A little more sunshine might help you live longer, according to a study suggesting that for some people health benefits from the sun outweigh the risk of skin cancer.
Sunlight spurs the body to produce vitamin D but fear of skin cancer is keeping many people in the shade and depriving them of an important protection from a range of diseases, researchers said.
"The skin cancer risk is there but the health benefits from some sun exposure is far larger than the risk," said Johan Moan, a researcher at the Institute for Cancer Research in Oslo, who led the study. "What we find is modest sun exposure gives enormous vitamin D benefits."
A number of studies have found protective effects from higher vitamin D intake for some cancers and ailments such as rickets, osteoporosis and diabetes, Moan said. Certain foods contain vitamin D but the body's main source comes from the sun.
The researchers calculated that given the same amount of time spent outside, people living just below the equator in Australia produced 3.4 times more vitamin D than people in Britain and 4.8 times more than Scandinavians.
This means even though rates of internal cancers such as colon cancer, lung cancer, breast cancer and prostate cancer rise from north to south, people in the sunnier latitudes were less likely to die from the diseases, the researchers said.
"The current data provide a further indication of the beneficial role of sun-induced vitamin D for cancer prognosis," said Richard Setlow of the US Department of Energy's Brookhaven National Laboratory, who worked on the study.
Getting more vitamin D – which helps the body's immune system work properly – is also critical for people living in places like Scandinavia where long winters and short days during the year limit sun exposure, Moan added.
In Norway, Moan estimated that doubling the sun exposure for the general population would also double the number of annual skin cancer deaths to about 300 but that 3,000 fewer people would die from other cancers.
"The benefits could be significant for people in other countries as well," he said in a telephone interview. "I would be surprised if they were different."
Moan, whose findings were published in the Proceedings of the National Academy of Sciences, recommended daily sun exposure for about half the time it takes a person to get sunburn.
Another way to get more vitamin D could be designing sunscreen that blocks long ultraviolet wavelengths that trigger the deadliest forms of skin cancer while letting through short ultraviolet wavelengths that produce the vitamin, the researchers said.
多曬太陽(yáng)可以幫助你活更長(zhǎng)時(shí)間,根據(jù)一項(xiàng)研究表明,一些人從日照得到的好處勝于得皮膚癌的危險(xiǎn)。
研究人員說(shuō),陽(yáng)光能促使身體產(chǎn)生維他命D,但是恐懼得皮膚癌使許多人躲在黑暗里,這種恐懼剝奪了一系列疾病的重要保護(hù)。
"得皮膚癌的危險(xiǎn)是存在的,但是從日照得到的益處遠(yuǎn)遠(yuǎn)大于得癌的危險(xiǎn)"奧斯陸癌癥研究中心的研究員Johan Moan說(shuō)"我們發(fā)現(xiàn)適當(dāng)日照產(chǎn)生大量維他命D"
Moan 說(shuō),大量研究發(fā)現(xiàn)服用高濃度的維他命D對(duì)某些癌癥和疾病有保護(hù)效果,如軟骨病,骨質(zhì)疏松及糖尿病。 某些食物也含維他命D但人體所需維他命D主要來(lái)自日照。
研究人員計(jì)算出同等時(shí)間戶(hù)外活動(dòng)的情況下,生活在赤道的澳大利的人產(chǎn)生的維他命D是英國(guó)人的3.4倍,斯堪的納維亞人的4.8倍。
研究人員說(shuō),這就意味著即使得體內(nèi)癌癥如結(jié)腸癌肺癌乳腺癌及前列腺癌的幾率從北向南上升,生活在日照多的地區(qū)的人死于這些疾病的可能性小的多。
當(dāng)前數(shù)據(jù)陽(yáng)光產(chǎn)生維他命D為癌癥預(yù)測(cè)提供了進(jìn)一步的征象。進(jìn)行這項(xiàng)研究的美國(guó)能源部Brookhaven國(guó)家實(shí)驗(yàn)室的 Richard Setlow 說(shuō)。
Moan補(bǔ)充道,獲得更多的維他命D有益于身體免疫系統(tǒng)適當(dāng)工作,同時(shí)對(duì)生活在像斯堪的納維亞那樣冬天長(zhǎng)白天短一年日照有限的地方來(lái)說(shuō)是至關(guān)重要的。
在norway,moan估計(jì)雙倍曬太陽(yáng)的人得皮膚癌的幾率也是雙倍,大約有300人,但是死于得其他癌癥的要少3000.
曬太陽(yáng)的益處對(duì)其他國(guó)家的人們同樣重要。moan在電話采訪中談到。"如果他們有什么不同我將很驚奇"
moan,他的研究成功發(fā)表在國(guó)家科學(xué)的公報(bào)上,他指出每天曬半天太陽(yáng)容易曬傷。
研究人員說(shuō),另一種獲得維他命D方法可能為設(shè)計(jì)一種防曬霜,她阻擋致癌的長(zhǎng)波紫外線,但能獲得產(chǎn)生維他命D的短波紫外線。