Fish oil will protect the brain from fructose
A huge number of diseases, ranging from cardiovascular diseases and Alzheimer's disease to hyperactivity and attention deficit disorder, are associated with changes in gene expression in brain cells. The results of a study by scientists at the University of California at Los Angeles, working under the guidance of Dr. Xia Yang, indicate that such changes can occur under the influence of fructose, a carbohydrate contained in large quantities in the so-called "Western diet".
However, there is also good news: omega-3 fatty acids, such as docosahexaenoic acid, can restore the harmful changes caused by fructose.
Docosahexaenoic acid is found in the membranes of brain cells, it helps strengthen synapses and improves memory and learning ability. Unfortunately, the human body cannot synthesize docosahexaenoic acid on its own, so it must enter the body with food. A large amount of this compound is found in salmon and, in smaller quantities, in other types of fish (fish oil), as well as in walnuts, flaxseed, fruits and vegetables.
Fructose, in turn, is part of the popular products in the United States, sweetened with high-fructose corn syrup, sugary drinks, honey and various desserts. According to statistics, in 2014, the average American ate about 13 kilograms of high-fructose corn syrup. In addition, fructose is part of most baby food products, as well as fruits. However, fruits contain fibers that significantly slow down the absorption of carbohydrates, and other substances that are useful for the brain and the body as a whole.
To study the effects of docosahexaenoic acid and fructose, the authors trained rats to get out of the maze, and then randomly divided the animals into three groups. For the next six weeks, the animals of one group drank water during the day, the fructose content of which was approximately equivalent to the amount of fructose in a liter of carbonated drink for a person. Animals of the second group received water containing fructose on the background of a diet enriched with docosahexaenoic acid. The rats of the third group received ordinary food and clean water.
Six weeks later, the rats were put back into the maze. Animals that received water with fructose got out of it about twice as slowly as rats who drank pure water, which indicated the destructive effect of fructose on memory. At the same time, the results of animals receiving fructose simultaneously with docosahexaenoic acid did not differ from the results of the control group rats, which indicated the ability of docosahexaenoic acid to neutralize the harmful effects of fructose.
Additional experiments on rats revealed other important differences. A fructose-rich diet was associated with increased levels of glucose, triglycerides, and insulin in the blood of animals compared to the indicators for the other two groups. These data are of great importance, since in humans, an increase in these indicators is associated with obesity, diabetes mellitus and other diseases.
The authors performed epigenomic sequencing of more than 20,000 genes in the DNA of rat brain cells and identified more than 700 genes in the cells of the hypothalamus (the brain region that is the main center of metabolism regulation), and more than 220 genes in the cells of the hippocampus (involved in the regulation of memory and learning), the expression of which was significantly influenced by fructose. This effect consisted in the attachment or removal of a methyl group to cytosine, one of the four nucleotide bases encoding genetic information in DNA. This type of epigenetic modification plays a key role in activating genes and blocking their activity.
The genes identified by the authors, the vast majority of which have analogues in the human genome, belong to genes interacting with each other to regulate metabolism, intercellular interaction and inflammation. Conditions that can be caused by changes in the methylation of these genes include Parkinson's disease, depression, bipolar disorder and other brain diseases.
Of the 900 identified genes, two, namely Bgn and Fmod, are among the first to suffer from fructose exposure. Changing their expression triggers a cascading process that eventually leads to a change in the expression of hundreds of genes. This means that the Bgn and Fmod genes are potential targets of new drugs for the treatment of diseases caused by changes in gene expression in brain cells.
Earlier studies have shown that fructose increases the concentration of toxic molecules in brain tissue and disrupts the interaction between its cells, so prolonged consumption of fructose-rich foods impairs the brain's ability to learn and memorize information. Therefore, experts recommend avoiding the use of sugary carbonated drinks and other fructose-containing products.
Dr. Yang also notes that, despite its rather pronounced positive effect, docosahexaenoic acid is not a solution to the problem. To determine its real capabilities in eliminating the destructive epigenetic modifications of human genes produced by fructose, additional research is necessary.
Article by Qingying Meng et al. Systems Nutrigenomics Reveals Brain Gene Networks Linking Metabolic and Brain Disorders published in the journal EBioMedicine.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the University of California, Los Angeles: Fructose alters hundreds of brain genes, which can lead to a wide range of diseases.
25.04.2016