The Truth About Saturated Fat: Not All Saturated Fats Are Unhealthy

Saturated fat has long been vilified as something we should avoid in order to reduce the risk of heart disease. Health organizations like the American Heart Association recommend limiting saturated fat intake and choosing unsaturated fats instead. But emerging research shows that not all saturated fats have negative health effects.

The source and structure of the saturated fat matters. This article will provide an overview of the different types of dietary fat, explain how saturated fat impacts health, and discuss which saturated fats may actually be good for you.

Overview of Dietary Fats

There are several main types of dietary fat:

Saturated fat – Found in animal products like meat, dairy, and eggs. Also in coconut and palm oils. Has hydrogen atoms bonded to every carbon atom so the chain is “saturated” with hydrogen. Tends to be solid at room temperature.
Monounsaturated fat – Found in plant oils like olive, canola, and peanut oil. Also in avocados and nuts. Has one double carbon bond so it has less hydrogen. Tends to be liquid at room temperature.
Polyunsaturated fat – Found in plant oils like soybean, corn, and sunflower oils. Has more than one double carbon bond so less hydrogen. Tends to be liquid at room temperature.
Trans fat – Formed through hydrogenation of plant oils. Has at least one trans double carbon bond which creates a straight fatty acid chain. Should be avoided completely.

In addition to differences in saturation, dietary fats can also vary in chain length. For example, medium chain triglycerides (MCTs) have shorter chains while long chain triglycerides (LCTs) have longer chains. The source and structure impact how different fats are metabolized and their health effects.

How Saturated Fat Impacts Health

For decades, saturated fat has been blamed for raising “bad” LDL cholesterol levels which can lead to atherosclerosis and heart disease. But research paints a more nuanced picture.

Large studies like the Women’s Health Initiative did not find a link between saturated fat reduction and decreased risk of heart disease. The Sydney Diet Heart Study found that replacing saturated fat with linoleic acid (an omega-6 polyunsaturated fat) actually increased heart attack risk by 60% even though LDL decreased. The Minnesota Coronary study found similar negative impacts when saturated fat was replaced by polyunsaturated corn oil.

It appears that saturated fat itself may not actually cause heart disease. Processed trans fats are clearly problematic, but inflammation generated by eating high amounts of refined carbs and omega-6 polyunsaturated fats may also contribute significantly to heart disease risk.

Additionally, not all saturated fats have the same health impact…

The Potential Benefits of Some Saturated Fats

While saturated fats as a whole tend to be portrayed negatively, emerging research indicates that certain types of saturated fat may actually be neutral or even beneficial when consumed in moderation as part of an overall healthy diet.

For example, stearic acid is a long chain saturated fat found in animal fat that does not appear to impact cholesterol levels. Shorter chain fats like butyric acid actually promote gut health.

Medium chain triglycerides (MCTs) like those found in coconut oil may boost metabolism and aid fat loss. And the odd-chain saturated fats in dairy fat are linked to positive metabolic effects.

Odd-Chain Saturated Fats in Dairy

Milk fat contains about 66% saturated fat. Around two-thirds of that is comprised of even-chain saturated fats like palmitic and stearic acid.

But milk fat also contains around 1.5% odd-chain saturated fats like pentadecanoic acid and heptadecanoic acid. These odd-chain saturated fats are metabolized differently than the more common even-chain saturated fats.

While higher intake of even-chain saturated fats has been linked to higher risks of metabolic disease and mortality, research shows that increased intake of odd-chain saturated fats is actually associated with lower risks of:

Metabolic syndrome
Type 2 diabetes
Obesity
Inflammation
Heart disease
Fatty liver disease
Pancreatic cancer
All-cause mortality

One of these odd-chain saturated fats, pentadecanoic acid, is gaining recognition for its health-promoting effects. Studies show it can:

Repair mitochondria
Reduce inflammation
Reduce scarring
Lower triglycerides
Improve glucose metabolism

Some researchers believe it may potentially even become classified as an essential fatty acid due to these beneficial effects.

In addition to occurring in dairy fat, odd-chain saturated fats are also found in smaller amounts in certain fish and coconut oil.

The Takeaway on Saturated Fats

Trans fats are unhealthy and should be avoided entirely.
Polyunsaturated fats are generally healthier than saturated fats, but high intake of omega-6 polyunsaturated fats from vegetable oils may promote inflammation.
Monounsaturated fats like olive oil are preferred for cooking at high heat.
Not all saturated fats have the same health effects. Odd-chain saturated fats from dairy and coconut, as well as shorter chain fats like butyric acid, may be neutral or beneficial when consumed in moderation as part of an overall healthy diet.
Focus on getting saturated fat from unprocessed whole food sources like dairy and coconut whenever possible, not processed foods high in saturated fat.
Limit added sugars, refined grains, and processed foods high in low-quality refined oils. An overall healthy, balanced diet is most important for long-term health.

How Different Types of Fats Impact Health

Our understanding of how different types of fats impact health continues to evolve. While saturated fats as a whole were previously demonized, it’s become clear that the reality is more nuanced. Not all saturated fats have negative effects, and some may even be beneficial when consumed in moderation from whole food sources as part of an overall healthy diet. But avoiding processed and refined foods high in low-quality fats remains advisable for good health.