Carrots for Immune Function

Research suggests that carrots, as a rich source of beta-carotene and other carotenoids, may support immune function through several proposed mechanisms, including antioxidant activity, conversion to vitamin A (retinoic acid), and the possible presence of carotenoid-oxygen copolymers that some studies indicate can influence immune responses at relatively low concentrations. A 2016 review of carotenoids and a related study on carotenoid copolymers in foods both point in a supportive direction, and a commentary on animal research suggests that retinoic acid — the active form of vitamin A — plays a regulatory role in certain immune responses, particularly in the liver. However, the available evidence includes limitations worth noting: a four-week randomized trial involving a mixed vegetable diet that included carrots found no meaningful changes in immune or antioxidant markers among participants at cardiovascular risk, and two 2025 studies examining gut microbiome and vaccine response introduce contextual complexity around how diet, including plant-based foods, interacts with immune outcomes in real-world conditions. Overall, the body of evidence — drawn from reviews, commentary, mechanistic studies, and one small randomized trial — is mixed in direction and limited in clinical scope, meaning firm conclusions about carrots specifically improving immune function in humans remain premature.