Real-World Data + AI Science Series: C15:0 & Cardiovascular Health

Healthy Aging

C15:0 & Cardiovascular Health: Evidence of Causality

As we shared last week, foundational nutrients are substances that are needed to protect our long-term health. While this may sound simple enough to test, it can be really difficult for clinical trials to answer, “Is this a foundational nutrient?” because either:

1. It would take too long and too many people to show that a nutrient helped people stay healthy over a lifetime; or
2. It would be unethical to purposely withhold a nutrient from people to see if they developed a disease.

On the flip side, human epidemiological studies showing that a nutrient is linked to better health are often cast aside as only showing associations with better health and not proving that it causes better health. This is, in part, why the Bradford Hill criteria for causality were developed… to use real-world data + experimental evidence to move a nutrient from the association bucket to the causation bucket.

In this Science Says! series, we’re putting C15:0 to the test against the old-school Bradford Hill criteria, using new-school AI to help evaluate C15:0 as a foundational nutrient that protects our long-term health.

This week, let’s focus on C15:0 & our cardiovascular health.

Leveraging the Bradford Hill criteria + AI

Sir Bradford Hill may have developed his nine criteria for causality back in 1965, but we are now able to apply his criteria to nutrients by synthesizing and analyzing data from peer-reviewed publications – thanks to science-specific AI programs.

We used one of our preferred science AI programs, Edison, and asked it to apply the Bradford Hill criteria as originally intended (aka, absent clinical trials) to answer the question: “Is there sufficient strength to say that pentadecanoic acid (C15:0) protects cardiovascular health?”

Here are the methods Edison used to grade C15:0 as a protector of our cardiovascular health.

Edison reviewed 411 observational studies, including four prioritized robust, peer-reviewed prospective cohort meta-analyses and applied a Bradford Hill Criteria Score, where evidence for each of the nine criteria were evaluated and categorized as “Strong” (3 points), “Moderate-Strong” (2.5 points), “Moderate” (2 points), and “Limited” (1 point).

Adding up these points across all nine criteria (aka, 9 criteria x 3 points each), a score of 27 would be a perfect A+.

So, how did C15:0 do?

In response to the question: “Is there sufficient strength to say that pentadecanoic acid (C15:0) protects cardiovascular health?”

C15:0 received a Bradford Hill Score of 25/27 (92.6%). The analysis concluded the following: “YES – The evidence strongly supports a causal protective effect of C15:0 on cardiovascular health, though the evidence is slightly weaker than for metabolic health.”

Below is a breakdown of scores and key evidence provided for each criteria:

• Strength of association: MODERATE-STRONG. Higher C15:0 has been associated with a lower risk of developing cardiovascular diseases, with lower risks ranging from 12% to 25%.
• Consistency: STRONG. The protective association with C15:0 was consistent across European, Asian, and US cohorts from 2010-2025.
• Specificity: MODERATE-STRONG. Evidence included odd-chain versus even-chain saturated fatty acid differential effects.
• Temporality: STRONG. ALL studies prospectively measured baseline C15:0 levels before cardiovascular events occurred.
• Dose-response curves: STRONG. Dose-response meta-analyses and linear gradient relationships were identified and well documented, showing that the higher the C15:0 level, the greater the benefit.
• Biological plausibility: MODERATE-STRONG. Mechanistic evidence was provided that C15:0 lowers pro-inflammatory cytokines relevant to cardiovascular health.
• Coherence: STRONG. Epidemiologic and mechanistic findings aligned with broader nutrition data indicating that odd-chain fatty acids and dairy-fat biomarkers are linked to favorable cardiovascular health outcomes and aligns with known pathophysiology.
• Experiment: MODERATE. Animal supplementation and dairy intervention studies demonstrate causal cardiovascular health benefits.
• Analogy: STRONG. C17:0, another odd-chain saturated fatty acid, has shown similar effects. Similar findings for C15:0 and metabolic health also support C15:0’s direct role in protecting cardiometabolic health.

Based on the Bradford Hill criteria, which used robust real-world meta-analyses tracking thousands of people throughout the world over years paired with gold-standard mechanism of action and experimental data, this evaluation concluded that C15:0 is not just associated with protected cardiovascular health – there is sufficient evidence to conclude that C15:0 causes protected cardiovascular health.