Flavonoids are a large group of polyphenolic compounds found in fruits, vegetables, and plant-derived beverages. Their use in supporting or treating autoimmune disorders is primarily justified by emerging scientific interest rather than by strong traditional or clinical practice. Flavonoids are recognized for their anti-inflammatory and immunomodulatory properties, which have been investigated in preclinical and some limited clinical studies. Research has shown that flavonoids such as quercetin, luteolin, and epigallocatechin gallate (EGCG) can inhibit pro-inflammatory cytokines, modulate immune cell activity, and reduce oxidative stress, all of which are relevant to autoimmune disease mechanisms.

However, most evidence to date comes from in vitro studies and animal models. Some small-scale clinical trials and observational studies suggest potential benefits in conditions such as rheumatoid arthritis and multiple sclerosis, but these findings are preliminary and not sufficient for definitive clinical recommendations. There is currently no strong consensus or high-quality, large-scale clinical trial data supporting the routine use of unspecified flavonoids for autoimmune disorders. Thus, while there is a scientific basis to further investigate flavonoids in this context, the current level of evidence is modest, and their use should be considered experimental rather than established therapy.