But for those wanting to reach 100, it seems a sheer determination to carry on could also keep us alive.
Having a positive outlook, stubbornness and continuing to keep busy could be key to a long life, a study suggests.
Love of one’s family, a strong work ethic and religious faith were also factors. Researchers studied 29 people aged between 91 and 101, who were unsurprisingly found to have worse physical health than their family members aged 51 to 75.
But when it came to mental health, the oldest inhabitants of nine villages in Cilento, southern Italy, were found to be in better shape than younger relatives, suggesting that advancing years lend a greater sense of well-being.
The study by the University of Rome and University of California San Diego also found high self-confidence and decision-making skills among the very old group.
Lead author Anna Scelzo said: "The group’s love of their land is a common theme and gives them a purpose in life. Most of them are still working in their homes and on the land. They think, 'This is my life and I’m not going to give it up'. We also found that this group tended to be domineering, stubborn and needed a sense of control, which can be a desirable trait as they are true to their convictions and care less about what others think.
"This tendency to control the environment suggests notable grit that is balanced by a need to adapt to changing circumstances."
The researchers assessed mental and physical health, and also let the participants tell their life stories. Topics included traumatic events, migration and their beliefs.
Among those interviewed was a long-living man who had lost his wife of 70 years and had been left feeling empty after her loss a month before. He said: "Thanks to my sons, I am now recovering and feeling much better. I have four children, ten grandchildren and nine great-grandchildren. I have fought all my life and I am always ready for changes.
"I think changes bring life and give chances to grow."
One nonagenarian said: "I am always thinking for the best. There is always a solution in life. This is what my father taught me - always face difficulties and hope for the best."
Another quoted in the study, published in International Psychogeriatrics, said: "I am always active. I do not know what stress is. Life is what it is and must be faced always."
One participant said: "I feel younger now than when I was young."
Dr Dilip Jeste, professor of psychiatry at UCSD, said: "There have been a number of studies on very old adults, but they have mostly focused on genetics rather than their mental health or personalities.
"The main themes that emerged from our study, and appear to be the unique features associated with better mental health of this rural population, were positivity, work ethic, stubbornness and a strong bond with family, religion and land."
Jeste added: "This paradox of ageing supports the notion that well-being and wisdom increase with ageing even though physical health is failing.
"Studying the strategies of exceptionally long-lived and lived-well individuals, who not just survive but also thrive and flourish, enhances our understanding of health and functional capacities in all age groups."
A previous study looked at the diet and lifestyle of residents in Acciaroli, south-west Italy, where one in 10 locals lives past the age of 100. It found many elderly locals continued to enjoy an active sex life and a healthy Mediterranean diet featuring olive oil, fresh fruit, home-grown vegetables and fish. - Daily Mail