Women are 3 times more likely to get MS than men — here’s what we know

This is the fourth story in a five-part series exploring multiple sclerosis in Canada and the implications the disease has on patients, health care and the country as a whole.
Click to play video: 'Brain interrupted: The types of MS'
Brain interrupted: The types of MS
What are the primary types of multiple sclerosis and how do they differ from one another? – May 14, 2018

When Michael Dalley was in his final year of high school in 2012, he lost feeling in both his elbows all the way down to his fingers.

Numb hands meant he couldn’t write his final exams or take notes in class.

Unsure of what was happening, Dalley saw specialist after specialist, some who even claimed the now 27-year-old St. John’s, Nfld., resident was just stressed. Later that year, he was diagnosed with primary progressive MS (PPMS) after doctors found lesions all over his brain.

Unlike so many other Canadians, Dalley’s diagnosis didn’t shock him. In fact, he was aware of what was about to happen, because two important women in his life already had the disease. 

It’s estimated that over 93,500 Canadians of all ages currently live with MS – an inflammatory neurological disease of the central nervous system that impacts one’s brain, spinal cord and optic nerves – and the Public Health Agency of Canada anticipates that number to rise to 133,635 by 2031. Canada is the country with the highest rate of MS in the world, Statistics Canada reports. While there are theories as to why that is, the ultimate cause of MS remains a mystery.

The rates between men and women are staggering. Experts say women are three times more likely to get diagnosed with all four stages of MS, while men often are diagnosed with later stages of the disease. Women are more likely to have relapsing-remitting MS (RRMS), while men are often diagnosed with PPMS.


WATCH: Allison Vuchnich explores how MS differs in men and women 

Click to play video: 'Brain Interrupted: How MS differs in men and women'
Brain Interrupted: How MS differs in men and women

Dalley says his MS is very similar to his sister Kayla’s. They both have aggressive stages of the disease and take the same medication. “They put me on the treatment that they put her on that actually worked for her, so luckily I don’t have permanent damage, but I deal with severe tremors in my hands on a day-to-day basis.”

He adds that just like his days in school, he isn’t able to write for a long period of time. He also has two braces on his legs because his feet often drag — this gets in the way of daily functions like working, walking or playing sports. Currently, Dalley works 40 hours a week at a Dairy Queen as well as in the cleaning department of Avalon Mall.

Men vs. women

Michelle Ploughman of Memorial University in St. John’s began studying MS patients and old age in 2011. Conducting research — the largest study of MS and aging in the world — her team interviewed 743 patients 55 and older who had MS for more than 20 years.

Ploughman says she wanted to see the difference between the sexes, as well as how men and women adapted to their diagnosis as their bodies aged.

“If we can figure out why women have MS three times more often than men do, we can really understand what causes this in the first place. I think that’s key … it should be 50/50. If we can determine that mechanism, we can really understand how this perfect storm of MS lands in your lap. I think if we could find out the gender/sex differences, we could find out how to end MS.”

Ploughman found men were likely to have higher levels of depression and lower levels of quality of life. They had lower levels of resilience and also participated less in life.

Women, on the other hand, had higher levels of resilience, a better diet and quickly learned how to adapt to life with their disease.

“One [reason for this] could be the fact that more men are diagnosed with a more progressive form of MS,” Ploughman continues. “What we found in our study is 75 per cent of older men and women have retired early because of their MS. That’s a huge change in life and life roles and it seems like women have perhaps learned to adapt, they have [a] higher level of household participation, outdoor participation [and] volunteerism where men tend not to participate in that.”

Living with the disease

Dalley’s younger sister, Kayla, was diagnosed with PPMS in 2007 when she was 13. She spent a lot of time at the hospital and didn’t experience many of the typical symptoms. But soon, Kayla began falling, had trouble seeing in school and also had bladder control issues.

“I was seeing double. I had to close one eye in order to just see what was in front of me. I had to tilt my head,” the now 24-year-old tells Global News.

She remembers once falling down a hill and thinking she had broken her ankle. After going back and forth between specialists, getting many X-rays and a spinal tap, a child neurologist told Dalley’s family that she had MS.

“I have a lot of permanent damage because it took so long to find any sort of treatment that worked for me,” she explains.

WATCH: Reasons why MS is much more common in women than men

Click to play video: 'Reasons why MS is much more common in women than men'
Reasons why MS is much more common in women than men

“I was so young. They were nervous to try me on a lot of the medications.” Dalley’s bladder is permanently damaged, she struggles with coordination and she uses a wheelchair.


