It's no secret that the so-called Western diet - which involves the consumption of large quantities of meat, eggs, fried and salty foods, bread, fatty dairy products, sweet desserts and drinks, chips and other "unhealthy goodies" - is harmful to our health. Previous studies have shown that this type of diet, in particular, affects reproductive functions and increases the risk of cardiovascular disease and cancer.
Now scientists from Australia's Macquarie University (Sydney) have decided to find out how the Western diet is harmful to brain function. In their work, which was published in the journal of the Royal Society of London, the researchers stated that frequent consumption of junk food can quickly accustom even adherents of a healthy lifestyle who monitor their weight to overeating.
The experiment involved 110 lean and healthy students aged 20 to 23 years, who usually adhered to the correct diet and did not allow themselves too much. They were divided into two groups: the first was a control group and ate as usual, and the second was on a "Western diet" for a week: in particular, its participants ate a lot of Belgian waffles and fast food. At the beginning and at the end of the test week, the volunteers - after breakfast, after eating - took tests on memorization of words.
In addition, young people were asked to rate how much they wanted to eat something else sweet (various cereals were offered: processed cereals, chocolate rings, and so on). They were then asked if they liked the food. The members of the group, who ate according to the Western model for seven days, not only performed worse on the memory test, but also seemed to forget that they had eaten recently, and they wanted more and more.
According to scientists, such an eating disorder suggests that the "Western eating pattern" disrupts appetite control and, apparently, causes malfunctions in the hippocampus - part of the limbic system of the brain that is responsible for the formation of emotions, the transition of short-term memory into long-term and spatial memory that helps us navigate.
“After a week of Western-style dieting, delicious foods like snacks and chocolate become more desirable even when you're full,” explains Richard Stevenson, professor of psychology at Macquarie University. "It stops you from resisting and forces you to eat more, which in turn leads to more damage to the hippocampus and a vicious cycle of overeating."
Earlier experiments on animals have already shown that fast food and sweets impair the functioning of the hippocampus: as scientists suggested, most likely, this part of the brain normally blocks and weakens the memory of food when a person is full. That is, when we have just eaten and suddenly saw the cake, we do not immediately begin to remember its taste and think how we want to taste it. When, on the other hand, the hippocampus is not functioning as efficiently, a person "gets this flood of memories, and the food becomes more attractive," the scientists say.
“The more desirable people who followed the Western diet found unhealthy and tasty food, the more they suffered from hippocampal dysfunction. Demonstrating that processed foods can impair memory ability and affect appetite and overeating in generally healthy young people should be a worrying discovery for everyone,”says Stevenson.
Although the brain dysfunctions that the participants in the experiment demonstrated are not so serious, in the long term, the love of junk food leads to obesity and diabetes and, as a result, increases the risk of developing dementia. According to the authors of the work, governments should impose restrictions on the sale of processed junk food, equating it to cigarettes.