In China, buy packaged cooking oil with an SC license number, not loose workshop-pressed peanut oil
Damp, moldy peanuts can contain aflatoxins, established carcinogens that mainly damage the liver. After Guangzhou tightened small-workshop regulation, abnormal liver tests in high-consumption communities fell by about 35%. In Guangxi, maternal use of homemade peanut oil was associated with about 90% higher low-birth-weight odds and 80% higher preterm-birth odds.
What it takes
Buy elsewhere for roughly the same price. Check for the Chinese food-production license number beginning “SC.” Convincing relatives accustomed to fresh-pressed oil may be the difficult part.
What you may gain
IARC classifies aflatoxins as group 1, carcinogenic to humans, chiefly causing liver cancer. A Guangzhou study measured aflatoxin B1 in workshop-pressed peanut oil during 2010–2022: median 1.29 μg/kg, middle half 0.12–6.58. After local workshop regulations, levels immediately declined by 2.865 μg/kg, then by another 2.593 annually. Abnormal liver function in high-consumption residents declined by about 35% (PR 0.650, 95% CI 0.469–0.902). A Guangxi cohort of 1,611 pregnant women found 81.7% consumed homemade peanut oil; use was associated with adjusted odds ratios of 1.9 for low birth weight (1.1–3.2) and 1.8 for preterm birth (1.1–3.0).
Context & considerations
Neither study randomized exposure. Guangzhou measured liver-test abnormalities, not liver cancer or mortality. Median toxin concentration was below China's peanut-oil limit of 20 μg/kg; concerns involve long-term consumption and unusually contaminated batches. The limit applies to all peanut oil, but packaged products undergo production licensing and factory testing, while small workshops follow provincial rules and receive fewer inspections. The main beneficiaries are you and those sharing your meals.
Research & references
Lei J, Li Y, Wang Y, et al. (2024). The impact of small food workshops management regulations on aflatoxin B1 in home-made peanut oil and the liver function of high-consumption area residents: an interrupted time series study in Guangzhou, China. Frontiers in Public Health, 12. https://doi.org/10.3389/fpubh.2024.1484414 ; Zhong Y, Lu H, Jiang Y, et al. (2024). Effect of homemade peanut oil consumption during pregnancy on low birth weight and preterm birth outcomes: a cohort study in Southwestern China. Global Health Action, 17. https://doi.org/10.1080/16549716.2024.2336312 ; IARC (2012). Chemical Agents and Related Occupations. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol 100F. https://publications.iarc.fr/123 ; National Health and Family Planning Commission and China Food and Drug Administration (2017). National Food Safety Standard: Maximum Levels of Mycotoxins in Foods, GB 2761-2017.