One of the main types of trans fat in people’s blood — called vaccenic acid — dropped by more than half in just nine years, showing that people were eating less of these harmful fats overall.

Scientific Claim

Vaccenic acid, a major trans-fatty acid, decreased by 56% in non-Hispanic white U.S. adults between 2000 and 2009, from 43.7 µmol/L to 19.4 µmol/L, indicating a significant decline in both industrial and possibly ruminant sources of TFAs.

Original Statement

“Levels of vaccenic acid decreased from 43.7 µmol/L in 2000 to 19.4 µmol/L in 2009 (difference of 56%: 24.3 µmol/L [95% CI, 19.6-29.0 µmol/L]).”

From study:Levels of plasma trans-fatty acids in non-Hispanic white adults in the United States in 2000 and 2009.

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

definitive

Can make definitive causal claims

Assessment Explanation

The claim reports a precise, measured change in a specific biomarker with confidence intervals. The language is descriptive and does not imply causation, matching the observational design.

Evidence from Studies

Supporting (1)

Levels of plasma trans-fatty acids in non-Hispanic white adults in the United States in 2000 and 2009.

Cross-Sectional Study

Human

2012 Feb 8

The study found that a harmful fat called vaccenic acid dropped by more than half in Americans between 2000 and 2009, likely because food companies started using less of it, which matches the claim.

Contradicting (0)

No contradicting evidence found

Source Study

Levels of plasma trans-fatty acids in non-Hispanic white adults in the United States in 2000 and 2009.

Score: 42

DOI: 10.1001/jama.2012.112

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