New study explores link between obesity and higher MS risk in women

A recent study sheds light on the possible connection between obesity and a higher risk of multiple sclerosis (MS) in women, suggesting that inflammation specific to females may play a crucial role in this increased susceptibility.

The research, published in Cell Metabolism, suggests that obesity triggers molecular changes associated with inflammation and MS signalling pathways specifically in women. These findings may help explain why women are more prone to MS than men.

The study, conducted by researchers at the Oklahoma Medical Research Foundation (OMRF), analysed data from both human participants and a mouse model of MS. Results showed that obesity was linked to more severe disease progression and heightened immune activation in females, a pattern not seen in males.

According to lead researcher Dr Bob Axtell, inflammation appears to be a key factor that predisposes women to not only MS but also other autoimmune diseases.

Dr Axtell said: “We’re still unclear why this inflammation affects women more than men, but it seems to be a major factor driving the higher MS risk in females.”

The study emphasises adolescence as a critical period during which this effect may begin, highlighting the potential importance of early lifestyle changes in reducing MS risk in girls and women.

MS is a chronic autoimmune disorder in which the immune system attacks myelin, the protective covering of nerve fibers. Today, women account for approximately 80 per cent of new MS cases, a significant increase from previous decades, leading researchers to believe that environmental factors like obesity could be contributing to this gender disparity.

To explore this connection, the research team performed protein analyses on blood samples from men and women with relapsing-remitting MS (RRMS) as well as sex-matched individuals without the disease. They discovered a striking increase in inflammation-related proteins in women living with obesity with MS. Similar patterns were found in women without MS, while the impact of obesity was far less pronounced in men.

Using a mouse model of MS, the researchers further demonstrated that obesity worsened MS symptoms, particularly in female mice. Obese female mice exhibited a significant increase in immune cells that attack the nervous system, mirroring the inflammatory profiles found in human females living with obesity.

The study’s findings also suggest that increased fat tissue and ovarian hormones may contribute to the heightened inflammation and MS risk. In particular, the researchers identified that obesity drives increased production of inflammatory signalling molecules called interferons, which lead to the activation of harmful immune cells implicated in MS.