Assessment of Vascular Function in Response to High-Fat and Low-Fat Ground Beef Consumption in Men.

Red meat is stigmatized as an unhealthy protein choice; however, its impacts on vascular function have not been evaluated. We aimed to measure the vascular impact of adding either low-fat (~5% fat) ground beef (LFB) or high-fat (~25% fat) ground beef (HFB) to a habitual diet in free-living men. Twenty-three males (39.9 ± 10.8 years, 177.5 ± 6.7 cm, 97.3 ± 25.0 kg) participated in this double-blind crossover study. Assessment of vascular function and aerobic capacity were measured at entry and in the last week of each intervention and washout period. Participants then completed two 5-week dietary interventions (LFB or HFB; 5 patties/week) in a randomized order with a 4-week washout. Data were analyzed via 2 × 2 repeated-measures ANOVA (p < 0.05). The HFB intervention improved FMD relative to all other time points, while lowering systolic (SBP) and diastolic blood pressure (DBP) relative to entry. Neither the HFB nor the LFB altered pulse wave velocity. The addition of either low- or high-fat ground beef did not negatively alter vascular function. In fact, consuming HFB improved FMD and BP values, which may be mediated by lowering LDL-C concentrations.

Consuming High-Fat and Low-Fat Ground Beef Depresses High-Density and Low-Density Lipoprotein Cholesterol Concentrations, and Reduces Small, Dense Low-Density Lipoprotein Particle Abundance.

We hypothesized that consumption of high-fat (HF) ground beef (24% fat) would not affect plasma concentrations of high-density lipoprotein cholesterol (HDL-C) or low-density lipoprotein (LDL-C), whereas low-fat (LF) ground beef (5% fat) would decrease HDL-C and LDL-C concentrations. In a randomized 2-period crossover, controlled feeding trial, 25 men (mean age and body mass index, 40 years and 31.2) consumed 115-g HF or LF patties, 5/week for 5 weeks with a 4-week washout. The HF treatment increased % energy from fat (p = 0.006) and saturated fat (p = 0.004) and tended (p = 0.060) to depress % energy from carbohydrates. The HF and LF treatments decreased the plasma concentrations of HDL-C (p = 0.001) and LDL-C (p = 0.011). Both ground beef treatments decreased the abundance of HDL3a and increased the abundance of HDL3 (p ≤ 0.003); the LF treatment also decreased the abundance of HDL2b and HDL2a (p ≤ 0.012). The HF and LF treatments decreased the abundance of LDL3 and LDL4 (p ≤ 0.024) and the HF treatment also decreased LDL5 (p = 0.041). Contrary to our hypothesis, the HF treatment decreased plasma HDL-C and LDL-C concentrations despite increased saturated fat intake, and both treatments decreased the abundance of smaller, denser LDL subfractions.

Producing high-oleic acid beef and the impact of ground beef consumption on risk factors for cardiovascular disease: A review.

This review summarizes the effects of high-oleic acid oil and high-oleic acid ground beef interventions on risk factors for cardiovascular disease (CVD) in human trials, and also summarizes studies designed to increase the amount of oleic acid (18:1n-9) in beef. In three human trials, high-oleic acid oils and high-oleic acid ground beef increased plasma high-density lipoprotein cholesterol over baseline values or over high-carbohydrate diets. Neither low-oleic acid nor high-oleic acid ground beef increased risk factors for CVD, confirming earlier studies that used high-oleic acid oils. High-oleic acid beef can be obtained from cattle fed a corn-based finishing diet to USDA Grade of USDA Choice or greater; from beef from cattle with Japanese genetics; and from the brisket. Beef from grass-fed cattle contains more n-3 fatty acids than beef from conventionally-fed cattle, but also contains greater amounts of saturated and trans-fatty acids.

Exercise raises high-density lipoprotein cholesterol in men after consumption of ground beef with a high but not low monounsaturated fatty acid-saturated fatty acid ratio.

Exercise and diets with higher monounsaturated fatty acid (MUFA):saturated fatty acid (SFA) ratios are independently linked to improved blood lipid profiles, yet interactive effects in men have not been studied. We hypothesized that dietary ground beef with a high MUFA:SFA ratio (HR = 1.1) would augment the beneficial changes in the lipid profile induced by exercise compared to dietary ground beef with a lower MUFA:SFA ratio (LR = 0.71). Untrained men (n = 13, age = 35 ± 12 y, weight = 91.4 ± 14.2 kg, body mass index = 27.8 ± 3.3kg/m(2)) consumed 5 HR or LR 114 g ground beef patties weekly for 5 weeks (random order) interspersed with a 4-week self-selected (SS) washout diet. One session of exercise (70% VO2max, 1675 kJ) was completed at the end of HR and LR diets, and again after a 5-week SS diet. Diets and physical activity were otherwise not controlled. Fasting blood samples for lipid and lipoprotein analyses were obtained 30 min before and 24 h after exercise. Subjects reported no other changes in diets or physical activity patterns, and body weight and body mass index did not change over the study duration. Diet (3) × Exercise Time (2) repeated measures analysis of variance (α = .05) and follow-up analyses revealed that blood concentrations (mmol/L ± SD) of total cholesterol (5.07 ± 1.16 to 5.73 ± 1.36), high-density lipoprotein cholesterol (HDL-C) (1.19 ± 0.20 to 1.36 ± 0.29), HDL2-C (0.24 ± 0.08 to 0.28 ± 0.11), HDL3-C (0.94 ± 0.14 to 1.08 ± 0.20), and non-HDL-C (3.88 ± 1.24 to 4.37 ± 1.38) were significantly elevated with exercise after the HR beef diet, but not after LR and SS diets. Thus, in healthy, untrained men the dietary beef MUFA:SFA ratio affects the blood lipid response to a single session of aerobic exercise.

