How Much Protein Is Too Much Protein? Myths & Facts

vegetables-versus-meat-on-forks

In our Western society we tend to break things down from a whole and look at individual parts. This is particularly true with food. How much protein do we need? Is it low-fat? Low carb? Am I getting enough calcium? We do this so that we can measure levels and compare them to standards, which can give us a clue as to where our amounts stand compared to everyone else. But this can also be misleading if we lose sight of the big picture of health.

Think of protein for instance. Protein is not a food, it’s a food part; a nutrient in food. What food comes to mind when you think of protein-Meat? Fish? Well, consider that there is protein in virtually all whole foods, in adequate amounts to sustain health and thrive. Further, we actually don’t need much of it; only 10% of our calories from the food that we take in. This actually, is roughly the amount we find in the assortment of whole plant foods. Just about all of us take in much more than that.

Too Much Protein

The average American takes in roughly 15% of their calories from protein, and we get the majority of protein from animal foods and then isolated protein from processed foods and supplements. Now understand that we just don’t see protein deficiency diseases in populations where malnutrition is not a problem, except for cases of immunodeficiency like HIV.

It’s virtually impossible to be deficient in protein if one is eating enough, unless perhaps eating only Twinkies and lettuce, (and even lettuce has some protein!).  Our concern should not be getting enough, but getting too much.

There is a limit to the amount of ingested protein we can break down and utilize at any one time-that limit is roughly 20 grams.  Any more than that places an extra burden on the body to break it down, stressing out our liver, kidneys and bones. It floods the body with acidic metabolites (uric acid) which can build up to harmful levels. Consuming protein supplements in the form of powders on top of eating may disrupt this delicate pH balance, giving the blood a burdensome acid load to break down. This is particularly true for whey, or other animal-based proteins which are acid-forming, potentially leading to inflammation, slowing down recovery from exercise, and producing more soreness than plant-based proteins 1,2 If the blood is too acidic it will use a buffer to combat it, which is calcium. This calcium just may be coming from bones, putting us at greater risk for fracture. Though we’re not entirely sure where this calcium is coming from to buffer the acid, we do know that high protein diets typical in the U.S. are associated with higher bone fracture.3

Protein intake (even plant protein) above the body’s requirements can be challenging to the body, particularly to the liver and kidneys. Dr. T. Colin Campbell, PhD, notes that while it is possible that performance of certain elite athletes (like professional football players) may benefit from higher protein supplemental to a healthy, low-protein diet, they are unlikely to benefit in terms of health. Increased protein intake stimulates muscle growth as well as that of all other tissues, by stimulating growth hormones including insulin-like growth factor-1 (IGF-1), known to promote cancer growth, particularly colorectal, breast, and prostate cancers. We see this in studies on dairy proteins-whey and casein. Bigger muscles in the short term through excess protein are not worth the long-term health risks.4-7

Any form of excess protein can be harmful in the long-term, but the only way plant protein can be consumed in dangerous amounts is when using isolated proteins in concentrated form, like protein powders or isolated soy protein, (or living on nothing but tofu). There is research showing that isolated soy protein, for instance, increases blood levels of IGF-1 as well. This doesn’t happen with protein coming from whole soybeans, (or any other bean), or grain, or other whole plant foods; just with this particular isolated food part – concentrated protein.8-10

We do know that we need more protein at certain stages of life or at times of high nutrient need; athletes for instance, who need more protein to repair muscle tissue and build enzymes, or babies and children supporting growth and metabolism, as well as those in a state of starvation. But at those times we also tend to need more fuel in the form of carbohydrate; and we need more calories. We may also need more fat to support brain health and energy stores. In other words, when more protein is needed, more food is needed. We need to eat more healthy whole food!

What to Eat

Food, whole plant food, has a combination of all these macronutrients. In fact, whole plant food, which include beans, whole grains, vegetables and fruits, have the right amounts of these nutrients, along with all the phytonutrients needed to support optimal health, without getting too much ________ ( fill in the blank with your nutrient of concern here). There is one exception to this rule, which is vitamin B12, not present in our soil as much nowadays, so consider a B-12 supplement. My advice to most people is to get the majority of your calories from whole plant foods, and limit or eliminate the rest. The rest includes animal and processed foods – meat, dairy, eggs, oils, and refined foods-those with added sugars, fat, salt and additives, (like pastries, chips, and prepared foods).

Protein is essential to life, but that does not mean the more the better. We just need to get enough, which isn’t hard to achieve!

In Good Health,

Kathy

Bio: Kathy Pollard MS is an instructor for the T. Colin Campbell Center for Nutrition Studies, offering a plant-based nutrition certification course through eCornell. She is also co-founder of Sustainable Diet , an online lifestyle transition program serving as a resource for doctors as well as individuals interested in successfully transitioning to a whole food, plant-based diet – to combat disease, support a sustainable environment, and live in accordance with personal values.

Sources:

  1. Burke, L. Deakin, V. Clinical Sports Nutrition, 4thMcGraw Hill Medical Australia. 2010.
  2. Bidwell, A. NTR5501 Exercise Physiology and Sports Nutrition. MSACN, New York Chiropractic College. January, 2012.
  3. Stubbs AK.  Nutrient-hormone interaction in the ovine liver: methionine supply selectively modulates growth hormone-induced IGF-I gene expression. J Endocrinol. 2002 Aug; 174(2): 335-41.
  4. Barzel US, Massey LK. Excess Dietary Protein Can Adversely Affect Bone. J. Nutr. June 1 1998 vol. 128 no. 6 1051-1053
  5. Yu H. Role of the insulin-like growth factor family in cancer development and progression.  J Natl Cancer Inst. 2000 Sep 20;92(18):1472-89.
  6. Levine ME.  Suarez JA, et al.  Low Protein Intake Is Associated with a Major Reduction in IGF-1, Cancer, and Overall Mortality in the 65 and Younger but Not Older Population.  Cell Metabolism. Volume 19, Issue 3, 407-417, 4 March 2014.
  7. Colin Campbell , PhD; Thomas M. Campbell II, MD. The China Study: Revised and Expanded Edition. BenBella Books.Dallas, TX. December 27, 2016.
  8. Khahil DA et al. Soy Protein Supplementation Increases Serum Insulin-Like Growth Factor-1 in Young and Old Men but Does Not Affect Markers of Bone Metabolism. J. Nutr. 132:2605-2608, September 2002.
  1. Juha J Hulmi, Christopher M Lockwood and Jeffrey R Stout.  Effect of protein/essential amino acids and resistance training on skeletal muscle hypertrophy: A case for whey protein.  Nutrition & Metabolism 2010, 7:51.
  2. Whey Proteins in the Regulation of Food Intake and Satiety.  Journal of the American College of Nutrition.  Vol. 26, No. 6, 704SA-712S. 2007.
  1. Gropper SS, Smith JL & Groff JLAdvanced Nutrition and Human Metabolism, 5th edition. Belmont, CA. P 364-368. . 2009.
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