Bone mineral density in Chinese elderly female vegetarians, vegans, lacto-vegetarians and omnivores

Abstract

Objectives: To compare the bone mineral density and dietary intake of elderly Chinese vegetarian women with omnivores, to compare the bone mineral density of Chinese`vegans' and`lactovegetarians', and to study the relationship between nutrient intake and BMD in vegetarians. Design: A cross-sectional survey. Setting and subjects: A community-based study. The vegetarian women (aged 70±89 y) (n 76) were noninstitutionalized subjects. All of them were Buddhists. Their bone mineral density were compared to normal elderly volunteers (aged 70±89 y) (n 109) who were recruited to establish normal BMD ranges. Their dietary intake was compared to omnivorous subjects from a previous dietary survey (n 250). Methods: Dietary assessment was by the 24 h recall method, and bone mineral density was measured by dual-Xray-densitometry. The analysis of co-variance was used to compare the BMD between vegetarians and omnivores, with adjustment for potential confounders. The BMD in`vegans' and`lactovegetarians' were compared by similar methods. The t-test was used to compare dietary intake between omnivores and vegetarians. The relationship between nutrient intake and BMD was studied by correlation and multiple regression. Results: The dietary calorie, protein and fat intake were much lower, but the sodiumacreatinine ratio was much higher in vegetarians than omnivores. The BMD at the spine was similar between vegetarians and omnivores. However, the BMD at the hip was signi®cantly lower in vegetarians at some sites (P`0.05). There was no signi®cant difference in BMD between`vegans' and`lactovegetarians'. BMD in vegetarians appeared to be positively correlated with energy, protein and calcium intake; and negatively associated with urinary sodiuma creatinine levels. Conclusions: There is a relationship between diet and BMD. The BMD at the hip was lower in vegetarians than omnivores, but no difference was observed between`vegans' and`lactovegetarians'. There is a complex relationship between the intake of various nutrient and BMD in vegetarians.

Comparative fracture risk in vegetarians and nonvegetarians in EPIC-Oxford

“…Three studies have reported lower bone mineral density or bone mineral content in vegans compared with omnivores or other vegetarians (Chiu et al, 1997;Parsons et al, 1997;Outila et al, 2000). Another study found no difference in bone mineral density between vegans and lacto-vegetarians, although the researchers noted a positive correlation between calcium intake and bone mineral density (Lau et al, 1998). A small, short-term intervention study found that calcium balance remained positive after 10 days consuming a vegan diet as well as after 10 days consuming a lacto-vegetarian diet, despite a significantly lower mean calcium intake on the vegan diet (Kohlenberg-Mueller and Raschka, 2003).…”

“…Overall, these studies found no differences in bone health indices between lacto-ovo-vegetarians and omnivores (New, 2004). However, three out of four of the studies reported lower bone mineral density or bone mineral content in vegans (who consume no animal products) compared with omnivores or other vegetarians (Chiu et al, 1997;Parsons et al, 1997;Lau et al, 1998;Outila et al, 2000), leading one reviewer to conclude that vegans have lower bone mineral density than nonvegans (Smith, 2006). Several dietary factors known or thought to influence bone health, and possibly also fracture risk, including intakes of calcium, vitamin D, protein (including the ratio of plant to animal protein), potassium, sodium and fruit and vegetables are likely to differ between vegetarians and nonvegetarians and between vegetarians and vegans (New, 2004;Prentice, 2004).…”

“…Many studies have reported indices of bone health in vegetarians (Marsh et al, 1988;Lloyd et al, 1991;Tesar et al, 1992;Reed et al, 1994;Chiu et al, 1997;Parsons et al, 1997;Barr et al, 1998;Lau et al, 1998;Outila et al, 2000;Siani et al, 2003;Fontana et al, 2005). Overall, these studies found no differences in bone health indices between lacto-ovo-vegetarians and omnivores (New, 2004).…”

Nutrition Society Medal Lecture: The role of the skeleton in acid—base homeostasis

“…In a 5-year prospective study of changes in radial bone density of elderly white American women no differences were seen in bone loss rates between the lacto-ovo vegetarians and the omnivorous group (Reed et al 1994). Furthermore, in the most recently published studies, bone mass was found to be significantly lower in the vegetable-based dietary groups (Chiu et al 1997;Lau et al 1998), although it is likely that protein 'undernutrition' may account for some of these differences (Rizzoli et al 1998).…”

Health effects of vegan diets

“…More recent studies with postmenopausal Asian women showed spine or hip BMD was significantly lower in long-term vegans (41,42). Those Asian women, who were vegetarian for religious reasons, had low intakes of protein and calcium.…”