By Genevra Pittman

NEW YORK (Reuters Health) - For years doctors have assumed black people are less likely to develop multiple sclerosis (MS) than whites, but a new study suggests the opposite may be true.

Researchers found black women were more likely than white women to be diagnosed with MS, in which the protective coating around nerve fibers breaks down, slowing signals traveling between the brain and body. Among men, there was no difference.

"The thing I was taught in medical school is that this is a disease primarily of white people," said Dr. Annette Langer-Gould, who led the new study at Kaiser Permanente Southern California in Los Angeles.

But most of that older data came from potentially unrepresentative research, she said, such as a study of veterans from the 1950s that found white men were twice as likely to get MS as black men. What's more, she pointed out, most MS clinics are in predominantly white areas - skewing how people perceive the disease.

The new report, Langer-Gould said, is the first to look at a group of patients representative of a large population.

She and her colleagues analyzed three years' worth of medical records for the 3.5 million patients in the Kaiser Permanente health system. During that time, 496 were diagnosed with MS.

The researchers found that over an average year, 10 out of every 100,000 blacks developed the disease, compared to 7 white patients, 3 Hispanics and just over 1 Asian per 100,000.

More than two-thirds of all MS diagnoses were in women, and that gender gap was particularly strong among blacks, Langer-Gould and her colleagues reported Monday in Neurology.

She said it's still not clear why the frequency of the disease varies by race, although her team is doing a follow-up study to try to answer that question.

Up to 25 percent of an individual's risk for MS is thought to be due to genes, Langer-Gould said - but the rest likely has to do with everything from environmental influences, such as smoking, to vitamin D and hormone levels.

Langer-Gould's group cannot say whether past research truly underestimated how often blacks develop MS, or whether the rates in the new study represent a more recent rise in cases.

The new study "very strongly implies that the rate has really gone up in blacks," said Dr. George Ebers, a neurologist who studies MS at John Radcliffe Hospital at theUniversity of Oxford in the UK but wasn't involved in the new research.

"This may be the conjunction of the Western lifestyle, whatever that is … plus the fact that they're living in the relatively northern section of the world," where there's less vitamin D from sunlight, for example, Ebers told Reuters Health.

If there has been an increase in blacks' risk, he said it would have to be due to the environment - since genes wouldn't change that much over a couple of generations.

MS symptoms typically start with numbness and tingling from the waist down or weakness on one side of the body - such as after a stroke. Because of the notion that they're at lower risk, many black patients are initially misdiagnosed, Langer-Gould said.

"This is a disease that affects all racial and ethnic groups," the researcher told Reuters Health.

"If somebody comes in with symptoms that are suspicious for it, particularly blacks, those symptoms should be taken seriously and worked up and not assumed that it can't possibly be MS because they're the wrong race or ethnicity."

SOURCE: http://bit.ly/Q5TNl Neurology, online May 6, 2013.

Also on HuffPost:

Loading Slideshow...
  • Ann Romney

    Republican Presidential candidate Mitt Romney's wife's MS is central to his campaign. They often discuss her 1998 diagnosis, as well as how she <a href="http://abcnews.go.com/Health/ann-romneys-ms-highlights-unpredictable-disease/story?id=16221663#.T99GaytYvJV" target="_hplink">managed the disease while raising five sons</a>, ABC reported. <br><br> But she recently had to take a break from campaigning when her symptoms were aggravated. "I start to almost lose my words. I almost can't think. I can't get my words out. I start to stumble a little bit and so <a href="http://www.etonline.com/news/121147_Ann_Romney_on_Recent_MS_Scare_on_Campaign_Trail/index.html" target="_hplink">those things were happening</a> and I thought, 'Uh oh, big trouble,'" she said in an interview with Entertainment Tonight.

  • Montel Williams

    The Daytime Emmy award-winning talk show host announced his diagnosis in 1999, and he started the <a href="http://www.oprah.com/health/Montel-Williams-Battle-with-MS-Overcoming-Depression-and-Pain" target="_hplink">Montel Williams MS Foundation</a> to raise money for research into the disease. <br><br> His <a href="http://www.oprah.com/health/Montel-Williams-Battle-with-MS-Overcoming-Depression-and-Pain/3" target="_hplink">main symptom is pain</a>, he told Dr. Oz on an episode of "Oprah." "I've got pain from my shins to my feet, 24 hours a day, 365 days a year, and it's been there for the last 10 years." Then the pain spread to his face. "It literally feels like you're taking a fork and stabbing me right now. People say, 'How the devil do you deal with this?'" he said. "You have to get a grip."

  • Richard Cohen

    The Emmy award-winning journalist and husband to Meredith Viera <a href="http://www.usatoday.com/news/health/spotlighthealth/2004-07-07-cohen-spotlight_x.htm" target="_hplink">first learned of his diagnosis in 1973</a>, but was reluctant to speak up about it, he told <em>USA Today</em> in 2004. "I always resisted being defined by my MS," he said. "That's why I was obsessively secretive about it in the early years. It never dawned on me that people thought I had a drinking problem. Police even followed me home a few times thinking I was under the influence."

