Foods for Better Concentration (cont.)

Where does your favorite "food for thought" fit in?

A Cup of Joe With a Lump of Sugar

Many everyday folk will swear by the virtues of caffeine and sugar in picking them up at opportune moments. Their tonic might be a stimulant such as coffee or tea, or a sweet such as ice cream or pastries, or a food rich in both such as chocolate, energy drinks such as Red Bull, and sodas.

Caffeine can energize the fatigued, but the benefit is short-lived, says Noralyn L. Wilson, RD, a spokeswoman for the American Dietetic Association (ADA). She says individual characteristics determine the length of the effect and someone's reaction to it.

Some people will feel "up" with the accelerated heart rate caused by the stimulant, while others may feel jittery and uncomfortable.

The discomfort may detract someone from concentrating on a task at hand. Problems may also come when the effects of caffeine wear off, or if too much of it is ingested.

"People can overdose on caffeine," says John Allred, PhD, professor emeritus of nutrition at Ohio State University, noting that too much of the substance could make a person become unfocused.

The effect of sugar on alertness, on the other hand, appears to be a bit more complex. It turns out that the brain uses glucose, a type of sugar, as a primary source of fuel.

In a study of 20 healthy older adults given a sweet drink or carbohydrates (which metabolize into glucose in the body), participants did significantly better in memory tests when they were given a placebo drink.

One of the investigators, Gordon Winocur, PhD, senior scientist for the Rotman Research Institute in Toronto, says the research demonstrates that a high serving of glucose may have a fast, short-term benefit on mental ability.

"With older people, in particular, where glucose metabolism isn't very efficient, if you do something to increase the glucose uptake, it seems to translate into improved memory function," says Winocur.

Paul E. Gold, professor of psychology and psychiatry in the neuroscience program at the University of Illinois, has done a number of studies on the effect of glucose on learning and memory. He says the compound can, indeed, boost memory and thinking processes in the brain.

Yet he does not recommend it for the public, because he says a number of factors can interfere with the process, such as stress levels, and differences in how people metabolize glucose.

The variables make it hard to tell how much glucose will help with memory, says Gold. Plus, he says, there is the "inverted U" effect to consider.

"The inverted U means that as you increase the dose, the effects on memory, for example, will get better and better and better," he explains. "But, then, after some peak dose, they begin to get worse and worse and worse."

With really high doses of glucose, memory could actually be impaired, Gold explains.

Steak or Bagel for Breakfast?