In July 2016, Nicole Hajjar, 35, was travelling across Europe with her husband when she started noticing she had trouble seeing from her right eye. Thinking it was a sunburn or a scratched cornea, a doctor advised her to see an optometrist, who suggested it could be MS.

“My husband’s aunt has it as well, which was scary,” the Toronto resident says. “She was diagnosed in her 20s and was much further into the disease. I was thinking … this is my future.”

By the time Hajjar returned home, she had lost the use of her right arm. By November, with stressful family events going on, she lost vision in both eyes. She was formally diagnosed with RRMS in December 2016.

“They explained there is some basic genetics, but because I don’t have a history in my bloodline, it could’ve been because I am female.” Hajjar started medication in 2017 and since then, hasn’t relapsed. “I still get tingles and get paranoid which really makes it worse,” she says, adding she still gets random itches on her right thumb and wrist.

What the research shows

When Hajjar was diagnosed, her doctor told her a lack of vitamin D was a key factor in why so many women have MS. Ploughman says studies have shown countries above the equator have higher rates of MS compared to those below, and areas with long winters (like Canada), have been linked to the vitamin D hypothesis.

“Canada is also well known for its higher rates of MS in European populations … so there are a lot of factors that put MS right in the middle of Canada’s plate.” Ploughman adds vitamin D is important because of its conjunction with calcium and strong bones.

“What we understand now about vitamin D is that it also involves the immune system … you need adequate levels to dampen an overactive inflammatory system.”

Studies have also shown when children are born in May, for example, they have higher rates of MS than children born in the fall. This hypothesis leads back to the possible vitamin D link. “It’s because of the mother’s exposure to the sun,” said Ploughman. “In May, a mother wasn’t exposed to the sun and this has been shown in Scotland, in Canada, [and] all parts of Scandinavia.”

Prevalence of MS by country in 2013

Dr. Robyn S. Klein of Washington University in St. Louis’ neurosciences program has been studying the disease for years. In 2014, Klein and her team conducted a mice and human study. They found that mice susceptible to MS produce higher levels of a blood vessel receptor protein called S1PR2. Klein then took findings from the animal study and applied them to post-mortem human brains (with a 20-patient sample) with MS and found similar results: women produced higher levels of the S1PR2 protein.

“People have used this model to look at sex differences, but mostly focus on effects of sex hormones,” Klein told Global News. “We were wondering if there were specific genetic signatures that occurred in male vs. female animals.”

While this is a small study conducted on animals, Klein hopes it can give researchers more insight as to why women are more likely to be diagnosed with the disease. Her team is currently working on research on how to find this protein in living MS patients.

Dr. Karen Lee, vice-president of research and managing director at the MS Society of Canada, adds hormonal differences between the sexes is also common in research. Experts wonder if hormones can trigger the onset of MS.

“An interesting piece that you’ll hear all the time with people with MS is, specifically women – their hormones, they’re changing all the time especially if they get pregnant,” she continues.

Lee says there has also been research looking at prolactin (a hormone produced in pregnant women) and estradiol, an estrogen steroid hormone, to see if these hormones are causing women to have MS.

Ploughman says genetics can also play a factor.

When Karin Worth was told she had PPMS eight years ago, she was told hormones could trigger the disease. The 51-year-old mom from Kitchener, Ont., was diagnosed after having her second child at 41. “Within three months the drop foot started … but I do believe I’ve had MS my whole life.”


Unable to use her right foot, Worth went from using canes to a walker and now a wheelchair. She went through weeks of chemotherapy and an MRI in 2014 concluded there were no other active lesions in her brain and she had gone into remission.

“The whole thing with PPMS is that you have permanent damage that isn’t going to reverse.”

Drugs are available but expensive and her condition has also led to chronic fatigue. But Worth doesn’t let her condition stop her, in fact, she lives life to the fullest.

And as Ploughman mentioned before, this is common for women as they age.

Raising awareness

And while we don’t know what causes MS, the people who live with it think educating the public and raising awareness on “Canada’s disease” is the best way to move forward.

Dalley says for men specifically, there is also a notion to be strong. “What MS has taught me is that your real strength comes from your ability to persevere and to fight whatever comes down your path.”

His sister Kayla feels she is still judged often because of her invisible disease.

“You don’t know how hard people’s lives are, so I feel like you should just keep an open mind and not judge so much.”

– with files from Allison Vuchnich, Veronica Tang, Dani-Elle Dube

Visuals by Deepak Sharma

Part 5 of Brain Interrupted, our series on multiple sclerosis, will be published May 18 at 6 a.m.