LOS ANGELES, April 22 (UPI) -- Fructose may damage genes in the brain, playing a role in changes in the brain linked to diseases ranging from Alzheimer's to diabetes, according to a recent study.
Mice exhibited evidence of metabolic diseases and memory problems when fed diets high in fructose, though the effects of the sugar appeared to be counteracted by an omega-3-fatty acid, researchers at the University of California Los Angeles report.
Researchers involved with the study previously found fructose damages the brain's ability to function, leading them to investigate whether an omega-3 fatty acid called docosahexaenoic acid, or DHA, could reverse changes to DNA caused by fructose.
The body does not make enough DHA to counteract the effects of fructose, but researchers say eating foods such as fish or taking supplements could suffice.
Most fructose in people's diets is from high fructose corn syrup, a liquid sweetener made from corn starch for drinks, desserts, candy and other processed and produced foods.
Fructose is also the form of sugar found in fruit, though the body absorbs it differently and other healthy components of fruit protect the body from the negative effects of fructose, researchers say.
"Food is like a pharmaceutical compound that affects the brain," Dr. Fernando Gomex-Pinilla, a professor of neurosurgery and and integrative biology and physiology at UCLA, said in a press release.
For the study, published in the journal EBioMedicine, the researchers trained rats to escape from a maze before dividing them into three groups, giving them one of three beverages for six weeks: Water with an amount of fructose equivalent to a person drinking a liter of soda per day; fructose water and a diet with high levels of DHA; or water without fructose and no DHA.
When the rats were put back in the maze, the ones given water and fructose made it through about half as fast as the rats given just water, while those given fructose and DHA did about as well as the rats that drank only water.
The rats with diets high in fructose but without DHA also had higher blood glucose, triglycerides and insulin levels, all of which are linked to obesity, diabetes and other diseases.
"DHA changes not just one or two genes; it seems to push the entire gene pattern back to normal, which is remarkable," said Dr. Xia Yang, an assistant professor of integrative biology and physiology at UCLA. "And we can see why it has such a powerful effect."
Of 900 genes fructose has an effect on, the researchers have identified two that are among the first and their change sets off a cascade of others, but more research is needed to find if DHA will successfully reverse DNA damage in humans.
Cutting back on soft drinks and other high fructose corn syrup-filled beverages, desserts and sugar would also help cut down on damage caused by the sugar, Gomez-Pinilla said.