Two recent studies suggest surprising but heartwarming keys to a longer life. You're more likely to rack up the years if you:

    Expect the best. Of 100,000 women in the Women's Health Initiative study, those rated optimistic by special questionnaires were 14 percent less likely than pessimists to die during the study's first eight years. "Optimists are master copers," points out investigator Hilary Tindle, MD. "They have strong social networks and handle stress better, which could make a difference."

    Care for a loved one. Despite the stress involved, men and women who put in the most time taking care of a spouse cut their own risk of dying by 36 percent over a seven-year period, researchers at the University of Michigan in Ann Arbor found. Aiding a loved one may release the "bonding" hormone oxytocin, countering cortisol, a stress hormone that can raise blood pressure and interfere with regulation of the immune system, the scientists speculate.

    最近兩個驚人但溫心的研究發現了可能能增加壽命的秘訣：

    樂觀：在倡議婦女健康研究的10萬婦女中，特別問卷評價樂觀的在研究的八年內去逝的機率低于悲觀者 40%. "樂觀者具強力適應力，" 醫學博士調查員希拉里葶荳指出。 "具有強大的社會人絡，對壓力具韌力，才造就其不同。"

    愛心：盡管存在壓力，無論是男性還是女性，推心照顧配偶的，能在在7年期間減低自己死亡風險 36%,美國密歇根大學安阿伯研究人員發現。幫助所愛的人時會釋放 "接合"荷爾蒙催產素，打擊皮質醇 -- 一種能使血壓高昇和影響調節免疫系統的應激激素，科學家們推測。