And the potential market is huge because age-related cognitive decline, which can range from mild memory lapses to more serious dysfunction such as Alzheimer's, affects most people after age 40. But brain-boosting products aren't just for elders. But some scientists say there's little hard research and brain-booster producers are making mountains out of mouse hills of data. It's easier, less expensive and more acceptable to put rats through a maze of clinical trials than to do so with humans. Studies of brain-boosting supplements can suffer from investigator bias, difficulty judging and interpreting behaviors, placebo effect and limited funding.
Scientists still have yet to determine exactly what causes memory problems.
A July 1999 study in Developmental Psychology attributed age-related working memory differences to lack of storage capacity, rather than processing efficiency. Circulation impairment theories are yielding to other possibilities. Alzheimer's disease, which affects nearly 50 percent of people over age 85, appears to involve widespread degeneration of brain cells, beginning with memory impairment and progressing to death. However, little effective medical treatment exists. Meanwhile, consumers buy products, hoping to avoid or alleviate memory problems, and researchers seek answers.