Mechanistic Effect of Walnut Consumption on Sleep Quality

Columbia University

Status

Enrolling

Conditions

Poor Sleep Quality

Treatments

Other: Walnut consumption

Other: HCHS consumption

Study type

Interventional

Funder types

Other

Other U.S. Federal agency

Identifiers

NCT06430086

AAAV1362

GRANT13949102 (Other Grant/Funding Number)

Details and patient eligibility

About

Poor sleep quality is very common in modern society. Walnuts contain many nutrients that may be helpful for sleep, including melatonin and polyphenols. Some studies show that eating foods high in melatonin and polyphenols improves sleep quality, but walnuts have not been studied specifically. This study proposes to test if eating walnuts improves sleep compared to a food that lacks these sleep-promoting factors. The investigators expect that walnut consumption for 4 days will increase melatonin levels and lead to better sleep quality compared to a high-carbohydrate, high-sugar food. The study will enroll middle-aged and older adults with sleep complaints to participate in this study. Each person will eat the two different foods for 4 days each in random order. The 4-day periods will be separated by at least 2-3 weeks. Sleep quality will be measured by questionnaire and with a wrist monitor every day. The investigators will also do a sleep study using electroencephalography (EEG) on night 3 and take measures of circadian physiology (natural body rhythms) in the laboratory on day 4 (including overnight) by measuring body temperature and blood and urine melatonin. The study findings may provide new options to improve sleep health from increased walnut consumption.

Full description

Walnuts are a nutrient-rich food which provides melatonin and polyphenols. While there is evidence that dietary intakes of foods high in melatonin and polyphenols positively influence sleep quality, the effect of walnuts has not been investigated. The investigators propose to fill this knowledge gap by testing the effects of walnut consumption on serum melatonin and resulting sleep and circadian biology. The study hypotheses are that walnut consumption for 4 days will increase melatonin levels, suggestive of more robust circadian rhythms, and lead to better sleep quality compared to a high-carbohydrate high-sugar (HCHS) equivalent. Using a randomized controlled crossover trial, the study aims to: 1) determine the effect of walnut vs HCHS consumption on melatonin levels; and 2) determine the effect of walnut vs HCHS consumption on sleep and circadian physiology. Adult males and females with poor sleep quality will consume three servings/day of walnuts or an equicaloric HCHS food for 4 days. Sleep quality will be measured nightly using the Karolinska Sleep Diary and wrist actigraphy; sleep architecture from polysomnography will be measured on night 3. Circadian physiology will be assessed on day 4 using body temperature and hourly serum melatonin and on the morning of day 5 from overnight urinary 6-sulfatoxymelatonin. Given the extent of poor sleep, our findings may open new avenues to improve sleep health from increased walnut consumption.

Enrollment

24 estimated patients

Sex

All

Ages

45 to 65 years old

Volunteers

Accepts Healthy Volunteers

Inclusion criteria

Equal numbers of men and women (12 male and 12 post-menopausal female)
Equal number of individuals with normal weight (18.5-24.9 kg/m2) and overweight (25-29.9 kg/m2)
Participants will self-report poor sleep quality, reflected by a global score >5 on Pittsburgh Sleep Quality Index

Exclusion criteria

Diagnosed sleep disorder
Participants with conditions that could affect sleep will be excluded:
- smoking, excessive caffeine intake (>300 mg/day)
- shift work
- chronic pain
- diagnosis of a chronic disease (e.g., uncontrolled hypertension, pre-diabetes, type 2 diabetes, chronic kidney disease, chronic obstructive pulmonary disease),
- autoimmune diseases
- cardiovascular event or cancer in the past 24 months
- psychiatric/neurologic disease or disorder, or sleep disorder (diagnosed or high risk for sleep apnea, chronic insomnia, restless leg syndrome, narcolepsy)
- use of medications that influence CYP1A2 enzymes
Allergy/intolerance to nuts, tree nuts, or unwilling to eat study foods

Trial design

Primary purpose

Treatment

Allocation

Randomized

Interventional model

Crossover Assignment

Masking

Single Blind

24 participants in 2 patient groups

Walnut - washout - HCHS

Experimental group

Description:

Participants will consume 3 servings/day of walnuts (3 oz/d) over 4 days and have a washout for 2-3 weeks then crossover to consume 3 equicaloric servings of a HCHS food over 4 days. Over each 4-day period, participants will sleep and eat at home for the first 3 days and will be admitted to the Inpatient Clinical Research Resource of the Irving Institute for Clinical and Translational Research of CUIMC on day 4 for in-depth profiling circadian physiology. Participants will be discharged on the morning of day 5.

Treatment:

Other: HCHS consumption

Other: Walnut consumption

HCHS - washout - Walnut

Experimental group

Description:

Participants will consume 3 equicaloric servings of a HCHS food over 4 days and have a washout for 2-3 weeks then crossover to consume 3 servings/day of walnuts (3 oz/d) for 4 days. Over each 4-day period, participants will sleep and eat at home for the first 3 days and will be admitted to the Inpatient Clinical Research Resource of the Irving Institute for Clinical and Translational Research of CUIMC on day 4 for in-depth profiling circadian physiology. Participants will be discharged on the morning of day 5.

Treatment:

Other: HCHS consumption

Other: Walnut consumption