The health effects of saturated fats are a controversial topic.
In the past, saturated fat was widely believed to be a major cause of heart disease. Today, scientists are not entirely convinced.
One thing is clear — saturated fat is not a single nutrient. It’s a group of different fatty acids with varying effects on health and metabolism.
This article takes a detailed look at the 10 most common saturated fatty acids, including their health effects and dietary sources.
Saturated and unsaturated fats are the two main classes of fat.
These groups differ slightly in their chemical structure and properties. For instance, saturated fat is generally solid at room temperature, while unsaturated fat is liquid.
The main dietary sources of saturated fat are fatty meat, lard, tallow, cheese, butter, cream, coconut oil, palm oil, and cocoa butter.
All fats are composed of molecules called fatty acids, which are chains of carbon atoms. The different types of saturated fatty acids can be distinguished by the length of their carbon chains.
Here are the most common saturated fatty acids in the human diet:
- Stearic acid: 18 carbon atoms long
- Palmitic acid: 16 carbon atoms long
- Myristic acid: 14 carbon atoms long
- Lauric acid: 12 carbon atoms long
- Capric acid: 10 carbon atoms long
- Caprylic acid: 8 carbon atoms long
- Caproic acid: 6 carbon atoms long
It’s rare to find saturated fatty acids other than these in the diet.
Saturated fatty acids that are less than six carbon atoms long are collectively known as short-chain fatty acids.
These are produced when gut bacteria ferment fiber. They’re created in your gut from the fiber you eat and can also be found in trace amounts in some fermented food products.
SUMMARY Saturated fatty acids are one of the two major categories of fat. Common dietary saturated fatty acids include stearic acid, palmitic acid, myristic acid, and lauric acid.
Most scientists now accept that saturated fats are not as unhealthy as previously assumed.
Evidence suggests that they don’t cause heart disease, though their exact role is still being debated and investigated (
However, replacing saturated fat with unsaturated fats, such as omega-3s, may reduce your risk of heart attacks (
This doesn’t necessarily mean that saturated fats are unhealthy. It simply suggests that certain unsaturated fats aid your health.
For this reason, eating low amounts of unsaturated fat is probably not a good idea. To reduce your risk of heart disease, make sure that unsaturated fats comprise a substantial proportion of your total fat intake.
In comparison, replacing saturated fat with carbs doesn’t provide any health benefits. It even impairs your blood lipid profile, which is a measurement of the levels of lipids in your blood, such as cholesterol and triglycerides (
Though it’s clear that some saturated fats may raise LDL (bad) cholesterol levels, the link between cholesterol levels and heart disease is more complex.
For instance, saturated fats raise the levels of large LDL cholesterol particles, which are not as strongly associated with heart disease as smaller and denser particles (
SUMMARY Saturated fats are not as harmful as previously believed. Growing evidence suggests that there are no strong links between saturated fat and heart disease.
Stearic acid is the second most common saturated fat in the American diet (
Compared with carbs or other saturated fats, stearic acid lowers LDL (bad) cholesterol slightly or has neutral effects. As such, it may be healthier than many other saturated fats (
Research shows that your body partly converts stearic acid to oleic acid, a healthy unsaturated fat. However, according to some estimates, the conversion rate is only 14% and may not have much health relevance (
The main dietary source of stearic acid is animal fat. The levels of stearic acid are usually low in plant fat, with the exception of coconut oil, cocoa butter, and palm kernel oil.
Stearic acid is considered a healthy saturated fat and does not appear to raise your risk of heart disease.
This held true even in a 40-day study in people whose stearic acid intake constituted up to 11% of their total calorie intake (
SUMMARY Stearic acid is the second most common saturated fat in the American diet. It appears to have neutral effects on your blood lipid profile.
Palmitic acid is the most common saturated fat in plants and animals.
This acid may comprise over half of the total saturated fat intake in the United States (
The richest dietary source is palm oil, but palmitic acid also makes up approximately a quarter of the fat in red meat and dairy.
Compared with carbs and unsaturated fats, palmitic acid raises levels of total cholesterol and LDL (bad) cholesterol without affecting HDL (good) cholesterol (
High levels of LDL cholesterol are a well-known risk factor for heart disease.
Still, not all LDL cholesterol is the same. More accurate markers of heart disease are the presence of a large number of LDL particles and of small, dense LDL particles (
Though palmitic acid raises total LDL cholesterol, this is mainly due to an increase in large LDL particles. Many researchers consider high levels of large LDL particles to be less of a concern, though others disagree (
When linoleic acid, a type of unsaturated fat, is eaten at the same time, it can offset some of palmitic acid’s effects on cholesterol (
Palmitic acid may also affect other aspects of your metabolism. Studies in both mice and humans indicate that a high-palmitic-acid diet may adversely affect mood and reduce physical activity (
Several human studies suggest that eating higher amounts of palmitic acid reduces the number of calories you burn, compared with eating more unsaturated fats, such as oleic acid (
These aspects of palmitic acid need to be studied further before clear conclusions can be reached.
