British Journal of Nutrition

Metabolism and Metabolic Studies

Effects of soya isoflavones and exercise on body composition and clinical risk factors of cardiovascular diseases in overweight postmenopausal women: a 6-month double-blind controlled trial

Stéphane Choquettea1a2, Éléonor Riescoa1a2, Éric Cormiera1, Tommy Diona1, Mylène Aubertin-Leheudrea1a3 and Isabelle J. Dionnea1a2 c1

a1 Faculty of Physical Education and Sports, University of Sherbrooke, Sherbrooke, QC, Canada J1K 2R1

a2 Research Centre on Aging, Social Services and Health Centre, University Institute of Geriatrics of Sherbrooke, 1036, Belvedere South, Sherbrooke, QC, Canada J1H 4C4

a3 Department of Kinanthropology, Université du Québec à Montréal, Montreal, QC, Canada H3C 3P8

Abstract

Results from a pilot project indicate that isoflavones and exercise could have an additive effect on body composition and clinical risk factors of CVD in postmenopausal women. The objective of the present study was to assess the combined effect of exercise and isoflavones in overweight-to-obese postmenopausal women. In this double-blind randomised controlled trial, 100 overweight-to-obese (BMI 29·9 (sd 3·2) kg/m2) postmenopausal women were assigned to four groups: (1) placebo (PLA); (2) isoflavones (ISO); (3) exercise and placebo (Ex+PLA); (4) exercise and isoflavones (Ex+ISO). The supplementation contained 70 mg/d of isoflavones. Exercise consisted of three weekly sessions of resistance training and aerobics. Outcome measures included fat mass (FM), lean body mass (LBM), bone mineral density, lipid profile, fasting glucose, fasting insulin and insulin resistance (homeostasis assessment model). The main effects of exercise were observed for total FM (P = 0·02), FM% (P < 0·01), trunk FM% (P = 0·05), arm FM% (P < 0·01), leg FM% (P = 0·02), arm LBM (P < 0·01), leg LBM (P = 0·02) and C-reactive protein (P < 0·01). A main effect was detected for isoflavones in improving leg FM% (P = 0·05). No interactions were observed between isoflavones and exercise. In conclusion, it was observed that 6 months of exercise brought favourable changes in total FM, FM% and LBM in overweight postmenopausal women. No synergistic effects were observed between exercise and isoflavones. However, isoflavones could have a beneficial effect on leg FM%.

(Received June 03 2010)

(Revised October 26 2010)

(Accepted October 27 2010)

(Online publication December 17 2010)

Correspondence:

c1 Corresponding author: I. J. Dionne, fax +1 819 829 7141, email isabelle.dionne@usherbrooke.ca

Footnotes

Abbreviations: BMD, bone mineral density; Ex, exercise; FM, fat mass; HOMA, homeostasis assessment model; HR, heart rate; HRRES, heart rate reserve; HT, hormonal therapy; ISO, isoflavone; LBM, lean body mass; PLA, placebo