In a study from The University of Texas Health Science Center at Houston (UTHealth), researchers didn’t find a significant link between dairy fats (the saturated fats found in milk, cheese, butter, and yogurt) and cause of death. More specifically, they did not find a link between these fats and heart disease and stroke.
That comes as big news to decades of scientific advice. Since the 1940s, doctors, nutrition experts, and researchers have promoted a low-fat diet as a healthy way to avoid cardiovascular disease–related deaths. Heart disease and stroke, two of the country’s biggest killers, have long been assumed to be a result of a diet that’s high in saturated fat.
In response to these recommendations, food manufacturers pump out low-fat, light, fat-free, and skim dairy products to supplant the full-fat versions.
Today, however, with the rise of research promoting “good fats” and fat-focused eating plans like the keto diet gaining popularity, researchers and consumers alike are giving the fat-phobic stance of yesteryear a new and skeptical look.
What did this new study find?
This new research, which was published in the American Journal of Clinical Nutrition, adds to a growing body of evidence that flips the table on the fat discussion. Indeed, the study suggests these same maligned fats may actually help protect people against these health conditions, not increase their risks.
For the 22-year study, researchers evaluated biomarkers of dairy-related fatty acids in blood samples of more than 2,900 adults ages 65 and older. During these years, blood plasma levels were measured for three different fatty acids: pentadecanoic, heptadecanoic, and trans-palmitoleic. Measures were taken at the study’s initiation in 1992, and then 6 and 13 years later.
In the time of the study, 2,428 people died. Deaths attributed to heart disease numbered 833. The people in this study that had high circulating levels of dairy-related fatty acids were less likely to die from heart disease than people with lower levels.
What’s more, people with the highest circulating levels of one particular fatty acid — heptadecanoic — were 42 percent less likely to die from stroke. This fatty acid, the researchers suggests, may have protective benefits against stroke.
This isn’t the first study to suggest that fat fears are unfounded. In fact, several studies have cast doubt on the relationship between heart health and limiting your intake of saturated fats. However, much of this research was conducted with the less-dependable self-reporting technique. The study from UTHealth relied on biomarkers in blood, which is a more reliable indicator of fatty acid intake.
The standard recommendation for limiting dairy fats may not go down without a fight, however. The 2015-2020 Dietary Guidelines for Americans still recommends “fat-free and low-fat (1 percent) dairy, including milk, yogurt, cheese, or fortified soy beverages (commonly known as “soymilk”).”
Yaffi Lvova, RDN, points out that many low-fat dairy products have unhealthy added ingredients, namely sugar.
“The way milk comes from a cow, there’s a balance of fat, protein, and natural sugar,” Lvova said. “When we micromanage that natural nutrition by decreasing the fat, we increase the sugar by volume while also throwing off the balance that’s most advantageous to digestion and absorption.”
Full-fat dairy is a rich source of nutrients beside fat, said Dr. Kiah Connolly, a board-certified emergency medicine physician at Kaiser Permanente and health director of Trifecta. “While whole-fat dairy products do contain saturated fats, they’re often still richly nutrient dense. Whole-fat dairy often contains the highest content of these nutrients, and while it does have saturated fat with bad cholesterol (LDL), it also provides good cholesterol (HDL) which can offset the negative effects of the LDL.”
Don’t go overboard
Just don’t take this study’s results — and some doctors’ acceptance of the role of full-fat dairy in a healthy diet — as a license to indulge.
“Does this mean you have a free pass to eat an unlimited amount of nacho cheese and call it healthy? No way,” Connolly said.
Still, this study — and ones before it — isn’t enough for every doctor to dump the low-fat dairy advice overboard yet.
“Eating whole milk is one piece of the complicated puzzle that is cardiovascular disease,” said Dr. Nicole Weinberg, cardiologist at Providence Saint John’s Health Center in Santa Monica, California. “Fortunately, or unfortunately, significantly modifying your diet only reduces your cholesterol by between 10 to 14 percent. A lot of the risks associated with cardiovascular disease are relative to your genetic predisposition.
“Truly a lot depends on genetic predisposition. If a patient has high cholesterol and a family history of heart disease, then I won’t recommend increasing fats in the diet,” Weinberg added.
Which dairy products are healthiest?
Keep these three guidelines in mind when searching for dairy products that are right for your nutritional needs:
- Look for shorter ingredient lists. Reach for full-fat dairy when the alternatives aren’t overly processed with added ingredients like sugar. Yogurt, cottage cheese, and mozzarella, all products that contain a healthy balance of fats without added ingredients, may make the cut.
- Make smart reduced-fat decisions. “While low-fat options like low-fat Greek yogurt may have somewhat fewer nutrients compared with its whole-fat counterpart, it’s still extremely rich in micronutrients and macronutrients, such as protein, with almost no saturated fats, sugar, or refined carbohydrates,” Connolly said. As a bonus, this reduced-fat option also has fewer calories, which could allow you a little extra room in your daily goals.
- Don’t take full-fat license. When you hear “full-fat,” don’t assume you can dig into three scoops of your favorite vanilla ice cream. “Serving sizes and other ingredients still need to be taken into consideration,” said Lauren Manaker, MS, RDN. “Choosing a serving of fat-containing Greek yogurt, skyr, or kefir that doesn’t have a lot of added sugar will provide clients with the benefits of the fat without adding more empty calories from sugar.”