How reading may protect the brain.

Workers at lead-smelting plants can suffer substantial neural damage from exposure to the toxic heavy metal. Workers who read well, however, experience comparatively less mental impairment, a new study finds.

It's not that the better readers were smarter, but that they have more "cognitive reserve," explains study leader Margit L. Bleecker, a neurologist at the Center for Occupational and Environmental Neurology in Baltimore. She says that people typically gain cognitive reserve--better or more resilient neural connections in the brain--through reading, puzzle solving, and other mentally challenging activities.

Her team recruited 112 men at a lead smelter to participate in a battery of neural assessments. After measuring the men's reading abilities--a rough gauge of cognitive reserve--the researchers split the volunteers into two groups of equal size, consisting of high or low scorers. In other respects--age, number of years worked, educational background--the two groups were similar. Most important, participants in each group exhibited the same range of blood-lead concentrations.

In the July 31 Neurology, the researchers report that in each group, men with higher blood-lead values scored more poorly on tests of hand-eye coordination. That's typical of lead poisoning. However, men in the better-reading group performed 2.5 times as well on tests of memory, attention, and concentration--tasks not necessarily related to reading.

The brain is like a muscle, Bleecker concludes: Exercising it strengthens it and makes it better able to counter the ravages of disease and poisoning.