The study, published online in The FASEB Journal, is the first time that scientists have used an animal model to show concrete evidence of a protective effect of an early-life soy protein isolate diet on adult bone loss.
“Nutritional status during intrauterine and early postnatal life impacts the risk of chronic diseases; however, evidence for an association between early life dietary factors and bone health in adults is limited,” noted the researchers. “Soy protein isolate (SPI) may be one such dietary factor that promotes bone accretion during early life with persistent effects into adulthood,” they added.
To make their discovery, researchers used a very young female rat model.
One group of rats was fed a soy protein isolate diet for 30 days (from postnatal day 24 to 55), and then was switched to a regular standard rodent diet until six months of age.
The rats were altered to mimic postmenopausal bone loss in women to determine the amount of bone loss. The second group of rats was fed a regular standard rodent diet throughout life.
This group was also altered to mimic postmenopausal bone loss and analysed to determine bone loss. The researchers found that the first group of rats compared to the second group of rats.
“We showed significantly increased bone mass in 30-day soy protein isolate-fed young rats compared with controls...[it also] diminished the loss of total, trabecular, and cortical bone mineral density.”
Jin-Ran Chen, a researcher involved in the work from the Skeletal Development Laboratory at Arkansas Children's Nutrition Center at the University of Arkansas for Medical Sciences, said: "Appropriate early-life nutrition can optimize peak bone mass. Consumption of soy foods has a variety of health benefits, including amelioration of bone loss during adulthood."
"The centuries-old mantra that children need milk to 'grow strong bones' remains true, but here we have evidence that the protein components of soy 'milk' have key osteogenic effects," added Thoru Pederson, editor-in-chief of The FASEB Journal.
The vast majority of soy products for humans are consumed in South East and East Asia.
Pederson added: "This finding could ultimately have major paediatric health impacts throughout various parts of the world."
Source: The FASEB Journal
Published ahead of print October 12, 2016, doi:10.1096/fj.201600703R
“Dietary factors during early life program bone formation in female rats”