Did you know that the consumption of meat has been linked to osteoporosis? It seems animal proteins are digested in our bodies in a way that is not copacetic for bone health. But, what is the scientific evidence out there: Does eating meat directly cause osteoporosis? And what can meat-eaters do to reduce these risks? One in two women and one in eight men will have an osteoporosis-related injury in their lifetime—will it be you? Read on to find out.

Proteins, Acids and Calcium

Animal proteins—beef, lamb, pork, chicken—contain sulfur that creates acid in our bodies when we digest them. A slightly acidic condition called acidosis occurs, which changes the pH of our bloodstream. One of the body’s common ways to reduce this acidity is by using calcium phosphate (which comes from our bones) to buffer the pH back to a normal range. This process of calcium coming from the bones to balance acidity caused from animal proteins is thought to cause—or contribute to—osteoporosis.

Research Supporting the Meat-Osteoporosis Connection

The National Institutes of Health (NIH) recently set out to test the effects of meat consumption on bone health. Measures they studied included acid excretion and urinary calcium—two factors that show the acidity caused by animal protein and the leaching of calcium from the body to buffer it on the way out. Researchers found, as expected, that those eating meat had more calcium leaving their bodies than the vegans in the study. The NIH concluded that this model of meat consumption could lead to a lower amount of bone formation in the meat-eaters, as well as a long-term decrease in bone density.

The Harvard School of Public Health cites a popular Nurses’ Health Study as a reference for the meat-osteoporosis connection. In this study, a large pool of participants following a high-protein (animal-based) diet was found to have weaker bones over the long-term. The school is quick to point out, however, that the studies are merely suggestive at this point, and further research needs to be done to see exactly how meat affects bone health.

Additional studies have also shown a correlation between meat consumption and compromised bone health, ranging from increased risk of hip fractures, arm fractures and increased loss of bone density. The correlation, interesting to note, is not just high protein and calcium leaching, but that of animal protein in particular. In certain studies, the bones appear to benefit by replacing some of the animal proteins with plant proteins.

What You Can Do to Protect Your Bones

As researchers have pointed out in the Journal of Nutrition, the consumption of vegetables and plant proteins safeguards against the effects of urinary calcium because of the incredible doses of nutrients they provide—antioxidants, vitamins and isoflavones, to name just a few. It appears to the researchers that the problem with animal proteins is that they tend to lack such a powerful constitution of such vital nutrients. The solution? Eat more plants.

Experts at Harvard recommend simply eating more fresh fruits and vegetables each day in order to pack in the nutrients that protect against bone loss (magnesium and potassium especially appear to be protective). And, of course, they recommend we eat fewer processed foods, if for no other reason, to get away from all of the extra sodium in them. Excess sodium intake has been linked to an increase in urinary calcium loss, so steer for fresh ingredients with few additives when dining out and shopping.

Start eating your way to bone health with these 7 non-dairy sources of calcium.

Image: stu_spivack

Sources:

http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/protein-full-story/index.html

http://jn.nutrition.org/content/133/3/862S.long

http://www.nutritionmd.org/health_care_providers/bone_joint_diseases/osteoporosis_nutrition.html

http://www.ncbi.nlm.nih.gov/pubmed/17686206