COMPARISON OF CHEESE, YOGURT, AND MILK EFFECTS ON GLUCOSE HOMEOSTASIS AND LIVER LIPID ACCUMULATION IN MICE FED HIGH-FAT DIET

• Author / Creator

  Salma Moftah MJ

• Abstract
  Background: Many human observational studies show an inverse or neutral association between dairy consumption and the risk of diabetes. Our lab’s previous work suggests that both low and high-fat cheese consumption improves glucose homeostasis in insulin-resistant (IR), prediabetic rats. IR also affects the hepatic lipid metabolism, which can lead to liver injury and non-alcoholic fatty liver disease. Previous studies have shown that low-fat dairy intake can improve liver function and reduce steatosis. This study examines whether regular-fat yogurt and milk have a similar effect on glucose homeostasis as regular-fat cheese and evaluates the impact of regular fat dairy intake on hepatic lipid accumulation in IR mice.

  Methods: An 8-week feeding intervention with dairy foods (regular-fat Yogurt, Milk, and Cheese) equivalent to half a serving was performed in a high-fat diet-fed (HFD) insulin-resistant male C57Bl6/J mice (N=48 with n=12/group). A low-fat diet (LFD) control group was included (n=12). Mice were weighed weekly, and body fat mass was measured at week 6. To evaluate IR and hepatic glucose output capacity, insulin tolerance test (ITT) and a pyruvate tolerance test (PTT) with n=6 mice/group were administered one week before euthanasia. Fasting serum at the time of euthanasia was used to measure alanine aminotransferase (ALT), triglyceride (TG), and non-esterified fatty acids (NEFA). Frozen liver tissue was used to measure liver TG. Liver histology was done to quantify the accumulation of fat droplets following dairy consumption.
  Results: All mice on HFD had significantly more body fat % than the LFD group independent of dairy consumption. However, there was no significant effect of diet on ITT and PTT. Milk diet significantly lowered serum TG, while Yogurt elevated both serum and hepatic TG with no significant impact on ALT compared to the LFD group. The dairy foods had no significant effect on serum NEFA; however, liver histology showed improvement in hepatic lipid-related morphological characteristics in the Milk group. This improvement was evidenced by decreased macrovesicle area and increased microvesicle area compared to the HFD group.

  Conclusion: The results did not support our hypothesis that regular fat dairy, in particular Milk, Yogurt, and Cheese improve insulin sensitivity. However, milk consumption, even in a small amount (equivalent to half a serving), was beneficial in reducing serum TG and improving hepatic lipid metabolism.

• Subjects / Keywords

  • Dairy
  • Insulin resistance
  • Fatty liver
  • Milk
  • Yogurt
  • Cheese

• Graduation date

  Spring 2022

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-d3rm-am68

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.