Table of Contents
- Key Points
- Why This Research Matters
- What Hormone Therapy Does to the Body
- How the Review Was Conducted
- How the Evidence Was Graded
- The Trials at a Glance
- What the Diets, Exercises, and Supplements Achieved
- Safety and Feasibility
- Medicines Being Studied Alongside Diet
- What These Results Mean for Patients
- Limits of the Evidence
- Practical Recommendations
- What Researchers Should Study Next
- Frequently Asked Questions
- Source Information
Key Points
- A review of 13 randomized trials found diet and nutrition programs safe and feasible for men on hormone therapy for prostate cancer.
- Mediterranean-style and low-carbohydrate diets combined with exercise reduced cardiovascular and metabolic risk factors, but some benefits faded over time.
- In one trial of 30 men, creatine showed a trend toward more lean muscle mass, but the difference was not statistically significant.
- Eleven of the studies had some overall risk of bias, often because exercise and diet interventions cannot be double-blinded.
Why This Research Matters
Prostate cancer is the most common cancer in men that is not a skin cancer. It accounts for about one in three cases of cancer in men. In the United States alone, more than 3.5 million men were living as prostate cancer survivors in 2025.
Men with prostate cancer have among the highest survival rates of all cancers. Because so many men live for many years after diagnosis, managing other health conditions becomes a central part of their care. Doctors call this comorbidity management.
Two other conditions are very common in this group. Diabetes affects an estimated 590 million adults worldwide, including 39 million in the United States. Obesity affects an estimated 2 billion adults worldwide, including 170 million in the United States.
Among men with prostate cancer, nearly one-third are diagnosed with type 2 diabetes (a condition in which the body cannot properly control blood sugar) or obesity. These conditions can disrupt inflammatory, neoplastic (tumor-forming), and hormonal pathways. That disruption may in turn promote tumor growth and metastasis (cancer spread).
Advanced age remains the most influential risk factor for prostate cancer. Even so, diabetes and obesity can affect both the risk of developing prostate cancer and the quality of survival afterward.
Recent studies have shown that certain eating patterns can lower the risk that prostate cancer is reclassified to a higher-risk form. Those patterns include diets scoring high on the Healthy Eating Index and the use of fish oil capsule supplements.
Earlier reviews of diet in men treated with hormone therapy had important gaps. They did not include nutritional supplements in their search terms. They did not focus on diet alone, because they also included exercise and behavioral programs. They also looked at outcomes beyond hormone therapy side effects, such as prostate specific antigen (PSA) levels. The authors of this new review identified an unmet need for a comprehensive, current review of dietary intervention trials.
What Hormone Therapy Does to the Body
Androgen deprivation therapy (ADT), also called hormone therapy, is a mainstay of treatment for aggressive prostate cancer. ADT lowers the level of male hormones that fuel prostate cancer growth.
ADT can have wide-ranging effects on health and daily life. It can harm metabolic, cardiovascular, sexual, and cognitive (thinking and memory) function, and it can reduce quality of life.
Men who receive long-term ADT have an increased risk of several conditions. These include:
- Obesity
- Diabetes
- Coronary heart disease (narrowed or blocked heart arteries)
- Osteoporosis (weakened bones)
- Dementia (decline in memory and thinking)
- Sexual dysfunction
Men receiving ADT also have a higher incidence of diabetes. Men who already have diabetes may see their blood sugar control worsen while on treatment.
A specific cluster of problems called ADT-induced metabolic syndrome (a group of conditions that raise heart and diabetes risk) is common. This syndrome causes impaired glucose tolerance (the body handles sugar less well), loss of muscle mass, and weight gain.
Because of these effects, lifestyle changes may matter a great deal for survivorship. The authors note that diet optimization and nutritional supplements could be important ways to improve long-term outcomes.
How the Review Was Conducted
The researchers searched two large medical databases, PubMed and Embase, in August 2025. They followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, which are a standard set of rules for this type of review.
