“Heart Healthy” Omega-6 Polyunsaturated Fat Doubles Risk for Ulcerative Colitis
Bottomline: Dietary linoleic acid, the most commonly eaten omega-6 polyunsaturated fatty acid, doubles the risk of developing ulcerative colitis, according to large European study. Gut 2009 0: gut.2008.169078
Background: Ulcerative colitis is a chronic inflammatory disease, which hampers quality of life and increases the risk of colon cancer. The cause of this disease is not known, but researchers believe it may be related to excess omega-6 polyunsaturated fat in the diet, because:
Study:This is the first prospective cohort study evaluating dietary linoleic acid intake and the risk of developing ulcerative colitis.
Over 200,000 men and women (yes, nearly a quarter-of-a-million people), ages 30-74. were enrolled in this study. Note these people were enrolled in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, which spans 10 countries. All participants were free of ulcerative colitis when enrolled in the study.
Diet was evaluated by country-specific food frequency questionnaires, which were validated against 24 hr recall questionnaires and plasma and urinary biomarkers for specific nutrients. In the analysis, using a nested case–control method, each person that developed ulcerative colitis was matched with four randomly selected controls.
Results: A high dietary intake of the omega-6 polyunsaturated fatty acid, linoleic acid, more than doubled the risk of developing ulcerative colitis. Even when the scientists adjusted for aspirin usage, the effect of linoleic acid remained statistically significant.
Nearly one-third of the cases of ulcerative colitis were attributed to the dietary linoleic acid levels among the highest three quartiles, as shown below:
Quote:“…there is substantial potential for reducing the incidence of ulcerative colitis through dietary modification.”
Comment: Note that eating daily amounts of linoleic acid higher than 6.1 grams for women and 7.8 grams for men, were associated with increased risk of developing ulcerative colitis. To put that into perspective, the mean intake of linoleic acid in the USA is 13.0 grams per day (USDA-ARS, 2001).
The top sources of linoleic acid in the USA are soybean oil, cottonseed oil, corn oil and many of so-called “heart healthy” foods made with these oils, including many margarines. To get an idea of the linoleic acid content of vegetable oils see: How Much Omega-6 in Vegetable Oils? The Omega-6 Fat Tracker Widget
The classic Mediterranean diet, replicated in the Lyon Diet Heart study, is low in omega-6 fatty acids, similar to the levels found in the no-risk quartiles in this EPIC study. For more information see:
Link to Study:.
Hart, ARLinoleic Acid, a Dietary N-6 Polyunsaturated Fatty Acid, and the Aetiology of Ulcerative Colitis - A European Prospective Cohort Study.Gut 2009 0: gut.2008.169078s, see:
Background: Ulcerative colitis is a chronic inflammatory disease, which hampers quality of life and increases the risk of colon cancer. The cause of this disease is not known, but researchers believe it may be related to excess omega-6 polyunsaturated fat in the diet, because:
• Omega-6 derived, pro-inflammatory eicosanoids are present in high levels in the intestinal lining of patients and in animal models of this disease.Dietary linoleic acid is the chief omega-6 polyunsaturated fat eaten in westernized countries, which has increased markedly in the last century. Linoleic acid is found in soybean oil, corn oil, cottonseed oil, margarines, and salad dressings.
• The level of these to pro-inflammatory eicosanoids correlate with the amount of tissue damage.
• The first-line medications used to manage ulcerative colitis contain 5-aminosalicyclic compounds, suppress pro-inflammatory eicosanoids levels, in a dose-dependent manner.
Study:This is the first prospective cohort study evaluating dietary linoleic acid intake and the risk of developing ulcerative colitis.
Over 200,000 men and women (yes, nearly a quarter-of-a-million people), ages 30-74. were enrolled in this study. Note these people were enrolled in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, which spans 10 countries. All participants were free of ulcerative colitis when enrolled in the study.
Diet was evaluated by country-specific food frequency questionnaires, which were validated against 24 hr recall questionnaires and plasma and urinary biomarkers for specific nutrients. In the analysis, using a nested case–control method, each person that developed ulcerative colitis was matched with four randomly selected controls.
Results: A high dietary intake of the omega-6 polyunsaturated fatty acid, linoleic acid, more than doubled the risk of developing ulcerative colitis. Even when the scientists adjusted for aspirin usage, the effect of linoleic acid remained statistically significant.
Nearly one-third of the cases of ulcerative colitis were attributed to the dietary linoleic acid levels among the highest three quartiles, as shown below:
Of note, the omega-3 fatty acid, DHA, was associated with a reduced risk of developing ulcerative colitis.
Quote:“…there is substantial potential for reducing the incidence of ulcerative colitis through dietary modification.”
Comment: Note that eating daily amounts of linoleic acid higher than 6.1 grams for women and 7.8 grams for men, were associated with increased risk of developing ulcerative colitis. To put that into perspective, the mean intake of linoleic acid in the USA is 13.0 grams per day (USDA-ARS, 2001).
The top sources of linoleic acid in the USA are soybean oil, cottonseed oil, corn oil and many of so-called “heart healthy” foods made with these oils, including many margarines. To get an idea of the linoleic acid content of vegetable oils see: How Much Omega-6 in Vegetable Oils? The Omega-6 Fat Tracker Widget
The classic Mediterranean diet, replicated in the Lyon Diet Heart study, is low in omega-6 fatty acids, similar to the levels found in the no-risk quartiles in this EPIC study. For more information see:
Hart, ARLinoleic Acid, a Dietary N-6 Polyunsaturated Fatty Acid, and the Aetiology of Ulcerative Colitis - A European Prospective Cohort Study.Gut 2009 0: gut.2008.169078s, see:
Posted by Evelyn Tribole MSRD at July 24, 2009 10:23 AM 
Categories: Nutrition, Linoleic Acid, Arachidonic Acid, Food, 2009 Studies, polyunsaturated fatty acids, DHA, Omega-6 Fat, Abstract, ulcerative colitis
Categories: Nutrition, Linoleic Acid, Arachidonic Acid, Food, 2009 Studies, polyunsaturated fatty acids, DHA, Omega-6 Fat, Abstract, ulcerative colitis
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