With commentary by Dariush Mozaffarian, MD, DrPH, dean, Friedman School of Nutrition Science and Policy, Tufts University, and Connie Diekman, MEd, RD, director of university nutrition, Washington University in St. Louis.
A dollop of butter on your morning toast or dinner-time baked potato can pack a wallop of flavor—and guilt. But is the guilt necessary?
According to researchers who just did a new large-scale analysis, a little butter may not make much difference in your risk of heart disease and may actually be very slightly protective against diabetes. "Butter is pretty neutral," says study leader Dariush Mozaffarian, MD, DrPH, dean of the Friedman School of Nutrition Science and Policy at Tufts University.
Even so, he says, "Overall, our results suggest that butter should neither be demonized nor considered 'back' as a route to good health."
While dietary guidelines recommend avoiding foods high in saturated fat, new research has found cardiac and other benefits from dairy products and dairy fat, Dr. Mozaffarian says. Since evidence is lacking on what role butter, with its high saturated dairy fat content, has on health, his team decided to focus on it.
The butter findings, he says, ''are 100% consistent with [our] findings about saturated fat. Saturated fat is not a villain, but not a route to good health. The same is true for butter."
The new study is published online June 29 in the journal PLOS One.
The researchers re-analyzed nine studies published between 2005 and 2015 that evaluated more than 600,000 men and women in 15 countries. Their average ages were 44 to 71. The follow up was more than 6.5 million person-years (the number of years times the number of people in the population affected by the condition studied).
The researchers standardized butter consumption across all the studies to consider a tablespoon, or 14 grams, one serving. On average, the men and women ate from a third of a serving a day to 3.2 servings, or more than three tablespoons.
The researchers tracked death from any cause, cardiovascular disease and diabetes. Over the follow up period, more than 28,000 died, nearly 10,000 got a diagnosed of cardiovascular disease and nearly 24,000 learned they had diabetes. In the studies, the researchers adjusted for other factors that might have affected the outcome, such as other diet habits.
Butter intake was weakly linked with the risk of death, the researchers found, but not with cardiovascular disease. It was weakly linked with a slightly lower risk of diabetes.
However, Dr. Mozaffarian says he doesn't make much of that finding, it was a very weak link.
"This study is association, not cause and effect, so it is not possible to say that eating butter is a good idea," says Connie Diekman, MEd, RD, director of university nutrition at Washington University in St. Louis. She reviewed the findings.
"Due to the saturated fat and cholesterol of butter, as a registered dietitian I still suggest caution to consumers." Overall, she advises, saturated fat should be less than 10% of total calories. If you eat 2,000 calories a day, that means a limit of 20 grams of saturated fat. A tablespoon of butter has roughly 7 grams of saturated fat, so three servings put you over the limit.
Diekman prefers other foods as healthier saturated fat choices. "Butter does not provide the nutrient density of other higher saturated fat foods like milk and meat, so it is better to get saturated fat from those more nutrient-rich foods," she says.
"Given that heart disease is the number one complication of diabetes, I, as an RD, would encourage people with diabetes and pre-diabetes to limit or avoid butter usage."
So, to have that pat of butter or not? While the study found it ''neutral,'' Dr. Mozaffarian views margarine, with its healthier vegetable oils, as a better choice. If you can't give up your butter, however, ''butter is probably better for you than the baked potato or bagel'' you slather it on, he says.
And of course, it's not just about the butter. In all the studies analyzed, Dr. Mozaffairan says, "people who had more butter had worse lifestyles."