The search combined three groups of terms. The first group covered prostate cancer. The second covered nutrition, diet, nutritional interventions, and specific drug names, including glucagon-like peptide-1 receptor agonists (GLP-1RA) and agents such as semaglutide, liraglutide, exenatide, and tirzepatide. The third group covered androgen deprivation therapy and specific hormonal agents.
The team limited the search to English-language studies published in the past 10 years, from 2015 through 2025. This window was chosen to capture modern ADT use and modern GLP-1RA treatment.
To be included, a study had to meet three conditions:
- It enrolled men with prostate cancer who were undergoing ADT.
- It tested a diet or nutrition intervention.
- It measured outcomes related to ADT side effects, such as laboratory values, metabolic syndrome, fatigue, or vasomotor symptoms (hot flashes and similar symptoms).
The team excluded studies that were not randomized clinical trials (RCTs) in humans. That removed reviews, retrospective studies, and observational studies.
Two authors extracted the data using the Covidence platform, screening titles, abstracts, and full texts. Three other authors reviewed and confirmed the extracted data. For each included article, the team recorded the author, year, country, sample size, patient population, nutrition intervention, ADT side effects addressed, study arms, outcome measures, and results.
Two authors independently assessed study quality using the Risk of Bias 2 (ROB2) tool. This tool uses a set of signaling questions to judge each trial's risk of bias. A third reviewer resolved any disagreements. The team then rated the certainty of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidelines and the GRADEpro software.
How the Evidence Was Graded
The review screened 2,799 publications. Of these, 16 publications met the inclusion and exclusion criteria.
The analytic sample represented 13 unique randomized clinical trials. Sample sizes ranged from 23 to 96 patients per trial.
Two of the publications were explicitly preplanned analyses of an outcome from an RCT. Three other publications were described as exploratory, hypothesis generating, or an ancillary analysis of an original trial.
Follow-up averaged 6 months, with a range of 3 to 12 months.
On the ROB2 quality assessment, no study had a high overall risk of bias. However, 11 studies had some overall risk of bias. This concern was often attributed to deviations from the intended intervention.
One reason for that concern was blinding. Some interventions, including exercise, could not be double-blinded. As a result, it was hard to tell whether a patient's knowledge of their treatment group influenced how the primary outcome was measured.
The Trials at a Glance
The 13 trials tested a range of intervention types. Some trials tested more than one approach.
- Diet: 4 trials
- Diet curriculum or education: 9 trials
- Supplements: 5 trials
- Exercise: 14 trials
Fourteen of the trials combined exercise with either a dietary or a supplement intervention.
The trials measured many different outcomes. Physical function and performance was measured in 12 trials. Body composition was measured in several ways: fat mass in 10 trials, lean mass in 8 trials, and muscle mass in 4 trials. Dietary intake was measured in 8 trials, and health-related quality of life was measured in 7 trials.
All participants had either started ADT or were planning to start ADT for at least 3 months.
Several individual trials illustrate how varied this field is. A small Australian trial of 30 men gave 20 grams of creatine per day or a placebo for 5 days in a double-blind, randomized, placebo-controlled design. A United States trial of 38 men started an individualized nutrition and resistance exercise program within 3 months of beginning ADT. A South Korean single-blind, single-center trial of 46 men focused on metabolic syndrome in men who had received ADT for at least 6 months.
Other trials included a Dutch trial of 69 men that compared protein supplementation plus exercise with exercise alone. An Australian trial of 70 men tested a multicomponent exercise program. Two Australian trials, one with 23 men and one with 32 men, tested Mediterranean-style diets, and one of them added an exercise program.
What the Diets, Exercises, and Supplements Achieved
The review found that Mediterranean and low-carbohydrate diets combined with exercise reduced cardiovascular and metabolic risk factors. The durability of those benefits varied from study to study. In other words, some improvements faded over time.
Creatine supplementation trended toward increasing lean muscle mass. A trend means the result moved in a promising direction but did not reach statistical significance.
Multidisciplinary care improved accountability and the durability of outcomes. Community involvement had a similar effect. Multidisciplinary care means a team of different health professionals working together with the patient.
