Surplus glucose levels cause damage at cellular level, study finds

04 Aug 2021 --- Surplus sugar may reduce the concentration of polyunsaturated fatty acids (PUFAs) in the mitochondrial membrane, causing them to be less efficient and reducing their energy output. This is according to a new study, which provides a new model to study the initial metabolic circumstances that lead to diabetes.

Mitochondria are the “powerhouses of the cell” as they assist in turning glucose the body receives from food into energy that cells use. Taking this into account, healthy mitochondria are essential for overall health and well-being.

“The body needs sugar or glucose to survive, but as the saying goes: ‘All good things in moderation,’” Ning Wu, corresponding author of the study, states. 

“We found that too much glucose in cells, which is directly linked to the amount of sugar consumed in one’s diet, affects lipid composition throughout the body, which in turn affects the integrity of mitochondria. The overall effect is a loss of optimal function.”

The study, published in Cell Reports, was led by Van Andel Institute scientists and supported by the National Institute of General Medical Sciences. 

Lipid balance function in mitochondria
The researchers found that excess glucose levels reduce PUFAs concentration in the mitochondrial membrane, making the mitochondria less efficient. 

PUFAs are essential in supporting mitochondrial function and mediating a host of other biological processes such as inflammation, blood pressure and cellular communication.Mitochondria are the cell’s powerhouses and assist in turning the glucose in food into energy that cells use.  

Additionally, excess glucose is combined into a different form of fatty acid that lacks flexibility and efficiency compared to the PUFAs. 

The scientists fed the mice used in the study low-sugar ketogenic diets, which suggests that reducing glucose and restoring normal membrane lipid composition supports healthy mitochondrial integrity and function.

“Although we may not always notice the difference in mitochondrial performance right away, our bodies do,” Wu continues. 

“If the lipid balance is thrown off for long enough, we may begin to feel subtle changes, such as tiring more quickly. While our study does not offer medical recommendations, it does illuminate the early stages of metabolic disease and provides insights that may shape future prevention and therapeutic efforts.”

The downside of increased sugar intake
US consumers consume 22 teaspoons of added sugar per day. This amount is three times more than the recommended amount for females and more than double the amount recommended for males.

Despite knowledge of excess sugar consumption resulting in diabetes and other disorders, there is a less clear link between sugar intake habits and metabolic diseases on a cellular level.

In this space, the UK’s Action on Sugar noted that festive drinks contained high-sugar content, showing a “lack of progress” within sugar reduction policies. Similarly, the Union of European Soft Drinks Associations (UNESDA) revealed its nutrition target of reaching a ten percent sugar reduction in the European soft drink industry by 2025.

By Nicole Kerr