Sleep - How much do you need for health and long life?

Hours of sleep and mortality

My comments and personal experience

References

Hours of sleep and mortality

Both too much and too little sleep can reduce your life expectancy and health. The optimal sleep for a long life seems to be between seven and eight hours per night, according to a study of 1.1 million men and women between 30 and 102 years of age. The best survival rate was among those who slept 7 hours per night. There was a 15% increase in risk of death among participants who reported sleeping less than 4.5 hours or more than 8.5 hours. (1)

Another study confirmed that sleeping less than four hours also significantly increases death rates, and even five hours is not enough for good health in the long term. (2)

In addition to being essential for your body's general health, sleep is a brain detox process. Without sufficient sleep your risk of depression, dementia and all kinds of psychological problems is significantly raised.

My comments and personal experience

From my mid-60's and onwards I have found that I don't need 7 to 8 hours of sleep per night. Six and a half or seven hours seems to do me well. If I had a very late night the day before then sometimes I will actually manage to sleep for 8 hours, but normally I find myself waking up after six and a half or seven hours. I don't need more sleep than that, and remain unusually fit and functional for my age.

I have no research to refer to, but I am confident to say that if you get plenty of exercise, and if you eat a diet of clean real food, then you don't need seven to eight hours of sleep in middle-age and especially after age 60 years.

In contrast, children, adolescents and even those in their late teens and early 20's do need their sleep, and find it easy to sleep that long.

Don't worry too much about the number of hours sleep that you get however, unless you are at an extreme. The regularity and depth of your sleep is more important. Several studies show that a regular daily schedule is more important for your health and longevity.

This means going to bed and rising at the same time every day, weekends included. Regular daily habits not only apply to sleeping, but also to eating, exercise and a large part of your lifestyle. Maintaining consistent Circadian rhythms will ensure health much more than a five-hour night followed by a nine-hour night. Regularity will help you to sleep deeply and avoid insomnia.

Not everyone needs the same amount of sleep. You can check your body type here, to get a good idea of the sleeping habits, diet and particular foods, climate, lifestyle, social habits and other factors that will best help your state of health, both mental and physical.

References

1. Daniel F Kripke, Lawrence Garfinkel, Deborah L Wingard, Melville R Klauber, Matthew R Marler. Mortality associated with sleep duration and insomnia. Archives of General Psychiatry, February 2002.

2. Severine Sabia, Aline Dugravot, Damien Leger, Celine Ben Hassen, Mika Kivimaki, Archana Singh-Manoux. Association of sleep duration at age 50, 60, and 70 years with risk of multimorbidity in the UK: 25-year follow-up of the Whitehall II cohort study. Published 18 October 2022, PLOS Medicine.