Lee Jounghee, Zhao Naisi, Fu Zhuxuan, Choi Jihee, Lee Hae-Jeung, Chung Mei
Department of Food and Nutrition, Kunsan National University, Gunsan 54150, Korea.
Department of Public Health and Community Medicine, School of Medicine, Tufts University, Boston, MA 02111, USA.
Nutr Res Pract. 2021 Dec;15(6):773-788. doi: 10.4162/nrp.2021.15.6.773. Epub 2021 Jul 26.
BACKGROUND/OBJECTIVES: Due to the rapid increase of global cancer incidence and mortality and a high level of interest in cancer prevention, a systematic review of garlic intake and cancer risk is needed.
SUBJECTS/METHODS: We implemented a systematic review to examine the effects of varying levels of garlic intake on cancer. We conducted comprehensive literature searches in three electronic databases (MEDLINE, Embase, and Web of Science) for studies published between database inception and July or September of 2018. Two investigators independently screened abstracts and full-texts, extracted data, and assessed risk of bias (RoB). A total of one medium-quality randomized controlled trial (RCT) and 13 cohort studies graded as high RoB were included.
The 1-year follow-up results from a RCT showed that a significant decrease in the number and size of colorectal adenomas among participants with colorectal adenomas who received high-dose aged garlic extract (AGE) compared with those who received low-dose AGE ( < 0.05). The results of prospective observational studies provided inconsistent associations of colorectal cancer risk with garlic supplements and garlic intake as food.
In summary, the AGE was effective in reducing the number and magnitude of colorectal adenomas in one RCT, but there were inconsistent associations between garlic intake and colorectal cancer in cohort studies. Therefore, we could not draw a firm conclusion regarding the effects of garlic on cancer, because the current strength of evidence is inadequate due to a lack of number of high-quality RCTs.
背景/目的：由于全球癌症发病率和死亡率迅速上升以及对癌症预防的高度关注，需要对大蒜摄入量与癌症风险进行系统评价。
对象/方法：我们进行了一项系统评价，以研究不同水平大蒜摄入量对癌症的影响。我们在三个电子数据库（MEDLINE、Embase和Web of Science）中进行了全面的文献检索，查找在数据库建立至2018年7月或9月期间发表的研究。两名研究者独立筛选摘要和全文，提取数据，并评估偏倚风险（RoB）。共纳入1项中等质量的随机对照试验（RCT）和13项偏倚风险等级为高的队列研究。
一项RCT的1年随访结果显示，与接受低剂量 aged garlic extract（AGE）的患有结肠直肠腺瘤的参与者相比，接受高剂量AGE的参与者的结肠直肠腺瘤数量和大小显著减少（<0.05）。前瞻性观察性研究的结果显示，大蒜补充剂和作为食物的大蒜摄入量与结肠直肠癌风险之间的关联并不一致。
总之，在一项RCT中，AGE能有效减少结肠直肠腺瘤的数量和大小，但在队列研究中，大蒜摄入量与结肠直肠癌之间的关联并不一致。因此，由于缺乏高质量RCT的数量，目前证据力度不足，我们无法就大蒜对癌症的影响得出确凿结论。
