By Michael Joseph, MSc
Clearly a contentious issue, there are many alternate opinions on the best dairy option for our health. But what do the studies show?
Studies on Dairy and Obesity
Is whole milk really fattening?
One study featured 12,829 participants who recorded their dairy intake for a 1-year period. The hypothesis was that subjects drinking greater quantities of dairy fat would gain more weight. However, the results were different to the expected outcome.
While the participants who drank more than three servings of milk per day had a greater increase in body mass, this was only in those drinking skim milk. In other words, only skim and 1% milk were associated with weight gain, but dairy fat was not.
Additionally, a 2013 study reviewed 16 different studies on a high-fat dairy intake. In 11 of these studies, high-fat dairy intake was inversely associated with obesity. The authors concluded that “the evidence does not support the hypothesis that dairy fat contributes to obesity or cardiovascular disease”.
Studies on Dairy and the Heart
A study aiming to establish links between milk drinking and vascular disease reviewed ten existing studies.
The combined trends presented in these studies showed that there is no convincing evidence milk is harmful, and that milk drinking may even have a positive impact on heart disease risk. Further, a 2014 study reviewed 18 pieces of prior research, with the results showing that total dairy intake did not contribute to cardiovascular disease.
Markedly, the authors concluded that the body of evidence suggests full-fat dairy—whether milk, cheese or yogurt—may be inversely related to cardiovascular disease.
Studies on Dairy and Stroke
A 2015 study examined links between dairy consumption and stroke in an elderly population. Low-fat dairy was “not significantly related” to the incidence of stroke, but high-fat dairy was “significantly inversely related”.
To make this clear: the data regarding low-fat dairy was mixed, whereas data on high-fat dairy showed it reduced the risk. In another paper, a prospective case-control study was designed to evaluate risk for stroke in relation to plasma dairy fat. The authors of this particular study noted that the idea of an inverse relationship between stroke and milkfat “may seem paradoxical due to the high amounts of saturated fat in milk.” Nevertheless, the results of their study confirmed this so-called “paradox,” as once again full-fat dairy appeared to have no links to stroke whatsoever. Following the results, the authors remarked: “At present, we hypothesize that estimated milk fat intake is associated with a lower risk of first event stroke (13).
Studies on Dairy and Type 2 Diabetes
Type 2 Diabetes is a global epidemic with incidence rates rapidly rising across the world. In fact, the number of people with diabetes has quadrupled since 1980.
Could this be why?
Perhaps, but moving on… an interesting study from 2014 analyzed dairy fat in relation to the incidence of type 2 diabetes. A total of 194,458 people were followed, 15,156 of who went on to develop diabetes.
The study found that neither low-fat nor high-fat dairy had any association with diabetes except for yogurt. The results noted that “yogurt intake was consistently and inversely associated with type 2 diabetes risk.” (15)
In a 2016 study, the American Heart Association (AHA) tested the hypothesis that higher plasma dairy fats are associated with reduced diabetes risk.
Their results confirmed this to be the case. The AHA remarked that their findings highlight the need to understand the possible health benefits of dairy fat.
Dairy and All-Cause Mortality
A 2010 Australian study found that there was no significant or consistent relationship between all-cause mortality and dairy intake.
However, the study did provide one interesting stat. Compared to the participants with the lowest intake of dairy fat, those with the highest intake of dairy fat had a reduced death rate from cardiovascular disease.
Summary
It’s immediately clear from these studies that the current dietary guidelines are poles apart from what the latest studies show.
Here is a quick summary:
• Full-fat milk had no association with chronic disease or mortality in any of these studies.
• Full-fat dairy was also inversely associated with diabetes and heart disease in many of these studies.
• Low-fat dairy had either no association or mixed data.
• It appears that consumption of dairy fat is possibly health-protective.
Final Thoughts
Personally, I would choose full-fat whole milk every single time. Skim milk may be lower in calories, but it’s also lower in naturally-occurring fat-soluble vitamins. To sum up, dairy fat appears to have health benefits, and whole milk tastes a lot better than skim.