Palm oil is better than partially hydrogenated oil in one critical way: it contains virtually no trans fats, while partially hydrogenated oils can be up to 30% to 40% trans fat by weight. Trans fats are the single most harmful type of dietary fat for cardiovascular health, which is why the FDA revoked all approved uses of partially hydrogenated oils in the U.S. food supply as of December 2023. But “better than hydrogenated oil” is a low bar, and palm oil comes with its own set of health trade-offs.
Why Partially Hydrogenated Oils Were Banned
Partial hydrogenation is the industrial process of bubbling hydrogen through liquid vegetable oils to make them solid at room temperature. This process creates trans fatty acids as a byproduct. In some products, trans fats made up as much as 60% of the total fat content. Lab tests on popular cooking fats in India found trans fat levels as high as 23% in certain brands.
Trans fats raise LDL (“bad”) cholesterol while simultaneously lowering HDL (“good”) cholesterol, a combination that significantly increases the risk of heart disease. The FDA determined that partially hydrogenated oils are not “generally recognized as safe” and set a final compliance date of January 1, 2021, for manufacturers to reformulate their products. The last regulatory cleanup, revoking outdated references to partially hydrogenated oils in standards for products like peanut butter, margarine, and canned tuna, took effect in late 2023.
If you’re reading ingredient labels in the U.S. today, you should no longer encounter partially hydrogenated oils in commercially sold food. However, they may still appear in products sold in countries without similar bans.
What Palm Oil Actually Contains
Palm oil is roughly 50% saturated fat, 40% monounsaturated fat, and 10% polyunsaturated fat. The dominant fatty acid is palmitic acid, which accounts for about 44% of the oil. A single tablespoon delivers 120 calories and 14 grams of total fat, with about 7 grams of that being saturated.
For comparison, olive oil is about 14% saturated fat. So while palm oil is free of the artificial trans fats that made hydrogenated oils so dangerous, it carries roughly three and a half times more saturated fat than olive oil. That distinction matters when you’re thinking about long-term heart health.
How Palm Oil Affects Cholesterol
A meta-analysis of clinical trials comparing palm olein (the liquid fraction of palm oil used in cooking) against other dietary oils found no significant overall differences in total cholesterol, LDL cholesterol, HDL cholesterol, or triglycerides. That sounds reassuring, but the picture changes depending on what you compare it to.
When matched against other high-saturated-fat sources like butter or coconut oil, palm oil performed better. People eating palm olein had total cholesterol levels that were meaningfully lower, and LDL cholesterol dropped by about 0.50 units compared to those on other saturated-fat-rich diets. Against monounsaturated fats (like olive oil) or polyunsaturated fats (like soybean or sunflower oil), palm oil showed no advantage. It performed about the same on most markers, with a slight tendency to lower HDL cholesterol compared to monounsaturated fat sources.
A USDA-funded study was more pointed in its conclusions. Researchers found that diets high in palm oil produced LDL cholesterol and apolipoprotein B levels (a protein that carries bad cholesterol through the bloodstream) that were similar to diets high in partially hydrogenated soybean oil. The researchers concluded that palm oil would not be a healthy substitute for trans fats. In other words, swapping one for the other may not improve your cardiovascular risk profile as much as you’d expect.
Inflammation and Metabolic Effects
Beyond cholesterol, palm oil may affect metabolism in other ways. Animal research has shown that mice fed a high-fat diet based on interesterified palm oil (a processed form commonly used in packaged foods) gained about 11% more body mass than mice on a standard high-fat diet. The palm oil group also showed elevated insulin levels, higher insulin resistance scores, and increased levels of IL-6, an inflammatory marker linked to chronic disease.
Both groups of mice on high-fat diets developed enlarged fat cells, fatty liver, and changes in pancreatic tissue. The palm oil group also showed increased production of inflammatory compounds in fat tissue and shifts in hormones that regulate appetite and metabolism. These are animal studies, so they don’t translate directly to humans, but they raise concerns about heavy palm oil consumption in processed foods.
Why Food Manufacturers Chose Palm Oil
When the trans fat ban forced the food industry to reformulate thousands of products, palm oil became the go-to replacement. The reasons are practical. Palm oil is naturally semi-solid at room temperature, which means it can replicate the texture of hydrogenated fats in cookies, crackers, pastries, and chocolate without any chemical modification. Palm stearin, the harder fraction of the oil, works as a baking fat and produces stable, consistent results.
Blending palm oil with liquid vegetable oils can mimic the properties of partially hydrogenated shortenings, reducing the levels of fragile fatty acids that go rancid quickly, all without creating trans fats. Palm oil also holds up relatively well during deep frying. Research comparing palm olein and partially hydrogenated soybean oil during industrial frying found that both oils degraded over repeated use, but soybean oil produced more harmful volatile compounds during the process.
From a manufacturing standpoint, palm oil solves the trans fat problem neatly. From a health standpoint, it simply trades one concern for another.
The Bottom Line on Choosing Fats
If your only two options are palm oil and partially hydrogenated oil, palm oil is the safer choice. The elimination of trans fats alone makes it less harmful. But palm oil is not a health food. It sits in a middle tier: better than trans fats and butter, roughly equivalent to other saturated fat sources, and clearly inferior to oils rich in monounsaturated or polyunsaturated fats.
For cooking at home, oils like olive, avocado, canola, and sunflower offer better fatty acid profiles. Where you’re most likely to encounter palm oil is in processed and packaged foods, where it replaced hydrogenated oils behind the scenes. Checking ingredient lists for “palm oil” or “palm kernel oil” can help you gauge how much saturated fat a product carries, even when the front of the package doesn’t make it obvious.