A recent study in the British Journal of Nutrition examined the influence of dairy foods on the symptoms and incidence of metabolic syndrome.
Metabolic syndrome affects a quarter of the world’s population. It is comprised of symptoms, such as high blood sugar and high blood pressure, which contribute to the increased risk of type 2 diabetes and cardiovascular disease.
There is evidence that dairy foods contribute to the development of metabolic syndrome, but not all dairy foods have the same effect. Differing levels of fat in the dairy products have been shown to have differing effects, and the effects also vary by population.
In a study published in The British Journal of Nutrition, researchers used data from existing studies to determine the effect dairy foods have on metabolic syndrome. Using PubMed and EMBASE, researchers searched for articles with keyword combinations including a term related to dairy, plus the term “metabolic syndrome” or one of the symptoms such as diabetes mellitus. They excluded articles that pertained to animals, did not have metabolic syndrome as an outcome, and were not in English. They also excluded studies that were randomised control trials, reviews and meta-analyses. Each article’s quality was rated by two investigators using the Newcastle-Ottawa scale, and if they did not agree on a rating, they discussed it until they did.
Dairy foods reduced the risk of symptoms of metabolic syndrome
In nine studies totalling 46,266 participants, the risk of metabolic syndrome decreased by 9% with consumption of 200 g per day of total dairy foods (foods such as milk, yogurt, cheese, custard etc). Specifically, studies involving participant consumption of 200 g of total dairy per day showed a lowered the risk of high blood pressure, high blood sugar and high triacylglycerol levels, which are involved in cardiovascular disease.
Researchers also analyzed six studies with 29,077 participants in total and found when participants consumed 200 g of milk every day, the risk of metabolic syndrome decreased by 13%. In seven studies where participants consumed 200 g of milk per day, there was a decreased risk of abdominal obesity.
Finally in three studies with 14,793 participants’ consumption of 100 g per day of yogurt resulted in an 18% reduction in the risk of metabolic syndrome. In nine studies examining the effects of yogurt consumption, the risk of high blood sugar reduced by 16% when participants consumed 100 g per day.
Future studies should examine the relationship through randomised controlled trial
Based on the results, dairy foods as a whole, and specific dairy foods do reduce the risk of many of the symptoms of metabolic syndrome. Since many types of studies were used for the analysis, the methods of assessing diets and diagnosing metabolic syndrome vary between the studies which may have affected the results. Furthermore, other kinds of specific dairy foods, such as cheese, were not analyzed due to an absence of relevant studies, but they could have an association with metabolic syndrome. Future studies should examine this relationship further through randomised control trials.
Written by Monica Naatey-Ahumah, BSc
Reference: Lee, M., Lee, H., Kim, J. (2018). Dairy food consumption is associated with a lower risk of the metabolic syndrome and its components: a systematic review and meta-analysis. The British Journal of Nutrition. https://doi.org/10.1017/S0007114518001460