Mixed
Daily butter consumption (approx. 14g) is associated with a small but statistically significant increase in all-cause mortality, while showing no significant association with cardiovascular disease or stroke, and a modest inverse association with type 2 diabetes incidence.
If you eat about one tablespoon of butter a day, current evidence suggests it will not increase your risk of heart disease or stroke, and may even be linked to a slightly lower risk of type 2 diabetes. However, it is associated with a very small (1%) increase in overall mortality risk. You do not need to eliminate butter, but you also shouldn't rely on it as a health food; prioritize overall dietary patterns over single ingredients.
Butter consumption was weakly associated with all-cause mortality (N = 9 country-specific cohorts; per 14g(1 tablespoon)/day: RR = 1.01, 95%CI = 1.00, 1.03, P = 0.045); was not significantly associated with any cardiovascular disease (N = 4; RR = 1.00, 95%CI = 0.98, 1.02; P = 0.704)... and was inversely associated with incidence of diabetes (N = 11; RR = 0.96, 95%CI = 0.93, 0.99; P = 0.021).
Why this rating
High-quality systematic review and meta-analysis of prospective cohorts with large sample sizes (636,151 participants), though limited by the lack of RCTs.
Source
Is Butter Back? A Systematic Review and Meta-Analysis of Butter Consumption and Risk of Cardiovascular Disease, Diabetes, and Total Mortality
Laura Pimpin et al. · PLoS ONE · 2016
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