Walnuts for Improving Sleep Quality

Overseen By Lena Navarro, BS

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Columbia University

Must not be taking: CYP1A2 influencers

Disqualifiers: Sleep disorder, Chronic disease, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 2

Duration: 4 days

24 Participants Needed

Trial Summary

What is the purpose of this trial?

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.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but you cannot participate if you use medications that influence CYP1A2 enzymes.

What data supports the effectiveness of the treatment Walnut Consumption, Walnut, Juglans regia L. for improving sleep quality?

Research shows that walnuts contain components like n-3 fatty acids and polyphenols, which have been linked to improved cognitive and motor functions in aged rats and better blood lipid profiles in humans. These components may also contribute to overall health benefits, potentially including improved sleep quality. ^{1 2 3 4 5}

Is walnut consumption safe for humans?

Walnut consumption is generally considered safe for humans, as studies have shown health benefits like improved blood lipids and fatty acid profiles without significant safety concerns. Additionally, potentially toxic elements in walnuts are below maximum allowed values, indicating they are safe to eat. ^{2 3 4 6 7}

How does walnut consumption as a treatment for improving sleep quality differ from other treatments?

Walnut consumption is unique because it is a natural dietary approach that may improve sleep quality due to its content of melatonin, a hormone that regulates sleep. Unlike conventional sleep aids, walnuts offer additional health benefits, such as improving lipid profiles and providing antioxidants, without the side effects associated with many sleep medications. ^{2 8 9 10 11}

Research Team

Marie-Pierre St-Onge, PhD

Principal Investigator

Associate Professor of Nutritional Medicine

Eligibility Criteria

This trial is for middle-aged and older adults who have trouble sleeping. Participants will be asked to eat walnuts or a high-carbohydrate, high-sugar food over two separate 4-day periods to see if walnuts help improve sleep.

Inclusion Criteria

Equal number of individuals with normal weight (18.5-24.9 kg/m2) and overweight (25-29.9 kg/m2)

I am either a man or a post-menopausal woman.

I often have trouble sleeping well.

Exclusion Criteria

I have been diagnosed with a sleep disorder.

I do not smoke, consume a lot of caffeine, work night shifts, have chronic pain or any listed chronic diseases, and I'm not allergic to nuts.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants consume 3 servings/day of walnuts or an equicaloric HCHS food for 4 days, with sleep and circadian physiology assessments

4 days

1 visit (inpatient on day 4)

Washout

Participants undergo a washout period between treatment phases

2-3 weeks

Crossover Treatment

Participants switch to the alternate food (walnuts or HCHS) for another 4 days, with similar assessments

4 days

1 visit (inpatient on day 4)

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

Treatment Details

Interventions

• Walnut Consumption

Trial Overview The study is testing whether consuming walnuts, which are rich in melatonin and polyphenols, can enhance sleep quality compared to a control food. Sleep will be monitored through questionnaires, wrist monitors, EEG during sleep studies, and measurements of body rhythms.

Participant Groups

Group I: Walnut - washout - HCHS Experimental Treatment 2 Interventions

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.

Group II: HCHS - washout - Walnut Experimental Treatment 2 Interventions

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.

Who Is Running the Clinical Trial?

Columbia University

Lead Sponsor

Trials

1,529

Recruited

2,832,000+

United States Department of Agriculture (USDA)

Collaborator

Trials

103

Recruited

287,000+

California Walnut Commission

Collaborator

Trials

25

Recruited

36,700+

Findings from Research

Aged rats fed a moderate walnut diet (2% and 6%) for 8 weeks showed improved motor skills, particularly in tasks like rod walking and medium plank walking, indicating that walnuts can enhance motor performance.

