Vitamin E Lowers Risk Of Liver Cancer

StephenW

Vitamin E Lowers Risk Of Liver Cancer

(Ivanhoe Newswire) – Vitamin E is good for many things, including prevention of heart disease, strokes, cataracts, and possibly some signs of aging. Now, a study finds that consuming higher amounts of Vitamin E can lower your risk for liver cancer.

As the third most common cause of cancer mortality in the world, liver cancer is the fifth most common cancer in men and the seventh most common cancer in women - 85% of liver cancers occur in developing nations, with 54% in China alone. Different epidemiological studies have been conducted to examine the relationship between vitamin E intake and liver cancer, but the results have been inconsistent.

Wei Zhang, MD, MPH., of the Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, and colleagues analyzed data from 132,837 Chinese individuals who were enrolled in the Shanghai Women’s Health Study (SWHS) from 1997-2000 or the Shanghai Men’s Health Study (SMHS) from 2002-2006. Both were population-based cohort studies that were jointly conducted by the Shanghai Cancer Institute and Vanderbilt University.

Using validated food-frequency questionnaires, the researchers conducted in-person interviews to gain data about the participants’ dietary habits. They compared liver cancer risk among participants who had high intake of vitamin E with those with low intake.

Included in the analysis were 267 liver cancer patients who were diagnosed between 2 years after study enrollment and an average of 10.9 (SWHS) or 5.5 (SMHS) years of follow-up. Both dietary intake of vitamin E and supplementary intake of vitamin E were associated with a lower risk of liver cancer, and the association was consistent among participants with and without self-reported liver disease or family history of liver cancer.

The authors noted a small difference between men and women in the risk estimate, which could be attributed to fewer liver cancer cases occurring among SMHS participants because of the shorter follow up period. Bottom line: a high intake of vitamin E from either the diet or supplements is related to a lower risk of liver cancer, as demonstrated by middle-aged or older people from China.

Source: Journal of the National Cancer Institute, July 2012

StephenW

维生素E降低肝癌的风险

（艾芬豪通社） - 维生素E是很多东西，包括预防心脏病，中风，白内障，可能还有一些老化的迹象。现在，一项研究发现，食用高量的维生素E可降低肝癌的风险。

作为癌症的死亡率在世界上第三大最常见的原因，肝癌是男性和第七次妇女最常见的癌症 - 肝癌的85％发生在发展中国家，仅在中国的54％，第五个最常见的癌症。不同的流行病学研究已经进行了探讨维生素E的摄入和肝癌之间的关系，但结果却不一致。

张炜，医学博士，公共卫生硕士，上海肿瘤研究所，上海交通大学医学院附属仁济医院，和他的同事分析了从132837谁是参加在上海妇女健康研究（SWHS）中国从1997年至2000年或个人数据上海男性健康研究（SMHS）2002-2006年。两者都是基于人群的队列，由上海癌症研究所和美国范德比尔特大学共同进行的研究。

使用验证的食物频率问卷，研究人员进行的，在人的访谈，以获得有关参与者的饮食习惯的数据。他们比较了参与者之间谁曾与高摄入维生素E的摄入量低的肝癌的风险。

在分析包括267肝癌研究入学后2年内，平均10.9（SWHS）或后续5.5（SMHS）年间确诊的患者。这两种维生素E和维生素E的补充摄入的膳食摄入量与肝癌的风险较低，该协会并没有自报的肝病或肝癌家族史的参与者之间一致。

作者指出，这可以归因于较少的肝癌病例SMHS，因为较短的随访期间参与者之间发生的风险估计在男性和女性之间的差异小。底线：无论从饮食或营养补充剂的维生素E的摄入量高有关肝癌的风险较低，来自中国的中年或老年人证明。

资料来源：国家癌症研究所杂志七月2012

StephenW

Vitamin E Intake May Pare Liver Cancer RiskBy Kristina  Fiore, Staff Writer, MedPage TodayPublished: July 17, 2012Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco and Dorothy Caputo, MA, BSN, RN, Nurse Planner


Action Points

• Vitamin E seemed to have a protective effect against liver cancer based on studies done in Chinese patients.
• Point out that in further analyses, the association appeared to be stronger among women, but the researchers noted that it was consistent among patients with and without liver disease, or a family history of liver cancer.
  

