A new, innovative study finds that a high-salt diet delays and reduces the growth of the tumor by changing the function of certain immune cells. The study used cell cultures and two separate mouse models for the experiments.
Excessive salt intake has been linked to the many pro-inflammatory effects. For instance, high-salt intake overstimulates immune reactions and intensifies the symptoms of multiple sclerosis and inflammatory bowel diseases. However, in the case of cancer, these pro-inflammatory effects are encouraged. This is because they may help to fight tumors.
In recent times, immunotherapy has appeared as one of the most promising avenues for treating cancer. Thus, the team of this respective research set out to examine the effects of a high-salt intake on tumor growth.
The findings of the study were published in the journal Frontiers in Immunology. The research team conducted a cell-culture experiment by replicating a high-salt environment. They found that excessive salt hindered the function of the myeloid-derived suppressor cells (MDSCs). These results were confirmed both in mice cells and in human MDSCs taken from cancer patients.
As per the research, the high-salt environment stopped MDSCs from inhibiting other immune cells. It was previously known that MDSCs are key in preventing the immune system from effectively attacking tumors. In this respective study, the researchers depleted MDSCs altogether while keeping the high-salt environment. Intriguingly, it reversed the inhibitory effects on tumor growth and confirmed that MDSCs are potentially crucial for anticancer immunotherapy.
Tumor inhibition via heavy salt intake
In a mouse model of melanoma transplantation, rodents fed with a high-salt displayed a significantly inhibited tumor growth. According to the team, delayed tumor outgrowth was evident as early as day 11 post-injection. This led to considerable differences in tumor size between both groups at day 13 [post-injection] and at the day of sacrifice.
The researchers of the study wanted to reproduce these results in a different model. Therefore, they used a mouse model of lung cancer. It showed the same results. For example, a diet high in salt significantly delayed [lung cancer] tumor growth in them.
Consequently, the research concludes that a high-salt diet is able to significantly inhibit tumor growth in two independent tumor transplantation models. The findings of the study are highly interesting. The researchers were surprised to see such an effect on tumor growth just by increasing the salt in the diet.
Scientists highly encourage future studies regarding the subject. This is because these kinds of studies van help to fully understand the effect and the detailed underlying molecular mechanisms behind. In this way, one can judge its therapeutic potential for anticancer immunotherapies.