Postmenopausal vegans and meat-eaters may have similar bone density, despite vegans' lower calcium and protein intake, a small study suggests.
Vegan diets are free of all animal products, including eggs and dairy; one concern has been that female vegans might not get enough of certain nutrients, including calcium, to maintain a healthy bone mass.
However, in the new study, researchers found that Buddhist nuns -- who follow a strict vegan diet free of all animal products -- had bone mass that was comparable to women their age who ate meat.
The study, and it’s findings
The study, reported in the journal Osteoporosis International, included 105 Vietnamese nuns who were 62 years old, on average, and
105 meat-eaters of the same age.
Using bone scans, the researchers found that women in both groups had similar average bone density in the spine, hip and body as a whole.
Rates of the bone-thinning disease osteoporosis were also comparable;
17 percent of vegans had osteoporosis in the hip area, as did 14 percent of non-vegans.
This was despite the fact that vegans generally consumed about half as much calcium and protein as meat-eaters did, according to senior researcher Dr. Tuan V. Nguyen, of the Garvan Institute of Medical Research in Sydney, Australia.
It was somewhat surprising that the vegan nuns got so much less calcium, Nguyen's team noted. "But there seemed to be no significant effect on health," Nguyen told Reuters Health.
The reasons are not clear, the researcher added, but may have to do with the nuns' intake of soybeans, which studies suggest may lessen postmenopausal bone loss - possibly due to estrogen-like compounds called isoflavones.
Whether the findings extend to all vegan women is not entirely clear, as Buddhist nuns have a different overall lifestyle from the general population. One difference, Nguyen noted, is that they may be more physically active in their daily lives, with activities such as gardening.
Regular exercise, particularly weight-bearing activities that make the body work against gravity, is known to build and maintain bone mass.
(Amy Norton/Reuters Health, May 2009)
SOURCE: Osteoporosis International, online April 7, 2009.