Why the Happy are Healthy

I wrote a while back about the link between health and happiness being related to the link between happiness and health; a virtuous spiral. Now a pair of American scientists seem to have moved one crucial step forward in finding a causal link between the two. This week's Economist carries a Most significant article about thinking yourself better. "...[R]espectable research has demonstrated that those who frequently experience positive emotions live longer and healthier lives. They have fewer heart attacks, for example, and fewer colds too."

The link discovered by Dr Barbara Fredrickson and Dr Bethany Kok at the University of North Carolina (and this warrants more research) is to do with the vagal tone index.

Apparently, there are subtle differences between the pulse rate when breathing in (faster) and breathing out (slower). If the heart beats at exactly the same rate when you're inhaling as when you're exhaling, your vagal tone index is One. Obviously, to measure this you need sophisticated, ultra-sensitive instruments to measure your heartbeat down to small fractions per second. Then, you need to link this data to information about how happy (or unhappy) you are - what emotions, positive or negative - you have experienced. The result? "[P]eople with high [vagal tone] tone are better than those with low at stopping bad feelings getting overblown. They also show more positive emotions in general. This may provide the missing link between emotional well-being and physical health."

OK - so if you let your bad feelings get control of you - does that condemn you to ill health? The article mentions meditation as an effective therapy, but it tends to improve the vagal tone index of those who already have a good vagal tone index. Meditation is of little benefit to those with low vagal tone index.

Are there other factors at work here? I just wrote about the link between higher educational attainment and longevity. Maybe IQ has something to do with this? More intelligent people can apply logical thought to their lifestyle, diet and habits, and are better able to control emotions (for example, through cognitive behavioural therapy). But then happy, intelligent people also succumb to deadly ailments. But less often.

And the biggest known unknown in all this is genes - until we have cheap gene mapping ($100 or less) that can unravel our DNA and tell us with total precision which variants of which genes we possess, we'll still be significantly in the dark. But will we want this knowledge? Will we want to know if there's some dark disease that will slay us in the near future? One day, of course, science will arm our doctors with a gene therapy tool-kit that will let us mend any faulty gene. This, coupled with greater understanding of how our brains work, may well lead to a future in which a child born today could (with luck and intelligence) live to the age of 300, picking up on healthcare developments along the way that we cannot even imagine today.

Along the way to this uplifting vision of the future is an intermediary stage, in which we can unravel and understand the gene map, but don't yet have the tools to fix all known genetically transmitted diseases. Here, the spectre of a genetic underclass looms; people whose DNA tests reveal variants of genes that portend life-threatening conditions that no insurer would wish to underwrite. At present, it's hit or miss. Signing up for (private) healthcare insurance, you answer questions about disease in your family history. Ethical questions will raise big issues for society and its legislators. We are on the verge of an immense healthcare revolution.

In the meanwhile, as we wait for advances, we are one step forward at least - in knowing that thinking positively about life does indeed lead to better health.

This time last year:
The black SUV, the black SUV... (with the darkened rear windows)

This time two years ago:
Atonement

This time five years ago:
Where I'm from, and why