The study, published by the American Society for Nutrition, tested this trade of sugar for fat to see if it could bring the same benefits to blood pressure, lipoproteins and plasma lipids that the original DASH diet does.
Designing the study as a randomized crossover trail, researchers looked at three groups, including “free-living healthy individuals” consuming a control diet, people consuming a DASH diet, and those who consumed a higher-fat, lower-carbohydrate version of the DASH diet for three weeks each. Participants then had a two-week washout period with laboratory measurements made at the end of each diet.
By the end of the study, 36 participants completed the dietary periods, and the researchers said blood pressure was similar between the DASH and high-fat DASH diets when compared with the control diet.
“The HF-DASH diet significantly reduced triglycerides and large and medium very-low-density lipoprotein particle concentrations and increased LDL peak particle diameter compared with the DASH diet,” the study found. “The DASH diet, but not the HF-DASH diet, significantly reduced LDL cholesterol, HDL cholesterol, apolipoprotein A-I, intermediate-density lipoprotein and large LDL particles, and LDL peak diameter compared with the control diet.”
A ‘landmark study’
Dr. Gregory Miller, executive vice president of research, regulatory and scientific affairs for the National Dairy Council, told DairyReporter that he sees this as an “almost landmark study” of whole milk dairy products.
“To me, as a scientist, I’m very excited about this piece of research,” he said. “It’s really well designed, well executed and has the highest standard level of science we have in nutrition; randomized control trial. This is a very, very strong piece of science that clearly demonstrates that the consumption of whole milk diary product as part of a balanced diet works.”
Miller said the DASH diet is one of the most well-studied diets in the world, with the US National Institutes of Health putting millions of dollars into studying it, and it has proven to be effective for heart health, blood pressure and bone health. However, he said it’s good to see a study that shows dairy products can be used to give a greater level of variety to the diet.
“The value is that people get variety in terms of food choices from the dairy category to implement this healthy pattern,” he said. “And it doesn’t have to be low-fat or fat-free, according to the research.”
Higher fat moving into the future
With a lot of research now showing that fat is not solely causing the obesity epidemic, Miller said he’s hoping many will be able to stop talking about individual nutrients and their risks and instead discussing building a healthy dietary pattern.
“The premier dietary pattern is the DASH dietary pattern. However, the original studies around DASH significantly restricted saturated fat,” Miller said. “This study is showing that it’s not necessary. You can get the same heart health benefits while consuming a little bit more saturated fat and total fat as long as you’re keeping your refined carbohydrates down.”
The 2015 Dietary Guidelines will likely be released in the next few weeks, Miller said, and will likely still restrict 10% of daily calories form saturated fat. However, Miller believes there will be more people who move away from this way of thinking due to studies such as this one.
“We’re going to continue to hear more and more about limiting refined carbohydrates in our diet,” he said.
"Comparison of the DASH (Dietary Approaches to Stop Hypertension) diet and a higher-fat DASH diet on blood pressure and lipids and lipoproteins: a randomized controlled trial"
Source: The American Journal of Clinical Nutrition 2015
Authors: S. Chiu, N. Bergeron, P. Williams, G. Bray, B. Sutherland, R. Krauss