Walnuts for Colon Health

Recruiting at 1 trial location

Overseen By Amy Pallotti

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: UConn Health

Must not be taking: Immunosuppressants, Steroids, Antibiotics, Anticoagulants

Disqualifiers: Cancer, Lynch syndrome, Crohn's, others

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

Compensation: Varies

Number of Visits: 4

200 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether eating walnuts can improve gut health, reduce blood inflammation, and benefit colon tissue. Participants will add 2 ounces of walnuts to their daily diet while avoiding certain foods and drinks for three weeks. It suits individuals preparing for a routine colonoscopy who have a family history of colon issues, received a positive colon screening, or have a personal history of colon polyps. As an unphased trial, this study provides a unique opportunity to contribute to scientific understanding and potentially enhance personal health.

Do I have to stop taking my current medications for the trial?

The trial requires participants to stop taking dietary supplements, including probiotics. It also excludes those who have used antibiotics or immunosuppressive agents recently. Other medications are not specifically mentioned, so it's best to discuss with the study team.

What prior data suggests that walnut consumption is safe for colon health?

Research has shown that walnuts are generally safe to eat and may benefit the colon. Studies have found that walnuts can help reduce swelling in the colon. Eating walnuts has been linked to less inflammation and a lower risk of colon cancer, suggesting they might protect the colon without causing major side effects.

One study found that a diet rich in walnuts helped heal damage in an inflamed colon, highlighting their potential to reduce inflammation. Overall, evidence suggests that walnuts are safe for most people and could help maintain colon health by lowering inflammation and other risks. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Unlike the standard treatments for colon health, which often involve medications or invasive procedures, this approach uses walnuts, a natural food source, to promote colon wellness. Researchers are excited about walnuts because they contain ellagitannins, compounds believed to support gut health by acting as prebiotics and potentially influencing gut flora favorably. Additionally, this method is non-invasive, making it an easy dietary adjustment rather than a medical intervention, which could appeal to individuals looking for natural ways to improve their colon health.

What evidence suggests that walnuts might be an effective treatment for colon health?

Research has shown that eating walnuts might benefit the colon. In this trial, participants will consume 2 ounces of walnuts daily. One study found that walnuts reduced swelling in the colon. Another study suggested that walnuts might lower the risk of colon cancer by increasing certain helpful substances called urolithins in the body. Additionally, eating walnuts has been linked to better survival rates for people with colorectal cancer. These findings suggest that walnuts could be beneficial for gut health, particularly for the colon. ^{1 3 6 7 8}

Who Is on the Research Team?

Daniel W. Rosenberg, Ph.D.

Principal Investigator

UConn Health

Christian Jobin, Ph.D.

Principal Investigator

University of Florida

Are You a Good Fit for This Trial?

This trial is for men and women aged 40-75 who are due for a colonoscopy, have a family history of colorectal cancer (CRC), or had positive fecal tests/colon polyps. Participants must not take dietary supplements/probiotics, avoid certain foods, and be willing to eat walnuts daily. Exclusions include walnut allergy, recent cancer other than skin cancer, severe illnesses, immune disorders, antibiotic use within the last month, and blood coagulation issues.

Inclusion Criteria

I am between 45 and 75 years old and have a history of colon polyps.

Willing and able to provide written informed consent for study participation

I am willing to provide blood, urine, and stool samples as required.

Exclusion Criteria

I have HIV or chronic viral hepatitis.

I haven't taken antibiotics in the last month and won't during the study.

I meet the criteria for Lynch Syndrome or have a history of FAP.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Wash-out

Participants undergo a 7-day wash-out period avoiding foods high in ellagitannins

1 week

1 visit (in-person)

Dietary Intervention

Participants consume 2 ounces of walnuts daily for 21 days while avoiding ellagitannins

3 weeks

2 visits (in-person)

Follow-up

Participants are monitored for changes in microbiome and inflammatory markers, and undergo a colonoscopy

1 week

1 visit (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• Walnuts

Trial Overview The study investigates if eating walnuts affects gut bacteria populations and reduces inflammation in the colon lining. Participants will consume two ounces of walnuts every day for three weeks while avoiding specific foods that could influence the results.

