SUN EXPOSURE ASSOCIATION WITH MS
Scientists at the University of Tasmania report new evidence that increased sun exposure between the ages of 6 to 15 is associated with decreased risk of multiple sclerosis (MS), a debilitating autoimmune disease.
The finding may help explain the reason for greater incidence of multiple sclerosis in places with higher latitudes. Conversely, incidence of MS is lower in tropical locations closer to the equator receiving more direct sunlight. The research results bolster the hypothesis that environmental factors may be at least partially responsible for development of the disease.
Results from laboratory experiments reveal mice induced to develop experimental autoimmune encephalomyelitis (EAE), the animal model of MS, avert the disease process when exposed to UV radiation or injected with the active form of vitamin D. UV radiation emitted by the sun triggers vitamin D synthesis in the skin. The University of Tasmania research team wanted to examine whether UV radiation had the same protective effect against MS in humans.
Scientists chose inhabitants from the island state of Tasmania for the study. Tasmania has a high prevalence of multiple sclerosis with nearly 76 out of every 100,000 people afflicted with the disease. The study included 136 participants with multiple sclerosis and 272 controls without the disease.
Scientists used a questionnaire to determine past sun exposure, protective measures against the sun, use of vitamin D supplements, medical history and other factors potentially associated with multiple sclerosis. Researchers assessed skin phenotype and measured skin damage to obtain objective markers of cumulative lifetime sun exposure.
The results indicate that higher levels of sun exposure during childhood and early adolescence and skin damage correlate with reduced risk of multiple sclerosis. Lack of sufficient UV radiation and insufficient vitamin D may be involved in development of the disease.
British Medical Journal (2003; 327:316)
GENETIC BASIS FOR MS?
A study of 370 sets of Canadian twins bolsters evidence of an underlying genetic basis for multiple sclerosis (MS), a disabling neurological disease in which the immune system attacks the central nervous system.
Diseases may be caused by a combination of factors including genetics, diet, exercise and exposure to environmental pollutants. Twin studies involving subjects with similar or identical gene arrangements afford scientists the opportunity to determine the extent to which genetics contribute to disease.
Research compiled over two decades from the Canadian twin study concludes that identical twins exhibit a 25% overall risk of developing MS when the other twin has the disease. The rate is higher in identical twin females who have a 34% chance of acquiring MS when their twin sister has the disease. As is the case with many autoimmune diseases, most people with MS are women. Two out of every three people with the disease are female. The risk drops to 5.0% for male identical twins and 5.4% for fraternal (non-identical) twins.
In addition to confirming the genetic susceptibility underlying MS, scientists concur that a person must be exposed to an appropriate trigger to initiate the disease. The list of suspected non-hereditary triggers includes viruses, lack of sufficient sunlight and exposure to environmental toxins. Identification of both the genetic and non-hereditary factors involved in the disease will enable scientists to devise targeted treatments for MS.
Drs. CJ. Willer and George C. Ebers published the study involving scientists from the Wellcome Academy of Sciences for Human Genetics (United Kingdom), Stanford University, the University of British Columbia and the Canadian Collaborative Study Group. The results appear in the September 29, 2003 Early Edition issue of the Proceedings of the National Academy of Sciences.
PNAS (Early Edition online September 29, 2003)
MS PATIENTS REPORT BENEFIT FROM COMPLEMENTARY AND ALTERNATIVE MEDICINE (CAM)
A new study concludes the majority of MS patients who use complementary and alternative medicine (CAM) for treatment of the disease report benefits from the therapies.
Complementary and alternative medicine (CAM) encompasses a broad range of disciplines outside the realm of Western medicine. Herbal supplements, acupuncture, massage therapy, chiropractic and meditation represent examples of CAM. While few controlled studies exist to prove the safety and efficacy of CAM, consumers are flocking to alternative practitioners in greater numbers than ever before. Studies in Canada reveal approximately 50% of the population reported using CAM in 1999, an increase from 20-22% in the early 1990s.
The study includes nearly 700 subjects from the Calgary MS Clinic database. The average age of participants was 48 years old. The majority (75%) of respondents were female. Eighty five percent of participants reported suffering moderate to severe disability from symptoms associated with MS. Patients reported pursuing alternative treatments to improve health (68%) and to treat MS symptoms (61%). Sixty percent of respondents took conventional medications for management of MS symptoms. Seventy percent of the respondents in the study reported using CAM within the last two years. The overwhelming majority (72%) reported positive effects from CAM treatments. Patients regarded massage therapy and acupuncture as particularly beneficial.
CAM users obtained information about alternative treatments most frequently from the media (50%) and from family and friends (50%). MS patients cited lack of knowledge of CAM (42%) as the single greatest reason for not utilizing these treatments. The majority of MS patients undergoing alternative treatments informed their primary care practitioners and neurologists of their CAM use.
Results from controlled studies could substantiate anecdotal evidence from MS patients who report perceived benefits from CAM in the treatment of MS symptoms. In the meantime, a majority of MS patients regard CAM a valuable adjunct to conventional management of their disease.