What is C-15 Fatty Acid (Pentadecanoic Acid)?
C-15 fatty acid, or pentadecanoic acid, is an odd-chain saturated fatty acid (OCFA) with a 15-carbon backbone. It is distinct from common even-chain saturated fats and is present in trace amounts in our diet. Scientific attention is growing regarding its potential to support cellular health. Dietary trends favoring low-fat options have potentially reduced the population's intake of C15:0. Research, including studies affiliated with the U.S. Navy, highlights the importance of healthy C15:0 levels.
Primary Dietary Sources of C-15 Fatty Acids
The most significant dietary source of C15:0 is full-fat dairy products from ruminant animals, particularly grass-fed varieties. The amount of C15:0 in dairy can vary depending on the animal's diet.
Dairy Products
- Butter: Full-fat butter is a concentrated source of C15:0.
- Cheese: Many full-fat cheeses contain C15:0, with high levels found in types like Roquefort and Pecorino Romano. Other options include cheddar and goat cheese.
- Milk and Cream: Whole milk and heavy cream are good sources, but low-fat versions contain significantly less.
- Yogurt: Full-fat yogurts, such as Greek yogurt made from cow or goat milk, also contribute to C15:0 intake.
Ruminant Meats
Ruminant meats like beef, lamb, and bison contain smaller amounts of C15:0. Grass-fed options and fattier cuts generally have higher levels.
Secondary and Trace Sources
Beyond dairy and ruminant meat, C15:0 is found in trace amounts in other foods.
Fish and Marine Sources
Certain fish, including sardines, mackerel, and salmon, contain C15:0, often concentrated in the skin and heads. Brown algae also contain small quantities.
Plant-Based Sources
Plant sources are not considered significant dietary contributors of C15:0 due to very low concentrations. Trace amounts have been found in tamarind kernel oil, rapeseed (canola) oil, and some dried spices.
Comparison of C-15 Fatty Acid Sources
| Source | C15:0 Availability | Caloric Density | Notes |
|---|---|---|---|
| Full-fat Dairy | High | High | Primary source, also contains other saturated fats. Grass-fed options may be higher in C15:0. |
| Ruminant Meat | Low to Moderate | Variable | Grass-fed varieties typically contain more. Content varies by cut. |
| Fatty Fish | Low | Variable | Skin and heads often contain the highest levels. |
| Plant-based Oils | Trace | Variable | Not a significant dietary source. Coconut oil has very low C15:0 despite being high in saturated fat. |
| Supplements (e.g., Fatty15) | High (Pure) | Very Low | Provides bioavailable, free fatty acid form of C15:0, without the other calories and fats. |
Considerations for Increasing C-15 Intake
Increasing intake of C15:0 through foods like full-fat dairy requires considering overall dietary balance, as these foods also contain other fats and calories. Supplements offer a way to increase C15:0 intake without these additional components and can be particularly useful for those on plant-based diets or managing caloric intake. The body can also produce C15:0 internally through the gut microbiome.
Conclusion
Key food sources of C-15 fatty acids include full-fat dairy products (butter, cheese, milk) and, to a lesser extent, ruminant meats and some fish. Research suggests potential benefits of this odd-chain saturated fatty acid for cellular and metabolic health. While increasing dietary intake is an option, the presence of other fats and calories in food sources, coupled with potential declines in C15:0 levels in modern dairy, may lead some to consider supplements for more targeted intake, especially for vegans or those monitoring diet closely. Incorporating these sources or considering supplementation can help optimize C15:0 levels.
