Like you, dear Readers, I tend to be focused on the biochemistry, and have to remind myself again and again that the mind and body are intertwined. I came out last week with my core belief about biology: Mechanistic physics explains only half of what we are. Life has its own laws which we will discover only if we admit they exist.
In fact, the most powerful thing we can do to prolong life expectancy is to have robust connections to other humans. The best-documented effects are for empowering relationships with community (especially cooperative action for change) and intimate relations of love. Together, these factors contribute more to life expectancy than any diet or exercise program, or any supplements you can take. The difference is comparable to life expectancy difference between heavy smokers and non-smokers. (I wrote about these topics 2 years ago: [1. Social status and depression, activism vs powerlessness, 2. Family]
Elissa Epel is famous for having elucidated the connection between stress and eroding telomeres. But she has also brought us positive messages: Meditation is associated with telomerase expression and longer telomeres. Altruism breeds telomerase. Loving-kindness is associated with longer telomeres. In a publication last summer, she and co-authors documented the benefits of sex. Women (all subjects were partnered females) who had sex at least once in the week surveyed had longer telomeres than women who did not.
The result added to evidence that goes back at least 20 years. The Caerphilly study showed that frequency of sex correlated with lower all-cause mortality in men. The conclusion extends to women. The tendency of medical professionals to interpret the result in terms of the biochemistry of orgasm has been tempered, as it became clear that sex with a partner, with or without orgasm, has benefits above masturbation [ref]. Intimacy without sex has its health rewards, as does the strength of one’s community fabric.
So, in this context, the headline result from the newest study is no surprise. The puzzle is that, even though powerful connections between social relations and health are confirmed again and again, the details keep changing, and consistency is elusive.
For example, the study just cited found that subjects who reported more sexual activity had longer telomeres, but they didn’t have more telomerase activity. In fact, they had (almost statistically significant) less telomerase activity. This was a short-term study. Telomerase activity is a short-term variable, and telomere length is supposed to respond in the longer term to telomerase activity. We should not have been surprised if an increase in telomerase had been observed, without a significant difference in telomerelength. The opposite finding suggests a missing link in the causal chain. (The Discussion text in the article is very open about this mystery.)
The study included only women. Women have been found to be more sensitive to the quality of loving attention and the depth of their connections in love, while men tend to respond to the cruder quantitative variable of sexual activity [ref]. But for women in this study, telomere length was related only to the frequency of sex, and not to the quality of relationship, or to relationship satisfaction. In fact, they found no significant association with any of the subjective questions asked concerning satisfaction with the relationship, or feelings of closeness. Again, the investigators themselves were surprised.
Paradoxical results from other studies: Men (>57yo) who had frequent sex (more than once per week) and men who self-reported that sex was “extremely satisfying” had twice as many heart attacks in the ensuing five years [ref]. In the same study, results for women were not strong enough to be statistically significant, but were strange enough to be puzzling. Women (>57yo) who reported sexual relations that were highly satisfying had higher risk of cardiovascular disease, but women who reported most intense pleasure from sex had lower risk. “These findings challenge the assumption that sex brings uniform health benefits to everyone.”
This classic study found that marriage offers substantial benefits in life expectancy for both men and women, but that the benfits for men are far larger. The relative risk in mortality rate, unmarried vs married, is 1.5 for women but 3.5 for men. The large disparity has not held up in more recent studies.
This is the most comprehensive recent review of the relationship between social variables and all-cause mortality, but it is confusingly written (I believe the verbal interpretation of statistics is incorrect). The message comes through loud and strong, that social integration accounts for a large benefit in decreased all-cause mortality, accounting for 5 to 10 years of life expectancy. But even more than in other fields of social science, there are contradictory results and inconsistencies that thwart anyone trying to tell a neat story.
Why is social connection so important to health
Bert Uchino distinguishes between “perceived support” and “received support”. The correlation of the former with health and mortality variables is robust. But the latter is sometimes found to be inversely correlated with health. This seems to say that if people are helping you and you don’t appreciate it, you’re worse off than if you had been on your own. If you think you’re embedded in a caring and supportive community, you’ll live longer. If you’re actually embedded in a caring community, but you devalue what you’ve got or if you isolate yourself because you’re more comfortable that way, your life expectancy is shortened. This is a morality tale if I ever heard one.
Conflictual interactions in the context of marriage (as in Western culture generally) contribute to higher levels of systemic inflammation [ref]. But this study found no relationship between job stress in men and measures of chronic inflammation. Maybe it depends on what is meant by “stress”. This study suggests that feeling out of control (powerlessness, low status) is associated with markers of inflammation.
Why do we care about this? Many of us are fanatical about following the best evidence when designing exercise and supplement regimens for ourselves. But is there anyone out there who is waiting for the latest correlation with telomere length before deciding whether to fall in love? (I didn’t think so.)
No, the reason we care about this subject is that it reminds us that aging is a social process almost as much as it is a biological process, even if the social correlates of longevity confound our best intuitions about how to live well.
And perhaps it reminds us, indirectly, that in the “rationalization” of our health care system, we have made a bad bargain. Over the course of my lifetime, medical practice in America has gone from a model of individualized care by family doctors to impersonal care by specialists. Medical care has become more evidence-based, and there is a much better chance that the doctor who treats your condition has a deep knowledge and experience of that condition. But what we’ve lost along the way is the doctor-patient relationship—both because you see a different specialist for each condition, and also because as doctors’ time is squeezed to optimize profit, the time for listening and empathizing has been eliminated. Despite the accumulation of studies showing that doctor-patient relationship has an outsized effect on prognosis, our present health care system is systemically deficient in human caring.