In a recent study published in the journal Nutrients, researchers in the United States evaluated the impact of high- (HFB) or low-fat ground beef (LFB) on vascular function.
Cardiovascular disease (CVD) is one of the leading causes of death worldwide. Central obesity, dyslipidemia, and hypertension increase CVD risk. Moreover, vascular function measures are independent risk markers for CVD. The consumption of red meat is associated with CVD risk due to high levels of heme iron, cholesterol, and saturated fatty acids (SFAs).
However, the highest risk is observed with processed meat intake, with no/little association with unprocessed meat intake when red meat consumption is within recommended levels. So far, studies have not assessed the impact of red meat on vascular function.
Study: Assessment of Vascular Function in Response to High-Fat and Low-Fat Ground Beef Consumption in Men. Image Credit: Mehmet Cetin / Shutterstock
About the study
In the present study, researchers examined the impact of LFB/HFB consumption on vascular function in males. Participants were recruited in October and November 2019, and ground beef treatments began in February 2020. Data presented here were collected from a sub-sample of a more extensive study. Participants were instructed not to change their habitual diet or physical activity.
Participants’ body composition, vascular function, and aerobic capacity were evaluated two weeks before initiating the intervention of LFB (5% fat) or HFB (25% fat). Participants completed two five-week interventions (five ground beef patties per week) with a four-week washout period in between. Vascular function and aerobic capacity were re-evaluated in the washout period and the last week of each intervention.
Carotid-femoral pulse wave velocity (PWV) measures were obtained via ultrasonography in a fasting state; participants refrained from alcohol consumption within 24 hours before measurements. Flow-mediated dilation (FMD) was assessed following an overnight fast. Body composition was analyzed by dual-energy X-ray absorptiometry (DXA).
Oxygen uptake (VO2) was examined pre- and post-intervention to account for confounders altering vascular measures. It was measured during an incremental graded exercise test on a treadmill using a metabolic gas analysis system. Maximal VO2 (VO2max) was calculated using an individualized linear regression based on VO2 and heart rate.
Thirty-two males were randomized to HFB or LFB intervention; seven quit voluntarily or were excluded, and two refused to provide vascular measurements. Overall, 23 males with an average age of 39.9 were included in the analyses. FMD results indicated a significant main effect of the test. A follow-up paired t-test showed a higher FMD response following HFB intervention than baseline, LFB intervention, and washout time point.
There were no differences in the baseline diameter of the brachial artery and the time to peak dilation at any time point. For PWV measurements, there were no significant condition, test, or interaction effects between study visits. Resting blood pressure (BP) measurements revealed a significant condition effect of systolic BP (SBP), with a lower SBP during HFB intervention relative to baseline or LFB intervention. SBP was lower during the washout period than in LFB or at baseline.
SBP was not significantly different between the HFB intervention and washout period. A significant condition effect was observed for resting diastolic BP (DBP), which was lower during HFB intervention than baseline or washout period levels. The mean arterial pressure (MAP) was significantly reduced after HFB intervention and in the washout period relative to the baseline.
Total calorie intake was consistent across study periods. A significant test effect was observed for percent energy (% EN) from carbohydrates; it was lower during HFB intervention than at baseline. Likewise, an interaction effect was noted for % EN from fats and protein. % EN from fats and proteins was significantly larger during either beef intervention. The estimated VO2max did not significantly differ between visits.
The researchers observed higher FMD response with HFB compared to LFB intervention, while PMV did not differ. Moreover, DBP and SBP were lower during the HFB intervention. The recovery of FMD during the HFB intervention to normal endothelial function levels suggests a lower CVD risk. PWV is unlikely to change with short-term dietary interventions, consistent with prior studies.
However, the findings demonstrated a decline in BP with short-term HFB consumption, contrasting the widespread conception that foods with high SFAs are unhealthy dietary choices. Taken together, the results showed that HFB or LFB diet does not negatively affect vascular function and that HFB intervention improved FMD response and was associated with a reduced risk of CVD.