Public guidelines have for decades recommended to cut down on high-fat dairy products such as butter due to the high content of saturated fat, which is known to increase low-density lipoprotein (LDL) cholesterol concentrations in the blood. However, meta-analyses of prospective cohort studies have found no association between saturated fat intake and cardiovascular risk and a recent meta-analysis found that evidence of an association of butter with cardiovascular disease (CVD), mortality or diabetes is small or neutral. These finding are based on cohort studies and not on randomized, controlled dietary interventions studies.

With the known cholesterol-raising effect, butter has often been included as a negative control in high amounts in dietary intervention studies, whereas the effect of a moderate butter intake on cholesterol has not been investigated.

We compared the effects of a moderate butter intake, olive oil or a habitual diet on blood lipids, glucose, and insulin. The study was a controlled, double-blinded, randomized 2 x 5 week-crossover dietary intervention study with a 14-day run-in period during which the subjects consumed their habitual diet. The study included 47 healthy men and women, who substituted a part of their habitual diet with 4.5% of energy from butter or refined olive oil. We found that a moderate intake of butter resulted in an increase in total and LDL cholesterol compared with olive oil intake and a habitual diet (run-in).

Furthermore, a moderate butter intake was also followed by an increase in high-density lipoprotein (HDL) cholesterol compared to habitual diet. These findings support that a moderate butter intake may be considered as part of the diet in the normocholesterolemic population, and that in moderate consumption butter is neither very harmful nor beneficial.