How Is the Trial Designed?

Group I: Walnut Consumption Experimental Treatment 1 Intervention

Following enrollment, participants will start a 7-day wash-out period where they will be asked to avoid foods and beverages high in ellagitannins. These include pomegranates, hazelnuts, pistachios, walnuts (besides the samples given by the researchers), strawberries, raspberries, blackberries, oak-aged wines and spirits; a full list of foods and beverages to avoid will be provided. Then, participants will consume 2 ounces of walnuts daily with their usual diet while continuing to avoid ellagitannins for 21 days prior to their routine colonoscopy.

Who Is Running the Clinical Trial?

UConn Health

Lead Sponsor

Trials

218

Recruited

59,100+

The Jackson Laboratory for Genomic Medicine

Collaborator

Trials

1

Recruited

200+

National Institutes of Health (NIH)

Collaborator

Trials

2,896

Recruited

8,053,000+

Weill Medical College of Cornell University

Collaborator

Trials

1,103

Recruited

1,157,000+

California Walnut Commission

Collaborator

Trials

25

Recruited

36,700+

Spanish National Research Council

Collaborator

Trials

10

Recruited

550+

University of Florida

Collaborator

Trials

1,428

Recruited

987,000+

National Cancer Institute (NCI)

Collaborator

Trials

14,080

Recruited

41,180,000+

University of Connecticut

Collaborator

Trials

194

Recruited

162,000+

Published Research Related to This Trial

Walnut phenolic extract (WPE) significantly reduces inflammation in both acute and chronic colitis models in mice, indicating its potential as a treatment for inflammatory bowel disease.

WPE not only inhibits key inflammatory markers and signaling pathways but also reduces tumor development in a model of colitis-associated colon cancer, suggesting its efficacy in preventing cancer related to intestinal inflammation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Walnut phenolic extract inhibits nuclear factor kappaB signaling in intestinal epithelial cells, and ameliorates experimental colitis and colitis-associated colon cancer in mice. Koh, SJ., Choi, YI., Kim, Y., et al.[2020]

Dietary supplementation with walnuts significantly reduced colonic mucosal injury in mice after exposure to the ulcerogenic agent dextran sodium sulfate (DSS), with the most notable effect observed at a 14% walnut diet, showing a reduction in ulceration from 7.5% to 0.3%.

Metabolite profiling revealed that walnut supplementation increased levels of beneficial compounds like polyunsaturated fatty acids (PUFAs) and S-adenosylhomocysteine (SAH), which may play a role in protecting against inflammation and promoting recovery from colonic injury.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dietary Walnut Supplementation Alters Mucosal Metabolite Profiles During DSS-Induced Colonic Ulceration. Nakanishi, M., Matz, A., Klemashevich, C., et al.[2020]

Walnut oil (WO) significantly improved gut health in mice by increasing the villous height/crypt depth ratio and enhancing antioxidant enzyme activities, indicating its potential to reduce oxidative stress and inflammation.

The study found that WO shifted gut microbiota from harmful bacteria like Helicobacter to beneficial ones like Lactobacillus, while also boosting immune responses, suggesting its role in preventing gastrointestinal diseases.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of walnut (Juglans sigillata) oil on intestinal antioxidant, anti-inflammatory, immunity, and gut microbiota modulation in mice. Miao, F., Shan, C., Shah, SAH., et al.[2021]

The study identified Jug r 4 as a relevant minor allergen in walnut allergy, recognized by 27% of walnut allergic adults, indicating its importance in diagnosing walnut allergy.

Jug r 4 showed a high positive predictive value of 90% for walnut allergy, suggesting that testing for this allergen could improve diagnostic accuracy, especially in patients with co-sensitization to other allergens.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A subset of walnut allergic adults is sensitized to walnut 11S globulin Jug r 4. Blankestijn, MA., den Hartog Jager, CF., Blom, WM., et al.[2019]

Walnut oil (WO) has protective effects against acute intestinal injury in mice, as shown by reduced levels of inflammatory markers like TNF-α, IL-6, and IL-1β after treatment with WO following lipopolysaccharide (LPS) exposure.

