Writing in the Wall Street Journal this week, nutrition expert Nina Teicholz explains why Americans came to misguided fears of saturated fats—like those in butter, cheese, and meat.
Her article comes on the heels of a report finding that the fats do not increase one's risk of heart attack.
Experts: We may have been wrong about the evils of saturated fats
How did we get here?
Although there has never been any "solid evidence" to support the theory, it has been generally accepted that saturated fats clog arteries. This theory comes from a "mixture of personal ambition, bad science, politics, and bias," Teicholz writes.
In the 1950s, University of Minnesota scientist Ancel Benjamin Keys began championing the idea that saturated fats raise bad cholesterol levels and, as a result, cause heart attacks. The country was struggling with a fast-growing epidemic of heart disease, and his theory fell on receptive ears, Teicholz writes. In 1961, Keys gained a seat on the American Heart Association's nutrition committee and that year the group issued the nation's first-ever recommendations targeted at reducing saturated fats consumption.
Shortly after, several studies touted the benefits of consuming vegetable oil—corn or soybean, but not olive—over animal fats, such as butter. Teicholz notes that the studies had "serious methodological problems," including not taking into account patients who smoked, but the bias had grown in "common sense."
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Dealing with the consequences
As a result, Americans began replacing foods they believed high in saturated fats—meat, eggs, and cheese with carbohydrates—grains, pasta, fruit, and potatoes. While saturated fat consumption dropped by 11%, carbohydrate consumption has increased by at least 25% since the early 1970s, Teicholz writes. Even seemingly healthy foods such as low-fat yogurt became less healthy as manufacturers replaced fats with carbohydrate-based fillers to make up for the lost texture.
When carbohydrates break down into glucose, the body releases insulin and stores fat, which can lead to obesity, Type 2 diabetes, and cardiovascular disease. So, while Americans were trying to avoid heart conditions, they actually put themselves at a higher risk for them, Teicholz writes. "The reality is that fat doesn't make you fat or diabetic. Scientific investigations going back to the 1950s suggest that actually, carbs do," Teicholz writes.
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Another consequence of the saturated fats scare is that Americans began consuming more vegetable oils, margarine, and Crisco. Some studies have linked the consumption patterns with higher rates of gallstones and cancer.
"It is time to put the saturated fat hypothesis to bed and to move on to test other possible culprits for our nation's health woes," Teicholz writes (Teicholz, Wall Street Journal, 5/6).
Next in the Daily Briefing
Daily roundup: May 8, 2014