French scientists have found that excess fructose, which the body cannot fully absorb, can disrupt gut function, cause inflammatory processes, and increase anxiety levels. The study showed that the connection between the gut and the brain is much closer than previously thought.
Excess fructose, which is not absorbed by the body, can disrupt the balance of gut microbiota and trigger inflammatory processes that affect brain function. French researchers have found that these changes may be associated with increased anxiety.
Scientists from the National Institute for Agricultural Research, Food and Environment in France conducted a series of experiments on humans and mice and concluded that undigested fructose contributes to the development of inflammatory reactions in the body and affects emotional state.
Over the past century, fructose consumption has significantly increased. While a person used to consume less than 5 grams of this sugar per day, today this amount can reach 80 grams. To absorb fructose, the body uses a special transport protein located in the mucosa of the small intestine. However, its capacity is limited, so excess fructose ends up in the lower parts of the intestine and the colon.
The study involved 55 healthy men with an average body mass index. For a week, they recorded their diet. It was found that the average fructose intake was about 30 grams per day, and 40% of participants exceeded the recommended limit for added sugar.
Breath tests showed that 60% of volunteers had impaired fructose absorption. Moreover, the ability to absorb this sugar varied significantly even among people with similar diets.
Blood tests revealed that participants with impaired fructose absorption had elevated levels of inflammatory proteins and bacterial toxins. Analysis of stool samples showed changes in the composition of gut microbiota. Additionally, according to the results of psychological questionnaires, these participants more frequently exhibited signs of increased anxiety.
To verify whether gut disturbances can indeed affect brain function, scientists conducted additional experiments on mice. Some of the animals lacked the protein responsible for fructose transport.
The mice were fed a fructose-rich diet, after which their behavior was assessed in special tests. Animals with impaired sugar absorption showed more pronounced signs of anxiety and fear compared to the control group.
Further analysis showed that in these mice, microglia—immune cells of the brain—were activated. They exhibited signs of an inflammatory response, indicating a direct link between changes in the gut and immune processes in the brain.
The results confirm that excess fructose can affect not only metabolism but also a person's psycho-emotional state. Impaired absorption alters the composition of gut microbiota, provokes inflammation, and may increase anxiety levels. Scientists believe that further study of the connection between the gut and the brain will help develop new approaches to the prevention of both metabolic and psychoneurological disorders.
Leave a comment