Barnard et al., 2019
TLDR
This review set out to examine whether industry-funded studies were more likely than non-industry-funded studies to report conclusions that were not supported by their objective data.
- The percentage of studies examining how eggs affect blood cholesterol that were funded by the egg industry has risen from 0% in the 1950s to 60% in 2010-2019
- 211 articles
- For studies focused specifically on blood cholesterol:
- 58% published between 2010 and 2019 were industry-funded.
- 93% of non-industry-funded studies reported net increases in cholesterol, with 51% of these increases being statistically significant.
- 86% of industry-funded studies reported net increases in cholesterol, with 34% being statistically significant.
- No studies reported significant net decreases in cholesterol concentrations.
- This review found that there was a notable difference in conclusions between industry-funded and non-industry-funded studies:
- 49% of industry-funded studies showed disagreement between their data and their conclusions (interpreting increases in cholesterol as favorable) versus 13% of non-industry-funded studies.
- Disagreement often involved non-statistically significant cholesterol increases being interpreted as no change or no negative impact.
- The review’s authors give the example of college freshmen being given an addition of 2 eggs at breakfast 5 days a week for 14 weeks. This was associated with an LDL increase of 15 mg/dL, a non-statistically-significant change, but which does not rule out any negative effects of eggs. Instead of noting this, the study’s authors concluded that the egg addition did not negatively impact blood cholesterol levels.