Mechanistic Effect of Walnut Consumption on Sleep Quality
Columbia University
Summary
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.
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-car…
Eligibility
- Age range
- 45–65 years
- Sex
- All
- Healthy volunteers
- Yes
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…
Interventions
- OtherWalnut consumption
Participants will add one serving (1 oz) of walnuts at their self-defined breakfast, lunch, and dinner for 4 days. The study will provide study foods at 3 main meals each day to evaluate a temporal effect of the food on melatonin concentrations throughout the day.
- OtherHCHS consumption
Participants will add one HCHS food (one PopTarts® pastry) to each of their 3 main meals of the day for 4 days. The study will provide study foods at 3 main meals each day to evaluate a temporal effect of the food on melatonin concentrations throughout the day. An energy-matched high-carbohydrate, high-sugar (HCHS) alternative, representative of a common US snack food, on sleep quality in adults with habitually poor sleep quality.
Location
- Columbia University Irving Medical CenterNew York, New York