Shine some winter light on the MS mystery

There is an old saying in medicine, “when you hear hoof beats, don’t look for unicorns.” It means that doctors should look for horses when they hear hoof beats. They should look for the obvious.

But when it comes to the mystery of multiple sclerosis, we have been looking far too long for those magical, one-horned horses! And we’ve been ignoring the obvious.

Until now, that is.

A new study recently published in the medical journal Neurology pulls back the curtain and shines some light on the mysterious origins of multiple sclerosis. And finally, we may have the answers we need to help prevent this devastating disease. 

I first learned about multiple sclerosis in the 1970s while studying diseases in the tropics. At the time, virologists wildly speculated that perhaps new viruses caused MS.

Viruses normally thrive in hotter, more tropical climates. But MS typically strikes men and women in colder climates, so this theory would represent a revolutionary, new cold-climate virus! 

Other tortured theories ran rampant. I remember one theory suggested that dogs somehow gave MS to humans. People in northern latitudes keep dogs more commonly as pets. And they keep them indoors. In the tropics, where MS rarely occurs, dogs aren’t kept as pets. And they stay outside.

I’m not sure how this dog theory got any traction by serious virologists. The dog is truly “man’s best friend.” And woman’s too. In fact, there is no known disease transmitted by dogs to humans. Virtually every other species of animal can transmit diseases to humans, however. But back then, they thought it just had to be those dogs!

Another theory supposed that MS arose after the Axis Powers introduced “something” into the northern, sub-arctic environment during WW II. Large numbers of military personnel were stationed at the time in Greenland, the Aleutian Islands, and elsewhere below the Arctic Circle.

The reductionists literally went around in circles with their theories.

Of course, this is also back when the words nutrition and medicine were never uttered in the same breath. And nobody ever considered a link to nutrition, sunshine, or vitamin D–despite the obvious pattern.

We already knew that MS occurs more commonly at higher latitudes in the northern hemisphere and in colder climates. And the same occurs at higher latitudes in the southern hemisphere. Both areas are further from the equator.

And what’s the most obvious thing about these higher latitudes?

They are colder, with less sun, right?

But it seems researchers never really put two and two together. Until now.

In fact, the new study suggests that low vitamin D levels may explain the increasing incidence of multiple sclerosis found in statistical studies.

I often report on the importance of maintaining adequate vitamin D levels, especially as we get into the late winter.

Your body stores vitamin D, but your sun exposure drops as the winter goes on. So your stores of vitamin D can take a hit in the late winter. Especially if you live in the higher latitudes. In fact, it is impossible to get enough sunlight to activate vitamin D from November to March in North America at latitudes north of Atlanta, Georgia.

And the government in the U.S. only compounds the problem. Its widely promoted, half-informed PR policies encourage people to avoid sunlight. Even medical professionals, who should know the importance of vitamin D, urge you never to go out in the sun without sunblock.

Well, the new study shows us just how poor this advice may really be, especially with regards to MS.

Researchers from Sweden just completed testing of nearly 300,000 blood samples. These samples came from healthy people who lived in Northern Sweden. They were stored in blood banks since 1975.

The researchers measured vitamin D levels in people who subsequently developed multiple sclerosis over the ensuing years.

Such an approach is useful because blood levels are actually measured long before the presence of any disease. This eliminates the chance that the disease itself would have affected blood levels.

The researchers found that the higher the level of vitamin D, the lower the risk of developing multiple sclerosis later in life. And the lower levels of vitamin D, the greater the MS risk.

The research focused on men and women living in Northern Sweden. Literally a place where the sun doesn’t always shine. So they focused on the part of the curve where most serious deficiencies can occur.

But we can apply the same principle to other latitudes as well. In general, decreasing vitamin D levels over time may explain the rising incidence of multiple sclerosis around the globe.

This study suggests that vitamin D levels are important in preventing the development of MS. However, the study did not test whether higher vitamin D levels can help manage this condition once it has occurred. But Northern Sweden is just the place where we would expect a real discovery to emerge concerning the treatment of MS with vitamin D. 

Although, you can no longer be sure about the Swedes. Remember, last year Sweden ran a politically-correct campaign against sun-tanned swimsuit models?

Let’s keep our fingers crossed and hope some of this new research does begin to spill over and inform public policy in Sweden. And around the world. Real help could be on the way.  

1. Neurology, Nov. 20, 2012: 79: 2083