Researchers at Tokyo Metropolitan University found that fruit flies with genetic modifications to increase glucose consumption have a significantly longer lifespan.
Looking at the brain cells of aged flies, they found that better glucose absorption compensates for age-related deterioration of motor functions and led to a longer life. The effect was more pronounced when associated with dietary restrictions. This suggests that a healthier diet plus improved glucose absorption in the brain could increase life expectancy.
The brain is a very strong part of our body, consuming 20% of the oxygen we take in and 25% of glucose. That is why it is so important that it can stay fed, using glucose to produce adenosine triphosphate (ATP), the body’s “energy courier”.
This chemical process, known as glycolysis, occurs both in the intracellular fluid and in some of the cells known as mitochondria. But as we age, our brain cells become less adept at producing ATP, which generally correlates with lower glucose availability.
This might suggest that more food for more glucose might actually be a good thing. On the other hand, it is known that a healthier diet actually leads to a longer life. The discovery of the mystery surrounding these two contradictory pieces of knowledge could lead to a better understanding of a healthier and longer life.
A team led by Associate Professor Kanae Ando studied this problem using Drosophila fruit flies. First, they confirmed that brain cells in older flies tended to have lower ATP levels and lower glucose absorption. They specifically linked this to smaller amounts of enzymes needed for glycolysis.
To counteract this effect, they genetically modified flies to produce more of a glucose transporter protein called hGut3. Amazingly, this increase in glucose uptake was necessary to significantly improve the amount of ATP in the cells.
Specifically, they found that more hGut3 led to a smaller decrease in enzyme production, counteracting the decline with age. Although this did not lead to an improvement in age-related mitochondria, they also suffered less impaired locomotor function.
But that’s not all. In another twist, the team put flies with increased glucose absorption under dietary restrictions to see how the effects interact. Now, flies had an even longer lifespan.
Curiously, increased glucose uptake did not actually improve glucose levels in brain cells. The results highlight the importance not only of the amount of glucose, but also of its efficiency, once taken into the cells, to produce the energy the brain needs.
Although the anti-aging benefits of a restricted diet have been shown in many species, the team was able to combine this with improved glucose uptake to benefit from the benefits of both for an even longer life in a model organism. Subsequent studies can provide vital clues as to how we can keep our brains healthier for longer.
Watch more stories Facebook and Twitter
This story was published from an agency stream with no text changes. Only the title has been changed.
