The scourge of loneliness has been with us since time immemorial, but only recently has its toll on human health gained appreciation. New research shows that feeling lonely or socially isolated bumps up a person’s average risk for coronary heart disease and stroke – two of the developed world’s most prolific killers – by 50 percent.

As a risk factor for heart attack, clogged arteries or stroke, those statistics put loneliness on a par with light smoking, anxiety and occupational stress. And they make social isolation a more powerful predictor of such vascular diseases than are either high blood pressure or obesity.

Moreover, the toxic effects of loneliness strike men and women equally, researchers found.

Added to research linking loneliness to higher rates of cognitive decline and poor immune system function, loneliness begins to look like a blight not just on society but on our collective well-being.

The new research, published Tuesday in the British Medical Journal’s publication Heart, aggregated the findings of 23 separate studies that asked people to characterize their level of social engagement. Each of those studies tracked participants for periods ranging from three to 21 years and noted if they had a first stroke or were newly diagnosed with, or died from, coronary heart disease.

The studies suggest that people who suffer from loneliness or social isolation were 29 percent more likely than those who are not to develop coronary heart disease – suffering either a heart attack or requiring intervention to clear blocked arteries. And they were 32 percent more likely than the socially engaged to have a stroke.

“Given projected increases in levels of social isolation and loneliness in Europe and North America, medical science needs to squarely address the ramifications for physical health,” stated an editorial published in Heart.