Milk and Dairy – friend or foe? - Professor Ian Givens
About a quarter of our daily protein needs and up to 60% of other important nutrients such as calcium and phosphorus come from milk and dairy products. But despite the benefits for the young and for bone health being widely known, it’s the effects of milk and dairy consumption on our long term health and disease risk that are in the spotlight because of the considerable risk posed by increasing obesity.
In recent times, the media has often portrayed milk as an unhealthy, high fat food that increases blood cholesterol. Recent research, however, has indicated that the health benefits of drinking milk probably outweigh any dangers. Our recent work has brought together published evidence from a large number of very long term studies carried out around the world, which looked at milk (whole and reduced-fat) consumption in relation to coronary heart disease, stroke and Type 2 diabetes. Importantly, this work has very specifically looked at studies that can tell us about the effects on so-called ‘disease outcomes’, individuals who actually have these diseases, and not predictors of disease (such as high cholesterol levels as a predictor of a future heart attack).
Overall, the results suggest that people who drank the most milk (over 450ml a day, so at least 0.8 of a pint) were 13% less likely to die (from any cause) during the period they were being studied than those who drank the least (less than 100ml – that’s about half a glass - a day). The benefits of milk drinking in terms of stroke risk and diabetes were even more impressive – the high-milk drinkers showed a 20% reduced risk of having a stroke and a 15% reduced risk of being diagnosed with diabetes. When it came to having a coronary heart disease ‘event’, such as a heart attack, the high-milk drinkers showed an 8% lower risk.
Unfortunately our work also highlighted that there is little research allowing a similar risk estimate to be made for people eating just reduced-fat milk, or a lot of cheese, butter or other dairy foods although there was no convincing evidence that eating these foods was ‘harmful’ in any way. Given that people are eating more cheese and fat-reduced milk these days, the lack of such information is concerning.
Our findings raise the question: how does milk have these apparent benefits? What does it actually do in the body? Milk is such a complex food that the answer is also likely to be complex too, but there is good evidence of reduced blood pressure in high compared to low-milk drinkers and this may be a key issue. There is also some evidence of a role for milk in controlling body weight and fatness.
Looking at all the evidence from long-term studies, for milk at least, there is much greater support for consumption being beneficial than being bad for you. However, when it comes to other dairy foods, the fact remains that we do need more information.