LAUSR

Objectives To evaluate the effects of a Mediterranean (Med) style diet with varying quantities of lean beef on non-HDL and HDL lipid subspecies. We hypothesized that a Med diet with lean beef would confer cardiovascular benefits beyond a standard lipid panel and be superior to an average American diet (AAD). Methods We conducted a multicenter, 4-period controlled feeding, randomized crossover study at Penn State University and USDA-Beltsville to evaluate the effects of a Med 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. Participants (n = 66) included generally healthy normal to overweight/obese males and females (BMI = 20-38 kg/m2) 30 to 67 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 diet period. Results All three Med diets decreased LDL-C versus AAD (-10.5 ± 2.0, -9.0 ± 2.0, -6.8 ± 2.0 mg/dL, P < 0.0001 for the 0.5, 2.5 and 5.5 oz., respectively). All Med diets elicited similar reductions in total LDL particle number and large particle number (P < 0.01 for both) compared to baseline, however only the Med diets with 0.5 oz./day (-91.2 ± 23 nmol/L) and 2.5 oz./day (-85.3 ± 23 nmol/L) were significantly decreased versus AAD (P < 0.01). There were no treatment differences for IDL or small LDL particles. All diets reduced HDL-C and HDL particle number from baseline (P < 0.01). Conclusions A healthy Med style diet containing 2.5 oz./day of lean beef elicits similar improvements in lipid subspecies compared to a traditional Med style diet containing 0.5 oz./day. The Med style diet containing 5.5 oz./day of lean beef had similar effects on lipid subspecies to the AAD, therefore our findings suggest that £2.5 oz./day of lean beef can be included in a Med diet and not compromise the cardiovascular benefits of a Med diet. Funding Sources This study was funded by the Beef Checkoff. This study also was supported by the USDA, ARS and the Penn State Clinical and Translational Research Institute.