  • Richard Pryor

    The comedian was first <a href="http://www.usatoday.com/life/people/2005-12-10-richard-pryor-obit_x.htm" target="_hplink">diagnosed with MS in 1986</a>, and eventually became debilitating enough to drastically affect his work,<em> USA Today</em> reported. <br><br> He died in 2005 of a heart attack at age 65.

  • Teri Garr

    The actress, well known for her roles in "Young Frankenstein" and "Close Encounters of the Third Kind" was diagnosed with MS in 1999, <a href="http://www.rd.com/health/actress-terri-garr-battles-multiple-sclerosis/" target="_hplink">after 16 years of symptoms</a> like tingling, tripping and stabbing pain, according to <em>Reader's Digest</em>. <br><br> She <a href="http://www.everydayhealth.com/multiple-sclerosis/teri-garr.aspx" target="_hplink">spoke out publicly about the disease in 2002</a>, according to Everyday Health, becoming a pair spokesperson for an MS medication and a National Ambassador for the National Multiple Sclerosis Society, and advocating for research and education.

  • Tamia Hill

    The singer and wife of NBA player Grant Hill opened up on "Extra" in 2005 about <a href="http://telepixtvcgi.warnerbros.com/v2/news/0505/27/3/text.html" target="_hplink">her diagnosis nearly two years before</a>. "I went from being physically active to not being able to get out of bed," she said. <br><br> But she knew she had to push through and <a href="http://www.nationalmssociety.org/online-community/personal-stories/tamia/index.aspx" target="_hplink">speak up about the disease</a>, she said. "I just felt it was important to get it out there and let people know it's not a sign of weakness. You have good days and bad days."

  • Clay Walker

    The country musician was <a href="http://www.nationalmssociety.org/online-community/personal-stories/clay-walker/index.aspx" target="_hplink">diagnosed in 1996 at the age of 26</a>, according to the National Multiple Sclerosis Society, after losing feeling in his right hand and leg. <br><br> Through mediation, diet and exercise, he has regained feeling, continued on in his music career and worked to raise money and awareness of the disease. He was <a href="http://www.nationalmssociety.org/online-community/personal-stories/clay-walker/index.aspx" target="_hplink">named Ambassador of the Year</a> by the National Multiple Sclerosis Society, only the fourth person to receive the distinction in nearly 60 years.

  • Alan And David Osmond

    Alan, entertainer and producer (and brother to Donny and Marie), noticed he was tripping on nothing while he was on stage in 1987 and was <a href="http://www.nationalmssociety.org/ms-awareness-week/alan-osmond/index.aspx" target="_hplink">diagnosed with MS</a> a few years later, he told the National Multiple Sclerosis Society. <br><br> His son, David, known for his turn on "American Idol," was <a href="http://www.nationalmssociety.org/online-community/personal-stories/david-osmond/index.aspx" target="_hplink">diagnosed in 2006</a>, and says one of Alan's favorite sayings -- "I may have MS but MS does not have me" -- keeps him performing. <br><br> <em>Photo: Left to right: Alan, David and Donny Osmond</em>

  • Joan Didion

    The writer, who <a href="http://www.independent.co.uk/life-style/health-and-families/features/lsquothis-is-what-ms-looks-likersquo-2122567.html" target="_hplink">detailed her diagnosis in "The White Album,"</a> told the <em>New York Times</em> she went <a href="http://www.nytimes.com/1979/06/10/books/didion-calif.html?pagewanted=3" target="_hplink">blind for six weeks</a> due to the disease.

  • Michaele Salahi

    The "Real Housewives of Washington D.C." star revealed a <a href="http://www.foxnews.com/entertainment/2010/09/15/exclusive-michaele-salahi-says-multiple-sclerosis/" target="_hplink">17-year battle with MS</a> on a 2010 Fox appearance. She said she hoped to use her fame to help others.

  • Michelle Obama

    The First Lady <a href="http://news.yahoo.com/blogs/cutline/michelle-obama-letterman-isn-t-oprah-where-laughs-231917424.html" target="_hplink">spoke about her father's multiple sclerosis</a> on a recent episode of "The Late Show With David Letterman." "I never knew him to be able to walk, but my dad worked so hard and he loved us so much," she said. "I think from him I learned just absolute, complete unconditional love, the notion that kids really don't need anything but to know that their parents adore them."

  • J.K. Rowling

    The author's mother passed away in 1991 after a <a href="http://www.people.com/people/article/0,,1147497,00.html" target="_hplink">10-year battle with MS</a>, People.com reported. She said that her greatest regret is that her mother didn't live to see the wild success of Rowling's Harry Potter series.

  • Related Video