Dietary fatty acids and inflammation

Abstract

<jats:title>Abstract</jats:title><jats:p><jats:bold>Introduction: </jats:bold> It is commonly believed that inflammation can be reduced by lowering the dietary ratio of n‐6 (linoleic acid) to n‐3 polyunsaturated fatty acids as a means of lowering arachidonic acid levels in cell membranes. This review will examine this proposition.</jats:p><jats:p><jats:bold>Results: </jats:bold> Although many pro‐inflammatory molecules can be produced from arachidonic acid and this long‐chain n‐6 fatty acid can be produced from linoleic acid, changing dietary linoleic acid intake over a wide range does not have any significant effect on arachidonic acid levels in cell membranes, inflammation or immune functions. There are no data that show lowering dietary n‐6 polyunsaturated fats reduces inflammation. In contrast, arachidonic acid levels in cell membranes and inflammatory parameters are lowered by increasing intakes of long‐chain n‐3 polyunsaturated fatty acids. Resolvins and protectins, both derivatives of long‐chain n‐3 fats, also have potential anti‐inflammatory activity. In high doses, long‐chain n‐3 fats may have modest, beneficial effects on inflammation in rheumatoid arthritis. However, many studies have shown no effects of fish oil on inflammation parameters.</jats:p><jats:p><jats:bold>Conclusions: </jats:bold> The dietary n‐6/n‐3 ratio is not a useful measure of the inflammatory nature of a diet, though the absolute amount of dietary long‐chain n‐3 polyunsaturated fatty acids may be a guide.</jats:p>