Fisetin, a unique polyphenol flavonoid found in strawberries and other fruits and vegetables, is adding to its science showing that it can help regulate blood sugar.  Previously I reported that fisetin can reduce the caramelizing effect of sugar on body structures known as advanced glycation end products – a major issue for type 2 diabetics and general aging for everyone.  A new study shows that fisetin can restore the metabolism of carbohydrates by correcting key metabolic enzymes that are malfunctioning.  This finding could help offer a path to solution for many people who struggle to incorporate carbohydrates in their diet without gaining weight.

In the study researchers worked with a special lab rat that is commonly used to help study diabetes, the streptozotocin-induced diabetic rat.  This enabled the researchers to document precisely which carbohydrate related enzymes were being modulated by fisetin that would help restore normal carbohydrate metabolism in this animal with “broken” carbohydrate metabolism.  Rather dramatically, the researchers found that many key enzymes of carbohydrate metabolism were reverted to near normal with supplemental fisetin.

The following carbohydrate-related enzymes were improved by fisetin:

Hexokinase.  Hexokinase acts on glucose that has entered a cell to “energize” it with ATP, thus converting it to glucose-6-phosphate, which means that sugar has been prepared to enter the cellular engines and combine with oxygen to be used as fuel and produce energy.  This step is required to keep sugar flowing in the right direction and it creates an opportunity for more sugar to flow into the cell, based on the cell’s metabolic needs, in turn helping to prevent insulin resistance at the cellular level.

Glucose-6-phosphate dehydrogenase.  This enzyme is stimulated into action once glucose-6-phosphate is formed.  It is vital to the health of your red blood cells because the chain of reactions leads to the production of the vital antioxidant glutathione which protects your red blood cells from damage.  The metabolic products of this enzyme’s function also stimulate fatty acid synthesis.

Lactate dehydrogenase.  When a cell is not able to burn sugar with oxygen then it switches to a back up system so that some energy can be made.  Example:  How many sprints can you run before you run out of energy?  Your last efforts are less efficient but very important if you happen to be running from a saber tooth tiger.  Lactate dehydrogenase converts glucose to pyruvate, a compound that can be “fermented” to make energy to keep you going.  This enzyme also makes lactic acid from pyruvate, and vice versa, once again as your body tries to figure out how to keep going as its running out of the ability to burn glucose with oxygen.  The function of this enzyme is required to maintain blood sugar metabolism under stress, and is typically malfunctioning in people with fibromyalgia or is pushed to the limit by athletic competition.

Glucose-6-phosphatase.  This enzyme operates in multiple ways but its main goal is to try to find a way to get more glucose so that low blood sugar (hypoglycemia) does not occur.  Its activities influence the conversion of lactic acid back into glucose.  It helps the liver break down stored sugar (glycogen) back into glucose (the process called glycogenolysis).  And, if needed, it helps convert proteins into blood sugar, a process called gluconeogenesis.

Fructose-1,6-bisphosphatase.  This enzyme is another important step in how glucose is made from non-carbohydrate sources, such as lactic acid and some amino acids (gluconeogenesis).

Glycogen synthase.  This enzyme works in your liver to convert extra glucose following a meal into its storage form, glycogen.  This helps your body have fuel in its gas tank reserve, which can then be used between meals as needed to sustain blood sugar.

Glycogen phosphorylase.  This enzyme helps break down stored glycogen in your liver and convert it back into glucose for use as cellular fuel.

The purpose for writing the above was not to overwhelm you with technical complexity but to help you appreciate the elaborate elegance in your body that must take place for blood sugar metabolism to work correctly.  Be thankful you don’t have to think about all this every time you eat, although maybe you might want to pay attention to not over-eating as it tends to overload these enzymes and make them malfunction.  Our genes and related enzymes are best suited for food scarcity, not food excess. 

The fact that fisetin can have a beneficial effect on all of these important carbohydrate-regulating enzymes is rather mind boggling. 

Posted by Byron J Richards at 05:23 PM.

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