Effects of Daily Avocado Consumption on Sleep and Skin Health in Postmenopausal Females

THE STUDY

About this study

Poor sleep quality and accelerated skin aging are common in postmenopausal women and may be linked, in part, through impaired vascular function. Avocados contain monounsaturated fats, carotenoids, vitamin E, magnesium, fiber, and other bioactive compounds that may support vascular health and, in turn, improve sleep and skin health. This randomized controlled trial will evaluate whether consuming one medium Hass avocado daily for 8 weeks improves sleep quality and skin health compared with a calorie- and fatty-acid-matched safflower oil control in postmenopausal women with poor sleep quality and overweight or obesity. The study will enroll 74 postmenopausal women aged 50-65 years who have poor habitual sleep quality. Participants will be randomly assigned to consume either one medium Hass avocado per day or 27 g of safflower oil per day for 8 weeks. Sleep will be assessed using wrist actigraphy, at-home electroencephalography, sleep diaries, and validated sleep questionnaires. Skin hydration, elasticity, barrier function, collagen, pigmentation, and wrinkles will also be assessed. Vascular function will be measured using flow-mediated dilation and blood biomarkers. The investigators expect that daily avocado consumption will improve sleep quality, skin health, and vascular function compared with the control condition and will explore whether improvements in vascular function contribute to improvements in sleep and skin health.

Full official title

Sleep and Skin Health Improvement Via Avocado-Induced Vascular Endothelial Responses in Postmenopausal Females With Poor Sleep

Detailed description

This study is an 8-week, randomized, parallel-group controlled trial designed to evaluate the effects of daily Hass avocado consumption on sleep quality, skin health, and vascular function in postmenopausal women with poor habitual sleep quality and overweight or obesity. A total of 74 women aged 50-65 years will be randomized to either an Avocado Arm or a calorie- and fatty-acid-matched Control Arm. Participants assigned to the Avocado Arm will consume one medium Hass avocado daily (150 g pulp; approximately 240 kcal) for 8 weeks. Participants assigned to the Control Arm will consume 27 g of safflower oil daily (approximately 243 kcal) for 8 weeks. Study foods will be consumed with breakfast or lunch while participants otherwise maintain their habitual diet. The control was selected to provide a similar amount of energy and a predominantly monounsaturated fatty-acid profile while lacking the fiber, carotenoids, minerals, phytosterols, and other components of the whole avocado matrix. Study assessments will be conducted at baseline, Week 4, and Week 8. Objective sleep quality will be assessed using 7-day wrist actigraphy to measure sleep efficiency, sleep fragmentation, sleep duration, sleep latency, nighttime awakenings, and wake after sleep onset. On the final night of each assessment period, participants will complete one night of at-home electroencephalography using the Zmachine Insight device to assess sleep architecture, including slow-wave sleep. Subjective sleep will be assessed using sleep diaries and validated questionnaires, including the Pittsburgh Sleep Quality Index, Insomnia Severity Index, Epworth Sleepiness Scale, and Ru-SATED multidimensional sleep health scale. Skin health will be assessed under standardized environmental conditions. Outcomes will include skin hydration, elasticity, transepidermal water loss, sebum, pigmentation, wrinkle severity, surface texture, and collagen integrity. Measurements will be obtained at the forehead, periorbital region, dorsal hand, and upper inner arm using noninvasive skin-assessment instruments. Participants will also complete a questionnaire assessing skin-related quality of life. Vascular function will be evaluated as a potential biological pathway linking avocado consumption with changes in sleep and skin health. Macrovascular endothelial function will be assessed using brachial artery flow-mediated dilation. Fasting blood samples will also be analyzed for markers of endothelial activation, inflammation, and oxidative stress, including VCAM-1, ICAM-1, P-selectin, E-selectin, C-reactive protein, total antioxidant capacity, and 8-oxo-deoxyguanosine. The primary hypothesis is that daily avocado consumption will improve sleep quality and skin health compared with the calorie- and fatty-acid-matched control. The study will also examine whether changes in vascular function during the intervention are associated with subsequent improvements in sleep and skin outcomes.

