Misconceptions of Protein

When it comes to how protein is marketed, Jodi Leslie, registered dietitian and instructor at UH Hilo, says that “I think a lot of it is myth and money-driven.” In fact, the Center for Disease Control (CDC) says that protein deficiency is quite rare in healthy adults. If anything, Dr. Michael Greger, founder of NutritionFacts.org claims, “People are more likely to suffer from protein excess than protein deficiency… there is no reasonable scientific basis to recommend protein consumption above the current recommended daily allowance due to its potential disease risks.”

Leslie explained that “I’m a big advocate of getting your protein primarily from plants. A lot of studies have shown health risks associated with animal proteins like meat products and dairy. If looking at it from a health perspective, many studies show about its link to cancer, diabetes, heart disease, alzheimer's disease… For me I see it from a logical perspective.”

Greger, who authored the New York Times best-selling book How Not to Die, concurs with Leslie’s opinion. “A significant convergence of evidence suggests that plant-based diets can help prevent and even reverse some of the top killer diseases in the Western world and can be more effective than medication and surgery.”

On his website, Greger lists just a few of the additional ailments that a plant-based diet can prevent from high cholesterol, high blood pressure, Parkinson’s disease, kidney stones, gallstones, cataracts, and Crohn’s disease, to the less obvious abdominal fat, acne, allergies, body odor, eczema and cellulite. Greger concludes, “In one study, within a matter of weeks, participants placed on the plant-based diet experienced improvements in blood pressure, cholesterol and insulin levels.”

In one video, ‘The Protein Combining Myth,’ Greger addresses the common myth that plant-based protein is not a ‘complete’ protein, and that it needs to be combined with some other type of animal protein to become a ‘complete’ protein.

“Protein contains essential amino acids, meaning our bodies can’t make them and so they are essential to get from our diet. All essential amino acids originate from plants... Those who don’t know where to get protein on a plant-based diet don’t know beans! Get it?” He adds that even the calcium from cow’s milk is sourced from the plants she eats which originally came from the soil.

Dr. Greger continues by both referencing and dismissing a study done over a century ago that began the concept that plant protein was inferior to animal protein. “Scientists found that infant rats don’t grow as well on plants and don’t grow as well on human breast milk... Ridiculous, they’re rats! Rat milk has ten times more protein than human milk because rats grow about ten times faster than human infants.”

To speak of protein intake from an evolutionary perspective, as some Paleolithic diet advocates may address, Dr. Greger asks the question, “What is the perfect food for human beings? The food that was fine-tuned just for us over millions of years to have the perfect amount of protein? Human breast milk.”

He claims that many people argue that protein is the ‘nutrient among nutrients’ that was paramount in our brain development throughout human evolution, so he expects that if it were that necessary for development, it should reflect in the amount of protein found in human breast milk, considering our most rapid growth period is during infancy.

He finds that “Human breast milk is one of the lowest-protein milks in the mammalian world. In fact, it may have the lowest protein concentration of any animal in the world, less than 1% protein by weight. This is one of the reasons why feeding straight cow’s milk to babies can be so dangerous. The protein content in human milk is described as extremely low, but it’s not low at all, it’s right where it needs to be. That’s the natural, normal level for the human species.” More information on this topic can be found in his video, ‘The Great Protein Fiasco.’

“I think that the U.S. is one of several developed countries that have just made it seem like protein is so pivotal to our health when in other countries their base diet is plant protein, beans and grains. I think it’s just evolved to be a cultural thing,” Leslie commented on the few students who continually disagree with her, “[They] still try to justify it in their head because I think it’s just so ingrained within them. They just can’t believe it and maybe a lot of it’s just their own personal preference...But there are also a number of students who didn’t know [about impacts of animal protein] and find it interesting.”

Dr. Leslie explains ideal sources of plant proteins, “Any type of whole grain, beans (including tofu and edamame and soy milk), and nuts (including peanut butter). In terms of vegetables - primarily from the dark green leafy vegetables, so broccoli, spinach, kale, all of those have protein and a lot of people don’t realize that.”

Greger echoes Leslie, in saying that “All nutrients come from the sun or the soil. Vitamin D is created when skin is exposed to sunlight. Everything else comes from the ground, minerals originate from the earth and vitamins from the plants.”

The U.S. Department of Agriculture’s recommended daily allowance of protein is 46 grams for women and 56 grams for men. The American Dietetics Association (ADA) recommends 0.8-1.0 grams of protein per kilogram of body weight.

These suggestions vary, as Leslie explains, “The recommendations set are not the minimal amount needed to survive, it is an adequate amount plus a little extra built-in to make sure that we are getting enough to cover our needs.”

A sedentary person would be recommended 0.8g whereas a more regularly active person may add roughly 0.5g to their protein intake. There are just three simple steps, as described on Livestrong’s website, to calculate personal protein intake:

First, get an accurate body weight, preferably in the morning on an empty stomach.

Next, convert your weight from pounds to kilograms. 1kg is 2.2lbs, so if you weigh 160lbs, divide it by 2.2 to get 72 kg.

Then, be honest with your activity level, and determine how many grams of protein your body needs. For example, a sedentary adult would multiply 0.8 grams by their weight in kg, 72 kilograms in this example, and would end up with 57.6 grams of protein daily.

As Men’s Fitness writer Michael Behar complains, “At 160 pounds, the RDA [Recommended Daily Amount] puts me at 58 grams per day, which is a scant more than a cup of Greek yogurt at breakfast and a small chicken breast for lunch, with zero protein for dinner.” His statement is true if he is eating no beans, grains, or vegetables, which if he were, Behar would already be eating more than enough protein for the day, so what is he eating for dinner with no protein? “Up to a certain point in life it hopefully switches from doing what you like versus what’s better for you,” Leslie said.