Fatty acids

What are fatty acids?

Fatty acids are the building blocks of fats. They are chains of carbon atoms with hydrogen atoms attached. Your body uses fatty acids for energy, cell membrane structure, hormone production, and brain function. Some fatty acids are essential—your body cannot make them, so you must get them from food ^[1].

The three main types

Saturated fatty acids

These have no double bonds between carbon atoms. They are solid at room temperature. Sources include butter, coconut oil, and animal fats. Saturated fats were linked to heart disease for decades, but newer research shows the connection is more complex. Moderate intake from whole foods appears safe for most people ^[2].

Monounsaturated fatty acids

These have one double bond. They are liquid at room temperature. Olive oil, avocados, and nuts are rich sources. Monounsaturated fats consistently show benefits for heart health, reducing LDL cholesterol and inflammation. The Mediterranean diet is partly attributed to high olive oil consumption ^[3].

Polyunsaturated fatty acids

These have multiple double bonds. They include omega-3 and omega-6 fatty acids. Both are essential. Omega-3s reduce inflammation and support brain health ^[4]. Omega-6s support skin and hair growth but are overconsumed in modern diets ^[1].

Understanding EPA and DHA

EPA and DHA are long-chain omega-3 fatty acids found in fatty fish. They are the most biologically active forms. DHA is a major structural component of the brain and retina, comprising about 25% of brain fat content ^[5]. EPA regulates inflammation and mood. Your body converts ALA from plants to EPA and DHA, but this process is inefficient—less than 10% becomes EPA and under 1% becomes DHA ^[6].

The omega balance problem

Omega-6 and omega-3 fatty acids compete for the same enzymes in your body. Omega-6 promotes inflammation while omega-3 reduces it. Humans evolved with roughly equal amounts, maintaining ratios between 1:1 and 4:1 ^[7]. Modern diets contain 15-20 times more omega-6, creating chronic low-grade inflammation that contributes to cardiovascular disease and other chronic conditions ^[7].

Clinical evidence for omega-3 supplementation

A comprehensive Cochrane review of 86 randomized controlled trials with over 162,000 participants found that increasing omega-3 intake slightly reduces coronary heart disease mortality and events ^[8]. The American Heart Association recommends 1-2 servings of fatty fish per week for cardiovascular protection ^[9]. For those with elevated triglycerides, prescription omega-3 fatty acids at 4 grams daily effectively reduce triglycerides by about 15% ^[8].

Measuring your omega-3 status

The omega-3 index measures EPA and DHA levels in red blood cell membranes. Levels above 8% correlate with significantly lower risk of sudden cardiac death, while levels below 4% indicate deficiency ^[10]. Most people eating a standard Western diet have levels between 3-5%, even those who eat fish occasionally.