The rise in obesity and diabetes in the last decade is of increasing concern as they deteriorate the quality of life of the sufferers and invoke a cascade of other, serious diseases, even fatality in some cases. With the increase in artificially “sweetened” beverages, sham sweets and added sugar in every food product, the sugar cravings only become worse.
However, in a recent study published in Cell Research journal, scientists claim they may have found an all-natural way to suppress those sugar cravings. They found that when monkeys and mice were given an added dose of the mammalian liver hormone fibroblast growth factor 21 (FGF21), they voluntarily went off sweets, even artificial ones.
FGF12 is a member of the Fibroblast Growth Factor (FGF) family, produced mostly in the liver, but also in the fat tissue. The interest in investigating the role of FGF12 in diabetes and obesity is that it stimulates glucose uptake in an insulin-independent manner in adipocytes (cells specialised in the storage of fat) but not in other cell types.
In this study, they took inspiration from a series of previous studies which showed that treatment with FGF12 resulted in increased energy consumption and fat burn and maybe helpful in treating obesity and type 2 diabetes. Some experiments on obese mice, monkeys and humans showed that increased FGF12 dosage resulted in weight loss and better adjustment to insulin fluctuations, thereby helping in the regulation of glucose and lipid metabolism. Other studies confirmed that FGF12 can indeed pass from the blood to the brain and influence the concentration of certain proteins in the central nervous system, affecting in turn food cravings.
This study inspired researchers David Mangelsdorf and Steven Kliewer at the University of Texas Southwestern Medical Center to take a closer look at what happens when FGF12 reaches cells in the central nervous system. Using mice, the researchers found that FGF21 caused a decrease in dopamine, a hormone that is released in reward-motivated behaviours such as cravings for sugary, high-calorie treats. Thus, FGF21 may manipulate the pleasure responses and desires for certain sugar-based food.
The results of this study were very encouraging: In the presence of FGF21, mice abstained from sugar water voluntarily and it didn’t alter their interest in other foods nor did it affect their mood.
The research team further examined if the same pattern is exhibited if water is spiked with alcohol and repeated the experiment and they voluntarily abstained from alcoholic beverages too. Further experiments showed that FGF21 administration markedly reduced the sweet and alcohol preference in mice and sweet preference in cynomolgus monkeys.
The authors concluded that FGF12 may constitute a feed-forward regulatory loop for limiting the consumption of sugar and alcohol. This means that more FGF12 decreases sugar levels in the body and further sugar uptake in turn stimulates the production of more FGF12. Since FGF21 production spikes on carbohydrates uptake, the hormone may act as a built in shut-off switch-one that may be exploitable, though it may be hard to disentangle from the complex network of controls that interlink pleasure and food.
Even though clinical trials are already in progress, the authors hope further studies are conducted to learn how FGF21 regulates food cravings in people.
The original article can be found here.