Obesity at a young age and the use of birth control pills appear to increase the risk of developing multiple sclerosis (MS) according to two new studies.
In a study of 420 people, half of whom had multiple sclerosis, researchers in Argentina found that those who were obese at age 20 had twice the risk of developing MS later in their lives than those who were not obese.
Researchers suspect that the so-called “obesity hormone” leptin may cause inflammation that can trigger MS. People with high body mass levels (BMI) had high levels of leptin, which regulates weight, appetite and immune system response.
“Leptin promotes inflammatory responses in the body, which could potentially explain the link between obesity and MS,” said study author Jorge Correale, MD, of the Raúl Carrera Institute for Neurological Research in Buenos Aires, Argentina.
MS is a chronic disease which attacks the body’s central nervous system and is characterized by the destruction of myelin, the membrane that protects nerves in the brain and spinal cord. Once damaged, the nerves’ ability to transmit electrical impulses is inhibited, causing cognitive impairment and poor mobility.
An estimated 400,000 Americans suffer from MS and more than two million people worldwide.
For the birth control study, researchers with Kaiser Permanente identified 305 women who had been diagnosed with MS and compared them to 3,050 women who did not have MS.
Women who had used hormonal contraceptives – such as estrogen and progestin — were 35% more likely to develop MS than those who did not use them. Those who had used the contraceptives but had stopped at least one month before symptoms started were 50% more likely to develop MS.
“These findings suggest that using hormonal contraceptives may be contributing at least in part to the rise in the rate of MS among women,” said study lead author Kerstin Hellwig, MD, Kaiser Permanente Southern California.
The most common form of MS, relapsing-remitting multiple sclerosis, is characterized by episodes of worsening neurologic function followed by periods of remission involving partial or complete recovery. Symptoms may be mild or severe, ranging from numbness in the limbs to paralysis or loss of vision.
There is no cure for MS. The only therapies currently available are ones that modify its symptoms.