Lactation as a window of opportunity for reversing cardiometabolic programming
Chief Investigator: Associate Professor Beverly Muhlhausler
Funding Amount: $75,000
Recipient: University of Adelaide
Being exposed to maternal high-fat and high-sugar diets before birth and in early infancy is a major risk factor for obesity and metabolic diseases in later life, however recent studies suggest that nutrition during lactation may be the more important driver. This study will be the first to test if switching mothers from a high-fat and high-sugar diet to a nutritionally balanced diet after birth can reverse the adverse effects of a poor quality diet during pregnancy on the offspring, and to determine how different maternal diets affect the nutritional and hormonal profile of their milk.
Researchers: Prof Beverley Muhlhausler, Prof Mary Wlodek
Research Completed: 2022
Research Findings: Further studies are required in order to be able to draw robust conclusions as to the effect of switching the maternal diet from a high-fat to nutritionally balanced diet during lactation on milk composition and offspring outcomes.
STUDY BACKGROUND: Maternal consumption of high-fat, high-sugar (HF/HS) diets increases their child’s risk of obesity, diabetes and heart disease. In a previous rat study, the negative effects of exposure to a HF/HS diet before birth were reversed when pups were cross-fostered onto mothers fed a healthy diet, which provided evidence that the nutritional exposure during the suckling period was more important in determining the long-term health of the offspring than those experienced before birth. However, while cross-fostering studies are informative, they do not reflect what occurs in humans, where the same mother will give birth and breastfeed the infant and therefore maternal diet and lifestyle factors both before and after delivery are likely to influence milk composition and infant outcomes.
STUDY AIMS: This study aims to determine whether the same benefits as observed in the cross-fostering study can be achieved by switching rat mothers from a HF/HS diet to a nutritionally balanced diet after they give birth. STUDY FINDINGS: Following a series of delays beyond the investigators control (delays in signing the collaborative agreement, closure of the CSIRO animal facility in Adelaide and then COVID restrictions and lockdowns), the study was commenced in mid-2021. To date, the study has provided evidence that the maternal high-fat/high-sugar diet had no effect on pregnancy rates (90% of animals in all groups were pregnant after their first or second mating) but was associated with lower litter sizes and average pup weights when compared with the control diet, consistent with our previous studies. In addition, the high-fat, high-sugar diet was associated with lower milk production and rates of pup growth during the suckling period, and lower body weights at weaning. Due to factors beyond our control (building works in the animal facility that significantly impacted the experimental animals), we have not been able to fully complete the entire study and analysis but are currently doing so (at our own cost) to ensure that we can achieve appropriate statistical power to be able to draw robust conclusions.