Isoflavone-supplemented soy yoghurt associated with resistive physical exercise increase bone mineral density of ovariectomized rats.
OBJECTIVE
To determine the effects produced by the ingestion of a fermented soy product (soy yoghurt), supplemented with isoflavones and associated with a resistive exercise program, on the bone metabolism of mature ovariectomized (Ovx) and sham-ovariectomized (sham-Ovx) rats.


METHODS
A total of 56 rats were used. They were divided into 2 sedentary control groups, the Ovx control group (C-Ovx) and the sham-Ovx control group (C-Sovx), each with 7 sedentary animals, and 2 treated groups, Ovx and sham-Ovx, with 21 animals each. These two treated groups were subdivided into three subgroups of seven animals each, which received the following treatments: consuming the soy yoghurt+sedentary, only subjected to resistive exercise, and consuming the soy yoghurt+resistive exercise. Both the program of resistive exercise and the consumption of soy yoghurt (at 3 mL/(kg body weight day)) continued for 12 weeks. The soy yoghurt was supplemented with isoflavones at 50mg/100g of product. The animals were sacrificed and their right-side femurs and tibias removed and assessed for bone mineral density (BMD). The alkaline phosphatase activity (AP) was determined in the blood serum.


RESULTS
There was a significant increase in both femur and tibia BMD values and in serum alkaline phosphatase activity in all the treated subgroups, compared with the control groups (p<0.05).


CONCLUSIONS
The ingestion of the soy yoghurt supplemented with isoflavones was capable of preventing a loss of bone mass in Ovx rats and of increasing bone mass in sham rats, whilst the resistive exercise program was effective in augmenting the bone mass in sham and Ovx rats.
Shiguemoto
Gilberto Eiji
GE
Department of Physiological Sciences, Federal University of São Carlos, São Carlos, SP, Brazil.
Rossi
Elizeu Antonio
EA
Baldissera
Vilmar
V
Gouveia
Cecília Helena
CH
de Valdez Vargas
Graciela Maria Font
GM
de Andrade Perez
Sérgio Eduardo
SE
D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D015519:Bone Density; D019587:Dietary Supplements; D005260:Female; D007529:Isoflavones / Q000008:administration & dosage*; D010024:Osteoporosis / Q000097:blood / Q000473:pathology / Q000628:therapy*; D010052:Ovariectomy; D010805:Physical Conditioning, Animal; D008517:Phytotherapy; D051381:Rats; D017208:Rats, Wistar; D013025:Glycine max; D015014:Yogurt
D007529:Isoflavones; D000469:Alkaline Phosphatase