ω-3脂肪酸保护抗肝纤维化的疾病

StephenW

For Protection Against Liver Disease, Some Omega-3 Oils Are Better Than Others

Article Date: 08 Feb 2013 - 0:00 PST



Research at Oregon State University has found that one particular omega-3 fatty acid has a powerful effect in preventing liver inflammation and fibrosis - common problems that are steadily rising along with the number of Americans who are overweight.

The American Liver Foundation has estimated that about 25 percent of the nation's population, and 75 percent of those who are obese, have nonalcoholic fatty liver disease. This early-stage health condition can sometimes progress to more serious, even fatal diseases, including nonalcoholic steatohepatitis, or NASH, as well as cirrhosis and liver cancer.

The study, published online in the Journal of Nutrition, was one of the first to directly compare the effects of two of the omega-3 fatty acids often cited for their nutritional value, DHA and EPA.

In research with laboratory animals, it found that EPA had comparatively little effect on preventing the fibrosis, or scarring, that's associated with NASH. However, DHA supplementation reduced the proteins involved in liver fibrosis by more than 65 percent.

"A reduction of that magnitude in the actual scarring and damage to the liver is very important," said Donald Jump, a principal investigator with the Linus Pauling Institute at OSU and a professor in the College of Public Health and Human Sciences.

"Many clinical trials are being done with omega-3 fatty acids related to liver disease," Jump said. "Our studies may represent the first to specifically compare the capacity of EPA versus DHA to prevent NASH. It appears that DHA, which can also be converted to EPA in the human body, is one of the most valuable for this purpose."

The issues have taken center stage as the weight of Americans continues to rise, with a related increase in the incidence of fatty liver disease and liver damage.

NASH is a progressive form of liver disease that is associated with chronic inflammation and oxidative stress, resulting from excess fat storage in the liver. Chronic inflammation can eventually lead to fibrosis, cirrhosis, or even liver cancer. While management of lifestyle, including weight loss and exercise, is one approach to control the onset and progression of fatty liver disease, other approaches are needed to prevent and treat it.

About 30-40 percent of people with nonalcoholic fatty liver disease progress to NASH, which in turn can result in cirrhosis, a major risk factor for liver cancer. While this research studied the prevention of fatty liver disease, Jump said, ongoing studies are examining the capacity of DHA to be used in NASH therapy.

The levels of omega-3 oils needed vary with the health concern, officials say.

"Omega-3 fatty acids are typically recommended for the prevention of cardiovascular disease," Jump said. "Recommended intake levels of omega-3 fatty acids in humans for disease prevention are around 200-500 milligrams of combined DHA and EPA per day."

Levels used in therapy to lower blood triglycerides, also a risk factor for cardiovascular disease, are higher, about 2-4 grams of combined EPA and DHA per day. The OSU studies with mice used DHA at levels comparable to the triglyceride therapies.

"DHA was more effective than EPA at attenuating inflammation, oxidative stress, fibrosis and hepatic damage," the researchers wrote in their conclusion. "Based on these results, DHA may be a more attractive dietary supplement than EPA for the prevention and potential treatment of NASH in obese humans."

http://www.medicalnewstoday.com/releases/255960.php

StephenW

文章日期：2013年2月8日 -  0:00 PST


美国俄勒冈州立大学的研究发现，一个特别的ω-3脂肪酸具有强大的作用，防止肝组织炎症和纤维化 - 常见的问题，谁是超重的美国人的数量稳步上升。

美国肝脏基金会估计，约25％的全国人口，75％的人谁是肥胖的，有非酒精性脂肪肝疾病。这种早期阶段的健康状况，有时会发展为更严重的，甚至是致命的疾病，包括非酒精性脂肪性肝炎，NASH和肝硬化和肝癌。

在网上公布的营养学杂志的研究，是第一个直接比较两个的ω-3脂肪酸经常引用其营养价值，DHA和EPA的影响。

通过动物实验研究发现，EPA的影响比较小，防止纤维化或疤痕化，这与NASH。然而，补充DHA降低了超过65％的参与肝纤维化的蛋白质。

“减少的，在实际的疤痕和肝脏的损害程度是非常重要的，说：”唐纳德Jump，在俄勒冈州立大学和公共健康和人类科学学院教授莱纳斯·鲍林研究所首席研究员。

“许多临床试验，正在做相关的肝脏疾病与ω-3脂肪酸，”JUMP说。 “我们的研究可以表示第一个具体的EPA与DHA的能力进行比较，以防止NASH​​。似乎，也可在人体内转化为EPA，DHA的，是一个用于此目的的最有价值的。”

问题已经引起了中心舞台的美国人的体重继续上升，相关的脂肪肝和肝功能损害的发生率增加。

NASH相关的肝脏疾病，慢性炎症和氧化应激反应，产生多余的脂肪储存在肝脏中是一个渐进的形式。慢性炎症，最终导致肝纤维化，肝硬化，甚至肝癌。尽管管理层的生活方式，包括减轻体重和运动，控制脂肪肝疾病的发生和发展是一种方法，其他的方法所需要的预防和治疗。

约30-40％的人与非酒精性脂肪肝疾病进展，NASH，这反过来又可以导致肝硬化，肝癌的主要危险因素。虽然这项研究研究，预防脂肪肝的发病，跳跃说，正在进行的研究，研究中使用的NASH治疗的DHA的能力。

水平的omega-3脂肪酸需要不同的健康问题，官员说。

“Jump说：”ω-3脂肪酸预防心血管疾病，通常建议。 “约200-500毫克的DHA和EPA每天推荐摄入量的ω-3脂肪酸在人类疾病的预防。”

降低血液中甘油三酯，也心血管疾病的一个危险因素，在治疗中使用的水平较高，合并的EPA和DHA，每天约2-4克。俄勒冈州立大学的研究，小鼠DHA水平相媲美的甘油三酯治疗。

“DHA比EPA更有效的减轻炎症，氧化应激，肝纤维化和肝损伤的研究人员写道，”他们的结论。 “基于这些结果，DHA可能是一个更具吸引力的膳食补充剂比EPA的NASH的预防和潜在的治疗肥胖的人。”

http://www.medicalnewstoday.com/releases/255960.php