The study, titled Dairy Consumption Lowers Systemic Inflammation and Liver Enzymes in Typically Low-Dairy Consumers with Clinical Characteristics of Metabolic Syndrome, was a six-week cross-over study that looked to determine if dairy could have a positive or negative impact on those with metabolic syndrome.
Dr. David Aguilar-Alvarez, an author on the study and the nutrition foods lab director at Weber State University, told DairyReporter that it was “really striking” to see a marked decrease in inflammation in study participants over the six weeks of observation.
“As soon as they switch [into eating dairy], these liver enzymes start going lower,” he said. “That was the most striking part of this study; dairy had a strong impact right away.”
How the study was undertaken and what was found
Over a six-week period, this randomized study had participants consume low-fat dairy, such as a 10oz serving of 1% milk or a 6oz serving of non-fat yogurt, or a carbohydrate-based control, such as 12oz of 100% juice. After a four-week washout, subjects were allocated to the alternate dietary treatment.
Inflammatory status of the subjects was measured by fasting plasma concentrates of C-reactive proteins, tumor necrosis factor alpha, and monocyte chemoattractant -1. Researchers also evaluated gene expression of interleukin-1 and -6.
The 17 subjects, 13 women and three men, also had liver enzymes assessed to evaluate whether the dairy they consumed helped hepatic function.
At the end of the study, Aguilar-Alvarez and his colleagues found lower concentrations of hepatic alanine aminotransferase and aspartate aminotransferase after the period of consuming dairy. Gene expressions of expression of interleukin-1 and -6 were reduced by 46% and 63% compared with the control period of the study.
Women seemed to score better after switching to dairy, something Aguilar-Alvarez said was likely due to better awareness of their state of metabolic syndrome. He noted that metabolic syndrome is not a disease, but rather a set of indications that shows chronic disease may be on the way.
“We conclude that three dairy servings per day improved both liver function and systemic inflammation in subjects with [metabolic syndrome],” the study said.
Conscious consumption of dairy
Aguilar-Alvarez said subjects who were previously skeptical about dairy consumption ended up continuing their daily consumption of milk, yogurt or cheese by the end of the study. The researchers had targeted a population that consumed a very low level of dairy; he said by the end, many liked the way they felt when consuming diary or simply rediscovered their love of the taste.
In addition, many of the participants tended to feel fuller when consuming dairy early in the day, something he believes warrants further studies.
As for the level of fat, Aguilar-Alvarez said they utilized low-fat dairy in this study to allow participants to have better control over their caloric intake. A subject who has metabolic syndrome, he said, should not be consuming a heavy amount of calories from fat.
“It’s not that I am against high fat, but its really hard to control your calories,” he said. “Low fat dairy makes it a lot easier to control the calories … You need to consume less to maintain the calories [in high fat dairy] in order to be healthy. That’s a little bit tricky when you consume foods that are dense in calories such as milk or cheese.”
Source Journal of the American College of Nutrition
Dairy Consumption Lowers Systemic Inflammation and Liver Enzymes in Typically Low-Dairy Consumers with Clinical Characteristics of Metabolic Syndrome
C. Dugan, D. Aguilar, Y. Park, J. Lee, M. Fernandez