Nutrition Truth

A study published in Cell Death Discovery on September 14, 2026, explored the potential effects of quercetin, a natural plant compound found in red onions, citrus fruits, and other plant-based foods.

Researchers from Friedrich-Alexander University Erlangen-Nürnberg in Germany examined how quercetin affected lung cancer cells in laboratory experiments, alongside studies involving mice and lung tissue samples.

The findings suggested that quercetin may slow the growth and movement of certain lung cancer cells. Researchers also observed changes in cellular pathways involved in cell division, oxidative stress, and immune responses. These results suggest that quercetin may influence several biological processes associated with tumor development.

In animal experiments, the researchers observed fewer tumor spots in lung tissue samples from quercetin-treated mice than in untreated mice. However, the overall difference in tumor burden was not statistically significant. The study also identified changes in gut bacteria and immune-related activity that may warrant further investigation.

What does this mean?

Quercetin is naturally present in a variety of fruits and vegetables, making it an interesting subject for scientific research. However, these findings are preliminary and come from laboratory and animal studies. More research, including human clinical trials, is needed to determine whether quercetin could have meaningful benefits for people with lung cancer.

Important note: These findings do not establish quercetin as a cancer treatment. No food or natural compound should replace medical care or prescribed cancer treatment.

Being intelligent isn’t only about how much you know; it’s also about noticing how you think. Metacognition helps you recognize when you’re making assumptions, understand why you react a certain way, and reconsider an idea when the evidence doesn’t support it. It gives you the chance to learn from mistakes instead of defending every decision you make. Sometimes, real growth begins when you stop asking only, “Am I right?” and start asking, “What makes me think I’m right?”

Polycystic o***y syndrome (PCOS) is a hormonal disorder that can disrupt ovulation, increase testosterone levels, and affect normal ovarian function. In PCOS, some ovarian follicles may stop developing properly and remain as small, fluid-filled structures instead of maturing and releasing an egg. Rosmarinic acid, a natural polyphenol found in rosemary, lemon balm, and several other herbs, has attracted scientific interest for its antioxidant and anti-inflammatory properties. Researchers are now investigating whether these effects could help protect ovarian tissue and improve hormonal balance in PCOS.

A study published in Physiological Reports investigated rosmarinic acid in 15 female rats divided into three groups, including five rats with experimentally induced PCOS that received 25 mg/kg of rosmarinic acid orally each day for 39 days. Compared with untreated PCOS rats, the treated animals showed an 86.7% reduction in ovarian cystic follicle volume, a 58.4% decrease in testosterone, and a 63.8% decrease in luteinizing hormone (LH). The number of mature Graafian follicles doubled, while degenerating follicles decreased by 51.7%. Researchers also observed improvements in ovarian structure and inflammatory markers, including TNF-α and IL-6.

PMID: 40170546

Lemon balm (Melissa officinalis) is a medicinal herb from the mint family that contains several biologically active compounds, including rosmarinic acid, caffeic acid, citral, citronellal, and other plant-derived chemicals with antimicrobial properties. Laboratory research has found that lemon balm extracts and essential oils can inhibit or kill various harmful bacteria, including strains associated with food poisoning, typhoid fever, skin infections, pneumonia, urinary tract infections, bloodstream infections, sepsis, and endocarditis. These include Staphylococcus aureus, Escherichia coli, Salmonella species, Pseudomonas aeruginosa, Klebsiella species, and Bacillus cereus. Some of these bacteria cause infections by damaging tissues, producing toxins, or spreading through the bloodstream. Lemon balm's antibacterial activity is thought to involve disruption of bacterial cell membranes, interference with essential cellular processes, and damage to structures needed for bacterial survival.
Across laboratory studies, lemon balm preparations have demonstrated antibacterial activity against at least 13 different bacterial strains, although the exact number depends on the studies and extracts examined. Researchers have tested these effects using methods such as measuring bacterial growth inhibition zones and determining minimum inhibitory concentrations (MICs), which indicate how much of an extract is needed to stop bacterial growth. The results suggest that certain lemon balm preparations can suppress bacterial multiplication, while some concentrations may directly kill susceptible bacteria. However, antibacterial effectiveness varies considerably depending on the extraction method, chemical composition, concentration, and bacterial species.