EFSA says synthetic zeaxanthin is safe at a daily dose of 0.75 mg/kg of body weight.
Synthetic zeaxanthin is safe for human consumption at a daily dose of 0.75 mg/kg of body weight, according to a statement from the European Union food safety watchdog EFSA (Parma, Italy).
Zeaxanthin is a compound found naturally in many plants. Its yellow-orange pigment colors many plants, including the leading source for commercial zeaxanthin production: marigold flowers. Published research suggests this compound can support eye health.
In 2008, EFSA denied an application for the safety of synthetic zeaxanthin, stating that the applicant, DSM Nutritional Products (Parsippany, NJ), had not proved the ingredient’s safety at the proposed dosage of 20 mg daily. DSM has since provided new data to support the ingredient’s safety, including a two-generation reproduction toxicity study on rats and 22 additional references.
EFSA was originally concerned that a substantial increase in zeaxanthin intake could possibly result in higher risk of lung cancer in heavy smokers. The effect has been reported with increased intake of beta-carotene, and both ingredients are members of the carotenoid family. Admittedly, no animal or human data is available on zeaxanthin and lung cancer risk, but EFSA now says a risk is not likely:
The effects of high-dose β-carotene observed in animal models of carotenoids research on lung cancer have been mainly attributed to the pro-oxidant properties of β-carotene, being a precursor of vitamin A, its interference with retinoic acid metabolism, and induction of CYP enzymes. There are differences in structure, metabolism, and function between zeaxanthin and β-carotene. Contrary to β-carotene, zeaxanthin is more polar and is not a precursor of vitamin A. In particular, it is more stable than β-carotene under pro-oxidant exposure and differs from β-carotene also with regard to its much lower or absent potential of acting as a pro-oxidant in vitro.
DSM notes, in its recent application, that daily doses as high as 1000 mg/kg of body weight have yielded no adverse effect reports in subchronic studies on mice, rats, and dogs.