Does Casein in Milk Exposure Trigger Type 1 Diabetes?

Does Casein in Milk Exposure Trigger Type 1 Diabetes?

September 15, 2019 48 By Ewald Bahringer


“Does Casein in Milk
Trigger Type 1 Diabetes?” Type 1 diabetes is an autoimmune
disease that typically strikes children and young adults, in which your own
immune system attacks and destroys the insulin producing
cells of your pancreas. If untreated, it’s deadly, but even with
well-managed insulin replacement, it could cut a decade off your life. Families are devastated when a child
receives a diagnosis of type 1 diabetes. Thus, one of modern medicine’s “holy grails”
is to understand what causes the body to attack itself in hopes
that we can prevent and cure it. Genetic susceptibility
plays an important role, but the concordance for type 1 diabetes
is only about 50% among identical twins, meaning even if someone with the
same DNA as you gets the disease it’s only about a 50%
chance you’ll get it, too, meaning there must be
external factors as well. Some countries have low rates,
some have high rates. Japan, for example, has type 1
diabetes rates 18 times lower than the United States, and
that’s not just genetics since when children migrate they tend
to acquire the risk of their new home, suggesting it’s got to have something to
do with the environment, diet, or lifestyle. In fact, the incidence rates vary more
than 350 fold around the world. Some countries have hundreds
of times higher rates than others and it’s on the rise. Researchers looked at 37
populations from around the world and the incidence is going
up at about 3% a year. In fact, they couldn’t find a single
population going the other direction— 3% higher every year.
Our genes don’t change that fast. Something is going on, starting
right around World War II. The best evidence available suggests
type 1 diabetes showed a stable and relatively low incidence over
the first half of the 20th century, followed by a clear increase
around the middle of the century. And the question is why? A number of factors have been postulated
for tipping children over into diabetes, including vitamin D deficiency, certain
infections, or exposure to cow’s milk. Decades ago cross-country
comparisons like this were published, showing a tight correlation
between milk consumption and the incidence of type 1
diabetes, insulin-dependent, childhood-onset diabetes, showing as much as 94% of the
geographic variation in incidence might be explained by differences
in milk consumption alone. This country with the highest
rates at the top, Finland, led much of the
research into this area. It all started with studies like this
showing the less babies are breastfed, the higher the rate of type 1 diabetes,
leading to the obvious conclusion: breast milk protects
newborn infants. On the other hand, if they’re
not getting breast milk, they’re getting formula, which
contained cow’s milk proteins. In the first few months of life the gut
is especially leaky to proteins. So maybe as our immune system
attacks the foreign cow proteins our pancreas gets
caught in the crossfire. But this was based
on animal experiments. In susceptible mice, a diet containing
the cow’s milk protein casein produced diabetes, but it doesn’t
cause diabetes in rats. So are we more like mice or rats? Researchers drew blood from children
with type 1 diabetes to see if they had elevated levels of antibodies that attack
bovine proteins compared to controls. And every single one
of the affected kids had elevated anti-bovine protein
antibodies circulating in their blood compared to much lower
levels in the control subjects. OK, that seems pretty convincing,
but what about Iceland? They drink more milk than Finland yet
have less than half the type 1 diabetes. We’ll cover the Icelandic paradox next.