近日,，6月刊的《胃腸病學(xué)》（Gastroenterology ）發(fā)表的一項(xiàng)以人口為基礎(chǔ)的日本成人研究顯示,，食用富含n-3多不飽和脂肪酸(n-3 PUFA)的魚類以及二十碳五烯酸(EPA),、二十二碳五烯酸(DPA)和二十二碳六烯酸(DHA)等n-3 PUFA與肝細(xì)胞癌(HCC)發(fā)生風(fēng)險(xiǎn)呈劑量依賴性負(fù)相關(guān)。
長期以來，食用n-3 PUFA被認(rèn)為可降低多種癌癥的發(fā)生風(fēng)險(xiǎn)，但對(duì)肝癌預(yù)防作用的專門研究報(bào)道甚少,。最近美國一項(xiàng)前瞻性研究表明,，食用包括魚類等“白肉”與肝癌呈負(fù)相關(guān)，但其他研究未發(fā)現(xiàn)上述相關(guān)性,。為此,，日本國家癌癥中心的Norie Sawada博士及其同事利用上世紀(jì)90年代日本衛(wèi)生部門開展的一項(xiàng)大規(guī)模隊(duì)列研究數(shù)據(jù)，對(duì)90,296例成年人(基線年齡40~69歲)飲食數(shù)據(jù)進(jìn)行詳細(xì)分析,，平均隨訪11年,。
受試者完成一份有關(guān)上一年138種日常食物攝入的問卷調(diào)查，攝入量以標(biāo)準(zhǔn)份量或單位計(jì)算,。其中19種食物涉及魚類和貝類，包括咸魚,、干魚,、金槍魚、鮭魚或鱒魚罐頭,、鰹魚,、金槍魚、鱈魚,、海鯉魚,、鯖魚、沙丁魚,、秋刀魚,、魚子、鰻魚,、魷魚,、章魚、蝦,、蛤,、螃蟹、田螺,、以及各種魚醬,。研究者根據(jù)問卷計(jì)算每日魚類消費(fèi)量以及n-3 PUFA總攝入量和4種脂肪酸的具體攝入量，并分別計(jì)算鮭魚,、鱒魚,、海鯉魚、鯖魚,、沙丁魚,、秋刀魚和鰻魚等富含n-3 PUFA魚類的攝入量。在常規(guī)體檢時(shí)采集血樣,，篩查丙型肝炎抗體和乙型肝炎表面抗原,，以確定受試者是否攜帶丙型或乙型肝炎病毒,。隨訪期間共計(jì)398例發(fā)生HCC。
結(jié)果顯示,，魚類總攝入量與HCC風(fēng)險(xiǎn)呈弱負(fù)相關(guān),，最高vs.最低五分位數(shù)多變量危險(xiǎn)比(HR)為0.64[95%置信區(qū)間(CI)為0.4~1.02，P=0.07],。若僅限于富含n-3 PUFA魚類的攝入,，則上述相關(guān)性達(dá)到統(tǒng)計(jì)學(xué)顯著水平，HR為0.64(95% CI,，0.42~0 .96,；P=0.04)。HCC風(fēng)險(xiǎn)與EPA,、DPA和DHA攝入量呈顯著劑量依賴性負(fù)相關(guān),。校正年齡、性別,、吸煙狀況和體重指數(shù)后,，上述相關(guān)性仍然存在，并且飲酒者和咖啡飲用者等亞組間也具有上述相關(guān)性,。乙肝或丙肝陽性患者亞組食用富含n-3 PUFA魚類與HCC風(fēng)險(xiǎn)也呈高度負(fù)相關(guān),。
研究者指出，PUFA對(duì)肝癌保護(hù)作用的機(jī)理尚不清楚,。鑒于HCC是一種與炎癥有關(guān)的癌癥,，肝炎病毒或酒精等毒性化合物暴露可引起慢性炎癥，推測(cè)PUFA的肝癌保護(hù)作用或許與其抗炎作用有關(guān),。
該研究的局限性表現(xiàn)為應(yīng)估算魚類和各種脂肪酸的攝入量,，而不是直接測(cè)定其含量。此外,，飲食數(shù)據(jù)僅來自于受試者一個(gè)時(shí)間點(diǎn)的自我報(bào)告,。
該研究由日本國家癌癥中心研究與開發(fā)基金會(huì)和厚生省資助。作者報(bào)告無相關(guān)利益沖突,。（生物谷Bioon.com）
doi:10.1053/j.gastro.2012.02.018
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Consumption of n-3 Fatty Acids and Fish Reduces Risk of Hepatocellular Carcinoma
Norie Sawada, Manami Inoue, Motoki Iwasaki, Shizuka Sasazuki, Taichi Shimazu, Taiki Yamaji, Ribeka Takachi, Yasuhito Tanaka, Masashi Mizokami, Shoichiro Tsugane
Background & Aims
Fish is a rich source of n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA). Although consumption of fish and n-3 PUFA has been reported to protect against the development of some types of cancer, little is known about its association with hepatocellular carcinoma (HCC).
Methods
We investigated the association between fish and n-3 PUFA consumption and HCC incidence (n = 398) in a population-based prospective cohort study of 90,296 Japanese subjects (aged, 45–74 y). Hazard ratios and 95% confidence intervals (CIs) for the highest vs the lowest quintile were estimated from multivariable adjusted Cox proportional hazards regression models. We also conducted subanalyses of subjects with known hepatitis B virus (HBV) or hepatitis C virus (HCV) status, and of subjects who were anti-HCV and/or hepatitis B surface antigen positive. All tests of statistical significance were 2-sided.
Results
Among all subjects, consumption of n-3 PUFA-rich fish and individual n-3 PUFAs was associated inversely with HCC, in a dose-dependent manner. Hazard ratios for the highest vs lowest quintiles were 0.64 (95% CI, 0.42–0.96) for n-3 PUFA-rich fish, 0.56 (95% CI, 0.36–0.85) for EPA, 0.64 (95% CI, 0.41–0.98) for DPA, and 0.56 (95% CI, 0.35–0.87) for DHA. These inverse associations were similar irrespective of HCV or HBV status.
Conclusions
Consumption of n-3 PUFA-rich fish or n-3 PUFAs, particularly EPA, DPA, and DHA, appears to protect against the development of HCC, even among subjects with HBV and/or HCV infection.
