Blood sugar.

• Author: Ayres, Ed
• Position: Note from a Worldwatcher - Connection between physical and mental health - Brief Article

Is there any strong link, either for individual humans or for whole societies, between physical health and mental health? Overwhelming evidence says yes. For one thing, as any psychopharmacologist can attest, mental illness is often associated with specific physical conditions--depleted neurotransmitters, or excessive spiking of blood sugar. If your nerves and hormones are out of whack, your attitudes and behavior are more at risk of deteriorating.

What, then, about a possible connection between physical fitness and mental fitness? Are flabby populations more likely to fall into flabby habits of thinking and reacting? Here the connection may be less obvious. To begin with, it's not so clear what mental fitness is. But here, too, the best available evidence now says there is a rather strong correlation between a robust body and a robust mind. Around two decades ago, many organizations began investing in corporate fitness programs because they had seen convincing evidence that physically fit employees are more productive. Aerobic exercise, it turns out, makes people not only less prone to heart attacks; it increases their stamina, oxygenates their brains, sharpens their senses, and heightens capacity to cope with stress.

It should be a matter of serious concern, then, when a nation finds that unprecedented numbers of its citizens are unfit and obese. Americans are the world's largest consumers not only of the planet's declining natural resources, but of its growing output of sugar and fat. If there's really a connection between physical and mental well-being, there's fair reason to believe that Americans--along with many Europeans and others--have grown soft.

In the aftermath of September 11, that softness could be costly. Many people seem to have fallen into a habit of equating "toughness" with having the technological capacity to wield heavy vehicles and weapons. But real toughness means having the cognitive sharpness to think through difficult challenges, and the patience and resilience to handle heavy stress. It means being able to exercise independent judgement rather than simply making easy substitutions of faith for education, or doctrine for discovery. It means being able to negotiate the risks of life, along with its wonders, without retreating into compulsive escapism and consumption.

Whether deliberately or not, the terrorists could hardly have picked a more devastating moment to attack. The U.S. economy was already...