A meta-analysis examining the effect of dairy fats on health has identified “a small positive association between butter consumption and all-cause mortality, no significant association with incident CVD [cardiovascular disease] or CVD subtypes, and a modest inverse association with type 2 diabetes.” Laura Pimpin, et al., “Is Butter Back? A Systematic Review  and Meta-Analysis of Butter Consumption and Risk of Cardiovascular  Disease, Diabetes, and Total Mortality,” PLoS One, June 2016.

Relying on data from nine studies that included 636,151 unique participants with 6.5 million person-years of follow-up, researchers reported that “each daily serving of butter (14g/d) was associated with a 1% higher risk of death” from all causes. The pooled data, however, also showed that each 14-gram serving of butter per day was associated with a 4-percent lower incidence of type 2 diabetes, while the studies found no association between butter consumption and stroke, coronary heart disease or total CVD.

“These findings should be considered against clear harmful effects of refined grains, starches, and sugars on CVD and diabetes; and corresponding benefits of fruits, nuts, legumes, n-6 rich vegetable oils, and possibly other foods such as fish on these endpoints,” said the study’s authors. “In sum, these results suggest that health effects of butter should be considered against the alternative choice. For instance, butter may be a more healthful choice than the white bread or potato on which it is commonly spread. In contrast, margarines, spreads, and cooking oils rich in healthful oils, such as soybean, canola, flaxseed, and extra-virgin olive oil, appear to be healthier choices than either butter or refined grains, starches, and sugars.”

Meanwhile, the Center for Science in the Public Interest (CSPI) has criticized the findings and their representation in the media, warning that increased saturated fat consumption is associated with a higher risk of heart disease regardless of the food source. CSPI Nutrition Director Bonnie Liebman opined, “The new study acknowledges that unsaturated oils and spreads are healthier than butter—the key takeaway message for consumers. Yet most people will simply hear that butter is a harmless or healthy food, thanks to headlines with various permutations of the ‘butter is back’ myth which is based on questionable evidence.” See CSPI Statement, July 1, 2016.