研究：多鍛鍊讓你青春永駐
Exercise keeps you younger - study
Exercise keeps you young
Exercise may hold the key to youth, according to a study published on Monday which showed people who keep fit are up to nine years biologically younger than those who do not.
The findings are the first to show in humans how keeping fit affects the ageing process.
The study of 2,401 twins found that a sedentary lifestyle raises the risk of a range of problems from heart disease to cancer and appears to play a key role in the ageing process.
It all appears to boil down to the length of structures called telomeres -- which protect the DNA on the chromosomes, the researchers from King's College London wrote in the Archives of Internal Medicine.
Many studies have shown telomeres get shorter over time, suggesting the cells are ageing or dying. The study, which extracted a DNA sample from their volunteers, found people who exercised more each week had longer telomeres.
Exercise lowers the risk of a range of problems such as heart disease, diabetes and cancer, the researchers said.
"It is not just walking around the block. It is really working up a sweat," said Tim Spector, a genetic epidemiologist who led the study, in a telephone interview.
The study found people who exercised vigorously 3 hours each week had longer telomeres and they were 9 years biologically younger than people who did under 15 minutes.
Spector's team, who also adjusted for body weight, smoking, economic status and physical activity at work, also said moderate exercise for 1-1/2 hours each week provided a four-year advantage.
Studying twins also provided a unique opportunity to gauge the effects of exercise on people with the same or similar genetic make-up, the researchers said.
The reason why exercise has this effect is not clear but the researchers said they believe physical activity somehow defends against the natural process called oxidative stress, which damages and kills cells.
本週一公佈的一項研究表明，鍛鍊身體是永葆青春的祕訣。研究發現，健身的人比不怎麼鍛鍊的人在生理上要年輕九歲。
這個研究結果首次表明健身對於人衰老進程的影響。
這項對2401對雙胞胎開展的研究發現，久坐的生活習慣會增大患心臟病和癌症等一系列疾病的風險，而且是影響衰老進程的關鍵因素。
倫敦國王學院的研究人員在《內科醫學檔案》中寫道，所有這些問題似乎都歸結於一種叫做“端粒”的特殊結構的長度，端粒能夠保護染色體上的DNA。
很多研究已表明，隨着年齡的增長，端粒會變短，這意味着人體的細胞正在老化或死亡。研究人員從志願者體內提取的DNA樣本中發現，每週鍛鍊較多的人端粒較長。
研究人員稱，鍛鍊身體能夠降低患心臟病、糖尿病和癌症等一系列疾病的風險。
該研究負責人、遺傳流行病學家蒂姆•斯派科特在接受電話採訪時說：“這裏所說的鍛鍊並不只是簡單的散散步，而是要運動到出汗。”
研究發現，每週進行3小時高強度鍛鍊的人端粒較長，而且比每週鍛鍊不到15分鐘的人在生理上年輕九歲。
在排除體重、吸菸、經濟狀況和工作中的身體活動量等因素的影響後，斯派科特領導的研究小組發現，每週進行一至一個半小時的適度鍛鍊仍可以讓你年輕四歲。
此外，研究人員稱，對於雙胞胎的研究爲衡量運動對於基因組成相同或相似的人所產生的影響提供了獨特的機會。
雖然鍛鍊能延緩衰老的原因目前還不清楚，但研究人員認爲，運動在某種程度上抵抗了氧化應激的自然過程，這一過程會損壞或殺死細胞。
boil down to:歸結於
oxidative stress:氧化應激
