Video interview: Protein & Your Bones. An expert weighs in

It’s easy to feel confused with all the conflicting news of how the protein in our diet affects bone health. Should we be more concerned about getting enough protein? Or is the greater risk from too much protein increasing calcium loss in the urine and bone loss?

While I was speaking in New York City recently, I was delighted to get some time with my long-time friend from graduate school at Cornell University, Jeri Nieves, PhD.  Dr Nieves is Associate Professor of Nutrition and Epidemiology at Columbia University and Helen Hayes Hospital, where she is known for research on bone health and osteoporosis.

Here is video from the third and final section of my interview with Dr. Nieves about nutrition for healthy bones.

Take-home points from Dr. Nieves

Are you getting enough protein for healthy bones? Protein is important for building and maintaining bones.  Most U.S. adults get plenty, however.  Current federal protein recommendations for children up to age 3 call for slightly more protein when expressed “per pound of body weight”, but because such young children are small, even “high” protein does not mean they need large portions of protein-containing foods.

Older adults may need somewhat more protein as they age to combat not only tendencies to lose muscle and bone strength.  Frail older adults sometimes tend to eat diets low in protein because of issues related to chewing, financial, food preparation and more.  One caution: older adults may be more likely to have reduced kidney function, and overdoing on protein a real burden on kidneys.

Do you need to cut back on protein?  You may have heard concerns that too much protein changes the pH (acid-base) balance in our bodies, which leads to calcium leaching from bones to neutralize the pH and thus weaker bones. Many Americans do consume protein far above the Recommended Dietary Allowance (RDA), and the consequences of this are still under study.  Dr. Nieves reports that as long as you are getting adequate calcium and not greatly exceeding protein recommendations, this is probably not a significant bone health issue.

Additional tips

You might see the current RDA for protein for adults listed as 46 grams/day for women and 56 grams/day for men.  That’s a rough average based on a formula of 0.8 grams/kg of body weight, which means that about one-third of your weight expressed in pounds is a reasonable personal target for adults for grams of protein per day.

For example, some daily targets for adults could be:

120 pounds = 44 grams protein           150 pounds = 54 grams protein

175 pounds = 64 grams protein           200 pounds = 73 grams protein

*Note that this is a basic recommendation for average adults to maintain good health.  Heed your doctor’s recommendations for higher or lower amounts of protein because of various health conditions.

Look at the big picture

For most adults, as long as kidney function is good, protein consumption with grams of protein equal to anywhere from one-third of your weight in pounds to almost equal to your weight in pounds can support healthy bones and muscle and overall health. (This is 0.8 to 2 grams of protein per kg weight.)

Two considerations:

*Getting enough of the nutrients, phytochemicals and dietary fiber in plant foods such as vegetables, beans, whole grains and nuts is strongly linked to many aspects of good health.

*Excessive amounts of meat and dairy products may pose some health risks.

So for overall health, especially at higher levels of protein, get a significant amounts of your protein from plant sources.  In other words, don’t assume that higher protein diets necessarily mean loading up on massive amounts of meat.

What about older adults?

Older adults are most likely to face conditions that bring these issues to the forefront: more likely to have osteoporosis, to lose muscle, and to have falls that can lead to hip fracture and its serious complications. Research suggests that older adults – which in some studies includes those over age 55, but mostly involves those over age 65 or 70 – may need somewhat more protein than younger adults to avoid the loss of lean body tissue like muscle and bone that can otherwise occur as we age.  This does not require huge amounts of meat or protein supplements, however.  Quite a few studies in recent years suggest that older adults lose less muscle, and gain muscle better if they do strength-training exercise, if they consume protein equal to their weight in pounds divided by two.  (So a person who weighs 160 pounds might target 80 grams of protein per day.)   Studies do not show any further benefit in maintaining or gaining muscle with protein consumption beyond that target.

Most adults, even those over age 70, already meet that slightly higher target.  However, about 25 percent of those over 70 may be getting less than the long-time protein recommendation, and another 25% may be getting less than this proposed higher target for seniors.

Making it doable

You can reach even this higher target with five to six ounces a day of lean poultry, fish or meat plus three servings of dairy products or dairy alternatives as part of a balanced diet that also provides protein from whole grains, vegetables, beans, nuts and seeds, and some eggs. Those who prefer to omit or minimize meat or dairy products need to include multiple servings of vegetarian sources of protein.  If you don’t eat meat, just having a half-cup of beans or one handful of nuts a day won’t do it.  Also, some research suggests that we use protein more efficiently when we spread it out through the day.  Let’s not forget: for both bone and muscle strength, as important as protein seems to be, research also emphasizes the vital role of weight-bearing and resistance (strength-training) exercise.

Next? In weeks and months to come, we’ll look at conflicting news stories about other nutrition questions. Sign up to get future posts by RSS feed or email  to make sure you don’t miss a thing.

Resources:

You can see how protein in your diet adds up from a variety of sources, check the MyPlate national website’s SuperTracker.

For general information about osteoporosis, check the Bone Health section of the National Institutes of Health website and the website of the National Osteoporosis Foundation.

References:

Bonjour, JP. Protein intake and bone health.  Int J Vitam Nutr Res, 2011. 81:134-42.

Fenton, TR et al. Causal assessment of dietary acid load and bone disease: a systematic review & meta-analysis applying Hill’s epidemiologic criteria for causality.  Nutr J. 2011. 10:41.

Cao, JJ et al. A diet high in meat protein and potential renal acid load increases fractional calcium absorption and urinary calcium excretion without affecting markers of bone resorption or formation in postmenopausal women.   J Nutr. 2011. 141(3):391-7.

Paddon-Jones et al. Role of dietary protein in the sarcopenia of aging.  AJCN, May 2008 vol. 87 (5):1562S-1566S

Campbell and Leidy. Dietary Protein and Resistance Training Effects on Muscle and Body Composition in Older Persons.  Journal of the American College of Nutrition, 2007.  26: 696S-703S.

Symons, TB et al. A moderate serving of high-quality protein maximally stimulates skeletal muscle protein synthesis in young and elderly subjects. J Am Diet Assoc. 2009 Sep;109(9):1582-6.

Gaffney-Stomberg et al. Increasing Dietary Protein Requirements in Elderly People for Optimal Muscle and Bone Health. Journal of the American Geriatrics Society, 2009.  57:1073–1079