Walnuts for Prostate Cancer

Recruiting at 1 trial location

Overseen by Stephen Freedland, MD

Age: 18+

Sex: Male

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Phase 2

Recruiting

Sponsor: Stephen Freedland

Must not be taking: Hormone therapy, Antiandrogens, 5-alpha reductase inhibitors

Disqualifiers: Nut allergy, Other active malignancy, others

No Placebo Group

Prior Safety Data

Trial Summary

What is the purpose of this trial?

This is a randomized control trial testing the effect of walnut supplementation on prostate cancer progression in 50 men with biopsy confirmed prostate cancer and planning to undergo RP. Patients consented to the study will be randomly assigned to either continue their usual diets (control arm) or to the walnut arm for 4-10 weeks depending on the window between their consent date and the date for RP.

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've used certain prostate medications recently or are on a diet program with omega-3 supplements.

What data supports the effectiveness of the treatment Walnuts for Prostate Cancer?

Research shows that a diet enriched with walnuts can slow the growth of prostate cancer tumors in mice, reducing both the number and size of tumors compared to a standard diet. This suggests that walnuts might have beneficial effects on prostate cancer, possibly due to their various bioactive compounds. ^{1 2 3 4 5}

Is it safe for humans to consume walnuts?

Walnuts are generally safe for human consumption and are associated with health benefits like reduced risk of heart disease. However, specific safety data for walnuts in the context of prostate cancer treatment in humans is not detailed in the available research. ^{1 2 3 5 6}

How does the walnut treatment for prostate cancer differ from other treatments?

The walnut treatment for prostate cancer is unique because it involves using a natural food source, walnuts, which are rich in nutrients and antioxidants, rather than traditional medical treatments like surgery or hormone therapy. This approach focuses on dietary intervention, which is not a standard treatment for prostate cancer. ^{7 8 9 10 11}

Research Team

Stephen Freedland, MD

Principal Investigator

Cedars-Sinai Medical Center

Eligibility Criteria

Men over 18 with confirmed prostate cancer (Gleason score ≥7) who read and understand English, are planning to undergo radical prostatectomy, and can eat walnuts. Excluded are those with nut allergies, hormone therapy history, recent use of certain drugs for prostate issues, prior prostate treatments, serious other diseases or conditions affecting protocol adherence.

Inclusion Criteria

Willing to adhere to a usual diet with the possible addition of 2 oz of walnuts per day

My biopsy shows a grade group 2 or higher.

I am planning to have prostate removal surgery.

Exclusion Criteria

I have used 5-alpha reductase inhibitors in the last 6 months.

Individuals with psychological/mental conditions which can affect the consent process and/or their adherence to the protocol

I have had radiation or cryotherapy for prostate cancer.

Trial Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants are randomized to either continue their usual diets or add 2 ounces of walnuts daily for 4-10 weeks

4-10 weeks

Baseline visit in conjunction with standard of care post-biopsy, final visit prior to RP

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

Treatment Details

Interventions

• Walnuts (Cancer Preventive Agent)

Trial Overview The trial is examining if eating walnuts affects the progression of prostate cancer in men awaiting surgery. Participants will either continue their normal diet or add 2 oz of walnuts daily for 4-10 weeks before their operation. They'll be randomly assigned to one of these two groups.

Participant Groups

Group I: Usual Diet + Walnuts Experimental Treatment 3 Interventions

Usual diet with the addition of two ounces of walnuts daily, phone counseling with dietitian, for 4-10 weeks

Group II: Usual Diet Active Control 1 Intervention

Usual diet for 4-10 weeks

Who Is Running the Clinical Trial?

Stephen Freedland

Lead Sponsor

Trials

2

Recruited

190+

California Walnut Commission

Collaborator

Trials

25

Recruited

36,700+

Findings from Research

A diet supplemented with walnuts significantly reduced the establishment and growth of LNCaP human prostate cancer cells in nude mice, with only 18.7% of walnut-fed mice developing tumors compared to 44.0% in the control group.

