Health for life

In my previous post I discussed a recent study that reported an association between vitamin D supplementation and risk for type 1 diabetes (Preventing Diabetes - Can Vitamin D Protect Against Type 1?)

I wanted to add a note for those looking to vitamin D-fortified cows milk for that supplementation. That may be problematic. Some studies, notably this 1992 investigation that appeared in the New England Journal of Medicine:

A Bovine Albumin Peptide As A Possible Trigger Of Insulin-Dependent Diabetes Mellitus

... documented the ability of cows milk protein to initiate type 1 diabetes.

Heres how that is thought to work:

Children fed cows milk at an early age may develop antibodies against a specific protein in that milk which resembles a protein on the surface of pancreatic beta cells. The childs immune cells may then attack not only the foreign cows milk protein, but also the similar-looking beta-cell protein.

In the study above, the serum of 142 children with type 1 diabetes, 79 children without diabetes, and 300 adults were analyzed for antibodies against bovine serum albumen (anti-BSA antibodies). Findings:

• All of the children with type 1 diabetes had elevated levels of anti-BSA antibodies (all were above 3.55, averaging 8.5 kfU/microliter).
  
• None of the children without type 1 diabetes had elevated levels of anti-BSA antibodies (all were below 3.55, averaging 1.3 kfU/microliter).
  
• The 300 adults also had much lower levels of anti-BSA antibodies.

A few years later, researchers in Canada performed a meta-analysis of relevant studies and concluded:¹

"Early cows milk exposure may be an important determinant of subsequent type I diabetes and may increase the risk approximately 1.5 times."

Although some find the body of evidence indicting cows milk in the development of type 1 diabetes convincing, the scientific community still has not reached consensus.

In looking for a recent study addressing this link, I found the following article by investigators from Finland reporting in the ADAs journal Diabetes in 2005:

Environmental Triggers and Determinants of Type 1 Diabetes, Diabetes, 2005

In it, they continued to present evidence that early feeding of cows milk ... when coupled with a genetic predisposition or to exposure to an enterovirus at a young age ... can lead to type 1 diabetes.

As long as there is a strong dairy industry, there is likely to be controversy over this issue. It doesnt hurt, though, to be informed.
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¹ Cows Milk Exposure And Type I Diabetes Mellitus. A Critical Overview Of The Clinical Literature, Diabetes Care, 1994

One of my earlier posts (Think Twice Before Feeding Your Child Cows Milk) discussed the possibility that early ingestion of cows milk can increase the risk for type 1 diabetes.

Last month, an article in a journal of the American Chemical Society reviewed the literature for this association:

Relation of Time of Introduction of Cow Milk Protein to an Infant and Risk of Type-1 Diabetes Mellitus, Journal of Proteome Research, April, 2008

Its author, Marcia Goldfarb, described a set of conditions which could explain how pancreatic beta cells are destroyed - leading to type 1 diabetes - when cows milk products are fed to infants:

"The newborn intestine does not have complete "closure" and can pass food antigens. Beta Lactoglobulin could generate antibody to glycodelin undermining T cell regulation of beta cells."

Mechanism

1. Beta-lactoglobulin is a protein present in cows milk, but not human milk. "It has the largest concentration of any whey protein in bovine milk. (Goldfarb)" Glycodelin is a human protein that affects our immune system, regulating our T-cells.
   
   
2. The cow beta-lactoglobulin and the human glycodelin have similar structures, such that an infants body may generate antibodies not just for the foreign beta-lactoglobulin, but also for the endogenous glycodelin.
   
   
3. Type 1 diabetes is thought to be caused by autoimmune destruction of pancreatic beta cells by T-cells. Destruction of glycodelin (by the antibodies generated to destroy the foreign cows milk protein) may allow proliferation of these beta-cell-destroying T-cells.

In a small investigation, Goldfarb indeed found antibodies to beta-lactoglobulin in the serum of children with type 1 diabetes. Those she tested who did not have diabetes did not have these antibodies.
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