A discovery about how breastfeeding babies absorb large amounts of calcium and build healthy bones could lead to treatment for osteoporosis…
Osteoporosis isn’t a disease of the elderly, it’s a paediatric disease.
“We build our bone mineral density until we’re early adults and then stop, so we think of osteoporosis as a disease of the elderly,” says Megan Beggs, a pediatric dietitian and PhD candidate in physiology at the University of Alberta who led the study.
“Really, it’s a paediatric disease with consequences in old age, so understanding what’s happening at these younger ages, when bones are being built, is critical.”
Babies and adults absorb calcium differently
The researchers identified calcium-absorbing channels in the lower two-thirds of the small intestines of breastfed infant mice in a paper published in the journal Cellular and Molecular Gastroenterology and Hepatology.
Previous work had revealed that, in adult mammals, most calcium absorption takes place in the upper part of the small intestines, where food spends much less time.
“It seems to be pretty much the opposite is happening in infants,” says Beggs.
Bone building in the first year or life
Babies need to take in massive amounts of calcium in the first year of life to build the cartilage they are born with into the body’s 206 bones. This mineral deposition continues at a lower rate until around age 25.
This is the first time that the infant mechanism for absorbing calcium has been understood.
Paediatric nephrologist Todd Alexander, Beggs’s PhD supervisor and senior author of the paper, says that it’s partly because women and children’s health has not traditionally been the subject of a medical study. He said the research required specially adapted lab equipment to perform experiments on the tiny intestines of genetically altered infant mice.
Alexander said that understanding this mechanism could be the first step in reversing diseases that cause weak bones in humans.
“You can imagine that if you have someone who has poor bone health, such as an elderly person or a sick child in neonatal intensive care who has not been able to breastfeed, it would be very useful therapeutically to turn this pathway on for them,” says Alexander.
The researchers said that their future research will look at the mechanism in pigs, which are even closer physiologically to humans than mice, and they will test their hypothesis that it is a hormone in breast milk that is responsible for regulating the channels.
“Understanding that would allow us to either take the active ingredient out of breast milk or synthesise it as an additive so we could give it to people as a tablet or an injection,” says Alexander.
The researchers say that this application could be five to 10 years away.
Source: University of Alberta Faculty of Medicine & Dentistry via www.sciencedaily.com