Failing to get at least seven to nine hours of sleep during teenage years is more likely to raise the risk of eventually developing multiple sclerosis, according to a new study. 

The study published in the Journal of Neurology, Neurosurgery & Psychiatry and led by Scientists in Sweden suggest maintaining good sleep hours at a young age may help ward off this disease. 

Multiple sclerosis is often influenced by genetics or environmental factors such as smoking, teen body mass index (BMI), Epstein-Barr virus infection, and exposure to sun and vitamin D.

In past studies, shift work has been tied to a higher risk of multiple sclerosis, particularly when the exposure took place at a young age. Now, the team wanted to examine the impact sleep duration, body clock disruption, and sleep quality had on the risk of developing multiple sclerosis.

Study Methodology

To close the knowledge gap, the researchers culled data from the Epidemiological Investigation of Multiple Sclerosis (EIMS) comprising Swedish residents aged 16 to 70 years. The team enrolled people with multiple sclerosis from hospital-based and privately run neurology units. Two healthy people were chosen randomly from the National population register between 2015 to 2013 and 2015 to 2018 and matched by age, gender, and residential area. 

In total, the study involved 2,075 people who suffered from multiple sclerosis and 3,164 people who did not. The team’s primary interest was in sleep patterns during the ages of 15 and 19. 

The team assessed participants’ sleep duration by asking them questions regarding when they slept and woke up at school or on work days and weekends or free days. They defined short sleep as less than 7 hours per night, sufficient sleep as 7 to 9 hours every night, and long sleep as 10 or more hours every night.

Next, they calculated participants’ changes in sleep timing during the teen years of 15 to 19 between days they went to school or work and days they were free or stayed home. This was grouped into less than an hour per night, 1 to 3 hours every night, and more than 3 hours.

Further, participants were asked to rate their sleep quality using a 5-grade scale ranging from very bad (1) to very good (5) during different age periods.

Results

Their analysis showed that indeed there was a link between sleep and multiple sclerosis and only grew stronger with poor or insufficient sleep. More specifically, they found that those who got less than 7 hours of sleep per night had a 40 percent higher risk of developing multiple sclerosis. That is after accounting for likely influential factors such as BMI at 20 years of age and smoking.

Meanwhile, those that slept longer including on workdays and weekends had no risk of getting the disease.

In the same way, the researchers noted that poor sleep quality appeared to raise the risk of eventually developing multiple sclerosis—up to 50 percent. However, a change in sleep timing—that is, catching up on sleep during weekends or free days—appeared not to influence multiple sclerosis risk.

“Although our supplementary analyses indicated that short sleep and poor sleep quality may be important and possibly modifiable lifestyle factors for MS, these findings should be interpreted with caution due to the potential of reverse causation,” they write in the paper.

This means it’s likely poor sleep could be due to neurological damage, rather than the other way around.

However, it is worth noting that too little or inadequate sleep and poor sleep quality affect immune functioning as well as disrupt the body clock involved in regulating the immune response.

And it’s no news that adolescents are the major population groups commonly affected by inadequate or disturbed sleep. This perhaps can be explained according to researchers by physiological and social changes that take place during this age period.

Likewise, easy access to the internet plays a huge role in causing inadequate sleep among teens and therefore, represents an important public health issue, the researchers explain. 

Regardless, their findings highlight the importance of education interventions being addressed to teens and their parents concerning the harm associated with too little sleep.