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 so sure.
However, one thing is clear: saturated fat is not a single
nutrient. It is a group of different fatty acids with varying
effects on health and metabolism.
This article takes a detailed look at the most common saturated
fatty acids, their health effects and dietary sources.
What Is Saturated Fat?
Saturated fat is one of the two main classes of fat, the other
being unsaturated 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
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
Here are the most common saturated fatty acids in the human
- 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
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 are created in your gut from the fiber you eat and can
also be found in trace amounts in some fermented food products.
Bottom Line: 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.
How Does Saturated Fat Affect Health?
Most scientists now accept that saturated fats are not as
unhealthy as previously assumed.
This doesn’t necessarily mean that saturated fats are
unhealthy. It simply suggests that certain unsaturated fats are
protective, while saturated fats are neutral.
In comparison, replacing saturated fat with carbs doesn’t
provide any health benefits and even impairs the blood lipid
profile. This is a measurement of the levels of lipids in your
blood, such as cholesterol and triglycerides (5).
Although it is clear that some saturated fats may raise the
“bad” low-density lipoprotein (LDL) cholesterol, the
association between cholesterol levels and heart disease is a
bit more complex than that.
For more information on the issue, read
Bottom Line: Saturated fats are not as
harmful as previously believed. Growing evidence suggests
there are no strong links between saturated fat and heart
1. Stearic Acid
Stearic acid, which consists of 18 carbon atoms, is the second
most common saturated fat in the American diet (8).
Compared with carbs or other saturated fats, stearic acid
lowers the “bad” LDL cholesterol slightly or has neutral
effects. This suggests it may be healthier than many other
saturated fats (9, 10, 11).
Research shows that stearic acid is partly converted to oleic
acid, a healthy unsaturated fat, within the body. However,
according to some estimates, the conversion rate is only 14%
and may not have much relevance to health (12, 13).
The main dietary source of stearic acid is animal fat. The
levels of stearic acid are usually low in plant fat, with the
coconut oil, cocoa butter and palm kernel oil.
Stearic acid is considered a healthy saturated fat.
It does not appear to raise the risk of heart disease. This
seemed to be true even in a study of people whose stearic acid
intake constituted up to 11% of their total calorie intake for
40 days (9).
Bottom Line: Stearic acid is the second most
common saturated fat in the American diet. It appears to have
neutral effects on the blood lipid profile.
2. Palmitic Acid
Palmitic acid is the most common saturated fat in plants and
animals. It is 16 carbon atoms long.
In 1999, palmitic acid made up an estimated 56.3% of the total
saturated fat intake in the US (8).
The richest dietary source is palm oil, but palmitic acid also
makes up approximately a quarter of the fat in red meat and
dairy, as shown in the chart below.
Compared to carbs and unsaturated fats, palmitic acid raises
the levels of total cholesterol and LDL cholesterol without
affecting the levels of “good” high-density
lipoprotein (HDL) cholesterol (9, 11, 14).
High levels of LDL cholesterol are a well-known risk marker of
Although palmitic acid raises the levels of 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, but some people disagree
(6, 16, 18).
Additionally, when other fatty acids, such as linoleic acid,
are eaten at the same time, they can offset some of palmitic
acid’s effects on cholesterol (19).
These aspects of palmitic acid need to be studied further
before clear conclusions can be reached.
Bottom Line: Palmitic acid is the most
common saturated fatty acid, making up over half of all the
saturated fat eaten in the US. It raises LDL cholesterol
levels without changing HDL cholesterol.
3. Myristic Acid
Myristic acid consists of 14 carbon atoms.
Consuming myristic acid causes a significant increase in total
cholesterol and LDL cholesterol compared to consuming palmitic
acid or carbs. However, it doesn’t appear to affect levels of
HDL cholesterol (11, 25).
These effects are much stronger than those of palmitic acid.
Yet similar to palmitic acid, myristic acid appears to increase
the levels of large LDL particles, which many scientists
consider to be less of a concern (6).
Myristic acid is a relatively rare fatty acid, not found in
high amounts in most foods. Yet certain oils and fats do
contain decent amounts, as shown in the chart below.
Although coconut oil and palm kernel oil do contain relatively
high amounts of myristic acid, they also contain other types of
fats, which may offset the effects of myristic acid on the
blood lipid profile (26).
Bottom Line: Myristic acid is a long-chain,
saturated fatty acid. It raises LDL cholesterol more than
other fatty acids.
4. Lauric Acid
Lauric acid is 12 carbon atoms long, making it the longest of
the medium-chain fatty acids.
It raises the levels of total cholesterol more than most other
fatty acids. However, this increase is largely due to an
increase in the “good” HDL cholesterol.
In other words, lauric acid reduces the amounts of total
cholesterol relative to HDL cholesterol. These changes are
associated with a reduced risk of heart disease (27).
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 contain only trace amounts of it.
Bottom Line: Lauric acid is the longest
medium-chain fatty acid. Although it raises total cholesterol
significantly, this is largely due to an increase in HDL
cholesterol, which is beneficial for health.
5–7. Caproic, Caprylic and Capric Acid
Caproic, caprylic and capric acid are medium-chain fatty acids
(MCFAs). They range from 6–10 carbon atoms in length.
Their names are derived from the Latin “capra,” which means
“female goat.” They are 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 are more easily absorbed and transported straight to the
liver where they are 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 burned and
weight loss, especially when compared with long-chain
fatty acids (28, 29, 30, 31, 32).
Increased insulin sensitivity: There is also
some evidence that MCFAs increase insulin sensitivity,
compared to long-chain fatty acids (33).
Anti-seizure effects: MCFAs, especially
capric acid, may have anti-seizure effects, especially when
combined with a ketogenic
diet (34, 35, 36).
Because of their potential health benefits, MCFAs are sold as
supplements, known as MCT oils.
These oils usually consist primarily of capric acid and
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.
Bottom Line: Capric, caprylic and caproic
acid are medium-chain fatty acids with unique properties.
They may promote weight loss, increase insulin sensitivity
and reduce the risk of seizures in certain epileptic
8–10. Short-Chain Fatty Acids
Saturated fatty acids that contain fewer than six carbon atoms
in their chains 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
Their dietary intake is minimal compared to the amounts of
SCFAs produced in the colon. They are uncommon in food and only
found in small amounts in dairy fat and certain fermented food
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 the colon
For more information on the potential health benefits of SCFAs,
Bottom Line: The smallest saturated fatty
acids are known as short-chain fatty acids (SCFAs), which are
formed when friendly bacteria ferment fiber in the colon.
They have many potential health benefits.
Take Home Message
Not all saturated fat is the same. Its health effects vary
depending on the type.
Although certain types of long-chain saturated fat may raise
your levels of “bad” LDL cholesterol, no strong evidence proves
any of them cause heart disease.