For years, doctors have recommended minimizing saturated fat intake for heart health. A new research review challenges this long-held belief, suggesting that saturated fat is only harmful for people who are already at high risk for heart disease.
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Cardiologists urge caution in accepting this conclusion. “These findings do not necessarily support the narrative that such foods high in saturated fat are good for you,” says Jennifer Wong, MD, medical director of noninvasive cardiology at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in Fountain Valley, California.
Here’s what the research suggests, plus important caveats.
Research Findings Challenge Conventional Advice on Saturated Fats
For the study, published today in the Annals of Internal Medicine, researchers reviewed 17 randomized trials that analyzed the impact of saturated fat on cardiovascular health in over 66,000 people.
The investigators discovered that reducing saturated fat intake was linked to a lower risk of dying from any cause during the five-year study period, and a possible lower risk of heart attack, stroke, and dying from cardiovascular disease. Reducing saturated fats led to drops in total cholesterol and LDL (“bad”) cholesterol.
The biggest benefit for preventing nonfatal heart attacks was when study subjects replaced saturated fats with polyunsaturated fats (the kind in fish, flaxseed, and corn oil), rather than simply eating less saturated fat.
But the most surprising finding was that reducing or replacing saturated fats had no impact over five years on heart health in people considered at low to intermediate risk of cardiovascular disease. Replacing saturated fats with polyunsaturated fats had no impact on the risk of death or heart-related issues over at least two years.
What Are Saturated Fats?
Saturated fats are a form of fat mostly found in animal-based foods like beef, pork, poultry, and eggs. However, some tropical oils like coconut and palm oil contain saturated fat. These fats are usually solid at room temperature.
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Cardiologists Are Hesitant to Say People Should Eat More Saturated Fats
Cardiologists point to some limitations in this research.
Because the new research is a systemic review — meaning it analyzes data from numerous clinical trials — it can be difficult to draw too many conclusions from the findings, according to Hosam Hmoud, MD, cardiology fellow at Northwell’s Lenox Hill Hospital in New York City. “Systematic reviews are often stronger with respect to interesting statistically significant findings,” Dr. Hmoud says. “However, the drawback is that systematic reviews may analyze a highly heterogenous population of patients from various studies which may lead to conclusions that don’t exactly fit your medical characteristics.”
The five-year time period may also be too short to see the impact of saturated fat on heart health in people who are considered lower risk, Dr. Wong says.
Hmoud agrees. “It’s premature to say that low-risk patients aren’t susceptible to the changes seen in high-risk patients,” he says. He points out that things like the build-up of plaque on artery walls, which raises the risk of heart attack and stroke, happens slowly over time.
The researchers also wrote in the study that the clinical trials “varied considerably” in how well patients were able to lower their saturated fat intake, what they replaced those fats with, and what other dietary changes they made. “New trials are needed to clarify uncertainty,” the study says.
Ultimately, Hmoud says that more research that tracks a wider group of people over a larger span of time is needed to understand the potential impact of saturated fat on heart health.
Bottom Line: Saturated Fats May Still Pose a Risk to Long-Term Heart Health No Matter Your Risk Factors
The research findings seem to align with the views of U.S. Health Secretary Robert F. Kennedy Jr., who has promoted foods high in saturated fat as healthy, as he posted on the social platform X.
But, Hmoud notes, “We’re not there yet with respect to butter, beef tallow and whole milk” — a few Kennedy favorites — adding, “More randomized data is needed to draw conclusions.”
Wong says, “These foods just may not be as deadly for those at low risk of cardiovascular disease.”
Overall, cardiologists suggest sticking with the AHA’s advice around diet and saturated fat. “I advise all of my patients to minimize saturated fats by implementing a Mediterranean diet consisting of fruits in moderation, fresh vegetables, fresh legumes, whole grains, lean meats, and fish,” Hmoud says.
