Last week a study about milk reached the popular media. A Dutch news website even had a heading which translates into: “Die because of too much milk”. The news site suggested that Coca Cola would be a healthier option. I had a look at the scientific article behind this news item and looked into more literature about milk.
The new research results concerning milk
In a large Swedish observational study researchers showed that drinking milk does not lower the risk of bone fractures. In this study the risk of bone fractures even slightly increased in women drinking a lot of milk. Additionally, during the course of this study (22 years), more women that drunk a lot of milk died compared to women that drunk less or no milk. In men this relationship was also present, although weaker. These are important results, that, like the researchers suggest themselves, should be interpreted with caution. We are talking about an observational study in which observations (here milk consumption and all cause mortality) can only be correlated. You cannot draw conclusion about causation in this study model.
In this same study researchers found opposite effects for fermented milk products (like yoghurt and cheese). Women that ate cheese or yoghurt had a lower chance of bone fractures and a lower mortality rate. The researchers speculate that the negative effects of milk are to blame on a component called D-galactose. This component is almost not present in fermented milk products. However, this study is not able to prove that. For that more research needs to be done.
Other studies on the health effects of milk
More observational studies have been performed on the relationship between dairy consumption and cardiovascular disease. In these no links have been found between milk consumption and all cause mortality. An example is a large Dutch observational study. In this study no higher mortality rate was found in people consuming more milk. They did find some protective effects of fermented milk products (mainly full fat yoghurt).
A large analysis of multiple observational studies even showed a light protective effect of one glass of milk a day on cardiovascular disease. In the Swedish study the main negative effects of milk consumption were seen at three glasses a day. So quantity seems important.
What do I do?
I don’t drink a lot of milk, but I like it every now and then. Most of the time I chose skimmed milk, because I prefer to eat my calories instead of drinking them. But I will not say no to a nice cappuccino made with full fat milk. Until the scientific results about milk are clearer, I am not going to change this. A glass of milk whenever I feel like it, but no gallons a day. To reach your protein intake it might be better to eat fermented milk products.
I understand that results like this can be quite confusing. There is so much we do not know about nutrition (lots of work for me!). My point of view is that I eat and drink what I like, unless it is solidly proven that it is better for my health to change that.
- Michaelsson, K., et al., Milk intake and risk of mortality and fractures in women and men: cohort studies. BMJ, 2014. 349: p. g6015.
- Soedamah-Muthu, S.S., et al., Milk and dairy consumption and incidence of cardiovascular diseases and all-cause mortality: dose-response meta-analysis of prospective cohort studies. Am J Clin Nutr, 2011. 93(1): p. 158-71.
- Goldbohm, R.A., et al., Dairy consumption and 10-y total and cardiovascular mortality: a prospective cohort study in the Netherlands. Am J Clin Nutr, 2011. 93(3): p. 615-27.
- Rice, B.H., Dairy and Cardiovascular Disease: A Review of Recent Observational Research. Curr Nutr Rep, 2014. 3: p. 130-138.
- Astrup, A., Yogurt and dairy product consumption to prevent cardiometabolic diseases: epidemiologic and experimental studies. Am J Clin Nutr, 2014. 99(5 Suppl): p. 1235S-42S.