The protective mechanism of walnut oil involves the inhibition of the TLR4/NF-κB signaling pathway, leading to decreased apoptosis in jejunum cells and improved antioxidant levels, indicating its potential as a therapeutic dietary supplement.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The protective effect of walnut oil on lipopolysaccharide-induced acute intestinal injury in mice. Miao, F., Shan, C., Shah, SAH., et al.[2021]

Walnuts are rich in beneficial compounds like polyunsaturated fatty acids, tocopherols, and ellagitannins, which may help reduce cancer risk and promote a healthy gut microbiome.

The ellagitannins in walnuts are converted by gut bacteria into bioactive compounds called urolithins, which have strong anti-inflammatory properties, supporting the idea that walnuts can be a valuable part of a cancer-preventive diet.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Antioxidant and Anti-Inflammatory Properties of Walnut Constituents: Focus on Personalized Cancer Prevention and the Microbiome. Fan, N., Fusco, JL., Rosenberg, DW.[2023]

The study evaluated 12 different walnut cultivars, revealing that total oil content ranged from 62.6% to 70.3%, indicating a high fat content beneficial for heart health.

All cultivars exhibited a similar amino acid profile, suggesting they provide high-quality protein, which is important for overall nutrition.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Chemical composition of walnuts (Juglans regia L.) grown in New Zealand. Savage, GP.[2019]

In a study involving 45 individuals at risk for cardiovascular disease, a walnut diet led to a significant reduction in central diastolic blood pressure compared to a diet where walnut-derived ALA was replaced with oleic acid, suggesting that whole walnuts may provide unique cardiovascular benefits beyond just their fatty acid content.

All diets tested, including the walnut diet, resulted in lowered total cholesterol and LDL cholesterol levels, indicating that moderate-fat, high-unsaturated-fat diets can improve overall cardiovascular risk factors.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Replacing Saturated Fat With Walnuts or Vegetable Oils Improves Central Blood Pressure and Serum Lipids in Adults at Risk for Cardiovascular Disease: A Randomized Controlled-Feeding Trial. Tindall, AM., Petersen, KS., Skulas-Ray, AC., et al.[2021]

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]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11357266/

Regulation of Intestinal Inflammation by Walnut-Derived ... The results revealed that a diet enriched with walnut oil led to an improvement in the damage score within the inflamed colon, notably restoring ...

2. ecancer.org ecancer.org/en/news/26356-walnut-consumption-curbs-inflammation-and-colon-cancer-risk

Walnut consumption curbs inflammation and colon cancer ... “Our study proves that dietary supplementation with walnuts can boost the general population's urolithin levels in those people with the right ...

3. clinicaltrials.gov clinicaltrials.gov/study/NCT05195970

Study Details | NCT05195970 | Walnuts and Colon Health The purpose of this research study is to examine whether adding walnuts to your diet can have a beneficial effect on the gut bacteria population, ...

4. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9317913/

The Role of Nut and Seed Consumption in Colorectal Cancer Both disease-free survival and overall survival in stage III CRC patients were significantly improved with tree nut consumption increase, [23].

5. aacrjournals.org aacrjournals.org/cancerpreventionresearch/article/9/8/692/50550/Effects-of-Walnut-Consumption-on-Colon

Effects of Walnut Consumption on Colon Carcinogenesis and ... Overall, these results indicate that walnut supplementation may suppress both colon tumor initiation and promotion when consumed at lower concentrations, but ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10215340/

Antioxidant and Anti-Inflammatory Properties of Walnut ... The results indicate that walnuts afford partial protection to the colon against potent carcinogenic insult, due in part to the ability of ...

7. sciencedirect.com sciencedirect.com/science/article/pii/S1756464624002949

Astounding the synergistic interplay of walnuts in ... Walnut, also known as Juglans Regia L. is a valuable nut that can significantly reduce OS and inflammation. Walnut contains a considerable amount of ...

8. researchgate.net researchgate.net/publication/394407355_Walnut's_Role_in_the_Prevention_of_Colon_and_Breast_Cancer

Walnut's Role in the Prevention of Colon and Breast Cancer Furthermore, 4) walnuts were observed to slow the progression of prostate, colon, and kidney cancers through mechanisms that inhibit cell ...