High fructose diets may harm the immune system

In a 2021 study conducted by several UK establishments, and published in the journal Nature Communications, researchers suggest that eating a diet high in fructose may cause the immune system to become inflamed and may reduce its ability to function properly.


Fructose is a natural sugar found in fruits, honey, and some vegetables such as asparagus and squash. In these forms, and with limited intake, fructose is not considered likely to contribute to ill health.

On the other hand, High Fructose Corn Syrup (HFCS) is a manufactured sweetener made from cornstarch. Being cheap to produce, HFCS became popular in the latter part of the 20th century as food manufacturers chose it to sweeten processed foods such as pizza and salad dressing, and it is found in soft drinks. Because it is so readily used, levels of intake can be high.

Whilst there doesn’t appear to be general consensus about the suggested ill-effects of HFCS, research has consistently shown links between consuming large quantities of HFCS and conditions such as obesity, diabetes, and non-alcoholic fatty liver disease.

The new study examined how human and mouse cells responded to fructose. Researchers found that fructose adjusts cellular metabolic pathways to promote the production of more reactive inflammatory cytokines. This type of inflammation can damage cells and tissues, contribute to organs and systems not working well, and lead to disease.



Jackie Day ND