Wong 和团队评估了与六种饮食习惯相关的单核苷酸多态性 (SNP)，这些饮食习惯被选为工具变量。五个、两个和六个 SNP 被确定为从不饮酒、饮酒和咖啡消费，而一个 SNP 被用于消费茶、牛奶和酸奶。分析表明，rs671 是 ALDH2 基因的一个变体，是关于从不饮酒和咖啡消费与 HCC 风险之间关联的最重要的 SNP。
Wong 及其同事指出，SNP 很少的饮食习惯无法通过多种孟德尔随机化方法进行测试，这是一项研究限制。由于 HCC 病例数较低，六种饮食习惯与 HCC 风险之间的每种关联的统计功效较低。此外，研究结果可能仅限于东亚人群。
作者['full_name']
Zaina Hamza 是《今日医学》杂志的特约撰稿人，报道胃肠病学和传染病。她常驻芝加哥。
披露
Wong 和合著者报告没有利益冲突。
主要资源
肝病通讯
来源参考：Deng Y, et al 《六种饮食习惯与肝细胞癌风险的关联：孟德尔随机化研究》Hepatol Commun 2022； DOI：10.1002/hep4.1960。作者: StephenW 时间: 2022-6-11 16:46
Coffee, Tea May Be Protective Against Liver Cancer
— Chinese study looks at association between six dietary habits and HCC risk
by Zaina Hamza, Staff Writer, MedPage Today June 10, 2022
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A photo of a young woman carrying a tray of take-out coffee in an office.
Certain dietary habits such as higher alcohol intake were associated with a higher risk of hepatocellular carcinoma (HCC), while others such as coffee and tea drinking were linked with a lower risk, according to a large Mendelian randomization study from China.
Among over 200,000 participants, regular consumption of alcohol was associated with risk of HCC (OR 1.57, 95% CI 1.32-1.86), as was ever drinking (OR 1.11, 95% CI 1.05-1.18; P<0.001 for both), reported Martin Wong, MD, MPH, of the Chinese University of Hong Kong, and colleagues.
On the other hand, consumption of coffee was inversely associated with HCC risk (OR 0.69, 95% CI 0.53-0.90, P=0.007), and the same was true for consumption of green or traditional tea (OR 0.11, 95% CI 0.05-0.26), and milk and yogurt (OR 0.18, 95% CI 0.09-0.34 for both; P<0.001 for all), they noted in Hepatology Communications.
"Our findings highlight the importance of maintaining healthy diet habits in the prevention of liver cancer," Wong told MedPage Today.
"Previous studies examining dietary habits and risk of liver cancer are mainly observational studies. The dietary habits may simply be associated factors, but not causal factors of liver cancer, hence limiting their implications," he noted.
"Mendelian randomization used in the present study was introduced as a study design to infer causality, which could tell whether dietary intake could possibly cause liver cancer," he explained. "It has a more significant impact on public health practices."
Because alcohol's first metabolic product, acetaldehyde, stimulates oxidative stress, generates DNA adducts, and modifies related genes, it could also promote liver carcinogenesis, the authors said. Moreover, long-term heavy alcohol use often results in cirrhosis, which progresses to HCC.
Coffee has previously been shown to have a protective effect against liver fibrosis. Wong and team suggested that the protective effect of milk and yogurt might be attributed to the calcium binding of toxic secondary bile acids and free fatty acids that inhibit carcinogenic effects.
Additionally, certain lactic acid bacteria (Streptococcus thermophilus) in yogurt prevent carcinogenesis and stimulate the immune system. The major active compounds in tea are polyphenols, such as epicatechin and epigallocatechin, which inhibit tumor cell growth, suppress angiogenesis and DNA methylation, and promote apoptosis of tumor cells.
For this study, Wong and colleagues examined data from genome-wide association studies from BioBank Japan on six dietary habits among over 200,000 participants of Eastern Asian descent ages 20 to 89 from 2003 to 2018: ever/never drinking (n=165,084), alcohol consumption (n=58,610), coffee consumption (n=152,634), tea consumption (n=152,653), milk consumption (n=152,965), and yogurt consumption (n=152,097).
Of the participants, 1,866 had HCC (1,384 men and 482 women, mean age 68); they were compared with 195,745 controls (97,655 men and 98,090 women, mean age 62), who were recruited from four other Japanese population-based prospective cohorts, as well as BioBank Japan.
Wong and team assessed single-nucleotide polymorphisms (SNPs) linked to the six dietary habits, which were selected as instrumental variables. Five, two, and six SNPs were identified for ever/never drinking, alcohol consumption, and coffee consumption, while one SNP was used for consumption of tea, milk, and yogurt. Analyses showed that rs671, a variant of the ALDH2 gene, was the most important SNP for the associations of ever/never drinking and coffee consumption with HCC risk.
Wong and colleagues noted that dietary habits that had few SNPs could not be tested across multiple Mendelian randomization methods, which was a study limitation. Since the number of HCC cases was low, the statistical power for each association between the six dietary habits and HCC risk was low. Furthermore, the findings may be limited to an Eastern Asian population.
author['full_name']
Zaina Hamza is a staff writer for MedPage Today, covering Gastroenterology and Infectious disease. She is based in Chicago.
Disclosures
Wong and co-authors reported no conflicts of interest.
Primary Source
Hepatology Communications
Source Reference: Deng Y, et al "Associations between six dietary habits and risk of hepatocellular carcinoma: a Mendelian randomization study" Hepatol Commun 2022; DOI: 10.1002/hep4.1960.