High-Protein Diets May Weaken Your Bones

Strong Bones Older Woman

We’re always looking for the best and healthiest way to shed unwanted pounds. With all the information out there about it can be very confusing which plan is best. Recent research from Purdue University suggests that a high-protein diet like the popular Atkins Diet might not be the way to go, especially for older women.

Higher loss of bone density might be anticipated with a high-protein diet because of an increase in the body’s acidity. Animal proteins, in particular, have proteins that when broken down by the body produce some acidity while plants produce a more balanced acid-base response. The theory is that when we consume a high-protein diet, particularly animal-protein, the body tries to reduce the acidity by releasing minerals from bone to neutralize it. These minerals help maintain an acid-base balance. However, losing minerals from our bones makes them less dense, and therefore, weaker.

The Purdue research includes two studies that looked at the effect a high-protein, calorie-restricted diet would have on bone mineral density (BMD) compared to a normal-protein, calorie-restricted diet in overweight and obese postmenopausal women.

Participants in the first study cut out 750 calories per day; half of the women had the amount of protein normally recommended for a 150-lb. woman (54.5 grams) and half had a high-protein diet (95.5 grams). In food terms, that’s a difference of about 6 oz. more of meat per day. Fat intake was the same in both groups. Additionally, the high-protein women ate much of their protein as pork, while the normal protein group was “lacto-ovo” vegetarian, meaning they ate eggs and dairy, but no poultry, pork, beef or fish.

In the second study, the women were randomly divided into four groups. One control group made no changes to their lifestyle. The other women all ate 1,250 calories/day where 1,000 of these calories were the same – a fixed lacto-ovo vegetarian menu. They were then split into one of three groups for the remaining 250 calories. These calories came from sweets, chicken, or beef. Thus, the chicken and beef groups had about 10 percent more of their calories coming from protein than the sweets group.

The end result from both studies was the same. Everyone with a caloric restriction lost weight, but the women who had a higher protein intake lost more of their bone mineral density than those on the normal protein, lacto-ovo vegetarian diet.

Bear in mind, this study looked at only one group (overweight and obese postmenopausal women) and the studies were small (28 and 54 women in the first and second study, respectively). While it does shed some light on the subject, more evidence is needed before firm conclusions can be drawn.

If you love the high-protein diet, a healthier option might be the Eco-Atkins Diet, which focuses more on vegetarian-protein (nuts, soy, beans) and less on animal-protein. Also, keep in mind other dietary factors that relate to bone health. We’ve previously covered the association between bone health and drinking soda, eating soy products as well as general tips to build healthy bones.  As far as the link between protein and bone density is concerned – stay tuned.

Tags from the story
, , ,

1 Comment

Leave a Reply

Your email address will not be published. Required fields are marked *