Answer: Sleep
Clues: “Hours” and “Pillow”
A study found that the sleep-time “sweet spot” for healthy aging is: 6.4 hours to 7.8 hours. People who hit that amount had better functioning of the immune system, brain and heart, as well as other organs, when measured on the molecular level.
Here are some tips on how to get the “just right” amount.
Too little sleep can be harmful for health in the long run, but a sweeping study suggests that too much sleep also may not be ideal: It’s associated with accelerated aging in nearly every organ in the body.
The amount of sleep each person needs varies based on genetics, environment, lifestyle and other factors. Some people need 6 hours, while others need 9. Women seem to need a bit more sleep than men to function best.