A study of over 220,000 people that looked at the consumption of butter versus plant oils has reached a conclusion that shows just how much better for you one is than the other. Making the switch might be one of the easiest ways to extend your life.
Crispy flaky pie crusts. Rich velvety sauces. The perfect addition to a chewy toasted bagel. In the world of culinary delights, it's hard to argue against butter. In the world of health studies, however, the spreadable source of fat and flavor doesn't get such high marks.
While many of us already know that butter isn't exactly a health food, a new study from researchers at Harvard, MIT, and Mass General Brigham has quantified just how its consumption impacts our longevity and how plant-based oils do exactly the opposite.
The team of researchers looked at data from 221,054 participants in three long-term health studies: the Nurses' Health Study; the Nurses' Health Study II, and the Health Professionals Follow-Up Study. In each of these studies, healthcare professionals were asked to answer questions about their eating habits every four years.
For the new study, the researchers looked at 30 years of data gleaned from these reports. They also looked at participants that died during that period.
The researchers concluded that people who ate the most butter had a 15% higher risk of dying than those who ate the least. Conversely, they found that those who consumed the most plant-based oils – olive, canola, and soybean, in particular – had a 16% lower risk of dying than those who ate the least.
Additionally the team found that for every 10-gram-per-day increase in plant-based oils there was an 11% reduction in the risk of death from cancer and a 6% reduced risk of death due to cardiovascular disease. On the other hand, for every 10 grams per day of butter intake, the researchers observed a 12% increased risk of cancer mortality. Butter intake was derived from all sources, including using it as spread, frying with it, and consuming it as part of baked goods and other foods.
Simple swap
The researchers then conducted a substitution analysis which modeled how swapping out butter for plant oils in a daily diet could affect death risk. They concluded that replacing just 10 grams of butter a day (about ¾ of a tablespoon) with the same amount of plant oils would lower both cancer deaths and the overall mortality rate by 17%.
The major difference between the two types of fat is that plant-based oils contain a larger amount of unsaturated fatty acids than butter, which is rich in saturated fatty acids. As you may know, saturated fats have been linked to an increase in heart disease and stroke due to raised levels of harmful LDL cholesterol in the blood.
And while that's been well established for some time, the researchers say that there hadn't been a large-scale study over a long period of time looking specifically at the sources of the two types of fat and comparing them head-to-head. Their work, however, does back up the findings of another massive study conducted last year that also concluded just how much better plant-based oils are for human health than butter.
"What's surprising is the magnitude of the association that we found – we saw a 17% lower risk of death when we modeled swapping butter with plant-based oils in daily diet," said study lead author Yu Zhang. "That is a pretty huge effect on health."
"People might want to consider that a simple dietary swap – replacing butter with soybean or olive oil – can lead to significant long-term health benefits," added corresponding author Daniel Wang, MD, ScD. "From a public health perspective, this is a substantial number of deaths from cancer or from other chronic diseases that could be prevented."
The study has been published in the journal JAMA Internal Medicine.
Source: Mass General Brigham
