Metabolic Effects of pH Enhanced Ground Beef in Diet-induced Obese Mice

Abstract

ObjectivesWestern diets, characterized by higher amounts of saturated fats, fatty proteins, and lower consumption of fruits, vegetables and lean proteins (alkaline diet) has been suggested to contribute to metabolic diseases (e.g., obesity), through low-grade metabolic acidosis (low pH). Hence, our objective was to test the effects of diets rich in beef prepared at various pH levels, in diet induced obese B6 mice. We hypothesized that metabolic health will be improved by consuming a diet containing pH-enhanced cooked ground beef, compared to a non pH-enhanced beef diet. MethodsB6 male and female mice were randomized (n = 5) into 6 groups; low fat (LF), pH-enhanced (ammonia) LF (LFN), high fat (HF), pH-enhanced HF (HFN), HF with beef (HFB), pH-enhanced HF beef (HFBN). Weight gain and food intake were measured weekly (for 12 weeks) and a glucose tolerance test (GTT) was performed at week 10. Tissues, including white adipose tissue (WAT) and liver were collected and used for histology, RNA and protein isolation, followed by analyses of gene (qRT-PCR) and proteins (Western blotting) related to fat and glucose metabolism. ResultsFinal body weight was significantly higher in HF group compared to LF and LFN groups in males, but not in females. Moreover, glucose clearance was significantly better in LF groups compared to HF group for both male and females. Interestingly, pH enhanced groups (HFN and HFBN) demonstrated significantly improved glucose clearance at the end of GTT compared to HF group only in males. Male WAT had smaller fat cell size, and greater fat cell number (P < 0.05) in HFN and HFBN compared to HF and HFB respectively. HFBN showed less hepatic fat accumulation in male mice compared to HFB group. Corroborating these, mRNA level of fatty acid oxidation marker Cpt1α was upregulated in HFBN group compared to HFB (P value 0.07) in male liver. ConclusionsFindings from this HF diet-induced obesity research suggest that there are potential metabolic benefits of increased dietary pH, through improved glucose clearance and fat metabolism. However, additional research is warranted to determine the underlying mechanisms and whether similar effects will be observed with LF pH-enhanced beef diets. These results can be further translated to human subjects to understand interactions between beef, pH and fat content on metabolic diseases. Funding SourcesEmpirical Foods, Inc.