Kari Sholing & Lindsay Ganong '12

Got Raw Milk? Is the nutritive value of milk compromised when it is pasteurized?

The 'got milk?' campaign is one of the most recognized marketing campaigns promoting the consumption and health benefits of pasteurized milk. But what if the health benefits are greater when milk is not pasteurized? A rising interest in raw milk has raised questions about the health benefits of consuming raw milk over pasteurized milk. Milk is a complex fluid that contains enzymes, probiotics, whey proteins, and many other components that, when pasteurized, become altered or damaged. Studies of milk raw consumption have supported health benefit claims such as reduced incidences of: asthma, atopic disease, allergies, digestive disorders, and more.

PURPOSE:  This study was designed to evaluate health claims that consuming raw milk has better outcomes for growth and fertility rates than pasteurized milk.

METHODS: Eighteen weanling mice were randomly assigned to one of two groups: raw milk or pasteurized milk. Both milks were whole and organic. Mice were grouped into breeding trios and given a fresh supply of milk every four hours between 7 am and 11 pm for 55 days. Milk was the primary source of food with access to unlimited water and timothy hay, which provided a source of fiber. Milk consumption was tracked at each feeding by measuring the amount of milk that was provided and the amount of milk that was left from the previous feeding. The Institutional Animal Care and Use Committee approved this study.

RESULTS:  On average, the mice in the raw milk group consumed less milk but gained more weight; however, weight gain differences between groups was not statistically significant. Data were analyzed using a two-sample t-test (raw: initial weight 18.59g-final weight 37.32g; pasteurized: initial weight 18.20g - final weight 38.37g, P-value of 0.904). The difference in consumption, however, was statistically significant (raw average consumption: 29.46mL; pasteurized average consumption: 34.01mL, two-sample t-test, P-value of 0.021). Volume of consumption compared to mean weight gain had a positive trend, but the difference was not significant. A paired t-test was conducted with a P-value of 0.056. The raw milk group gained 0.105 grams per mL of milk consumed; the pasteurized milk group gained 0.086 grams per mL of milk consumed.

CONCLUSION: In conclusion, there was a trend toward greater growth efficiency with raw milk. There was no statistical difference between the groups with regard to birth rates or pup mortality rates.

To view Poster, click on link below:
Got Raw Milk? Is the nutritive value of milk compromised when it is pasteurized?

Research Advisor: Amy Olson, PhD, RDN, LD