Researchers are demonstrating how milk can cause MS symptoms

For decades, people with multiple sclerosis have been suggested dairy products may worsen symptoms of their disease. Now researchers from the Universities of Bonn and Erlangen-Nuremberg have demonstrated exactly how this can happen, finding that a specific protein in cow’s milk can trigger immune cells that are known to damage neurons in MS.

“We hear from patients over and over again that they feel worse when they consume milk, cottage cheese or yogurt,” said Stephanie Curten, a researcher who has been working on this study since 2018. “We are interested in the reason for this correlation.”

The first step was the introduction of a specific ingredient in milk that could aggravate the symptoms of MS. In a series of experiments with mice, researchers found that the main culprit was casein. But this observation only confirmed the correlation. The researchers were most interested in how exactly this milk protein could cause neuronal damage associated with MS.

Rittica Chunder, another researcher working on the project, explained the hypothesis that casein causes an abnormal immune response. This meant that casein must resemble the same antigens that cause immune cells to misalign healthy brain cells.

“We compared casein with different molecules that are important for myelin production,” Chander said. “In the process, we came across a protein called MAG. In some ways, it looks remarkably similar to casein – so much so that antibodies to casein have also been active against MAG in laboratory animals. ”

The final step was to establish that this autoimmune reaction, caused by casein, does occur in humans. To investigate this, the researchers looked at how these casein antibodies behave in human brain tissue.

The hypothesis was tested, casein antibodies did aggregate in brain cells responsible for myelin production. In addition, the researchers found that immune B cells taken from patients with MS were particularly sensitive to casein.

The study ultimately concludes that the relationship between dairy symptoms and MS is related to the casein protein in milk, which causes an influx of immune antibodies. These immune cells mistakenly attack certain cells in the brain due to the similarity of the MAG protein with casein.

Researchers cautiously note that this mechanism can only occur in people with pre-existing allergies to dairy products. Kurten said her team is already working on a test for MS patients that can determine their predisposition to casein allergies.

“We are currently developing a self-test that allows victims to test whether they carry the appropriate antibodies,” said Kurten. “At least this subgroup should refrain from drinking milk, yogurt or cottage cheese.”

One of the questions that raises new conclusions is what role can casein sensitivity play in the development of MS?

Kurten points out that observational studies have found higher levels of MS in populations that are known to consume large amounts of cow’s milk. Thus, it is likely that an allergic reaction to casein can lead to antibodies inadvertently damaging brain cells and initiating a cascade of reactions that lead to MS.

Further research will be needed to study this hypothetical scenario, and Kurten shows that casein allergies alone are not enough to develop multiple sclerosis because there are several other known risk factors which must unite for the disease to progress.

A new study was published in the journal PNAS.

Source: University of Bonn