If you have a naturally grumpy disposition, then here’s some news that’s sure to put a smile on your face (if only temporarily): A new study from the University of Oxford in the United Kingdom has found that happiness is not associated with living a longer life, as previous research has frequently suggested.
That earlier research confused cause and effect, say the authors of the new study. “Our findings show that unhappiness is associated with poor health mainly because poor health causes unhappiness,” they write, “and partly because unhappiness is associated with lifestyle factors such as smoking. After adjustment for these factors, no robust evidence remains that unhappiness or stress increase mortality or that being happy, relaxed, or in control reduces mortality.”
Or, as lead author Bette Liu, an epidemiologist who is now at the University of New South Wales in Australia, put it in a released statement: “Illness makes you unhappy, but unhappiness itself doesn’t make you ill.”
For the study, which was published this week in The Lancet, Liu and her colleagues analyzed data collected from more than 700,000 British women, aged 55 to 63, who had been recruited into the University of Oxford’s Million Women Study between 1996 and 2001. At the time they entered the study, none had been diagnosed with a serious health problem, such as cancer, heart disease or emphysema.
Each of the participants filled out a questionnaire that asked them, among other things, “How often do you feel happy?” According to the responses, 39 percent of the women said they were happy “most of the time,” 44 percent stated they were “usually” happy, and 17 percent indicated they were unhappy (happy only “sometimes” or “rarely/never”).
An analysis of those answers revealed that women were more likely to report being happy if they were older, physically active, and not economically deprived, and if they did not smoke, got adequate sleep (but not too much), had a partner, and either belonged to a religious group or participated in social activities.
The women who reported being unhappy were more likely to say they were in poor health.
All the women were followed for an average of 9.6 years, a period during which about 4 percent (30,000) of them died. Liu and her colleagues then analyzed the data to see if they could find a connection between those deaths and the women’s happiness levels. They found such a connection — but it disappeared once they adjusted for how healthy the women reported being at the time they entered the study.
About 20 percent of women had rated their health as “fair” or “poor” at the start of the study, while the other 80 percent had said their health was “excellent” or “good.” The analysis revealed that women in the fair/poor group were 67 percent more likely to die during the study period than the others. But women in both groups who said they were happy died at a similar rate as women who said they were unhappy, including from cancer and heart disease.
In other words, being happy did not protect the women from dying early.
Liu and her colleagues crunched the data further and found women who said they felt “in control, relaxed or not stressed” were also not protected against an early death.
“Happiness and related measures of well-being do not appear to have any direct effect on mortality,” the researchers conclude.
“In our view, the previous studies [which did suggest such an effect] haven’t been well done,” explained study co-author and medical statistician Richard Peto to reporter Julie Beck of The Atlantic. “All that’s going on is ill health actually was causing unhappiness and stress. There’s a pathetic old joke, where the question is ‘What’s the most dangerous place in the world to be?’ and the answer is ‘Bed, look at the number of people who die in bed.’ Well, that’s just a pathetic old joke, but that’s reverse causality.”
Of course, this new study has its limitations. Most notably, it involved only middle-aged British women. It’s not clear if the findings are also applicable to men or people of either gender living in other countries.
Still, it was a massive and well-conducted study. It would seem the Scrooges of the world can sleep a little better tonight.
You can read the study in full on The Lancet website.