Is luteolin a beneficial supplement?

Is Luteolin a Beneficial Supplement?

Luteolin from food sources appears beneficial for health, but supplementation cannot be recommended due to insufficient clinical evidence, potential drug interactions during cancer treatment, and concerns about bioavailability.

Evidence Quality and Context

The available evidence for luteolin supplementation is predominantly from preclinical studies, with very limited high-quality human clinical data 1, 2, 3. The most relevant guideline evidence comes from cancer and nutrition contexts, where luteolin is discussed primarily as a dietary component rather than a supplement 4.

Food Sources vs. Supplementation

• Dietary luteolin from vegetables (celery, thyme, green pepper) provides antioxidant and anti-inflammatory properties with established safety 4
• Typical dietary intake is less than 1 mg/day, which is substantially lower than supplement doses 1
• Luteolin exists as glycosides in plants, which are cleaved and metabolized after consumption, making in vitro supplement studies difficult to translate to clinical practice 1

Critical Safety Concern: Cancer Treatment Interactions

• Luteolin has a biphasic effect on breast cancer cells when combined with doxorubicin chemotherapy, potentially attenuating the cytotoxic effects of the chemotherapy drug 4
• This cytoprotective effect on cancer cells could theoretically reduce chemotherapy efficacy, similar to concerns about other antioxidants during cancer treatment 5
• Most oncologists advise against higher-dose antioxidant supplements during chemotherapy or radiotherapy because they may repair oxidative damage to cancer cells that contributes to treatment effectiveness 5

Limited Clinical Evidence

• Only one small phase I study (n=5) in prostate cancer patients under active surveillance showed safety with 50 mg daily for 6 months, but efficacy was mixed with 2/5 patients showing disease progression 6
• No high-quality randomized controlled trials demonstrate clinical benefit for any specific condition in humans 4, 7
• The theoretical benefits for long COVID neurological symptoms remain entirely speculative without clinical evidence 4

Bioavailability Limitations

• Luteolin has low water solubility and poor oral bioavailability, which significantly limits its therapeutic potential 2
• More quantitative research on oral and topical bioavailability is needed before therapeutic recommendations can be made 1
• The gap between promising preclinical data and clinical application remains substantial 2

Perioperative Considerations

• No specific recommendation exists for holding luteolin before surgery, unlike many other supplements 4
• However, the general principle of caution with supplements having anti-inflammatory or antioxidant properties applies 4

When Dietary Luteolin May Be Beneficial

• Increased consumption of luteolin-rich vegetables may contribute to reduced cardiovascular disease risk through anti-inflammatory mechanisms 1
• Dietary sources provide luteolin alongside other beneficial compounds (vitamins, fiber, other flavonoids) that work synergistically 4
• Epidemiological studies suggest protective effects from luteolin-containing foods, though causality cannot be established 1

Clinical Bottom Line

Focus on increasing dietary intake of luteolin-rich vegetables rather than supplementation. If supplementation is considered despite limited evidence, avoid use during active cancer treatment, particularly chemotherapy 4, 5. The preclinical promise of luteolin for inflammation, pain, and metabolic conditions requires validation through rigorous human clinical trials before supplementation can be recommended 1, 2, 3, 8.