A study by the University of Michigan has analyzed the impact of a high sugar diet on brain health. The results have shown that sugar can deplete the key metabolites linked to the brain of a fruit fly. The journal Nature Communications has presented this study.
High sugar intake leads to a delay in satiety
When a person eats food, it gets metabolized by the body. And breaks down into small molecules – metabolites. These molecules perform many functions in the body. Such as activating or inhibiting an enzyme’s production or providing energy to the cells. This study has examined the change in brain metabolites of fruit flies as flies shift between hunger and satiety.
Where the change was larger in the brain of fruit flies in contrast to the body. A high sugar diet can affect brain health. As it can deplete the level of N-acetyl aspartate (NAA) and kynurenine, the two key metabolites in the brain. This alteration can delay satiety in the fruit fly, causing them to eat more food. While such an alteration can lead to overeating and weight gain.
The scientists are still not clear on the exact role of NAA in the brain. But NAA appears to provide energy for brain cells and regulates cell volume in the brain. On the other hand, the low levels of kynurenine in the brain can lead to depression. The team has also found a completely different metabolic profile in fruit flies, by the seventh day of the high sugar diet.
This change in metabolic profile is known as metabolic remodeling. That is also present in the case of cancer cells to fuel their growth. This is the reason why diet plays a role in cancer treatment and the research team wanted to analyze the alteration in the levels of brain metabolites.
Sugar depletes the key metabolites of the brain
In this study, the research team has assessed how a high sugar diet can affect brain health. For this purpose, the research team has compared a group of fed flies with a group of fasting flies. In the former group, the team skipped giving dinner, and then fed them breakfast the next day.
Where the breakfast contained moderately sweet jelly, mixed with green or blue dye. The team has placed the flies on lickometer coated with glucose jelly, to make sure they have eaten. Then, the team froze both, the group of the fed flies and the fasting flies in separate tubes.
That stopped the metabolic process, enabled the researchers to look at the brain. And find out what’s going on at the moment of satiety. The fly shattered with the shaking of tubes. And a sieve separated its head, thorax, abdomen, and legs. Mass spectrometry measured the metabolites in these parts.
While a tool FlyScape helped to refine the list of metabolites in the flies. This tool produces imaging of the metabolic networks of the fruit flies. And helps to view and understand the shifts in metabolites and genes between different conditions. And can also tell what metabolic pathways may be involved in these changes.
The study results have found that besides the depletion of NAA and kynurenine, sugar intake can affect 20 other metabolites of the brain. In the future, the research team plans to track the pathway by which these metabolites affect brain health and in return, alter the food intake and affect learning, memory, and sleep.