A sugar substitute's effect on learning might be sour for older populations.
Elderly female rats in a three-year study couldn't master a simple maze after ingesting regular doses of aspartame, Carbon High sophomore Susie Morris discovered.Three years of poring over rat behavior in her bathroom lab brought sweet rewards for the 16-year-old Price resident. Her project reaped $9,000 cash from Intel and the Andrus Foundation, affiliated with the American Association of Retired Persons, and a choice of three college scholarships totaling $21,000.
"Results could be compared to humans," said Morris, whose study includes an 80-page paper. "I'm not saying it's conclusive. More study is warranted. But aspartame may not be as safe as once thought and those in elderly populations who consume it could be at considerable risk."
The awards came at the Intel International Science and Engineering Fair, held last month in Fort Worth, Texas. The competition drew 1,200 entrants from 34 countries. Morris won the fair's gerontology division.
Aspartame, used in diet drinks and snacks, was approved by the Food and Drug Administration in 1981, but the agency's Center for Food Safety continues to study it, as with other additives and drugs, said Virlie Walker, spokeswoman for FDA's Denver district, which covers Utah.
"Her research would be collected as part of the data regarding that particular additive," Walker said. "After a product is in the marketplace, the FDA still tracks it . . . it's our job to monitor safety."
Morris' study, which she wants to send to the FDA, blossomed from her eighth-grade science project on long-held beliefs that sugar adversely affects child behavior.
An experimental group of young, genetically identical rats ingesting sugar-water learned a maze 30 percent faster than an identical control group.
Morris was hooked. In ninth grade, she found that teenage rats consuming aspartame exhibited unusual behavior, while a control group did not.
But international science fair judges in Kentucky were unimpressed. So was the author of a study published in the New England Journal of Medicine, the inspiration for Morris' study.
"He said my results were inconclusive and that aspartame was safe," Morris said.
Yet the stickler for research was undaunted. She turned her studies to aspartame's effects on elderly female rats, working over Christmas break and during other school vacations.
"I've observed in society that the elderly often are used as scapegoats," she said. "They are seen as helpless and impotent and using the federal budget but not contributing to the betterment of society. I feel that is inaccurate and the only way to reverse that stereotype was (studies) in gerontology."
She gave 27- to 30-month-old rats, equal to 90- to 100-year-old humans, the equivalent of aspartame defined by the FDA as safe for daily human consumption.
Morris attempted to teach rats a maze by dotting the path with Froot Loops, then taking away the cereal O's until the maze was mastered.
The control group learned the path in 34 tries. But the experimental rats never did, and instead circled the entry and displayed aggressive behavior, which could indicate brain damage, Morris said.
"I expected adverse effects, but not to the point it was," said Morris, whose study has a confidence level of 99.9 percent, a statistical analysis shows.
Other studies have been conducted on aspartame's effect on the brain. A 1996 medical journal article questions whether brain tumors are associated with aspartame, but the National Cancer Institute's public database does not support an association, according to an FDA statement on the sweetener.
The incidence of such cancers has flattened since 1985. Independent scientific advisers to the FDA in 1980 concluded aspartame did not cause brain damage, but said further study was needed on the cancer inquiry.
Two schools cashed in on Morris' win: Mont Harmon Junior High received $2,000; Carbon High got a graphing calculator and projector from the Navy.
Morris also received her choice of $1,000 to go to the University of Texas at Austin, $12,000 to go to Indiana University, or $8,000 from the Navy to attend the college of her choice.
Most appealing to Morris is Wellesley College, the Massachusetts all-female alma mater of First Lady Hilary Clinton.
"I want to go to a small school to have a more individualized atmosphere. I don't want to be just a number."