Some specific trial results stood out in the review:
- A trial of 38 men in the United States reported significant decreases in total cholesterol, LDL cholesterol, and HDL cholesterol. These decreases occurred after an individualized nutrition and resistance exercise program began within 3 months of starting ADT (effect size d = -0.39).
- A trial of 46 men in South Korea used health coaching in a metabolic syndrome program. Participants improved their fasting blood sugar, waist circumference, body composition, and blood pressure, and they reduced abdominal fat.
- A trial of 69 men in the Netherlands compared protein supplementation plus exercise with exercise alone. Total fat mass and fat percentage increased in the control group, while the intervention group did not show the same increase (partial eta-squared values of 0.172 and 0.145).
- Mediterranean-style diet trials in Australia measured body composition, lean mass, fat mass, and cardiovascular fitness, and the interventions were compared with usual care.
- Creatine supplementation in the Australian trial was associated with a trend toward more whole-body lean mass, and the trial found no significant increase in fat mass.
Across the trials, nutrition and exercise programs were studied for their effects on metabolic laboratory values, body composition, and quality of life. The outcomes varied widely across the 13 trials, and so did the size of the benefits.
Safety and Feasibility
The review concluded that the nutritional interventions studied were safe and feasible. Feasible means that patients could realistically follow the program.
Several trials reported on how well patients could take part. One trial measured whether patients could travel to a worksite for telephone counseling, and it also assessed whether patients could follow accompanying eating guidelines.
One trial reported that, overall, the program was feasible and acceptable to participants. Another trial documented the ability of patients to attend exercise sessions and complete the assigned training.
These details matter for patients. A diet or exercise plan only helps if a patient can actually carry it out in daily life.
Medicines Being Studied Alongside Diet
Diet is not the only approach under study for the metabolic side effects of ADT. Researchers are also testing drugs that treat metabolic syndrome in men with prostate cancer.
The STAMPEDE trial provides one important example. Arm K of STAMPEDE compared standard of care with metformin against standard of care without metformin. The participants were non-diabetic men with high-risk locally advanced or metastatic hormone-sensitive prostate cancer who were undergoing ADT.
In that trial, the adverse side effects of ADT, including weight gain and dyslipidemia (abnormal blood fat levels), were significantly reduced with metformin.
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are another class of drugs of growing interest. These drugs are incretin mimetics, which means they mimic a gut hormone that affects insulin and appetite. Doctors increasingly prescribe GLP-1RAs to manage several parts of metabolic syndrome, including type 2 diabetes and obesity.
Emerging evidence suggests that GLP-1RAs are associated with an estimated 20% to 50% relative risk reduction in prostate cancer diagnosis. The study did not report the absolute rate of prostate cancer diagnosis, so it is not possible to say how many men this represents in a given group.
Because GLP-1RAs are effective for weight management and for maintaining glucose homeostasis (stable blood sugar), the review authors consider them a compelling target for research in prostate cancer survivorship. Notably, no randomized clinical trial in this review evaluated a GLP-1RA.
What These Results Mean for Patients
This review offers encouraging news for men receiving hormone therapy for prostate cancer. Nutritional interventions appear to be safe, feasible, and worth discussing as part of treatment and survivorship care.
The strongest signal came from programs that combined eating changes with physical activity. Mediterranean-style diets and low-carbohydrate diets, paired with exercise, reduced cardiovascular and metabolic risk factors in several trials.
One caveat is durability. Some benefits faded during follow-up, which averaged 6 months. This suggests that ongoing support may be needed to maintain improvements.
Another important message is the value of a team. Trials that used multidisciplinary care and community involvement reported better accountability and more durable outcomes. For patients, this means that dietitians, exercise specialists, and other clinicians may all play a role in care.
The review found no evidence from randomized trials on GLP-1RAs in this population. Patients who are interested in these medicines should understand that the evidence in prostate cancer and ADT is still emerging.
