Yesterday, I mentioned how a paper reported that 3 weeks of dietary restriction increases social activity in rats. And we know, from many papers over the last 90 years, that dietary restriction increases the life span of organisms. Could there be a link between the two?
In this weeks Science magazine there is a mini review of the health effects of social isolation. Lisa Berkman from Harvard University, is a leading scholar on this subject and discusses a study of 7,000 individuals and notes that those who had a low social score (low integration into society) were 2-3 times more likely to die within the subsequent 7 years compared to those that had a higher social score (not sure if there was a difference between the people with an average social score and the low scorers). She points out that they controlled for risk factors such as alcohol use and other factors. She goes on to say,
“What social isolation was doing was making you more susceptible or less resilient to any disease you might get.”
A dozen similar papers have replicated this general finding. But there is still an open argument about the cause-effect relationship.
When researchers tried a very large study ($ 40 million) to increase the social network of individuals who have suffered a heart attack in an attempt to prevent a second heart attack they found reduced depression but the increased social network intervention not change any measurement of heart disease. A second study in stroke patients confirmed the first study and the researchers concluded that social isolation does not cause cardiovascular disease (though there might still be lonely hearts). However, Berkman offers the argument that the damage of the social isolation had already done its harm to the cardiovascular system, and any social intervention after a heart attack or stroke is too late. This is a reasonable argument since most pharmaceutical interventions do not work after the damage has occurred. Like almost everything else in health science the best policy is prevention, prevention, prevention.
While we found out from about that social support does not improve the cardiovascular system but what about cognitive recovery after a cardiovascular incident? People with higher social support and integration have better cognitive scores 6 months after stroke (Glymour et. al., 2008). The social support did not improve the rate of recovery – but it appear the subjects with social support were more resilent and suffered less cognitive loss from the stroke. An additional study found that socially isolated women were more negatively affected by breast cancer, as measured by a larger drop in quality of life measurements compared to non-isolated cancer survivors (Michael et. al., 2002).
You could argue this only makes common sense that good social support is better for your health than being socially isolated. I guess at a societal level the question becomes can we intervene by increasing the social support and network for socially isolated people to improve their health, and is this a cost effective health policy.
Does an intervention that increases your health and longevity increase your socialness (according to yesterday’s post at least one intervention does); and does increasing socialness improve your health and possibly longevity – potentially (see above), most likely if done prior to disease onset. Interesting parallels I think.
Potential interactive and feed forward cascades: go out there and get your daily dose of social interaction and support, but also do the right fundamental health things that have been linked with longevity.
Update: Check out this piece on do longevity treatments make you more social?