Reacción a "A study in mice and human tissue shows that the antioxidant glutathione feeds cancer cells"

The study by Hecht and colleagues is impeccably conducted, and its experimental rigour allows for a solid demonstration of the importance of extracellular glutathione as a source of cysteine in breast tumours, at least in the murine models analysed.

However, a potential limitation of the work is that other alternative sources of amino acids, including cysteine, may exist in the tumour interstitial fluid, and their relative contribution has not yet been defined. Likewise, the origin of the glutathione that accumulates in this compartment remains unclear, as does whether external factors, such as glutathione-rich diets or direct intake of this compound as an antioxidant supplement, might influence its levels in the tumour microenvironment.

Given the potential relevance of these findings, it will be essential to validate the results in patient samples and correlate them with clinical information and dietary habits. If confirmed, these data could have significant public health implications and would challenge the widespread perception of glutathione as an inherently beneficial compound for human health.