Statement on the safety of β-carotene use in heavy smokers
Following a request by the European Commission the Scientific Panel on Food Additives and Nutrient Sources added to Food (ANS) was asked to conclude on the possible link between the ingestion of β-carotene and cancer enhancement in heavy smokers. The safety of (synthetic) β-carotene [E 160a (ii)] has been evaluated previously by JECFA (1975) and by the SCF (2000a). In 2000, the SCF concluded that there were insufficient data to set a precise figure for a Tolerable Upper Intake Level (UL) of β-carotene (SCF, 2000b). Unexpectedly, two independent trials revealed that heavy smokers (at least 1 package/day for 36 years on average) receiving long-term β-carotene (20 mg/day) supplementation or β-carotene (30 mg/day) + retinol (25 000 International Unit (IU) vitamin A) supplementation, showed increased rather than decreased incidences of lung cancer. A meta-analysis of randomized controlled trials (RCT) demonstrated absence of any protective effect associated with β-carotene supplementation with regard to cancer risk. Epidemiological studies reported no increased lung cancer incidence in heavy smokers at supplemental dose levels of β-carotene varying from 6 – 15 mg/day for about 5 up to 7 years. The Panel concluded that exposure to β-carotene from its use as food additive and as food supplement at a level below 15 mg/day do not give rise to concerns about adverse health effects in the general population, including heavy smokers.