Hass avocado health effects across clinical trials and observational studies
What it found
Hass avocados improved blood lipids, weight management, cognitive function and gut bacteria in the studies reviewed.
The evidence comes from 19 clinical trials in people, five observational studies in people, and lab work on biological mechanisms.
What they found
Studies in people
Heart health in overweight adults
In overweight or obese adults with high cholesterol, eating at least one Hass avocado a day for 4 to 5 weeks improved blood lipid profiles and reduced oxidized LDL compared to control diets.
Blood vessel health after meals
Short-term trials found that adding Hass avocado to meals improved blood vessel dilation and reduced inflammation compared to meals without avocado.
Hunger and fullness
Trials found that meals with avocado increased feelings of fullness and satisfaction and reduced hunger compared to control meals.
Cognitive function
In older normal-weight adults, a daily avocado for 6 months improved some measures of attention and problem-solving. In younger overweight adults, a daily avocado for 3 months improved attention accuracy.
Gut bacteria
Trials in overweight adults found that a daily avocado for 12 weeks increased gut bacteria diversity and changed the types of bacteria present, along with changes in fecal metabolites.
Studies in people and animals
Weight and body fat
Observational studies found that avocado consumers had lower body weight, BMI, and waist circumference than non-consumers. Clinical trials showed that a daily avocado did not cause weight gain and may help reduce visceral fat in women.
What the authors conclude
“Hass avocados are compatible with healthy dietary regimens such as the Mediterranean diet.”
Also in their conclusions
- They conclude that Hass avocados have four primary health effects: promoting cardiovascular health, healthier weight and body composition, better cognitive function, and colonic microbiota health.
- They state that these effects are primarily due to the Hass avocado's unique combination of four nutritional features: a high oleic acid to saturated fat ratio, multifunctional prebiotic and viscous fiber, relatively low energy density, and uniquely high bioavailable lutein along with other carotenoids.
- They advise that larger and longer clinical trials are needed to better understand the effects of Hass avocados on health, especially in glycemic and insulinemic control in normal and type 2 diabetic subjects.
How it was done
The authors wanted to gather all the research on fresh Hass avocados specifically, because previous reviews included other avocado varieties or were outdated.
They searched for published papers on Hass avocados and health, and included 19 randomized controlled trials, five observational studies, and studies on biological mechanisms. The trials lasted from 4 weeks to 6 months and involved adults with various health conditions.
What it can’t tell you
- Many of the clinical trials were relatively short and had a small number of subjects.
- The clinical trials and observational studies were not scored for quality or assessed by statistical analysis of mean effects or heterogeneity.
- Observational studies can show a link between avocado intake and health outcomes, but cannot prove that avocados cause the effects.
Who paid
- Funding
- Funded by CSRD VA (from the PubMed record).
- Conflicts
- M.L.D. is an ad hoc nutrition research consultant, and F.W.C. and N.A.F. are employed by the Avocado Nutrition Center.
- Authors work at
- Avocado Nutrition Center, USA
The paper
- Title
- A Comprehensive Review of Hass Avocado Clinical Trials, Observational Studies, and Biological Mechanisms
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Dreher ML, Cheng FW, Ford NA (2021). A Comprehensive Review of Hass Avocado Clinical Trials, Observational Studies, and Biological Mechanisms. Nutrients. doi:10.3390/nu13124376Free full textPubMed 34959933DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error