All walnut diets improved working memory in cognitive tests, but the highest dose (9%) led to impaired reference memory, suggesting that while walnuts can be beneficial, too much may have negative effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dose-dependent effects of walnuts on motor and cognitive function in aged rats. Willis, LM., Shukitt-Hale, B., Cheng, V., et al.[2009]

A meta-analysis of 13 randomized controlled trials involving walnut intake showed significant reductions in total cholesterol (TC), low-density lipoprotein (LDL-C), and triglycerides (TG), indicating that walnuts can improve blood lipid profiles and potentially reduce cardiovascular disease risk.

The study found that individuals who were overweight or had comorbidities experienced greater improvements in lipid levels with walnut consumption, suggesting that walnuts may be particularly beneficial for these populations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Effect of Walnut Intake on Lipids: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Alshahrani, SM., Mashat, RM., Almutairi, D., et al.[2022]

A study of Serbian walnuts revealed they are rich in alpha-linolenic acid (ALA), a type of n-3 polyunsaturated fatty acid (PUFA), which is beneficial for health.

In a 4-week intervention with 18 participants, walnut consumption significantly improved the n-3 fatty acid profile in the plasma, indicating that including walnuts in the diet could help address low n-3 PUFA intake in the region.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Effect of Walnut Consumption on n-3 Fatty Acid Profile of Healthy People Living in a Non-Mediterranean West Balkan Country, a Small Scale Randomized Study. Petrović-Oggiano, G., Debeljak-Martačić, J., Ranković, S., et al.[2020]

In a study involving 40 healthy participants aged 50 and older, consuming 43g of walnuts daily for 8 weeks significantly reduced non-HDL cholesterol and apolipoprotein-B levels, which are important markers related to heart disease risk.

Despite these positive changes in cholesterol levels, other factors such as fasting glucose, insulin, and markers of inflammation and endothelial function did not show significant changes, indicating that walnuts may specifically target lipid profiles without affecting other metabolic parameters.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Walnut-enriched diet reduces fasting non-HDL-cholesterol and apolipoprotein B in healthy Caucasian subjects: a randomized controlled cross-over clinical trial. Wu, L., Piotrowski, K., Rau, T., et al.[2022]

The study identified 30 components in walnut extracts, including three new compounds, and highlighted glansreginin A as a potential quality indicator for walnuts.

Glansreginin A demonstrated neuroprotective effects in mice by preventing inflammation-induced behavioral changes and microglial activation, suggesting its role in brain health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Identification of the characteristic components in walnut and anti-inflammatory effect of glansreginin A as an indicator for quality evaluation. Haramiishi, R., Okuyama, S., Yoshimura, M., et al.[2020]

Walnuts are rich in essential macro-elements like calcium, potassium, magnesium, and sodium, which are beneficial for health, with potassium being the most abundant at 2771 mg/kg.

The study found that potentially toxic trace elements like arsenic, cadmium, and lead were present in walnuts but below the maximum allowed values, indicating that walnuts can be considered safe for consumption.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mineral Composition of Elements in Walnuts and Walnut Oils. Juranović Cindrić, I., Zeiner, M., Hlebec, D.[2020]

A randomized controlled trial with 90 healthy adults showed that a daily walnut supplement (about 12% of daily energy intake) significantly improved the nutrient profile of participants' diets, increasing levels of vegetable protein, total fat, polyunsaturated fatty acids (PUFAs), and dietary fiber.

Participants on the walnut-supplemented diet also had higher mineral levels, particularly calcium, phosphorus, magnesium, and zinc, suggesting that walnut intake may help in chronic disease prevention by enhancing overall nutrient intake.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Food and Nutrient Displacement by Walnut Supplementation in a Randomized Crossover Study. Natto, ZS., Siapco, G., Jaceldo-Siegl, K., et al.[2023]

Walnut oil, rich in fatty acids and bioactive compounds like phenols and squalene, exhibits a wide range of health benefits, including anti-inflammatory, antioxidant, and cardioprotective effects, making it a valuable natural oil for nutrition and health.

