Mentally fit into old age with fibre!
As we get older, we become more and more annoyed by our fading memories. This worsens our ability to remember and reduces our ability to learn and concentrate. Scientists believe that the reason for this is the fact that in old age the brain is more susceptible to chronic inflammatory processes, which mainly affect the “microglia”. The microglia are special immune cells that fight as guards on the front line of the brain. They fend off dangerous germs and keep their territory under control. The researchers also assume that since the microglia play a decisive role in inflammatory processes in the brain in eliminating bacteria and other cells, they could also overshoot their targets. This means that more cells and neurons may be destroyed than necessary, contributing to the memory being affected over time.
However, American researchers have only recently discovered that this aging process can be slowed down very easily with the help of dietary fibres.
Short chain fatty acids such as acetate, propionate and butyrate are important for the function of the microglia in the brain. According to Professor Rodney Johnson, butyrate in particular has an anti-inflammatory effect on the mirkoglia. Butyrates are produced when intestinal bacteria metabolise fibre. For example, the oat fibre beta-glucan is broken down by intestinal bacteria into the short-chain fatty acid butyrate. The short-chain fatty acids enter the blood via the intestinal cells and are then transported to the brain, where they can help the microglia cells to fight inflammatory reactions quickly and efficiently.
The researchers demonstrated this in a series of experiments. They fed different groups of young and older mice a diet rich or low in fibre, then analysed the butyrate level, as well as other short-chain fatty acids in the blood and inflammatory messengers in the intestine. It was found that butyrate levels and the proportion of other short-chain fatty acids in all groups – young and old mice – increased significantly with a fibre-rich diet. With a low-fibre diet, the scientists only detected increased inflammatory processes in the intestines of older mice. The younger mice, on the other hand, seemed to compensate better for the unhealthy diet.
It was also interesting to note that the older mice, which had developed inflammatory processes in the intestines and microglia, were able to significantly reduce these inflammations when subsequently fed a high-fibre diet.
The researchers assume that although the studies were only carried out on mice, the results can also be transferred to humans. According to the German Nutrition Society (DGE), the dietary fibre content consumed by older people is significantly lower than the recommended 30 g per day. Dietary fibre-rich foods, the metabolism of which produces plenty of butyrates and short-chain fatty acids, are contained in fruit and vegetables, psyllium husks, oat bran, linseed, barley and dried fruit.