Consumption of high-oleic acid ground beef increases HDL-cholesterol concentration but both high- and low-oleic acid ground beef decrease HDL particle diameter in normocholesterolemic men.

On the basis of previous results from this laboratory, this study tested the hypothesis that ground beef high in MUFA and low in SFA would increase the HDL-cholesterol (HDL-C) concentration and LDL particle diameter. In a crossover dietary intervention, 27 free-living normocholesterolemic men completed treatments in which five 114-g ground beef patties/wk were consumed for 5 wk with an intervening 4-wk washout period. Patties contained 24% total fat with a MUFA:SFA ratio of either 0.71 (low MUFA, from pasture-fed cattle) or 1.10 (high MUFA, from grain-fed cattle). High-MUFA ground beef provided 3.21 g more 18:1(n-9), 1.26 g less 18:0, 0.89 g less 16:0, and 0.36 g less 18:1(trans) fatty acids per patty than did the low-MUFA ground beef. Both ground beef interventions decreased plasma insulin and HDL(2) and HDL(3) particle diameters and increased plasma 18:0 and 20:4(n-6) (all P ≤ 0.05) relative to baseline values. Only the high-MUFA ground beef intervention increased the HDL-C concentration from baseline (P = 0.02). The plasma TG concentration was positively correlated with the plasma insulin concentration (r = 0.40; P < 0.001) and negatively correlated with HDL-C (r = -0.47; P < 0.001) and plasma 18:0 (r = -0.24; P < 0.01). Plasma insulin and HDL diameters were not correlated (r = 0.01; P > 0.50), indicating that reductions in these measures were not coordinately regulated. The data indicate that dietary beef interventions have effects on risk factors for cardiovascular disease that are independent (insulin, HDL diameters) and dependent (HDL-C) on beef fatty acid composition.

Hamburger high in total, saturated and trans-fatty acids decreases HDL cholesterol and LDL particle diameter, and increases TAG, in mildly hypercholesterolaemic men.

The consumption of high-fat hamburger enriched with SFA and trans-fatty acids may increase risk factors for coronary vascular disease, whereas hamburger enriched with MUFA may have the opposite effect. Ten mildly hypercholesterolaemic men consumed five, 114 g hamburger patties per week for two consecutive phases. Participants consumed high-SFA hamburger (MUFA:SFA = 0.95; produced from pasture-fed cattle) for 5 weeks, consumed their habitual diets for 3 weeks and then consumed high-MUFA hamburger (MUFA:SFA = 1.31; produced from grain-fed cattle) for 5 weeks. These MUFA:SFA ratios were typical of ranges observed for retail ground beef. Relative to habitual levels and levels during the high-MUFA phase, the high-SFA hamburger: increased plasma palmitic acid, palmitoleic acid and TAG (P < 0.01); decreased HDL cholesterol (HDL-C) and LDL particle diameter percentile distributions (P < 0.05); and had no effect on LDL cholesterol or plasma glucose (P>0.10). Plasma palmitoleic acid was positively correlated with TAG (r 0.90), VLDL cholesterol (r 0.73) and the LDL:HDL ratio (r 0.45), and was negatively correlated with plasma HDL-C (r - 0.58), whereas plasma palmitic, stearic and oleic acids were negatively correlated with LDL particle diameter (all P

Increased beef consumption increases apolipoprotein A-I but not serum cholesterol of mildly hypercholesterolemic men with different levels of habitual beef intake.

The objective of this research was to compare the effects of a lean beef enriched in oleic acid to a beef that is typical of the commercial beef consumed in the United States. Ten mildly hypercholesterolemic men, ages 34-58 years old, were selected from the Texas A&M University faculty and staff. Subjects were randomly assigned to one of two diets for a 6-week duration followed by a crossover after a 4-week habitual diet washout period. Diets were consumed daily for a 6-week study period. Participants substituted lean beef obtained from Wagyu bullocks or commercial beef for the meat typically consumed. Total cholesterol, apolipoproteins A-I and B, triacylglycerols, and low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol were measured in serum samples collected weekly. Beef type had no effect on any measured variable. There were no significant differences between baseline HDL or LDL cholesterol concentrations after the consumption of the beef test diets. Apolipoprotein A-I, serum glucose, and uric acid concentrations were elevated by the additional dietary beef. Analysis of records of customary diets indicated that one group consumed 160 g of beef daily, whereas the other group consumed only 26 g of beef daily. Therefore, post hoc analyses tested the habitual beef intake x treatment time interaction. LDL cholesterol concentration was markedly higher in the group with low habitual beef intake (180 vs 144 mg/dl), and HDL cholesterol was slightly higher (44 vs 40 mg/dl; post-test values) than for the group with high habitual beef intake, but there were no habitual intake x time interactions for LDL or HDL cholesterol. Creatinine and blood urea nitrogen concentrations also were greater in the individuals habitually consuming less beef. This study had three important findings: i) a lean beef source enriched with oleic acid was no different from commercial beef in its effect on lipoprotein fractions; ii) neither previous level of beef intake nor baseline LDL cholesterol concentration influenced the serum cholesterol response to added dietary beef, which was negative; and iii) apolipoprotein A-I, but not HDL or LDL cholesterol, was sensitive to the additional dietary beef.