Walnuts for Aging

Overseen By Sandra Uesugi, RN, BSN, MS

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Oregon State University

Must not be taking: Insulin, Opioids, Anti-seizure, Psychotropics

Disqualifiers: Cancer, Heart disease, Liver disease, others

Compensation: Varies

Number of Visits: Unknown

Duration: 12 weeks

80 Participants Needed

Trial Summary

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 regularly use insulin, opioids, anti-seizure medications, or certain psychotropic medications. You also need to stop probiotic supplements 2 weeks before and during the study.

What data supports the effectiveness of the treatment Walnuts for aging?

Research shows that eating walnuts can help lower blood pressure, especially in older adults with mild hypertension (high blood pressure). Walnuts are also linked to lower cholesterol levels and may have benefits for heart health, which can be important as we age. ^{1 2 3 4 5}

Is walnut consumption safe for humans?

Research shows that walnuts can be safely included in the diet of healthy older adults without negative effects on body weight or body composition. Studies also indicate that walnuts may improve cholesterol levels and have no adverse effects on metabolic health markers. ^{1 3 6 7 8}

How do walnuts as a treatment for aging differ from other treatments?

Walnuts are unique as a treatment for aging because they are a natural food source rich in polyunsaturated fatty acids and antioxidants, which may help improve health by reducing oxidative stress. Unlike synthetic treatments, walnuts offer nutritional benefits and are consumed as part of a regular diet. ^{9 10 11 12 13}

What is the purpose of this trial?

The purpose of this study is to examine the impact of daily consumption of walnuts for 12 weeks on cognitive function, markers of inflammation and oxidative stress, and the gut microbiome in healthy adults age 55 years and older.

Research Team

Emily Ho, PhD

Principal Investigator

Oregon State University

Eligibility Criteria

This trial is for healthy adults aged 55 and older who are interested in seeing if eating walnuts daily for 12 weeks can improve brain function, reduce inflammation, and affect gut bacteria. Specific eligibility criteria details were not provided.

Inclusion Criteria

Willing to stop consuming almonds, Brazil nuts, cashews, chestnuts, hazelnuts, macadamia nuts, peanuts, pecans, pistachios, walnuts, persimmons and pomegranates for 14 weeks - are nuts or contain ellagitannins or ellagic acid - compounds/foods of interest for this study

Willing to limit oak aged wines and spirits to 1 serving/day and limit blackberries (including similar berries like boysenberries, marionberries, and olallieberries), cloudberries, cranberries, currants, elderberries, lingonberries, raspberries, strawberries, wolfberries, other native berries; guava, mango, muscadine grapes, nectarines, peaches, plums, pluots to 1 cup/day for 14 weeks; REMAIN CONSISTENT (consistent intake levels of): Coffee, tea, apple, apricots, blueberries, cherries, grapes (table/common)

Able to see well enough to read and respond to printed instructions and fill out questionnaires (corrective lenses are allowed)

Exclusion Criteria

I have been taking oral anti-inflammatory medications regularly for the last month.

Nut, wheat, or gluten allergy/intolerance

Consumption of walnuts, pecans, and chestnuts combined greater than 2 oz / week in the past 3 months

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants consume either 1.5 ounces of walnuts or caloric equivalent crackers daily for 12 weeks

12 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

Treatment Details

Interventions

• Walnuts

Trial Overview Participants will consume either walnuts or crackers every day for three months. The study aims to see how these foods impact cognitive abilities, signs of aging and inflammation, as well as the diversity of gut microbes.

Participant Groups

Group I: Walnuts Active Control 1 Intervention

Daily consumption of 1.5 ounces (42.5 g) of plain walnuts for 12 weeks

Group II: Crackers Placebo Group 1 Intervention

Daily consumption of non-whole grain crackers for 12 weeks (caloric equivalent to 1.5 ounces of plain walnuts)

Who Is Running the Clinical Trial?

Oregon State University

Lead Sponsor

Trials

51

Recruited

8,300+

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]

References

1. Switzerland pubmed.ncbi.nlm.nih.gov

Effects of Long-Term Walnut Supplementation on Body Weight in Free-Living Elderly: Results of a Randomized Controlled Trial. [2018]

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

Effect of a Walnut Diet on Office and 24-Hour Ambulatory Blood Pressure in Elderly Individuals. [2020]

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

Walnut Intake Interventions Targeting Biomarkers of Metabolic Syndrome and Inflammation in Middle-Aged and Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. [2022]

4. Switzerland pubmed.ncbi.nlm.nih.gov

The Walnuts and Healthy Aging Study (WAHA): Protocol for a Nutritional Intervention Trial with Walnuts on Brain Aging. [2020]

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

Favourable nutrient intake and displacement with long-term walnut supplementation among elderly: results of a randomised trial. [2019]

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

Association of Walnut Consumption with Total and Cause-Specific Mortality and Life Expectancy in U.S. Adults. [2023]

7. England pubmed.ncbi.nlm.nih.gov

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

8. Poland pubmed.ncbi.nlm.nih.gov

Moderate walnut consumption improved lipid profile, steroid hormones and inflammation in trained elderly men: a pilot study with a randomized controlled trial. [2021]

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

Improving walnuts' preservation by using walnut phenolic extracts as natural antioxidants through a walnut protein-based edible coating. [2021]

10. India pubmed.ncbi.nlm.nih.gov

HS-SPME GC-MS characterization of volatiles in processed walnuts and their oxidative stability. [2021]

11. England pubmed.ncbi.nlm.nih.gov

Walnut (Juglans regia L.): genetic resources, chemistry, by-products. [2010]

12. Switzerland pubmed.ncbi.nlm.nih.gov

Brief Research Report: Estimation of the Protein Digestibility-Corrected Amino Acid Score of Defatted Walnuts. [2021]

13. Switzerland pubmed.ncbi.nlm.nih.gov

Walnut (Juglans regia L.) Volatile Compounds Indicate Kernel and Oil Oxidation. [2021]