Dear Health-Conscious Reader,
People still mistakenly believe that eating a lot of protein from meat hurts your bones.
The reason is that some studies found that people would lose lots of calcium through their urine after eating protein.
Scientists have speculated for decades on the reason for all that calcium leaving people’s bodies. Way back in 1968, a piece published in The Lancet theorized that you use calcium from bones to counter the acidity produced when you break down the meat you eat when you digest it.
And the theory stuck.
But just speculating it was “because of meat” doesn’t make it true.
In fact, a newer analysis by the Journal of Nutrition says plainly:
“No convincing data have been published showing that a high protein diet, using complex proteins for prolonged periods of time under strictly controlled dietary conditions, causes calcium loss.
“Dietary proteins other than red meat, such as milk and cheese… do not cause calcium
loss in controlled studies in humans. The generalization that ‘protein’ causes calcium loss or may be a risk factor for osteoporosis, without specifying the type and source of protein, is therefore incorrect.”1
And listen to this… I love this study. I read it in the American Journal of Clinical Nutrition.
These guys gave people a pound of red meat every day for 4 months. I’d love to have been in this study. Point is, urinary calcium did not change.2
Yet many “experts” still warn that a high-protein way of eating will cause osteoporosis. And vegetarians have grabbed on to this as a reason not to eat meat.
But not only is the meat-calcium theory a myth, it turns out the opposite is true about bone strength and vegetarianism.
It’s plant protein, not animal protein, that leeches calcium from your bones and causes lower bone mineral density.
A study focused on 572 women and 388 men from 55–92 years old living in Rancho Bernardo, California. This bar chart describes the results of their bone mineral density (BMD) measurements:
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Sorry to vegetarians who think they are eating healthy but facts are facts. Note that for every 15 gram per day increase in animal protein intake, overall bone mineral density increased, especially in the hip, neck and spine.
Yet the opposite happened with vegetable proteins. The more vegetable protein, the lower the bone mineral density.3 The study also showed that high calcium intake did not seem to protect those who ate a lot of plant protein. The women who took in the most calcium lost bone mineral density.
The simple fact is that your body can’t build bones from plants because they contain incomplete proteins.
So if you want stronger bones, your real sources of protein are the same as they have been through the entire course of human existence: animals and animal products. That means meat, eggs and fish.
Vegetarians will try to tell you that there’s plenty of protein from plant sources like brewer’s yeast or soy. No, there isn’t. Plus, soy is not a natural protein, and neither is gluten from wheat. You have to process soy and wheat to get these proteins out of them. You would otherwise never encounter them in a natural setting.
Don’t get me wrong, you can get amino acids from fruits and vegetables. The avocado, for example, has a high amino acid rating of 129. A rating over 100 means the food is a fairly good source of essential amino acids in the right proportions.
But what about some of the plants vegetarians like to tout for their protein content? Soy and flax only score a 96. Adzuki beans? Only 74. Oat bran has an amino acid rating of only 86.
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And what about those “whole grains” every dietician, nutritionist and even the USDA are telling you to eat more of? Whole grain wheat flour only has an amino acid rating of 54.
Now check out the chart to the right – it gives you amino acid scores from various animal sources.
Their protein quality is off the charts.
To build stronger bones from complete proteins, I recommend you stick with with the true proteins your body evolved with: animal products.
To Your Good Health,
Al Sears, MD
1 Spencer, Herta, Kramer, Lois, Osis, Dace, “Do Protein and Phosphorus Cause Calcium Loss?” J. Nutr. 1988;118: 657-660
2 Spencer. H., Kramer L., Osis, D. & Morris C. “Effect of a high protein (meat) intake on calcium metabolism in man,” Am. J. Clin. Nut 1978;31: 2167-2180
3 Promislow, J.H.E., Goodman-Gruen, D., Slymen, D.J., & Barrett-Connor, E. “Protein consumption and bone mineral density in the elderly.” American Journal of Epidemiology, 2002;155(7), 636–64