There's little doubt that negative emotions can be hazardous to your health, especially when cancer is in the picture. As in a previous study we featured in this space about absence lessening a spouse's ability to survive cancer, isolation can be a very deadly variable too.

These latest findings in a series of reports from the University of Chicago investigating the connection between social isolation and breast cancer development on Norway rats (very social creatures, as are humans) underscore just how harmful loneliness, stress and isolation can be, especially for females.

Rats kept in isolation or subjected to stressful situations (like the smell of a predator) were more likely to produce the stress hormone corticosterone, and it took them longer to recover from stressful situations than rats living in small groups. Moreover, isolation had a greater impact on the formation of tumors than the availability of high-energy food.

The numbers paint an even grimmer picture.

* Rats living in isolation developed 135 percent more tumors than those in groups.

* Tumors grew by more than 8,000 percent among isolated rats.

* Overall, stress and isolation increased a rat's risks of developing cancer more than three-fold.

Insciences.org December 7, 2009 Free PDF Study

EurekAlert December 7, 2009