Lonliness leads to High Blood Pressure ...
There are all sorts of studies out there (decent summary here) that suggest that being married can help you live a healthier, longer life. We can add to this literature new evidence that suggests that being older and lonely is positively bad for your health. A new study out of the University of Chicago that looked at the physical health of people 50 years and older was able to demonstrate that subjects who thought of themselves as lonely and who reported lacking companionship had blood pressure measurements which were as much as 30 points higher than those subjects who reported adequate social interactions and that they were not particularly lonely. Study co-author Dr. John Cacioppo has already observed similar findings (blood vessel problems indicative of later-life blood pressure issues) in a separate study of younger adults. So - here is the mind-body connection at work. People are social creatures by nature, and as it seems to be turning out, isolation (a psychological condition) has real negative physical health consequences.
An interesting and useful followup to this new study would be to tease apart whether the negative health effects are due to an actual lack of social contact, or just a perceived one. In other words, it is entirely possible, that some people have little contact, don't miss it and have no negative heath problems, but other people have little or even average contact, but perceive a lack, and do have negative health consequences. If I was a betting man, that's the outcome I'd be betting on. Depression may be a factor as well, in as much as it is easier to perceive a lack (of anything) when you are depressed.
Regardless of whether my speculation works out or not, the take home message is clear. People who perceive themselves to be lonely could do themselves a favor by spending some of their energies to grow new social relationships, intimate or otherwise. We're talking finding opportunities to date, yes, but also just simple things like going out to religous services, doing volunteer work at the local animal shelter, taking a class, etc. Anything that will get you out of the house and interacting positively with others on a regular basis, so that you feel engaged and a part of something important. If you meet someone who makes you happy, so much the better. If you are unable to make this sort of thing happen, becuase you are depressed and can't believe anyone would want to hang around you, becuase you are afraid that other people will reject you, or becuase of some other reason, you'd be best off seeking professional mental help (e.g., the care of a physician or psychotherapist) to get over your blocks and address any health issues you might have.