AUTOIMMUNE DISEASES^191As we have seen with other diseases of affluence, when people migrate
from areas of the world where disease incidence is low to areas of the
world where disease incidence is high, they quickly adopt the high inci-
dence rates as they change their diet and lifestyle.^3 O-^32 This shows that even
though individuals may have the necessary gene(s), the disease will occur
only in response to certain dietary and/or environmental circumstances.
Disease trends over time show the same thing. The worldwide preva-
lence of Type 1 diabetes is increasing at an alarming rate of 3% per year.^33
This increase is occurring for different populations even though there
may be substantial differences in disease rates. This relatively rapid in-
crease cannot be due to genetic susceptibility. The frequency of anyone
gene in a large population is relatively stable over time, unless there are
changing environmental pressures that allow one group to reproduce
more successfully than another group. For example, if all families with
Type 1 diabetic relatives had a dozen babies and all the families without
Type 1 diabetic relatives died off, then the gene or genes that may be
responsible for Type 1 diabetes would become much more common in
the population. This, of course, is not what is happening, and the fact
that Type 1 diabetes is increasing 3% every year is very strong evidence
that genes are not solely responsible for this disease.
It seems to me that we now have impressive evidence shOWing that
cow's milk is likely to be an important cause of Type 1 diabetes. When
the results of all these studies are combined (both genetically suscep-
tible and not susceptible), we find that children weaned too early and
fed cow's milk have, on average, a 50-60% higher risk of Type 1 diabetes
(1.5-1.6 times increased risk).34
The earlier information on diet and Type 1 diabetes was impressive
enough to cause two Significant developments. The American Academy
of Pediatrics in 1994 "strongly encouraged" that infants in families
where diabetes is more common not be fed cow's milk supplements for
their first two years of life. Second, many researchers^19 have developed
prospective studies-the kind that follow individuals into the future-
to see if a careful monitoring of diet and lifestyle could explain the onset
of Type 1 diabetes.
Two of the better known of these studies have been underway in Fin-
land, one starting in the late 1980S^15 and the other in the mid-1990s.^35
One has shown that cow's milk consumption increases the risk of Type
1 diabetes five-to sixfold,36 while the second^35 tells us that cow's milk
increases the development of at least another three to four antibodies