Do We Overemphasize Protein?
by Michael Singer, food scientist
If you’ve ever made the switch from a traditional to a plant-based diet, you’re probably familiar with the phenomenon of your relatives and friends suddenly becoming dietitians when you tell them about the change to your personal menu.
“But where do you get your protein?” they all ask—a surprisingly common query in a country that by all indications consumes too much protein already. In fact, several studies show that excessive protein intake is implicated in conditions ranging from kidney disease to certain malignant cancers. Certainly, experience has taught us to be cautious in a world already inundated by processed foods that bear little resemblance to our ancestral diet.
Here’s the scoop on protein, without the powder. Proteins, simply, are chains of amino acids bound together into different shapes and functions depending on their composition and order. Ten to fifteen percent of human caloric needs are generally provided by amino acids. Hundreds of different amino acids exist in nature, but humans utilize 20 of them as the building blocks for everything from our skin to the enzymes that break down our food. Of these, our bodies can only synthesize 11, meaning the other 9 types have to come from our diet. Nervousness, exhaustion and dizziness have been reported in people receiving inadequate levels of these “essential” amino acids.
Too Much Protein
Western dietary and culinary modes have an unhealthy fixation on protein. In fact, some studies suggest that the large amounts of animal protein Americans typically ingest are tied to the higher incidence of inflammatory conditions and some diseases. A 1997 report by the World Cancer Research Fund and American Institute for Cancer Research noted that animal-sourced, high-protein diets were linked with increased incidence of some types of cancer. Current research and epidemiology support these assertions.
When people eat too much protein, they take in more nitrogen than they need. This places a strain on the kidneys, which must filter out the extra nitrogen from our blood, excess amounts of which can lead to kidney disease. Diets rich in animal protein cause more calcium loss than normal and increase the risk of osteoporosis, while osteoporosis and hip fracture rates are significantly lower in countries with lower-protein diets.
Keep It Green, Keep It Lean
There are studies on both sides of the protein issue, but the current RDI [Reference Daily Intake] for the amount of protein required by the “average” adult is about 50 grams, but can change based on metabolism, exercise, or if you are pregnant or nursing. More specifically, the standard RDA [Recommended Daily Allowance] is around .8 g/kilogram or .36 grams per pound of body weight. If you are an endurance athlete or are trying to build muscle via anaerobic exercise, your requirements will be slightly higher; but even if you’re going trail running with Artemis or lifting with Atlas, seeds, legumes and green vegetables are some of nature’s best in terms of protein density per calorie. The humble broccoli contains upward of 11 grams of protein per 100 calories compared to ~6-8 grams of protein per 100 calories of steak (1.2 ounces). Eating fewer calories and getting twice the protein plus plenty of fiber, vitamins, minerals and other phytonutrients translates to eating smarter. Now that’s what we call thinking green.