The average tumor size in walnut-fed mice was about one-fourth that of the control diet mice, indicating that walnuts may slow tumor growth effectively.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A walnut-enriched diet reduces the growth of LNCaP human prostate cancer xenografts in nude mice. Reiter, RJ., Tan, DX., Manchester, LC., et al.[2021]

In a 12-month randomized crossover study involving 40 middle-aged men, consuming an average of 35 grams of walnuts daily did not significantly change serum prostate-specific antigen (PSA) levels compared to a control diet.

The findings indicate that short-term walnut consumption is unlikely to negatively impact PSA levels, suggesting it is safe for prostate health in otherwise normal men.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Lack of effect of walnuts on serum levels of prostate specific antigen: a brief report. Simon, JA., Tanzman, JS., Sabaté, J.[2019]

In a study of 47,299 men over 26 years, nut consumption was not linked to the incidence of prostate cancer (PCa) or PCa-specific mortality.

However, men who ate nuts five or more times a week after being diagnosed with PCa had a 34% lower overall mortality rate compared to those who consumed nuts less than once a month, suggesting potential benefits of nut consumption for overall health post-diagnosis.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Nut consumption and prostate cancer risk and mortality. Wang, W., Yang, M., Kenfield, SA., et al.[2019]

In a study using the TRAMP mouse model, a high-fat diet containing whole walnuts significantly reduced prostate tumor weight and growth rate compared to a high-fat diet with soybean oil, despite both diets having the same total fat content.

The beneficial effects of the walnut diet on prostate cancer are likely due to the complex mixture of compounds in whole walnuts rather than a specific type of fat or tocopherol, indicating that dietary composition matters in cancer progression.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A high-fat diet containing whole walnuts (Juglans regia) reduces tumour size and growth along with plasma insulin-like growth factor 1 in the transgenic adenocarcinoma of the mouse prostate model. Davis, PA., Vasu, VT., Gohil, K., et al.[2022]

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]

A study of 1459 men aged 55-74 with newly diagnosed localized prostate cancer from 1983-1987 revealed significant excess mortality and a notable loss of life expectancy during this period.

The routine treatment approach at the time, which primarily involved observation and endocrine therapy only if the cancer progressed, may have contributed to these poor survival outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Localized prostatic cancer. Survival and loss of life expectancy]. Brasso, K., Friis, S., Juel, K., et al.[2006]

In a study of 248 patients in Taiwan undergoing radical cystoprostatectomy for bladder cancer, the incidence of incidental prostate cancer was found to be 4.03%, with most cases being at early stages (T1 or T2).

This rate is lower than what has been reported in similar studies from the USA, suggesting that while the incidence is not high, screening methods like digital rectal exams and PSA tests are still important for older men with bladder cancer.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Synchronous primary carcinomas of the bladder and prostate. Lee, SH., Chang, PL., Chen, SM., et al.[2006]

References

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

A walnut-enriched diet reduces the growth of LNCaP human prostate cancer xenografts in nude mice. [2021]

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

Lack of effect of walnuts on serum levels of prostate specific antigen: a brief report. [2019]

3. England pubmed.ncbi.nlm.nih.gov

Nut consumption and prostate cancer risk and mortality. [2019]

4. England pubmed.ncbi.nlm.nih.gov

A high-fat diet containing whole walnuts (Juglans regia) reduces tumour size and growth along with plasma insulin-like growth factor 1 in the transgenic adenocarcinoma of the mouse prostate model. [2022]

5. Germany pubmed.ncbi.nlm.nih.gov

Urolithin A causes p21 up-regulation in prostate cancer cells. [2018]

6. 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]

7. Denmark pubmed.ncbi.nlm.nih.gov

[Localized prostatic cancer. Survival and loss of life expectancy]. [2006]

8. Brazil pubmed.ncbi.nlm.nih.gov

Prevalence of prostate adenocarcinoma according to race in an university hospital. [2019]

9. England pubmed.ncbi.nlm.nih.gov

Changing presentation of prostate cancer in a UK population--10 year trends in prostate cancer risk profiles in the East of England. [2021]

10. England pubmed.ncbi.nlm.nih.gov

Screening by lower urinary tract symptoms vs asymptomatic prostate-specific antigen levels leading to radical prostatectomy in Danish men: tumour characteristics and treatment outcome. [2009]

11. China pubmed.ncbi.nlm.nih.gov

Synchronous primary carcinomas of the bladder and prostate. [2006]