Do I live longer with more social contact?
More social contact is associated with a longer lifespan, but the effect is far more specific than you might think: the type of contact and your sex make a difference, and quality counts more than quantity.
More social contact is on average associated with a lower risk of premature death. But the effect is more specific than the well-known message suggests. A meta-analysis1 found that people with less social contact had a 13% higher chance of dying than people with more contact. However, this only held for women and for contacts outside the family. For men and for exclusively family contact, there was no significant association.
Whether the feeling of loneliness itself shortens your life is less certain than is often assumed. An Israeli long-term study of people aged 70 to 902 followed participants for seven years. The researchers found no association between feeling lonely and dying sooner or declining faster, even after accounting for depression.
What you count as 'social contact' also matters a great deal. A 14-year Danish study of older adults3 showed that most network measures were weak and not statistically significant. Only the quality of the network, assessed by an outside observer, reliably predicted longevity. Notably, the feeling of loneliness in men was associated with higher mortality from cardiovascular disease. That is almost the opposite of what the meta-analysis found for women.
A larger network also has drawbacks. Research among two hunter-gatherer populations4 showed that women with a more central position in the network had more living children. But in one of the two groups, that same central position was associated with more illness, probably due to greater exposure to infections.
Finally, the Georgia Centenarian Study5 found that centenarians with more social resources more often lived independently rather than in a nursing home. Whether this extended their lifespan itself cannot be determined on the basis of that study. The effect also depended on which measurement instrument was used.
Five observational studies and long-term cohorts; no randomised experiments. The associations are associative, not causal. Populations, outcomes and measurement methods vary widely, making direct comparison difficult.
Will I live longer if I have a sense of purpose in life?
A strong sense of purpose in life is associated with a lower risk of premature death, but whether the relationship is also causal is not yet known. Still, there is no reason to avoid cultivating a sense of purpose: the association is consistent and robust.
Do you age faster if you have chronic pain?
Chronic pain is linked to faster biological ageing, primarily through reduced physical activity and the side effects of medications. If you have long-term pain, it is worth working with your doctor to find ways to stay active nonetheless.
Does having a pet benefit your health and longevity?
A pet can contribute to more physical activity, less loneliness, and a better sense of wellbeing, but whether it also extends your lifespan has not yet been demonstrated. If you are considering a pet primarily for your health, a dog is the best-supported choice, but weigh the practical burdens as well.
Do your eyes age faster than the rest of your body?
The lens of the eye ages noticeably early and quickly, but whether your eyes as a whole age faster than the rest of your body has not been demonstrated. The retina actually reveals a great deal about your overall health, so the two track more closely together than you might think.
How do I keep my kidneys healthy as I age?
The two best-supported steps to limit kidney damage as you age are keeping your blood pressure under control and exercising regularly. Moderate salt intake and a healthy weight demonstrably contribute to both.
How do I know whether my fatigue is caused by my thyroid?
Thyroid blood tests can rule out or confirm whether your thyroid is the cause, but a mildly abnormal TSH alone does not explain fatigue and treating it often does not help. In Hashimoto's, symptoms can persist even when your values are normal.