Eating butter is mildly protective of developing diabetes
Far from being a metabolic rascal, it appears that, if anything, butter may be protective against the development of type 2 diabetes, Australian researchers have found.
The first combined analysis of several studies (a meta-analysis) to evaluate the effect of butter consumption on the incidence of diabetes has found a weak inverse relationship between eating butter and developing diabetes, meaning eating butter is slightly protective of developing diabetes.
The finding comes from a systematic review and meta-analysis of butter’s effects conducted by researchers from the US and the George Institute for Global Health in Sydney.
They found only very small or no associations of butter with mortality, cardiovascular disease (CVD) and diabetes after analysing 9 studies covering more than 600,000 people in 15 countries. No randomised controlled trials - the gold standard of scientific studies - were identified for inclusion in the review.
The studies provided data on more than 28,000 deaths, 9700 cases of CVD and 24,000 cases of diabetes.
The results show each daily tablespoon (14g) of butter is associated with a 1% higher relative risk of death.
Pooled data from several studies showed no associations with CVD or stroke.
Among the 4 studies looking at type 2 diabetes, a 4% lower risk was associated with every 14 g/day serve.
The authors say that given the adverse effects of dairy fats on LDL-cholesterol (bad cholesterol) and fasting glucose, their findings suggest there are other benefits of butter – such as calcium, fat-soluble vitamin D and other fats - that might offset these harms.
Overall, the results suggest the health effects of butter should be considered against the alternatives available, such as healthy oils, they say.
“Our findings suggest a major focus on eating more or less butter, by itself, may not be linked to large differences in mortality, cardiovascular disease or diabetes,” the researchers write.
They conclude that their evidence doesn’t support a need for a major emphasis in dietary guidelines on butter compared with other priorities.
The researchers also note that butter is returning to the table in America: the US Department of Agriculture said consumption in 2014 was the highest for 40 years.