Head K A
Alternative Medicine Review. P.O. Box 25, Dover, ID 83825, USA.
Altern Med Rev. 1998 Jun;3(3):174-86.
Proposed mechanisms of action for ascorbic acid (ascorbate, vitamin C) in the prevention and treatment of cancer include enhancement of the immune system, stimulation of collagen formation necessary for "walling off" tumors, inhibition of hyaluronidase which keeps the ground substance around the tumor intact and prevents metastasis, prevention of oncogenic viruses, correction of an ascorbate deficiency often seen in cancer patients, expedition of wound healing after cancer surgery, enhancement of the effect of certain chemotherapy drugs, reduction of the toxicity of other chemotherapeutic agents such as Adriamycin, prevention of free radical damage, and neutralization of carcinogenic substances. Scottish as well as Japanese studies have pointed to the potential benefit of high dose vitamin C for the treatment of "terminal" cancer. Mayo Clinic studies, however, have contradicted the Scottish and Japanese findings, resulting in accusations of methodological flaws from both sides. Numerous epidemiological studies have pointed to the importance of dietary and supplemental ascorbate in the prevention of various types of cancer including bladder, breast, cervical, colorectal, esophageal, lung, pancreatic, prostate, salivary gland, stomach, leukemia, and non-Hodgkin's lymphoma.
抗坏血酸（维生素C）在癌症预防和治疗中的作用机制包括：增强免疫系统；刺激“隔离”肿瘤所需的胶原蛋白形成；抑制透明质酸酶，该酶可保持肿瘤周围基质完整并防止转移；预防致癌病毒；纠正癌症患者中常见的抗坏血酸缺乏；加快癌症手术后的伤口愈合；增强某些化疗药物的效果；降低其他化疗药物（如阿霉素）的毒性；预防自由基损伤；中和致癌物质。苏格兰和日本的研究均指出高剂量维生素C对“晚期”癌症治疗的潜在益处。然而，梅奥诊所的研究与苏格兰和日本的研究结果相矛盾，双方因此互相指责对方研究方法存在缺陷。大量流行病学研究表明，饮食和补充抗坏血酸对于预防多种癌症至关重要，这些癌症包括膀胱癌、乳腺癌、宫颈癌、结直肠癌、食管癌、肺癌、胰腺癌、前列腺癌、唾液腺癌、胃癌、白血病和非霍奇金淋巴瘤。