PARTICIPATION

Who may participate

Minimum age: 50 Years
Maximum age: 65 Years
Sex eligibility: Female
Healthy volunteers: Accepted

Only the study team can confirm eligibility. The registry criteria below are not a medical recommendation.

Full inclusion and exclusion criteria

Inclusion Criteria:

* Postmenopausal women aged 50-65 years
* Individuals with overweight or obesity, defined as BMI 25-35 kg/m²
* Postmenopausal, defined as no menstrual period for at least 12 months
* Participants with poor habitual sleep quality, reflected by a global score \>5 on the Pittsburgh Sleep Quality Index (PSQI)
* Participants with Fitzpatrick skin types II-IV
* Participants willing to maintain their usual skin-care routine throughout the study, avoid excessive sun exposure, and not initiate new skin treatments

Exclusion Criteria:

* Current smokers
* Individuals with caffeine intake \>300 mg/day
* Excessive alcohol or drug use
* Individuals engaged in shift work
* Current use of hormone replacement therapy
* Individuals with chronic pain or major chronic disease/medication likely to affect study outcomes, including uncontrolled hypertension, prediabetes/type 2 diabetes, chronic kidney disease, COPD, autoimmune disease, recent cardiovascular event, or cancer within the past 24 months
* Psychiatric or neurologic disease/disorder likely to affect sleep
* Individuals with a diagnosed sleep disorder or high risk for sleep apnea, defined as a STOP-Bang score ≥3
* Individuals using medications to regulate sleep
* Individuals planning time-zone travel during the study
* Pregnancy or lactation
* Allergy or intolerance to study foods
* Individuals who dislike avocado and/or safflower oil, defined as a taste pleasantness rating \<50 mm on a 100-mm visual analog scale
* Individuals who habitually consume \>2 avocados per month

NEAR YOU

Study locations worldwide

0 sites

Check the individual site’s status and contact the listed study team for current availability.

No study sites are currently reported in this record. Location information may have changed.

WHAT IS BEING STUDIED

Treatments and study groups

Interventions

Hass AvocadoOther

One medium Hass avocado (150 g pulp) consumed once daily for 8 weeks.

Study groups: Avocado Arm (AA)

Safflower OilOther

A 27-g portion of safflower oil consumed once daily for 8 weeks.

Study groups: Safflower Oil Control Arm

Study groups

Avocado Arm (AA)Experimental

Participants will consume one medium Hass avocado daily (150 g pulp; approximately 240 kcal) for 8 weeks. The avocado will be consumed with breakfast or lunch while participants maintain their habitual diet.

Interventions: Other: Hass Avocado

Safflower Oil Control ArmActive comparator

Participants will consume 27 g of safflower oil daily (approximately 243 kcal) for 8 weeks. The control is designed to approximate the avocado intervention for energy and fatty-acid profile while lacking the avocado whole-food matrix. The safflower oil will be consumed with breakfast or lunch while participants maintain their habitual diet.

Interventions: Other: Safflower Oil

RESEARCH DETAILS

Study design

Study type: Interventional
Phase: Not applicable
Primary purpose: Treatment
Allocation: Randomized
Study model: Parallel
Masking: Single
Enrolment: 74 participants · Estimated
Who is masked: Investigator

Study model details

A two-arm, randomized, double-blind, placebo-controlled parallel assignment in which participants allocated to either the avocado or control group and remained in the same group for the duration of the 8-week intervention.

Masking details

Statistician will be masked to study condition. Participants cannot be masked Participants will be instructed not to disclose their assigned group to masked staff. Other personnel involved in the study cannot be masked.

TIMELINE & MEASURES

Dates and outcomes

Study started: 1 Jan 2027 · Estimated
Primary completion: Apr 2029 · Estimated
Study completion: Apr 2029 · Estimated
First registered: 19 Oct 2026 · Actual
Last registry update: 19 Oct 2026 · Actual
Status last verified: Oct 2026

Primary outcomes (4)

Change in Actigraphy-Derived Sleep Efficiency

Sleep efficiency will be assessed using 7-day wrist actigraphy and expressed as the percentage of time in bed spent asleep. Change from baseline will be assessed at each follow-up.