Baby Charlie Johnson is helping to solve a longstanding medical
mystery.
The six-month-old boy, from Sydney's eastern suburbs, has been recruited
for an international study to determine if cow's-milk-based infant formula is
a trigger for the development of childhood diabetes.
About 8000 babies worldwide, including 200 from Australia, will be examined
over the next 10 years as part of the study - the Trial to Reduce the
Incidence of type 1 diabetes in the Genetically at Risk (TRIGR).
Diabetes Australia NSW president Dr Neville Howard, the Australian
principal investigator, said testing had begun on 24 Australian babies.
Howard said children eligible for the study must be genetically predisposed
to diabetes.
"The way we identify at-risk pregnancies is if the mother, the father or a
sibling has type 1 diabetes," he said.
"To tell whether they are susceptible or not, genetically, we take a blood
sample from the cord."
Charlie was chosen to participate in the trial after blood tests confirmed
he had a genetic risk of developing diabetes.
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His father, Andrew Johnson, has type 1 diabetes. The first-time father said
Charlie's involvement in the study could help other children.
"This is really valuable research," he said. "I am pretty keen to do
anything to help kids and adults."
Johnson, 34, was diagnosed with type 1 diabetes when he was 18 and he must
have five insulin injections each day.
"There was no one in my family who had it," he said.
Johnson said he and his wife Jo were concerned Charlie may also one day
have to live with the disease.
"It scares me, especially the thought of him developing diabetes as a
juvenile," he said.
Animal experiments and population studies have shown that cow's milk may
increase the risk of diabetes, but Howard said human trials were needed to
prove the "controversial" hypothesis.
"The theory is that those human beings who are genetically susceptible to
getting diabetes have an auto-immune problem," he said.
"In the first few months of life, when they are exposed to macro molecules
in their gut, [the milk] is treated as foreign [matter] rather than as
food.
"The result is an abnormal immune coding, and various tissues in the body
become targets of the immune system, including the pancreas.
"Up to four macro molecules are found in cow's milk which offend babies who
are genetically susceptible. Human milk doesn't do that."
The study encourages mothers to breastfeed for the first six months, but
when their babies need a supplement formula, some will be given modified
formula and the others cow's-milk-based formula.
Howard said the risk of childhood diabetes could be reduced or prevented if
a child's diet was modified in the first six to eight months of their
life.
About 100,000 Australians suffer from type 1 diabetes and it is one of the
most common chronic childhood diseases.
It occurs when the pancreas gland no longer produces enough insulin, the
hormone needed to convert glucose to energy. Type 1 diabetes sufferers must
have insulin injections every day, undergo regular blood glucose level tests
and maintain a healthy lifestyle.
Symptoms include excessive urination, thirst, unexplained weight loss,
fatigue, irritability and weakness.
The TRIGR study will answer two questions: does cow's milk protein cause
antibodies that can predict the incidence of type 1 diabetes, and can it cause
the disease?
Howard said he expected researchers to answer the first question by the end
of 2008.
"The deferral of childhood diabetes would be a wonderful improvement in the
world," he said.
"We hope this might stop it in its
tracks."
