Medscape Article - Bones/Bone Loss Study

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Hi all -- Interesting article from Medscape.

Bobbie

Anchorage, AK

Journal Scan

Lifestyle, November 2002 -- Posted 12/02/2002

A. New, PhD

Medscape Ob/Gyn & Women's Health Journal Scans are the clinician's guide to

the latest published clinical research findings relating to gynecology,

obstetrics/maternal-fetal medicine, and general women's health.

Bones - October 2002 (Volume 31, Number 4)

Milk Supplementation Prevents Bone Loss in Postmenopausal Chinese Women Over

3 Years

Lau EM, Lynn H, Chan YH, Woo J

Bone. 2002;31(4):536-540

The aim of this study was to determine whether supplementation with a milk

powder positively influenced bone mass over 3 years in a group of Chinese

postmenopausal women (N = 200, age 55-59 years) who had been recruited via

community centres. Subjects took 50 g of high-calcium (800 mg), low-fat,

low-lactose milk powder every day, which also contained 240 IU vitamin D,

18.8 g protein, 24.9 g carbohydrate, and 0.4 g fat as well as key

micronutrients (particularly vitamin B complex, folate, magnesium, and zinc).

The control group subjects were not given a placebo. Bone mineral density

(BMD) of the hip, spine, and total body was measured at 6-month intervals

using dual X-ray absorptiometry (DXA).

The study groups had been previously investigated over 2 years; women in the

milk supplementation group were shown to have had a lower rate of bone loss.[

1] In this 1-year extension of the study, bone loss was reduced. According to

intention-to-treat analysis, the differences in rate of bone loss (i.e. the

percentage decrease in the control group compared with percentage decrease in

the milk supplementation group) was 0.23% for total body BMD, 0.31% for spine

BMD, and 0.44% for hip BMD.

The authors conclude that the effects of milk supplementation in preventing

bone loss in postmenopausal Chinese women were sustained after a period of 2

years.

Clinical Commentary

This group has previously shown that supplementing the diet of postmenopausal

Chinese women with a high-Ca milk powder (800 mg Ca) was effective in

preventing bone loss over 2 years. The aim of this extended study was to

determine whether these benefits could be sustained after 3 years. It is the

only long-term study examining the effects of milk supplementation in Asian

women whose dietary calcium intake was low. The results suggest that the

percentage reduction in bone loss attained by milk supplementation at 3 years

was substantial. In addition, the results indicate that the effects of

calcium supplements were not transient. It has been suggested that Ca

supplementation was associated with a reduction in bone turnover, leading to

a reduction in the total volume of osteoclastic resorption lacunae over the

bone surface and thus an on-off effect.

It is important to note that the milk powder contained a number of other

factors that are likely to have a protective effect against bone loss in

postmenopausal women, although it is not possible within this study design to

delineate which nutrient/element had the greatest effect.

Given that osteoporosis is a growing public health problem in Asia and that a

large proportion of Asian women have a low Ca intake, these findings are

important. They suggest that supplementation with milk powder in the general

population may help prevent osteoporosis.

Reference

1. Lau EMC, Woo J, Lam V, Hong A. Milk supplementation of the diet of

postmenopausal Chinese women on a low calcium intake retards bone loss. J

Bone Miner Res. 2001;16:1704-1709.

Abstract

A. New, PhD, RPH Nutr, is a Lecturer in Nutrition at the University of

Surrey, Guildford, United Kingdom, and a member of the Scientific Advisory

Council of the UK National Osteoporosis Society and the British Nutrition

Foundation.

Medscape Ob/Gyn & Women's Health 7(2), 2002. © 2002 Medscape