Some omega-3 oils better than others for protection against liver disease

CORVALLIS, Ore. – 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.”

This work was the result of a four-year study supported by the USDA National Institute of Food and Agriculture, as well as the National Institutes of Health. Co-authors on the paper included Christopher M. Depner and Kenneth A. Philbrick, both graduate students in the Nutrition Graduate Program at OSU-02/05/2013

創立已經接近150個年頭的美國奧勒岡大學,雖然擁有廣大安德魯森林的實質管理權,然而真正讓奧勒岡大學永垂不朽的卻是鮑林博士那一脈相傳的化學研究機構 By Greg Keene From Wikimedia

美國奧勒岡州的奧勒岡州州立大學，證實了有某一種特別的奧米茄-3不飽和脂肪酸，能夠強力的抑止肝臟細胞的慢性發炎與硬化症狀（此種病症，一直都是體重過重之美國人的共通性困擾）!根據美國肝臟基金會的研究資料所顯示，全美國有1/4的人口，屬於體重過重的族群；而25％肥胖族群其中的75％人群，基本上都罹患有所謂的脂肪肝；如果脂肪肝沒有受到進一步的抑制，很快的就會有可能演變成肝臟細胞的慢性發炎，甚至形成對生命俱有威脅性的肝硬化乃至於肝癌！此外依照奧勒岡州立大約的實驗數據也明白指出：魚油脂肪中的DHA和EPA不飽和脂肪酸（特別是DHA）可以大幅減少肝臟細胞的損傷與硬化之可能性!

即使是聰明絕頂的愛因斯坦,看到了鮑林博士,恐怕也要豎起大拇指?!原來謙虛為懷的鮑林博士,竟然史無前例的贏得過二次諾貝爾獎,而這個記錄至今無人能破!

按照奧勒岡州州立大學鮑林研究學院（鮑林博士為諾貝爾獎化學獎得主，生前以研究倡導賴胺酸和維他命C的大量使用而聞名全美國（鮑林博士發現賴胺酸除了可以預防帶狀疱疹（俗稱的皮蛇）以外，對於降低膽固醇亦極俱功效;另外維他命C除了能夠影響細胞產生干擾素來對病毒以外，亦俱有積極增強免疫力的效果）,鮑林博士最後享壽92歲）首席研究學者督納-將普的專業分析說法：積極減少肝臟的實際受損面積，絕對是肝臟保健的首要任務！且本次的實驗理論基礎主要是建立在EPA或DHA不飽和脂肪酸，各別保護肝臟細胞的區別性價值；事實上以非酒精中毒所引起的肝臟慢性發炎為例，非酒精中毒所引起的肝臟細胞慢性發炎症狀，如果任由長期的發炎和氧化反應持續進行下去，肝臟器官將有可能從慢性發炎，演變成組織纖維化，進而形成肝臟組織全面的硬化，或者是末期所最不願意見到的肝癌絕症（減輕體重與保持運動雖然可以幫助減緩肝臟發炎症狀，但很顯然的是,我們仍然需要別種的有效加持方式,來處理肝臟慢性發炎現象？否則在美國每一年也不會有30％-40％的脂肪肝患者，會毫無警覺的就轉換成所謂的肝臟慢性發炎病患）！

堅信食物是最好之藥物的鮑林博士Dr.Pauling,雖然生前屢屢被藥廠金脈主流勢力所刻意的冷嘲熱諷,不過鮑林博士的食補信念,卻益發的歷久彌新與迭創將佳績,而讓人對心念蒼生的鮑林博士感念不已!上列圖片為肝臟的Gross前視素描圖檔

一般而言，奧米茄-3不飽和脂肪酸的攝取量與所要保持健康的病因問顯，基本上是息息相關的！例如像是在維持心血管健康時，每一天至少要食用200至500毫克（MG）左右的DHA與EPA不飽和脂肪酸營養補充品；另外如果想要降低血液中的三酸甘油酯(Triglycerides)的脂肪含量時，也可能要攝取到更高劑量的EPA和DHA不飽和脂肪酸(大約每天要攝取2000-4000毫克的EPA和DHA總合劑量)才行!至於EPA和DHA對於肝臟細胞發炎症狀的抑制劑量又該是多少？依據鮑林研究學院的研究所顯示（此項研究耗時4年，由美國農業部與國家健康局所主持），目前仍在計算之中,尚未有結論！然而令人驚豔的是,DHA不飽和脂肪酸已經經由實驗結果,被證實擁有絕佳的保護肝臟發炎細胞之療養效果（甚至比起實力型的EPA不飽和脂肪酸更為出色）!關於這一點,倒真是令實驗人員始料未及唄！

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