What are the effects of dairy on health?
Dairy is likely to benefit heart disease, stroke, and diabetes risk
Nutrients in dairy improve bone health and increase bone mineral density
Dairy does not appear to have any strong association with the incidence of cancer
Dairy does not appear to have any effect, positive or negative, on cognition
Increased intakes of dairy might exacerbate acne
In The Carbohydrate Appropriate Diet, I wrote about the health benefits of dairy…and why some people should still avoid it. Since that book was published there has been a huge volume of research published and many reviews of that research summarising the most important results. There is also a lot of uncertainty around the topic of dairy. Some people promote it as a health panacea, others deride it as a pro-inflammatory dietary nightmare.
So, what does the evidence tell us about the impact of dairy overall, and for whom it is (and isn’t) appropriate?
At the time of writing The Carbohydrate Appropriate Diet, despite dairy avoidance being a common theme in alternative and complementary health circles, the evidence for the absolute avoidance of dairy by most people was very thin on the ground. In fact, the research had demonstrated that in an adequate protein diet, a moderate dairy intake helped to retain lean mass during dieting more effectively than the same protein intake but with lower dairy intake, and that high protein, high dairy intake increased fat-loss.1 Typically, people lost more fat when they supplemented with calcium, and more again when the same amount of calcium was provided from a diary containing diet,2, 3 and it’s is likely that dairy promotes a synergistic effect because of its relatively high content of protein (especially the BCAAs found in dairy in abundance) and angiotensin-converting enzyme inhibitors, to mitigate fat-gain.4
Systematic reviews and meta-analyses of the published studies have concluded that the inclusion of dairy in energy-restricted weight-loss diets significantly reduces weight and body-fat and improves lean-mass.5, 6 There is also an association between the intake of dairy products and reduced rates of type-2 diabetes.7, 8 Furthermore, high-dairy consumption might reduce insulin resistance without negatively impacting bodyweight or cardiometabolic markers.9
You might think that not a lot has changed since 2014-2016 when I wrote and released The Carbohydrate Appropriate Diet. But since 2016 there have been nearly 60 systematic reviews or meta-analyses published on the effects of diary on various parameters of health! These include the studies I originally referenced but also many more.
So, let’s do a deep dive into what the research tells us about dairy and its effects on health, whether good or bad.