Dutch researchers have found that exposing children that are genetically predisposed to develop multiple sclerosis (MS), to cigarette smoke in the family home could raise that risk even higher.

Results of the study were published December 10 in the ‘Journal of Neurology Neurosurgery & Psychiatry’.

“A higher genetic MS risk is associated with an increased vulnerability to the negative effects of household smoking on brain development,” concluded a Dutch team led by Dr. Rinze Frederik Neuteboom of Erasmus Medical Center in Rotterdam.

The new study also probes the roots of MS, suggesting that even though most people develop the autoimmune illness between their 20s and 40s, it might originate as far back as childhood.

MS occurs when the body’s immune system goes awry, attacking the myelin sheath that protects nerves.

Over time, this can lead to a debilitating loss of movement, balance, cognitive abilities and other symptoms. In the new study, Neuteboom and colleagues looked at data from a large database tracking the health of Dutch children.

Among other factors, data was collected on known environmental risk factors for MS, such as infection with the Epstein Barr virus, blood levels of vitamin D, parents’ smoking, childhood weight and levels of outdoor activity at the age of five.