High vitamin E intake seemed to have a protective effect against liver cancer, Chinese researchers found.
Among people ages 40-70, higher dietary intakes of the vitamin were associated with a significantly lower cancer risk (P=0.01 for trend), and taking vitamin E supplements almost cut the risk in half (HR 0.52, 95% CI 0.30 to 0.90), Xiao-Ou Shu, MD, PhD, of the Vanderbilt Epidemiology Center in Nashville, and colleagues reported online in the Journal of the National Cancer Institute.
If confirmed, the findings "could open a new venue for prevention of liver cancer," the researchers wrote.
The link between dietary factors, vitamin supplementation, and liver cancer hasn't been clear, so Shu and colleagues assessed data on 132,837 Chinese patients from the Shanghai Women's Health Study and the Shanghai Men's Health Study.
They evaluated vitamin intake from diet and supplements via food frequency questionnaires.
During follow-up, 267 patients developed liver cancer over an average of 10.9 years for women and 5.5 years for men.
Shu and colleagues found that greater levels of dietary vitamin E intake were associated with lower risk of liver cancer. Patients in the two highest quartiles of intake had significantly lower risk (HR 0.66, 95% CI 0.46 to 0.94 and HR 0.60, 95% CI 0.40 to 0.89, respectively, P=0.01 for trend).
Using vitamin E supplements nearly halved the risk of liver cancer compared with not taking these supplements (HR 0.52, 95% CI 0.30 to 0.90).
In further analyses, however, the association appeared to be stronger among women, but the researchers noted that it was consistent among patients with and without liver disease, or a family history of liver cancer.
Some explanations for the vitamin's potential protective effects could be its ability to prevent DNA damage, enhance DNA repair, prevent lipid peroxidation, inhibit the activation of carcinogens, or boost the immune system.
When looking at other vitamins, the researchers found that vitamin C appeared to increase the risk of liver cancer (HR 1.96, 95% CI 1.29 to 2.98), as did multivitamins among men (HR 1.84, 95% CI 1.13 to 2.98).
Yet use of both of these supplements was associated with an increased risk among patients with liver disease and a family history of liver cancer (P=0.01 and P=0.06, respectively).
That could lead to a case of reverse causality, the researchers noted, as patients with liver disease or a history of liver cancer may be more likely to take supplements in an attempt to lessen disease risk.
Shu and colleagues also noted that intake of vitamin C and other vitamins from dietary sources wasn't related to liver cancer risk. Nor was there any association between the use of vitamin B or calcium supplements and risk of liver cancer.
The study was limited by a relatively short follow-up time, its reliance on a food frequency questionnaire to assess dietary intake, lack of information on specific doses of vitamins, and an inability to rule out unmeasured confounders such as hepatitis B and C and other risk factors.
Still, the researchers said vitamin E may play an important role in liver cancer prevention for Chinese patients.
The study was supported by the National Institutes of Health and the Key State Project Specialized for Infectious Diseases of China.
The researchers reported no conflicts of interest.

  Primary source: Journal of the National Cancer Institute
             Source reference:
       Zhang W, et al "Vitamin intake and liver cancer risk: A report from two cohort studies in China" J Natl Cancer Inst 2012; DOI: 10.1093/jnci/djs277.

IC

http://www.hbvhbv.com/forum/thread-621939-1-1.html
http://www.hbvhbv.com/forum/thread-621953-1-1.html
http://www.hbvhbv.com/forum/thread-34698-1-1.html
http://www.hbvhbv.com/forum/thread-1105550-1-1.html

MP4

http://infect.dxy.cn/article/25500
美国叶史瓦大学爱因斯坦医学院（Albert Einstein College of Medicineof Yeshiva University）的研究人员发现，年龄的增长可能会削弱人体的抵抗力从而影响免疫接种的效果。研究显示，给衰老中的小鼠注入抗氧化剂或许能扭转其免疫功能的退化。此项研究结果发表在本月的《Cell Reports》杂志在线版。

“众所周知，衰老会影响免疫功能，这个现象称作为免疫衰老，但个中缘由尚未明确。”爱因斯坦医学院病理学、微生物学和免疫学副教授Laura Santambrogio博士负责此项研究。她说，“我们的研究洞悉了衰老导致机体免疫应答效力减弱的多种途径。”

所有的细胞都会产生一种叫做自由基的化学物质作为新陈代谢的正常部分。通过氧化反应（物质与氧发生的化学反应），这些高度活跃,极不稳定的分子能很容易地破坏蛋白质、脂质及其他细胞成分。细胞通过产生能清除自由基的各种酶来保持它的“氧化应激”（oxidative stress）能力。但在衰老过程中，随着抗氧化酶的消耗和自由基的产生，蛋白质和其他一些分子被破坏，从而导致了细胞毒害。

目前所进行的研究是就与“氧化应激”老龄化是否会削弱树突状免疫细胞功能这个课题的首次验证。“树突细胞被称作为‘免疫系统的哨兵’，当有病原侵袭时能随时为免疫系统拉响警报。”Santambrogio博士解释道，“当我们感染了细菌或者病毒后，这些树突细胞能吞噬病原体，再呈递给免疫系统，形象地说，‘感染是元凶，树突细胞负责揪住它’。”

Santambrogio博士与医学院的同事Fernando Macian-Juan博士, Ana Maria Cuervo博士合作，从衰老的老鼠中将树突细胞分离出来，发现细胞中有氧化损伤蛋白的聚集，从而造成了细胞损害。例如，病原体在胞内体灭活，氧化后的蛋白限制了胞内体的功能。

连续两周在小鼠腹腔内注入某种强效抗氧化剂后，小鼠神经细胞的氧化应激状态出现了逆向恢复。这项发现对疫苗的设计和临床治疗具有提示意义，尤其是对老年人，免疫力低下造成感染率高，癌症多发，接种效果差。Santambrogio博士指出：“许多老年人接种免疫的效果很差，因此，在接种之前的进行一轮抗氧化治疗是很有可能增强接种效力的。”