A Link Between Sunshine and Leukemia?

Leukemia, or cancer of the blood cells, accounted for more than 350,000 of the new cases of cancer worldwide in 2012, with some 54,000 instances of those being in the United States. Scientists are still unsure of the exact causes of the disease, although a variety of genetic and environmental factors are thought to play a role.

 

There have been a number of studies published in recent years linking vitamin D levels with lower Leukemia rates. The good news here is that vitamin D is found in a variety of food sources, ranging from oily fish (especially salmon), egg yolks, cheese, and certain fortified cereals. Unfortunately, in these cases, the concentration of vitamin D is generally quite low. The best overall source is sunlight. Ultraviolet B (UVB) rays from the sun penetrate bare skin, which induces the synthesis of vitamin D.

 

A recent study, coauthored by adjunct professor Cedric Garland in the Department of Family Medicine at the San Diego campus of the University of California investigated the connection between UVB exposure and Leukemia rates.

 

Their findings, while not conclusive, are interesting, to say the least.

 

The study clearly shows that Leukemia rates tend to be highest in countries farthest from the equator, where UVB exposure rates tend to be lower. The data used for the study was gained from the IARC (International Agency for Cancer Research) 2012 database.

 

Adjusting for age, they were able to examine the incidence rates for 172 countries around the world, and their findings painted a clear picture. Citizens living in nations such as Canada, Ireland, the United States, Australia and New Zealand were at least twice as likely to have leukemia as people living closer to the equator in countries such as Bolivia, Samoa, Madagascar, and Nigeria. This association remained, even after accounting for gender specific life expectancy and altitude.

 

The database proved to be a treasure trove of information for the research team, but they note that it is not without its limitations. For instance, they were unable to control for a variety of other factors that may fuel (and in some cases, quite significantly) the difference between varying rates of incidence on a country by country basis. Even so, the correlation seems quite clear, and is certainly worth of further inquiry and deeper study.

 

Given the number of cases in the US alone, this information gives medical providers an important opportunity. It’s no secret that the typical US lifestyle is quite sedentary, and that we, as a nation, don’t get enough exercise. Now, there’s another reason to suggest getting more.

 

Many of your patients have no doubt made New Year’s Resolutions, and odds are excellent that many of these revolve around getting fit, exercising more and losing weight. Those are all good things, but now, there’s another reason to exercise, and more specifically, to do some outdoor activity that will get your blood pumping. The bottom line is, the sunshine is good for you, and it appears that doing so will not only improve your health in a general sense, but it could also lower your risk of developing Leukemia. That’s good news all around.