Study analysis · The Journal of nutrition · 2005

Adding avocado to salsa boosted lycopene absorption 4.4 times — but that is relative absorption, not a 4.4x lower disease risk.

In two small studies, adding avocado or avocado oil to salsa or salad helped healthy adults absorb more carotenoids like lycopene, beta-carotene, and lutein.

Reading level
Low certainty
Level 2b · Individual cohort studyAssociation, not causationNo causal claims

Overview

What the study found

The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.

In simple terms

This study is like a test where the same people ate salad with and without avocado, and scientists measured how much vitamins got into their blood. It shows that adding avocado may help the body absorb more vitamins from vegetables, but because it wasn't a perfectly controlled experiment, we can't be sure avocado is the only reason. It doesn't prove long-term health benefits.

What’s the bottom line?

In two small studies, healthy adults ate salsa or salad with or without avocado. The avocado made it easier for their bodies to take up certain carotenoids from the food.

How strong is this study?

The study was small (only 11 people) and the order of meals wasn't random, so there could be other explanations for the results. But it was carefully done with controlled meals and measured blood levels, so the findings are interesting but not definitive.

Reporting

0 / 100

  • COI disclosureconflicts of interest not disclosed
  • Data availabilitydata not shared
  • Code availabilitycode not shared
Methodology

33 / 100

  • Randomizationnot randomized
  • Blindingblinding unclear
  • Control group+15/15
  • Sample size (n=11)+1.1/20
  • Follow-up+10/10
Publication

100 / 100

Statistical

54 / 100

  • P-values+15/15
  • Effect size+20/20
  • Confidence intervalsno confidence intervals
  • Pre-registrationnot pre-registered

Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.

Where it sits

RCT reviews

Max 100

Randomized Trials

Max 90

Reviews of Cohort Studies

Max 85

Cohort Studies

Max 72

Reviews of Case-Control Studies

Max 63

Case-Control Studies

Max 58

Cross-Sectional & Case Series

Max 50

Expert Opinion

Max 5
StrongerWeaker
Cohort Studies
Level 2b
45

45 / 100

Probability of being correct

Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.

This design cannot establish causation — the findings describe an association, not a cause. This was a non-randomized crossover feeding study with a small sample (n=11). The order of avocado-containing meals was not randomized, there was no blinding, and the study was acute (postprandial 9.5 h). Although it used a within-subject control, it cannot rule out confounding, order effects, or other dietary factors. Therefore, it cannot establish a cause-effect relationship.

COI Unknown

Could not determine conflict of interest status

No conflict of interest or funding statement was included in the provided text, so COI cannot be assessed.

The provided text does not include a COI declaration or funding statement. Footnote markers [1] and [2] are present but their content is not shown. Assessment is limited to the visible text.

Key takeaways

  1. 01

    Adding 150 g avocado to salsa increased lycopene absorption by 4.4 times relative and beta-carotene by 2.6 times relative versus salsa alone.

  2. 02

    Absolute AUC for lycopene rose from median 18.97 to 68.97 nmol·h/L; beta-carotene rose from 7.37 to 18.26 nmol·h/L.

  3. 03

    Adding 150 g avocado or 24 g avocado oil to salad increased alpha-carotene by 7.2 times relative, beta-carotene by 15.3 times relative, and lutein by 5.1 times relative.

  4. 04

    Absolute mean AUC rose from -1.32 to 8.12, 2.38 to 36.31, and 6.45 to 33.04 nmol·h/L, respectively.

  5. 05

    75 g and 150 g avocado did not differ significantly, and avocado oil worked similarly to avocado fruit.

  6. 06

    These are relative increases in nutrient absorption, not disease risk.

  7. 07

    In absolute terms, the study measured carotenoid AUC in blood lipoproteins over 9.5 hours.

  8. 08

    For example, avocado raised lycopene AUC by about 50 nmol·h/L and beta-carotene AUC by about 11 nmol·h/L from salsa; from salad, beta-carotene AUC rose by about 34 nmol·h/L.

  9. 09

    The study did not report disease outcomes or absolute risk changes.

