Diets rich in lean beef increase arachidonic acid and long-chain omega 3 polyunsaturated fatty acid levels in plasma phospholipids.
Diets rich in meat are claimed to contribute to the high tissue arachidonic acid (20:4 omega 6) content in people in Westernized societies, but there are very few direct data to substantiate this assertion. Because meat contains a variety of long-chain polyunsaturated fatty acids (PUFA) that are susceptible to oxidation, we initially examined the effect of cooking on the long-chain PUFA content of beef, and then determined the effect of ingestion of lean beef on the concentration of long-chain PUFA in plasma phospholipids (PL). First, we examined the effect of grilling (5-15 min) and frying (10 min) different cuts of fat-trimmed lean beef on the long-chain PUFA content. Second, we investigated the effect of including 500 g lean beef daily (raw weight) for 4 wk on the fatty acid content and composition of plasma PL in 33 healthy volunteers. This study was part of a larger trial investigating the effect of lean beef on plasma cholesterol levels. In the first two weeks, the subjects ate a very low-fat diet (10% energy) followed by an increase in the dietary fat by 10% each week for the next 2 wk. The added fat consisted of beef fat, or olive oil (as the oil or a margarine) or safflower oil (as the oil or a margarine). This quantity of beef provided 60, 230, 125, 140 and 20 mg/d, respectively, of eicosatrienoic acid (20:3 omega 6), 20:4 omega 6, eicosapentaenoic acid (20:5 omega 3), docosapentaenoic acid (22:5 omega 3) and docosahexaenoic acid (22:6 omega 3).(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Medical Laboratory Science, Royal Melbourne Institute of Technology, Melbourne, Victoria, Australia.
A J
AJ
Sinclair
L
L
Johnson
K
K
O'Dea
R T
RT
Holman
D000328:Adult; D000818:Animals; D016718:Arachidonic Acid / Q000032:analysis*; D002417:Cattle; D002784:Cholesterol / Q000032:analysis; D003296:Cooking; D004041:Dietary Fats; D004044:Dietary Proteins; D005231:Fatty Acids, Unsaturated / Q000032:analysis*; D005260:Female; D006801:Humans; D008055:Lipids / Q000032:analysis; D008297:Male; D008460:Meat / Q000032:analysis; D000069463:Olive Oil; D010743:Phospholipids / Q000097:blood* / Q000737:chemistry; D010938:Plant Oils; D012450:Safflower Oil
D004041:Dietary Fats; D004044:Dietary Proteins; D005231:Fatty Acids, Unsaturated; D008055:Lipids; D000069463:Olive Oil; D010743:Phospholipids; D010938:Plant Oils; D016718:Arachidonic Acid; D012450:Safflower Oil; D002784:Cholesterol