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The China Study Findings on Protein

Even though many of us worry about getting enough protein, evidence suggests that the real danger is consuming too much protein, especially if it is protein from the wrong foods.

Let’s say you?re strolling along outside in a park and you see two men eating lunch. One is eating a cheeseburger on a bun made of refined flour topped with lettuce, pickles, and tomatoes, and the other is eating a hearty vegetable stew with whole grain bread. If you found out that those two men always eat the same lunch day after day, which would you think is in greater danger of having nutrient deficiencies? Many people would undoubtedly say that the main concern is for the man eating the vegetables without any meat, he might not be getting enough protein.

Protein is the most sacred nutrient, the king of our nutritional worries. It has been this way ever since nutrition as a biochemical science emerged over 150 years ago. But when we look at the recommendations and research findings related to protein intake, we find that our concerns and beliefs may not be justified.

The government’s long-standing required level of protein intake is about 0.8 grams of protein per kilogram of body weight. This is about the equivalent of 56 grams of protein for a 155 pound man and 48 grams of protein for a 132 pound woman. This level was set because it provides more than enough protein for growth and maintenance for almost the entire population, based on laboratory-based studies.

In practice, however, Americans consume far more protein than required. On average, we consume about 90-95 grams of protein a day, with many people (people on high-protein diets or supplements) going far higher. In addition, Americans derive the vast majority of their protein from animal foods ? meat, fish, and dairy foods. This is a double whammy ? not only is it too much protein, it also turns out to be the unhealthiest kind.

Many findings already published in the scientific literature suggest that the health results of this dietary pattern are disastrous:

  • Populations that consume more animal protein have higher blood cholesterol levels, which in turn are linked to greater rates of heart disease and cancer.
  • Experimental animal research has consistently shown that proteins from animal sources consistently promote higher cholesterol levels than proteins from plant sources.
  • A high animal protein diet allows more dangerous chemical carcinogens into our cells and then facilitates the process by which these carcinogens are transformed by enzymes and then bound to our DNA, creating cancer. In these experiments, plant protein has been shown to inhibit these processes.
  • Animal protein has been found to promote high levels of Insulin-like Growth Factor I, or IGF-1, which, in turn, has been found to be a predictor of certain cancers.
  • Women consuming diets high in animal-based protein produce greater amounts of reproductive hormones, which are linked to higher rates of breast cancer.
  • Diets high in animal-protein have been shown to exacerbate the formation of kidney stones and draw calcium out of the bones, encouraging osteoporosis.

Conversely, diets that derive most of their protein from a rich variety of unrefined vegetables, legumes and whole grains, have the ability to prevent and sometimes even treat the conditions mentioned above, including heart disease, certain cancers, kidney stones, and osteoporosis.

This tiny sample of findings, which represents a large body of scientific literature, points to one conclusion: Americans consume too much protein and too much of it comes from animal sources. The dual beliefs that we need as much protein as we can get and that meat is the only good source of this vital nutrient are the most dangerous myths in nutrition and health.

Furthermore, because protein so often trumps all the other nutrients in our collective conscience, we forget all the other nutrients and micronutrients that have been shown to promote health. To return to the two men in the park, the man eating a hamburger on a bun made of white flour should probably be the one worrying about nutrient deficiencies. He?s likely not getting enough vitamins, minerals, fiber or antioxidants. And as long as the man eating the vegetable stew eats plenty of unrefined legumes, and vegetables, he can forget protein and feel confident that he is getting all the other good nutrients to boot. It is just the opposite of what so many people tend to believe.