SUMMARY Palmitic acid is the most common saturated fatty acid, making up over half of all the saturated fat eaten in the United States. It raises LDL (bad) cholesterol levels without affecting HDL (good) cholesterol.
Myristic acid causes a significant increase in total cholesterol and LDL (bad) cholesterol compared with palmitic acid or carbs. However, it doesn’t appear to affect HDL (good) cholesterol levels (
These effects are much stronger than those of palmitic acid. Yet, similar to palmitic acid, myristic acid appears to increase your levels of large LDL particles, which many scientists consider to be less of a concern (
Myristic acid is a relatively rare fatty acid, not found in high amounts in most foods. Yet certain oils and fats contain a decent amount.
Though coconut oil and palm kernel oil boast relatively high amounts of myristic acid, they also provide other types of fats, which may offset the effects of myristic acid on your blood lipid profile (
SUMMARY Myristic acid is a long-chain, saturated fatty acid. It raises LDL cholesterol more than other fatty acids.
With 12 carbon atoms, lauric acid is the longest of the medium-chain fatty acids.
It raises total cholesterol more than most other fatty acids. Still, this increase is largely due to an increase in HDL (good) cholesterol.
In other words, lauric acid reduces the amount of total cholesterol relative to HDL cholesterol. These changes are associated with a reduced risk of heart disease (
In fact, lauric acid appears to have more beneficial effects on HDL cholesterol levels than any other saturated fatty acid (
Lauric acid makes up approximately 47% of palm kernel oil and 42% of coconut oil. In comparison, other commonly eaten oils or fats provide only trace amounts.
SUMMARY Lauric acid is the longest medium-chain fatty acid. Though it raises total cholesterol significantly, this is largely due to an increase in HDL cholesterol, which is beneficial for health.
Caproic, caprylic, and capric acid are medium-chain fatty acids (MCFAs).
Their names are derived from the Latin “capra,” which means “female goat.” They’re sometimes referred to as capra fatty acids, due to their abundance in goat’s milk.
MCFAs are metabolized differently than long-chain fatty acids. They’re more easily absorbed and transported straight to your liver, where they’re rapidly metabolized.
Evidence suggests that MCFAs may have the following benefits:
- Weight loss. Several studies indicate that they may slightly increase the number of calories you burn and promote weight loss, especially when compared with long-chain fatty acids (
28, 29, 30, 31, 32).
- Increased insulin sensitivity. Some evidence suggests that MCFAs increase insulin sensitivity, compared with long-chain fatty acids (
- Antiseizure effects. MCFAs, especially capric acid, may have antiseizure effects, especially when combined with a ketogenic diet (
34, 35, 36).
Due to their potential health benefits, MCFAs are sold as supplements, known as MCT oils. These oils usually consist primarily of capric acid and caprylic acid.
Capric acid is the most common of these. It constitutes around 5% of palm kernel oil and 4% of coconut oil. Smaller amounts are found in animal fat. Otherwise, it is rare in foods.
SUMMARY Capric, caprylic, and caproic acid are medium-chain fatty acids with unique properties. They may promote weight loss, increase insulin sensitivity, and reduce your risk of seizures.
Saturated fatty acids that contain fewer than six carbon atoms are known as short-chain fatty acids (SCFAs).
The most important SCFAs are:
- Butyric acid: 4 carbon atoms long
- Propionic acid: 3 carbon atoms long
- Acetic acid: 2 carbon atoms long
SCFAs are formed when beneficial gut bacteria ferment fiber in your colon.
Their dietary intake is minimal compared with the amounts of SCFAs produced in your colon. They’re uncommon in food and only found in small amounts in dairy fat and certain fermented foods.
SCFAs are responsible for many of the health benefits associated with fiber intake. For instance, butyric acid is an important source of nutrition for the cells lining your colon (
Types of fiber that promote the formation of short-chain fatty acids are known as prebiotics. They include resistant starch, pectin, inulin, and arabinoxylan (
SUMMARY The smallest saturated fatty acids are known as short-chain fatty acids (SCFAs). They’re formed when friendly bacteria ferment fiber in your colon and have many potential health benefits.
Different saturated fatty acids have varying effects on health.
Most studies have investigated the health effects of saturated fat as a whole — without distinguishing between the different types.
The evidence is largely comprised of observational studies that investigate associations. Many of them link a high intake of saturated fat to an increased risk of heart disease, but the evidence is not entirely consistent.
Though certain types of long-chain saturated fat may raise your levels of LDL (bad) cholesterol, no compelling evidence proves any of them cause heart disease. More high-quality research is needed.
Nevertheless, most official health organizations advise people to limit their intake of saturated fat and replace it with unsaturated fat.
While the harmful effects of saturated fat are still a matter of debate, most agree that replacing saturated fat with unsaturated fat has benefits for heart health.