole grains and veggies, plus a cup of oatmeal for the guys. You may need more if you're extremely active, over age 65, or if you're pregnant or breastfeeding.
Cut way back on red and processed meats. Saturated-fat-packed red meats put you at risk for heart-stopping atherosclerosis, but that's not the only way they threaten your cardiovascular system and other vital bodily functions. They also contain carnitine, lecithin and choline: amino acids that are transformed into TMAO (or trimethylamine n-oxide) by intestinal bacteria when you eat egg yolks, processed meats, beef and pork. TMAOs increase your risk for heart attack, stroke, memory loss and cancer, not to mention more wrinkles, poorer orgasm quality and impotence. And stay away from the nitrite preservatives found in bacon, lunch meat, ham and sausage: They raise your blood pressure and make arteries less flexible. Great on your plate (less than 4 ounces, once a week): Grass-fed beef has higher levels of good-for-you omega-3 fatty acids. Enjoy it by adding a little to stir-fries, skewering it with veggies or adding to chili and casseroles.
Choose other animal proteins wisely. There are animal proteins that deliver healthy nutrients: Fish like salmon and ocean trout provide heart-smart, brain-friendly DHA omega-3 fatty acids. Skinless chicken and turkey breast deliver plenty of protein with little saturated fat. Stick with smart portions (about the size of a deck of cards).
Go meatless more often. Beans, soy products like tofu and tempeh, well-flavored with healthy spices and herbs, and nuts are satisfying alternatives to meat. Three ounces of animal protein provides 15-27 grams of protein. Equivalent plant sources: 1 cup cooked lentils equals 18 g; 1/2 cup tofu equals 20 g; 1 cup cooked black beans equals 15 g; 1 cup cooked bulgur wheat equals 5 g; 1 cup cooked quinoa equals 11 g; 2 tablespoons peanut butter equals 8 g; 1 cup cooked spinach or broccoli equals about 5 g.
Have some protein at every meal. Don't wait for dinner. Spreading your protein out over the day helps muscles make the most of it, especially as you age. Add nuts to your salad or cereal. Use eggs whites for that morning omelet. Spread peanut, almond or walnut butter on sandwiches. Dig into a bowl of fresh fruit and nonfat, no-sugar-added Greek yogurt for dessert.
Mehmet Oz, M.D. is host of "The Dr. Oz Show," and Mike Roizen, M.D. is Chief Wellness Officer and Chair of Wellness Institute at Cleveland Clinic.