Abstract 045: The Dose-Response Effect of a Mediterranean Style Diet With Lean Beef on Lipids and Lipoproteins

A Mediterranean dietary pattern is widely recommended because of an extensive evidence base showing beneficial effects on cardiovascular disease (CVD) risk and mortality. The reduction in cardiovascular mortality is due, in part, to the improvements in lipids and lipoproteins versus a Western dietary pattern. Plant-based diets such as a Mediterranean diet are recommended for CVD risk reduction. However, adherence to plant-based diets is often hampered by the limited or restricted intake of red meat, a staple of the American diet. We conducted a multicenter, 4-period controlled feeding, randomized crossover study at Penn State University and USDA-Beltsville to evaluate the effects of a Mediterranean diet (CHO 42%, PRO 17%, FAT 41%, SFA 8%, MUFA 26%, PUFA 8%) with different quantities of lean beef (0.5, 2.5 and 5.5 oz/day) compared to an Average American diet (AAD; CHO 52%, PRO 15%, FAT 33%, SFA 12%, MUFA 13%, PUFA 8%) on CVD risk factors. We tested the hypothesis that including 0.5, 2.5 or 5.5 oz/d (based on 2100 kcals) of lean beef in a healthy Mediterranean style diet will confer similar cardioprotective benefits, and be superior to an AAD. Each Mediterranean diet included 7oz. equivalents of protein, of which 0.5, 2.5 or 5.5 oz. came from beef and the remainder from fish, poultry, pork, nuts, eggs, and legumes. The quantities of beef reflect amounts consumed in a traditional Mediterranean diet (0.5 oz.), current consumption in the U.S. (2.5 oz.), and an amount that represents all animal protein equivalents (5.5 oz.). Participants (n=60; 30 per site) included generally healthy normal to overweight/obese males and females (BMI= 20-38 kg/m 2 ) 30 to 60 years. Participants were randomized to each of the 4 diets for 4 weeks with an approximate 2-week break between treatments. Fasting blood samples were collected on two consecutive days at baseline (start of study) and at the end of each 4-week period. All three Mediterranean diets elicited similar lowering of total cholesterol (TC; p<0.0001), LDL-C (p<0.001), non-HDL-C (p<0.0001) and apolipoprotein B (apoB) (p<0.0001) that was greater than the AAD. All diets (AAD, MED0.5, MED2.5 and MED5.5) decreased HDL-C (-3.46 ± 1.11, -4.93 ± 1.14, -4.44 ± 0.93, and -3.31 ± 1.20 mg/dl, respectively; p<0.01) and apolipoprotein A1 (apoA1) (-8.63 ± 1.77, -11.45 ± 1.72, -11.21 ± 1.71, and -7.97 ± 1.90 mg/dl, respectively; p<0.0001). The MED5.5 attenuated the reduction in apoA1 versus the other two MED diets (p<0.05). In conclusion, a healthy Mediterranean Style diet containing 0.5 to 5.5 oz/day of lean beef improves multiple CVD risk factors compared to a current American dietary pattern.