Dietary Interventions for Cancer Prevention

Recruiting at 1 trial location

Overseen By Patricia G Wolf, PhD, RD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Purdue University

Must not be taking: Antibiotics, Illicit drugs, Supplements, others

Disqualifiers: Cancer, Organ transplant, Obesity, others

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

Compensation: Varies

Number of Visits: 10

40 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to determine if altering the amount of cysteine (an amino acid) in the diet can affect gut health and inflammation. Researchers are particularly interested in comparing how Black and White participants process cysteine, which is found in certain foods. Participants will alternate between diets high in cysteine (High Cysteine Diet) and low in cysteine (Low Cysteine Diet) to observe the effects on their health. Ideal candidates are aged 45-75, identify as Black or Non-Hispanic White, and have a history of non-cancerous polyps. As an unphased trial, this study provides a unique opportunity to contribute to groundbreaking research on dietary impacts on health.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. However, it does exclude participants who have used antibiotics, illicit drugs, or dietary supplements recently, so you may need to discuss your specific medications with the trial organizers.

Is there any evidence suggesting that this trial's dietary interventions are likely to be safe?

In a previous study, researchers examined diets high in cysteine, commonly found in animal proteins, to assess their potential in treating cancer. However, little direct evidence exists regarding the safety of these diets for humans or their possible side effects. Most research has focused on cysteine's effects on cancer cells in the lab, rather than its safety for humans.

Conversely, studies on diets low in cysteine, which rely more on plant proteins, indicate they might lead to significant weight loss. One study reported up to a 30% weight loss with reduced cysteine intake, suggesting the diet can strongly affect the body. However, there was no clear evidence of harmful side effects on organs or overall health.

Overall, these findings suggest that both high and low cysteine diets have been studied for their effects, but limited safety data exists for humans. Participants should consider this when deciding to join the trial. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about these dietary interventions for cancer prevention because they explore how altering cysteine levels in the diet might impact cancer risk. Unlike typical cancer prevention strategies that often involve medications or supplements, these interventions focus on dietary changes using natural sources of protein. The high cysteine diet emphasizes animal-based proteins, while the low cysteine diet relies on more plant-based proteins. This approach could offer a more accessible and less invasive option for individuals looking to reduce their cancer risk through everyday food choices.

What evidence suggests that this trial's dietary interventions could be effective for cancer prevention?

This trial will compare a high cysteine diet with a low cysteine diet. Research has shown that foods high in cysteine might help the gut heal and stay healthy. However, cysteine also helps cancer cells survive under stress. Conversely, eating less cysteine might aid in weight loss and could even lead to the death of cancer cells. Studies suggest that a low-cysteine diet might reduce inflammation and weaken cancer cells. Both dietary approaches offer promising but different health benefits. ^{1 3 6 7 8}

Are You a Good Fit for This Trial?

This trial is for Black and Non-Hispanic White individuals aged 45-75 who have a history of non-cancerous polyps, suggesting a higher risk of colorectal cancer. Participants must be willing to provide oral, stool samples, complete dietary recalls, and be up-to-date with colonoscopy screenings.

Inclusion Criteria

I identify as either Black or Non-Hispanic White.

I am willing to record everything I eat for 24 hours.

I am willing to provide samples of my saliva and stool.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2 weeks

1 visit (in-person)

Dietary Adjustment

Participants consume a moderate cysteine diet for 1 week before each study diet

2 weeks

2 visits (in-person)

High Cysteine Diet

Participants consume a high cysteine diet for 3 weeks

3 weeks

3 visits (in-person)

Low Cysteine Diet

Participants consume a low cysteine diet for 3 weeks

3 weeks

3 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

1 week

1 visit (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• High Cysteine Diet
• Low Cysteine Diet

Trial Overview The study tests the effects of high and low cysteine diets on cortisol levels, gut bacteria activity related to cysteine metabolism, and inflammation in the gut. Over 11 weeks, participants will switch between these diets while providing biological samples and maintaining food logs.

How Is the Trial Designed?

Group I: Low cysteine diet Experimental Treatment 1 Intervention

Participants will eat a diet lower in cysteine, relying on more plant based protein.

Group II: High cysteine diet Experimental Treatment 1 Intervention

Participants will eat a diet higher in cysteine, relying on more animal based protein.

Who Is Running the Clinical Trial?

Purdue University

Lead Sponsor

Trials

239

Recruited

72,200+

Indiana University

Collaborator

Trials

1,063

Recruited

1,182,000+

American Cancer Society, Inc.

Collaborator

Trials

237

Recruited

110,000+

Citations

1. news.mit.edu news.mit.edu/2025/cysteine-rich-diet-may-promote-intestinal-lining-regeneration-study-suggests-1001

A cysteine-rich diet may promote regeneration ... - MIT News A diet rich in the amino acid cysteine may have rejuvenating effects in the small intestine, according to a new study from MIT.

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7921671/

Cysteine metabolic circuitries: druggable targets in cancer Cysteine is also essential for the ability of cancer cells to evade drug exposure and cell injury and adapt to other stressful conditions such as hypoxia. As ...

3. spandidos-publications.com spandidos-publications.com/10.3892/ol.2024.14654

Cystine/cysteine metabolism regulates the progression and ... Dietary supplementation with the antioxidant n-acetylcysteine (NAC) significantly accelerated tumor growth and reduced the survival of an animal ...

4. sciencedirect.com sciencedirect.com/science/article/abs/pii/S104084282500294X

Cysteine metabolism at the crossroads of ferroptosis and ... Cysteine metabolism plays a pivotal role in ferroptosis regulation by modulating antioxidant defense, lipid peroxidation, and iron homeostasis. Cancer cells ...

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10290234/

Nutrition as prevention for improved cancer health outcomes We identified 15 unique studies examining nutrition support interventions before cancer treatment (Table 4) (23-37).

6. sciencedirect.com sciencedirect.com/science/article/pii/S0002916522045919

Prospective study of serum cysteine and cysteinylglycine ... The study reported that N-acetyl-cysteine inhibited human gastric cancer SJ-89 cell growth by inducing DNA synthesis arrest and apoptosis (41). The authors ...

7. nutritionandmetabolism.biomedcentral.com nutritionandmetabolism.biomedcentral.com/articles/10.1186/s12986-020-00439-x

Dietary restriction of amino acids for Cancer therapy Cumulating research findings show that amino acid restrictions are potential strategies for cancer interventions. Meanwhile, dietary strategies are popular ...

8. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10749912/

Science-Driven Nutritional Interventions for the Prevention ... Low-protein diets have been rarely applied to cancer patients, although the available evidence suggests that such diets reduce tumor growth in mice, an effect ...