How C15:0 Does Under Pressure (Blood Pressure, That Is)

Healthy Aging

The Building Case for C15:0 & Heart Health

A robust body of evidence continues to build around C15:0’s role in supporting our whole-body health, including our heart health. Whether it’s lowering LDL-cholesterol, decreasing proinflammatory cytokines in our vessels, or managing healthy iron metabolism, the gap between C15:0 being associated with versus causing optimal heart health is getting smaller. Along these lines, a recently published paper hypothesized that people with higher C15:0 serum levels would have healthier blood pressure. Let’s dive in.

How was this most recent study done?

Since the 1960s, the U.S. has conducted a National Health and Nutrition Examination Survey (NHANES), which routinely collects individuals’ data from health exams, laboratory tests, and dietary intake. This reliable health database has been used by research teams throughout the world to conduct and publish nearly 80,000 studies since its inception.

The latest study by Chen et al. used 2011-2014 NHANES data collected from 4,775 participants who were adults (mean age of 45 years) and had adequate data related to their C15:0 levels, blood pressure, and numerous potential confounding factors (like age, gender, race, education, marital status, diabetes, smoking, alcohol frequency, BMI, economic status, total nutrient intake, and blood biomarkers of renal, lipid, and glucose health).

They then applied numerous statistical models, controlling for the confounding factors above, to evaluate associations between C15:0 levels and blood pressure.

Got it. What did they find?

Well, thanks to the myriad of statistical modelling applied by this team, Chen et al. had a healthy handful of really interesting results:

• Most people had circulating C15:0 levels of around of 20 uM, or about 0.2% of total fatty acids. Chen et al. showed that people, on average, had C15:0 concentrations ranging from around 5 to 70 uM, while the C15:0 percentage range was around 0.05% to 0.45% (see below). These distributions are consistent with many other studies, which we summarized in our Metabolites publication.

• The higher the serum C15:0 concentration, the lower the blood pressure. When controlling for all potential confounding factors above, people with the highest C15:0 levels (the top 75th percentile, C15:0 around > 30 µM) were twice as likely to have healthy blood pressure compared to people with low C15:0 levels (the bottom 25th percentile, C15:0 around < 15 µM). This relationship was linear: the higher the C15:0 concentration, the healthier was one’s blood pressure. This is also consistent with our Metabolites and Nutrients papers, where we provided evidence of optimal C15:0 levels between 20 and 50 µM.
• Across all ages, folks with serum C15:0 % above 0.15% had significantly healthier blood pressure. When it came to C15:0 %, the team demonstrated a threshold effect. Specifically, there is a clear inflection point for healthy blood pressure seen among people with C15:0 levels > 0.15%. While there were still improvements with increasing C15:0 % at blood pressure > 0.15%, the most remarkable change toward healthy blood pressure was to get C15:0 > 0.15%. Again, this finding is consistent with the proposed definition by Venn-Watson et al. of nutritional C15:0 deficiency, which is < 0.2% C15:0.

• If you’re over 65 years old, there is a strong linear association in healthy blood pressure as C15:0 increases from 0.15% to 0.4%. Interestingly, the association between higher C15:0 % and healthy blood pressure gets even stronger among people who are older than 65. This linear improvement in blood pressure as C15:0% increases from 0.15% to 0.4% is consistent with Trieu et al., which also showed this continued associated better heart health as C15:0 % increased from 0.2% to 0.55% (see below). Additionally, Manca et al. showed that people living in Sardinia’s High Longevity Zone, who have strong long-term heart health, have C15:0 levels between 0.4 to 0.6%.

The bottom line.

Importantly, Chen et al. not only demonstrated that higher C15:0 levels are associated with healthy blood pressure, but they are also revalidating two key discoveries:

1. There is building evidence for a threshold effect, where a minimum C15:0 percentage (around > 0.2%) is needed to maintain our baseline health (aka not being C15:0 deficient). This is holding not only for blood pressure, but also for red blood cell, immune, liver, and heart health.
2. Beyond just not being deficient, this most recent study, along with others, support that optimal C15:0 levels may be 0.3-0.6%.