November 27, 2004

Protein Hope for Bone Growth; Protein Hope for Bone Growth Excites

A milk protein that dramatically improves bone density in laboratory tests offers hope to the tens of thousands of women and men who suffer from debilitating osteoporosis.

Auckland University's osteoporosis research group has found that lactoferrin -- a protein found in milk -- not only boosts bone growth, but also inhibits the natural breakdown of bone.

Associate Professor Jill Cornish, whose results were presented at a conference in Melbourne on Wednesday night, said much research had been done on treatments to inhibit bone absorption but little was known about how to build bone.

"This is what differentiates lactoferrin and makes it so exciting -- it's a double whammy."

While bone had a static "limestone cave" appearance it was a dynamic tissue constantly breaking down and rebuilding with a human skeleton completely renewing itself every 10 years, she said.

Canterbury Osteoporosis chairwoman Trish Adams said the research breakthrough was wonderful particularly for the people who could not drink milk and would welcome an extract as a pill or other formulation.

Osteoporosis occurs when the bone absorption process outstrips the bone-building process. About 60 per cent of women and 30% of men over 60 suffered osteoporotic fractures. One in three women who suffer a hip fracture will die within a year, and half will never walk again unassisted.

It is estimated to cost New Zealand $200 million a year in health care and related costs.

Lactoferrin was found naturally in milk and in particularly high concentrations in colostrum, the substance produced immediately before breast milk was established. It was also present in small amounts in the body, though not enough to prevent osteoporosis.

"It is a goody molecule," Cornish said.

"It's good for bones, it's good for the immune system. It's an anti- bacterial, anti-viral and anti-fungal. Interestingly, when white blood cells in the body respond to infection they spurt out lactoferrin naturally. This is the body's first line of defence."

Incorporating lactoferrin into a pill or drink could prevent the onset of osteoporosis.

To A2 From A1

One of its first uses may be to incorporate it into infant formula where it could enhance bone development. Making it available to adults could prove more difficult as lactoferrin was a large protein and may not be able to cross the gut wall. Infants had "leaky" guts, allowing easier lactoferrin access.

A more immediate use could see the protein injected directly into fracture sites to boost healing.

Cornish said toxicology studies were yet to be done, but she did not expect lactoferrin to show problems because it was effective in concentrations similar to that found naturally.

The discovery that lactoferrin was active in bone growth was an exciting development, Osteoporosis New Zealand executive manager Julia Gallagher said.

"We're delighted that this work has been done in New Zealand."

Former politician Margaret Austin, who has had osteoporosis for 17 years, said the new research was welcome as osteoporosis could be "quite disastrous" for the elderly, many of whom never recovered fully from a serious fracture.

"I'm sure it will make an enormous difference to people who are at risk of osteoporosis," she said.

Christchurch elder-care specialist Dr Nigel Gilchrist said the lactoferrin announcement was "a very interesting and exciting development".