Dietary intake of carotenoid isomers in Israel.

Controversy exists regarding the possible protective role of carotenoids against cancer. Evidence is mainly against all-E-beta-carotene, while there is no evidence against other carotenoids or against mixtures of beta-carotene stereoisomers. Carotenoid isomers could account for the variability in study results but are rarely estimated, and reference to the degree of their consumption is lacking. The aim of our study was to create a comprehensive database of carotenoid isomers content in food items commonly consumed in Israel. Food items were analyzed using a liquid chromatography system to determine the content of carotenoid isomers in Israeli food. The main sources of carotenoids detected in Israeli foods were tomato juice, tomato, watermelon, parsley, coriander, spinach, carrot, sweet potato, banana, zucchini, mango, loquat, pepper, eggplant, and chickpeas. Data were used to measure consumption in healthy participants of a case-control study, using a semi-quantitative food-frequency 187-item questionnaire. Compared to reference studies, the median carotenoid isomers intake in 712 Israeli healthy controls (age range 23-95 years, mean 71 +/- 10.9 years, median 73 years) was higher for beta-carotene, alpha-carotene, beta-cryptoxanthin, and zeaxanthin, while the intake of lycopene was lower. Major differences in consumption were noticed between ethnic groups consuming Mediterranean diets and those consuming Western-type diets. Population consumption patterns of carotenoid isomers using a comprehensive database are used to improve our understanding in disease prevention. Consumption in Israel seems to be generally higher than that reported in studies conducted elsewhere, and varies by ethnic group.