Various extraction methods can influence the quality and properties of walnut oil, highlighting the need for further clinical studies to explore the therapeutic potential and mechanisms of its numerous bioactive constituents.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Research progress on Walnut oil: Bioactive compounds, health benefits, extraction methods, and medicinal uses. Song, H., Cong, Z., Wang, C., et al.[2023]

Feeding pregnant and lactating rats a diet including walnut kernel (6% of food intake) significantly improved the learning and memory abilities of their offspring, as demonstrated by the Morris water maze test.

The study suggests that the beneficial constituents in walnuts, such as unsaturated fatty acids and vitamin E, may play a role in enhancing cognitive functions in the next generation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Maternal feeding with walnuts (Juglans regia) improves learning and memory in their adult pups. Asadi-Shekaari, M., Karimi, A., Shabani, M., et al.[2021]

In a study of 52 volunteers over 8 weeks, consuming 20 grams of walnuts daily led to a significant 17.1% reduction in triglyceride levels and a 9% increase in HDL cholesterol, indicating beneficial lipid-lowering effects.

The results suggest that regular walnut consumption may lower the risk of coronary artery disease by improving lipid profiles, highlighting walnuts as a healthy addition to the diet.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Walnut consumption in hyperlipidemic patients. Zibaeenezhad, MJ., Shamsnia, SJ., Khorasani, M.[2022]

In a study involving 15 obese participants with metabolic syndrome, a short-term walnut-enriched diet (48 g/day for 4 days) led to a significant increase in serum apolipoprotein A concentrations, suggesting potential improvements in lipid profiles.

Despite the increase in apolipoprotein A, walnut consumption did not significantly affect other markers of inflammation or vascular injury, indicating that the benefits of walnuts may specifically relate to lipid metabolism rather than broader inflammatory responses.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Short-term walnut consumption increases circulating total adiponectin and apolipoprotein A concentrations, but does not affect markers of inflammation or vascular injury in obese humans with the metabolic syndrome: data from a double-blinded, randomized, placebo-controlled study. Aronis, KN., Vamvini, MT., Chamberland, JP., et al.[2021]

References

1. England pubmed.ncbi.nlm.nih.gov

Dose-dependent effects of walnuts on motor and cognitive function in aged rats. [2009]

2. Switzerland pubmed.ncbi.nlm.nih.gov

The Effect of Walnut Intake on Lipids: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. [2022]

3. Switzerland pubmed.ncbi.nlm.nih.gov

The Effect of Walnut Consumption on n-3 Fatty Acid Profile of Healthy People Living in a Non-Mediterranean West Balkan Country, a Small Scale Randomized Study. [2020]

4. United States pubmed.ncbi.nlm.nih.gov

Walnut-enriched diet reduces fasting non-HDL-cholesterol and apolipoprotein B in healthy Caucasian subjects: a randomized controlled cross-over clinical trial. [2022]

5. England pubmed.ncbi.nlm.nih.gov

Identification of the characteristic components in walnut and anti-inflammatory effect of glansreginin A as an indicator for quality evaluation. [2020]

6. Switzerland pubmed.ncbi.nlm.nih.gov

Mineral Composition of Elements in Walnuts and Walnut Oils. [2020]

7. Switzerland pubmed.ncbi.nlm.nih.gov

Food and Nutrient Displacement by Walnut Supplementation in a Randomized Crossover Study. [2023]

8. United States pubmed.ncbi.nlm.nih.gov

Research progress on Walnut oil: Bioactive compounds, health benefits, extraction methods, and medicinal uses. [2023]

9. Iran pubmed.ncbi.nlm.nih.gov

Maternal feeding with walnuts (Juglans regia) improves learning and memory in their adult pups. [2021]

10. United States pubmed.ncbi.nlm.nih.gov

Walnut consumption in hyperlipidemic patients. [2022]

11. United States pubmed.ncbi.nlm.nih.gov

Short-term walnut consumption increases circulating total adiponectin and apolipoprotein A concentrations, but does not affect markers of inflammation or vascular injury in obese humans with the metabolic syndrome: data from a double-blinded, randomized, placebo-controlled study. [2021]