However, the researchers from University of California, Los Angeles (UCLA) who conducted the study also said that these harmful changes can be reversed by the omega-3 fatty acid DHA. So eating healthy foods rich in omega-3s can restore the health of people who consume unhealthy amounts of fructose.
For their study, the researchers examined the genes, pathways, and networks affected by fructose. They first taught rats how to escape from a maze then divided the trained animals into three groups.
They gave the rats in the first and second group water containing the same amount of fructose found in a liter of soda but they also fed the second group foods rich in DHA. Meanwhile, they did not give the third group any sweetened water or DHA.
The rats lived on those diets for six weeks. Then the researchers returned them to the same maze to test their memory. (Related: Are you one of the 60 percent of people who have trouble digesting fructose?)
The UCLA researchers reported that the rats given fructose-sweetened water appeared to experience problems with their memories. They took twice as long to navigate the maze as the animals from the control group despite having successfully completed the test in the past.
Meanwhile, animals that received both DHA and fructose were able to match the performance of the control group. Based on these results, they concluded that DHA can mitigate the harmful effects of fructose on memory.
Other tests showed that rats who were given a high fructose diet had higher levels of glucose, insulin, and triglycerides in their blood. In humans, these symptoms could lead to obesity, diabetes, and many other diseases.
After the maze experiment, the researchers analyzed more than 20,000 genes from the brain cells of the rats. They found that fructose negatively affected more than 700 genes in the hypothalamus, which controls metabolism, and more than 200 additional genes in the hippocampus, which controls learning and memory.
Two of the genes they sequenced were among the first ones to be altered by fructose. These genes then caused the other genes to be altered as well. Since most of them are similar to the genes found in humans, excessive amounts of fructose could conceivably affect human genes the same way.
Worried about the harm that fructose can cause to the brain? Avoid foods that contain high fructose corn syrup to reduce its bad effects on genes and brain cells.
Also, read food labels very thoroughly. If a label lists corn syrup or other sources of fructose as an ingredient, drop that food product. Instead, get whole foods that do not have additives or other ingredients. Make sure to include lots of vegetables and nutritious fruits for a healthy diet.
Start eating more foods that contain DHA. Any damage caused by fructose can be repaired by getting adequate amounts of DHA, which is found in many animal products. The best sources for this omega-3 fatty acid are oily fish. Herring, mackerel, salmon, sardine, and trout contain 10 to 100 times the amount of DHA found in other natural foods. Dark green, leafy vegetables, nuts, seeds, and whole grains are also good sources of omega-3s.