Some fruits and vegetables are particularly rich in alpha-carotene, and alpha-carotene often coexists with beta-carotene such as carrots and palm fruits. Although vitamin A activity of alpha-carotene is only half of beta-carotene, study has shown that alpha-carotene possesses stronger antioxidant efficacy than beta-carotene in phosphatidyl choline vesicles (cellular organelles that transport nutrient into tissues), and thereby minimizing free radical-mediated peroxidative damage against cell membrane in vivo [1].

Alpha-Carotene is More Potent than Beta-Carotene

When comparing to beta-carotene, research demonstrates that alpha-carotene shows

  1. 10 times stronger protective effects in a cancer setting such as human neuroblastoma cells (ie: a type of cancer that affects early stages of neuronal cells development in infants or young children) in a dose-dependent manner [2];

  2. Suppression of the initiation of cancer formation in liver, lung and skin more effectively in mice [3];

  3. Significant inverse relationship with the risk of cervical dysplasia among Japanese women aged 55 and above [4].

References:

  1. Farombi, E.O. & Britton, G., (1999). Antioxidant activity of palm oil carotenes in peroxyl radical-mediated peroxidation of phosphatidyl choline liposomes. Redox Report; 4(1-2):61-68.
  2. Murakoshi M, et al. (1989). Inhibitory effects of alpha-carotene on proliferation of the human neuroblastoma cell line GOTO. J Natl Cancer Inst., 81(21), 1649-52.
  3. Murakoshi M, et al. (1992). Potent preventive action of alpha-carotene against carcinogenesis: spontaneous liver carcinogenesis and promoting stage of lung and skin carcinogenesis in mice are suppressed more effectively by alpha-carotene than by beta-carotene. Cancer Res., 52(23), 6583-7.
  4. Nagata C, et al. (1999). Serum carotenoids and vitamins and risk of cervical dysplasia from a case–control study in Japan. Br J Cancer, 81(7), 1234-1237.