Why a sweet tooth may rule your life


If you’ve ever spoken the words, “I have a sweet tooth,” there may be a good explanation for that. And it looks to be not as easy as simply having more willpower to refrain from indulging in goodies and desserts.  It may actually be more of a biological aspect motivating and rewarding some people to go into sugar craving overdrive that could be the explanation.

It is known that sugar is an especially palatable substance and that the intake of it rewards us with its sweet taste and feelings of satisfaction and pleasure.  It is also known that from a previous study in rodents, a hormone secreted by the liver can suppress the intake of sweets. 

A new study published in the journal Cell Metabolism, looked at that same hormone secreted by the liver called FGF21 that may possibly be the link bridging those whose sweet tooth takes over their appetite while others have a much easier time of avoiding sugary concoctions.  The research reviewed data from a previous study called the Inter99 study involving over 6,500 Danish participants.  Each participants metabolism, lifestyle, and dietary habits were analyzed of which was self-reported, in addition to taking measurements of their blood cholesterol and blood glucose.

Besides looking at that data, the FGF21 gene was sequenced to try to decode it and its variants.

What was found was participants who had either of two variants – FGF21 rs838133 or FGF21 rs838145 – were 20 percent more likely to consume large amounts of sweets on a regular basis.  These two genes had been linked from previous studies to causing a higher consumption of simple carbohydrates.  These same hormones have also been correlated with possibly causing individuals to consume a higher level of alcohol and to have a propensity for smoking. 

A clinical study was also used to examine the link between fasting levels of FGF21 of 86 participants who were considered “young, healthy, and lean” but who had a preference for sweets.   Each participant first answered a questionnaire looking at their liking for sweet, salty, and fatty-sweet food.  Then, after fasting for 12 hours, each had their blood levels of FGF21 measured.  After that, they were to consume the sugar equivalent of two cans of Coke.  For a 5 hour period afterwards, their hormone levels of FGF21 were monitored.  

Discovered was that right after the fasting period, their FGF21 levels rose 50 percent higher than participants who did not have a preference for sweets.  But, after consuming sugar, FGF21 increased to approximately the same level in both groups.

At this time, this research is preliminary and there needs to be similar studies on a larger scale to have a better idea of the effects of FGF21 blood levels and the preference in some people for sugary foods.  So far, the findings from this study do suggest that there could very well be a hormonal link that is triggering why some people find it difficult to avoid sweets while others have no problem.  This research is showing more and more that the strong liking for sweets may be biologically controlled and could be what may cause some to have unhealthy eating habits that can lead to obesity and diseases such as type 2 diabetes. 

It also may help open up a new means of discovering therapies for helping to reduce appetite and reducing the intake of sugary foods.