Surprising findings

  • Doubling avocado from 75 g to 150 g did not significantly increase carotenoid absorption.Common assumption is more fat means more absorption, but this study found a nonlinear relationship within moderate fat intake.
  • Avocado oil worked as well as avocado fruit despite containing no detectable carotenoids.Supports that avocado's fat, not its own carotenoids, drives absorption.
  • Avocado fiber did not inhibit postprandial carotenoid absorption.Contradicts some prior studies suggesting dietary fiber may entrap carotenoids and reduce absorption.
  • 75 g avocado increased alpha- and beta-carotene but not lutein (P=0.07).Suggests carotenoids have different lipid requirements; lutein may need more fat.

Practical takeaways

Add avocado or avocado oil to a carotenoid-rich salad or salsa to increase relative carotenoid absorption.

Small n=11, short 9.5h, nonrandomized, industry-funded; no disease outcomes.

low-to-medium confidence

For alpha- and beta-carotene, 75 g avocado (about half a fruit) may be enough; for lutein, 150 g or avocado oil may be better.

Lutein result for 75 g was P=0.07 and n=8; not definitive.

low confidence

Use avocado oil if you want the fat effect without avocado fruit; it performed similarly in this study.

Only 24 g oil tested; long-term effects unknown.

medium for short-term absorption, low for health outcomes confidence

Do not interpret 15.3x as 15.3x disease protection; focus on overall diet quality.

Study measured plasma TRL AUC, not clinical endpoints.

high that no disease risk was measured confidence

Why this study matters

The headline number: 4.4x more lycopene (relative)

In Study 1, adding 150 g avocado to 300 g salsa increased lycopene absorption by 4.4 times relative and beta-carotene by 2.6 times relative versus salsa alone. Absolute median AUC rose from 18.97 to 68.97 nmol·h/L for lycopene and 7.37 to 18.26 nmol·h/L for beta-carotene over 9.5 h. This is nutrient absorption, not disease risk.

It sounds like a huge win for avocado, but the absolute change is modest and the study did not measure health outcomes.

Salad study: beta-carotene jumped 15.3x relative

In Study 2, adding 150 g avocado or 24 g avocado oil to a 220 g salad increased alpha-carotene by 7.2 times relative, beta-carotene by 15.3 times relative, and lutein by 5.1 times relative. Absolute mean AUC rose from -1.32 to 8.12, 2.38 to 36.31, and 6.45 to 33.04 nmol·h/L, respectively. The negative baseline-corrected AUC for alpha-carotene in the control is possible due to baseline correction and variability.

Shows how a fat source can dramatically change nutrient bioavailability from vegetables.

Avocado oil matched whole avocado

Adding 24 g avocado oil to salad produced similar carotenoid absorption increases to 150 g avocado fruit, and the study detected no carotenoids in the commercial avocado oil. This suggests the lipid component of avocado is the main driver, not its own carotenoid content.

If you do not like avocado, avocado oil may offer the same absorption benefit in this context.

75 g vs 150 g avocado: no significant difference

Increasing avocado from 75 g to 150 g (12 g vs 24 g lipid) did not significantly affect alpha-carotene, beta-carotene, or lutein absorption. However, 75 g avocado significantly increased alpha-carotene and beta-carotene but not lutein (P = 0.07), hinting that different carotenoids may need different lipid amounts.

Suggests you may not need a whole avocado for some benefits, but lutein may need more fat.

Small, short, nonrandomized, industry-funded

Each study had n=11; the 75 g avocado lutein comparison had n=8. Meal order was nonrandomized, follow-up was 9.5 h, and funding came in part from the California Avocado Commission. No clinical disease outcomes were measured.

Important for judging how much to trust the flashy relative numbers.

Want the whole report?

Detailed mode opens the full scientific breakdown — every score component, the methodology, conflicts of interest, the evidence analysis behind each claim, and the raw study data.

Standing

Who’s using this study?

The videos and claims on this site that lean on this study, and the researchers who wrote it.

1 video from Thomas DeLauer cite this study, drawing 3 claims from it.

Thomas DeLauer
All 1 video linked this study in their descriptions.

Authored by

4 researchers

If this is your work, this is how we attribute it on Fit Body Science. Nuray Z. Unlu is listed as the lead author.