Type 1 Diabetes Prevention
Several efforts examine the possibility of halting the development of type 1 diabetes. So far the results are mixed -- at best.
The Trial to Reduce Diabetes in the Genetically At-Risk (TRIGR)
is based on an intriguing but controversial idea. Both human and animal studies
from Finland, which has among the highest rates of type 1 diabetes in the
world, suggest that children who are breastfed exclusively from birth and are
not exposed to proteins from cow's milk (in either infant formula or regular
milk) may have a lower risk for developing type 1 diabetes.
"In studies done both in Toronto and Finland in mice, those
mice that were fed the cow-milk protein were more likely to come down with
diabetes than those fed a hydrolyzed formula [in which the proteins have been
pre-digested and are not detected by the immune system]," says Peggy
Franciscus, RN, coordinator for the U.S. arm of the TRIGR trial, based at
Children's Hospital of Pittsburgh.
"Based on that and looking at some of the Finnish studies,
those children who were weaned early from breastfeeding -- say before 4 months
-- and then given a cow-milk protein formula had a higher incidence of type 1
diabetes than those who were either exclusively breastfed past that three-month
period, or were put on a formula with pre-digested protein.'
The theory, Franciscus tells WebMD, is that the whole protein
is seen by the child's still-developing immune system as foreign, causing it to
produce antibodies that attack both the protein and the child's own store of
insulin producing beta-islet cells of the pancreas. The theory is supported by
data from a small Finnish study that shows children who received cow-milk
protein formulas had evidence in the bloodstream of islet-cell autoantibodies,
which are thought to be a possible cause of type 1 diabetes.
"The beginning of the story is that people noticed that in
Western Samoa, there was no type 1 diabetes. But when those people move to
societies that use milk products -- and in Western Samoa until recently they
did not -- they begin to get diabetes, and they do get it in Western Samoa now
and they do consume milk proteins," explains Dupre, who is a principal
investigator for the Canadian branch of the TRIGR study.
Similar observations have been made in the island of Sardinia,
where until recently goat's milk but not cow's milk was common in the diet, and
in Puerto Rico, where government-sponsored nutrition programs have increased
the use of infant formulas based on cow's milk, Dupre tells WebMD.
The final results from the TRIGR study are not expected until
The DAISY trial (the Diabetes AutoImmune Study in the Young)
was designed to answer the question whether certain types of stomach virus
(enterovirus) could cause increased susceptibility to diabetes. The study
looked at two alternate hypotheses: that enteroviruses are either transmitted
from the mother at birth or acquired in early childhood, resulting in a chronic
infection that leads to an autoimmune response, or that late infections
acquired by children who already have abnormal beta-islet cell function can put
the final nail in the coffin of the insulin-secreting cells.
But like the DPT-1 trial, this study yielded negative results.
"There is no evidence from this study that enterovirus infection is a risk
factor for development of beta-cell autoimmunity," researchers write in the
January 2003 issue of the journal Diabetes Research and Clinical