More than 34 million Americans have diabetes, according to the CDC. Of these, 90 to 95% have "type 2," which is caused by insulin resistance (as opposed to "type 1," which is caused by a failure to produce insulin at all). If you don't manage insulin resistance, it can elevate your blood sugar levels and lead to severe and life-threatening health consequences, according to the Mayo Clinic (here are 20 warning signs you may have diabetes that you should never ignore).
While some diabetes risk factors are beyond your control, others are "modifiable," including your weight. Since weight is so heavily influenced by diet, scientists have attempted to identify which foods are associated with diabetes risk. For example, studies have demonstrated that excess dietary sugar can play a role in increasing your risk of diabetes. Studies have also demonstrated that high-fat diets—especially those high in saturated fats (e.g., animal fats)—are associated with insulin resistance that's at the heart of type 2 diabetes. That's why public health organizations have been recommending Americans limit their fat intake to less than 30% of their total calories and eat only unsaturated fats and omega-3 fatty acids (typically found in vegetable fats and some fatty fish). This also means eliminating saturated and trans fats. (Related: The One Vitamin Doctors Are Urging Everyone to Take Right Now.)
In recent years, however, scientists have been questioning whether the role of dietary fat may be more nuanced than previously believed. That's why researchers from the German Center for Diabetes Research set out to investigate the relationship between diabetes and various kinds of dietary fat. The results of their meta-analysis (of 23 existing clinical studies addressing that relationship), which were published in the peer-reviewed scientific journal, PLOS Medicine, may appear startling.
The team found no association between the consumption of dietary fat and the risk of type 2 diabetes, and also concluded that vegetable oil was associated with lower diabetes risk, but only in amounts lower than 13 grams daily. Given that this completely contradicts current recommendations, should you really be consuming up to 13 grams of vegetable oil daily in order to reduce the risk of diabetes?
The fact is, the team of scientists from the German Center for Diabetes research did not specify which vegetable oil they might be talking about. And, as we know, not all vegetable oils have been given an across-the-board scientific seal of approval. Some, like palm oil, may come with negative health consequences—but as Harvard Women's Health Watch explains, even though palm oil is not as healthy as olive oil, it's still a better choice than butter. (And butter is welcome on the keto diet, which, just weeks ago, scientists argued could help lower your risk of diabetes.)
Seeking clarity, Eat This, Not That! reached out to the study authors as well as the German Center for Diabetes Research, but found they were already on holiday. So, we checked with physician Leann Poston, M.D., in hopes of gaining insight into what to make of these novel results.
"Overall, not much can be gleaned from this study," Dr. Poston advised Eat This, Not That! "The authors pointed out that they had only low to moderate confidence in their results, nor did they go so far as to make specific dietary recommendations."
Dr. Poston also says the study findings were correlational, not causational, meaning they merely point out that people who eat a certain amount of vegetable oil also have less of a tendency to develop diabetes.
The best way to reduce your diabetes risk? Continue striving to eat the healthiest diet possible by following one of these nutritious eating plans. And for more healthy eating news, sign up for our newsletter.