Digestery
Diet and food › Seed Oils and the Heart › Studies

Pooled review (meta-analysis)

Pooled review of 15 trials: less saturated fat cut heart events by 21%

Hooper and colleagues · The Cochrane database of systematic reviews · 2020

Original title: Reduction in saturated fat intake for cardiovascular disease.

Under review. A person has not yet checked this summary against the paper. It is written from the PubMed abstract. Until a person checks it, search engines are asked not to list this page.

What the study found

Points to benefit

Pooled 15 trials (~59,000 people). Cutting saturated fat cut combined heart and blood vessel events by 21% (RR 0.79; 95% CI 0.66 to 0.93). Swapping it for polyunsaturated fat or carbohydrate looked equally useful. No separate polyunsaturated fat number.

The study at a glance

Type of study
Pooled review (meta-analysis)
Who or what was studied
15 studies, 59,000 people · adults with and without heart disease
What was tested
Eating less saturated fat for at least 2 years, replaced by polyunsaturated fat, carbohydrate or other, vs usual diet
What it measured
The question itself: heart disease and inflammation
Trial registration
NCT00000611, NCT02062424, NCT00692536, NCT01954472
Who has a stake
No stake declared
Funded by the World Health Organization; no company ties declared.
Journal
The Cochrane database of systematic reviews, 2020
Source
PubMed record 32428300. This page is based on the abstract only.

How much this study counts

  • ✓Pools the results of 15 studies with 59,000 people.
  • •A pooled review is only as strong as the studies it pools.
  • ✓Measured the question itself: heart disease and inflammation.
  • ✓No competing interests declared.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

This paper is not on the ladder. It is a pooled review (meta-analysis), and reviews and opinion pieces discuss studies that are already counted on the steps below.

↑ Stronger evidence

  1. Trials in people: heart disease

    1

    1 harm

  2. Trials in people: other measures

    0

    None among the papers we read.

  3. Trials in people: lab tests or safety

    4

    1 benefit, 3 no difference

  4. Population studies

    2

    2 mixed

  5. Blood levels and genes

    0

    None among the papers we read.

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “Are seed oils bad for your heart?”

Not clearly; the evidence conflicts.

Confidence: very low. Based on 13 on-topic papers.

Read the full answer
  • Quoted in “What we found”: A review of 15 trials found cutting saturated fat lowered combined heart and blood vessel events by 21%; replacing it with polyunsaturated fat looked as useful as carbohydrate.
  • Part of the finding “Cutting saturated fat lowered heart events in pooled trials”.
  • Summed up in “What reviews found”: Pooled 15 trials (about 59,000 people) of cutting saturated fat for at least two years. Combined heart and blood vessel events fell 21% (RR 0.79). Swapping in polyunsaturated fat or carbohydrate looked useful; no separate polyunsaturated fat number.
  • Marked as a key paper in the research timeline: Cochrane review of 15 saturated fat trials.
  • Open item for a person: Hooper 2020 (Cochrane saturated fat) added as relevant and Dehghan 2017 (PURE) kept, though both cover all polyunsaturated fat, not seed oils; confirm inclusion.
  • Open item for a person: The updated linoleic acid meta-analysis in Ramsden 2013 may share trials with Cochrane Hooper 2020; abstracts do not list included trials.

Other reviews on this question

See all 13 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The reviewer corrected 7 fields after reading the abstract. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
Not yet. Required before search engines may list this page.

Spot an error? Email a flag with a link to your source, or use the form on the question page.