Effects of increases in dietary fat intake on plasma lipid and lipoprotein cholesterol concentrations and associated enzyme activities in cats

Objective To determine the effects of increases in dietary intake of polyunsaturated and saturated fatty acids on plasma lipid and lipoprotein concentrations and activity of associated enzymes in healthy domestic cats. Animals-16 healthy adult sexually intact female cats. Procedures A baseline diet (40% energy from fat) and 4 test diets, with increased amounts of fat (51% and 66% energy from fat) from the addition of polyunsaturated and saturated fatty acids, were fed for 6 weeks each. Plasma cholesterol, triglyceride, and lipoprotein cholesterol concentrations, along with activities of lipoprotein lipase, hepatic lipase, and lecithin-cholesterol acyl transferase, were measured at the end of each feeding period. Results Diet, amount of fat, or ratio of polyunsaturated to saturated fatty acids had no effect on plasma concentrations of cholesterol, triglycerides, and very low-density or high-density lipoproteins or the activity of lecithin-cholesterol acyl transferase. Low-density lipoprotein concentrations were significantly lower in cats fed a high-fat diet containing polyunsaturated fatty acids. Lipoprotein concentration and hepatic lipase activity were significantly higher in cats fed the fat-supplemented diets, and this was unrelated to whether diets were enriched with polyunsaturated or saturated fatty acids. Conclusions and Clinical Relevance Diets containing up to 66% of energy from fat were tolerated well by healthy cats and did not affect plasma lipid concentrations. Therefore, high-fat diets probably will not contribute to hypercholesterolemia or hypertriglyceridemia in cats. (Am J Vet Res 2012;73:62-67)