New study questions sun avoidance in northern latitude countries like Canada
Toronto With summer just around the corner, a new study out of the Netherlands has questioned if sun-avoidance advice actually benefits a person’s general health.
In the study “Sunlight: For Better or For Worse? A Review of Positive and Negative Effects of Sun Exposure,” Dr. Han van der Rhee and his team reviewed 115 studies and found that there is no unequivocal scientific proof that eliminating time spent in the sun has a beneficial effect on the human body.
The researchers found that the present ‘epidemic’ of skin cancer is mainly caused by the increase of intermittent sun exposure, coinciding with the decrease of chronic exposure. Meaning that most people are just not outside in the sun on a regular daily basis. The researchers claim that it’s unlikely that continuous protection during daily life contributes to our health, particularly in countries with a temperate climate, and warns that both too much and too little sunlight may be harmful to our health.
The researchers found that regular exposure to UV leads to an almost complete disappearance of DNA damage in the basal and suprabasal layers of the epidermis, where the initiating of skin cancer occurs. This might explain the ‘risk-lowering’ effect of regular exposure, whereby photosynthesis of extra vitamin D and/or other effects ofsunlight may contribute to this phenomenon as well.
Supplements may not provide all of the health benefits that sunshine (UV) exposure provides. Dr. van der Rhee reports: "Experiments in humans show that UV can lower blood pressure and increase insulin secretion. In addition to the production of vitamin D,immunomodulation, the role of circadian clocks, the formation of nitric oxide, melatonin, and serotonin are important as well. These biological effects may function simultaneously and in some instances even re-enforce each other's effect."
“Avoiding the sun entirely has a negative effect on a person’s overall health,” says Dr. Reinhold Vieth, Scientific Advisor for the Vitamin D Society and professor at the University of Toronto. “Sunlight is the easiest and best way for us to generate natural vitamin D, which is crucial for promoting bone and muscle health, in addition to lowering the risk of developing serious diseases such as cancer, heart disease, diabetes, multiple sclerosis and osteoporosis.”
The Vitamin D Society, a Canadian non-profit group organized to increase awareness of the many health conditions linked to vitamin D deficiency, is encouraged by the study.
“According to the research, northern countries like Canada should not be following sun guidelines from high ambient UV countries such as Australia, which is what we are currently doing, because the intensity of the sun is much higher there,” says Perry Holman, Executive Director of the Vitamin D Society. “Twelve million Canadians fall below the minimum vitamin D blood level requirements set by Health Canada and the Institute of Medicine due primarily to reduced sun exposure so it is critical to advise smart sun exposure, especially between the months of May and October.”
The Vitamin D Society urges Canadians to know their skin type and to be sensible about their sun exposure. Sunlight has many positive health benefits but it is important to avoid burning or allowing your skin to turn red.