Limits of the Evidence
The review has several limitations that patients and clinicians should keep in mind. Acknowledging them helps put the findings in context.
- No included trial evaluated a GLP-1RA, so the review cannot draw conclusions about that drug class.
- The evidence base was small: 13 unique randomized clinical trials, with 23 to 96 patients per trial.
- Follow-up was short, averaging 6 months and ranging from 3 to 12 months. Long-term effects remain unknown.
- Eleven studies had some overall risk of bias, often because of deviations from the intended intervention.
- Exercise and diet interventions cannot be double-blinded. Patients knew which program they were in, which may have influenced some measurements.
- Benefits were variable in how long they lasted, which limits conclusions about sustained benefit.
- The trials studied many different diets, supplements, and outcomes, so their results cannot easily be combined into one clear answer.
Two publications were preplanned analyses of a single RCT outcome, and three were exploratory, hypothesis generating, or ancillary analyses. These types of analyses provide weaker evidence than a preplanned primary trial outcome.
Practical Recommendations
Based on the review findings, the authors support nutritional interventions as part of prostate cancer treatment and survivorship. The following points summarize the practical takeaways.
- Ask your care team about a Mediterranean-style or low-carbohydrate eating pattern. These diets were associated with reduced cardiovascular and metabolic risk factors when paired with exercise.
- Combine eating changes with physical activity. Fourteen of the included trials combined exercise with a diet or supplement program.
- Expect to need ongoing support. Benefits were variable in how long they lasted, so long-term follow-up and continued coaching may help.
- Ask about a multidisciplinary team. Reviews of the trials found that team-based care and community involvement improved accountability and outcome durability.
- Talk with your clinician before starting any supplement, including creatine. Creatine showed a trend toward more lean muscle mass, but the difference was not statistically significant.
- Discuss metabolic and cardiovascular health at every visit. ADT raises the risk of obesity, diabetes, coronary heart disease, osteoporosis, dementia, and sexual dysfunction.
- If you have diabetes, monitor your blood sugar closely during ADT. Existing diabetes control can worsen with treatment.
- Ask whether GLP-1RA therapy is appropriate for you, while understanding that no randomized trial has yet tested it in this setting.
What Researchers Should Study Next
The review authors made several recommendations for future randomized clinical trials. These recommendations aim to fill the gaps identified in the current evidence.
- Determine the optimal duration of a dietary intervention.
- Extend follow-up beyond the current average of 6 months.
- Include multidisciplinary patient support as part of the trial design.
- Test novel anti-metabolic therapies, such as GLP-1 receptor agonists.
The STAMPEDE metformin results and the emerging GLP-1RA evidence suggest that drug therapy for metabolic side effects could complement diet and exercise. Randomized trials will be needed to confirm any benefit in men receiving ADT.
Future studies should also address blinding and adherence, since these issues contributed to the "some risk of bias" ratings in 11 of the included studies.
Frequently Asked Questions
I'm starting hormone therapy for prostate cancer. Can changing my diet actually help?
A review of 13 randomized trials found that Mediterranean-style and low-carbohydrate diets combined with exercise reduced cardiovascular and metabolic risk factors in men receiving hormone therapy. The interventions were safe and feasible, meaning patients could realistically follow them. However, some benefits faded over time, so ongoing support may be needed to maintain improvements.
What side effects does hormone therapy cause that diet might address?
Hormone therapy, also called androgen deprivation therapy, can harm metabolic, cardiovascular, sexual, and cognitive function and reduce quality of life. It raises the risk of obesity, diabetes, coronary heart disease, osteoporosis, dementia, and sexual dysfunction. A specific cluster called ADT-induced metabolic syndrome causes impaired glucose tolerance, loss of muscle mass, and weight gain. Diet and exercise programs in the reviewed trials targeted these metabolic and cardiovascular risk factors.
Does creatine supplementation build muscle during hormone therapy?
In one small Australian trial of 30 men, creatine supplementation showed a trend toward increasing whole-body lean muscle mass, but the difference was not statistically significant. A trend means the result moved in a promising direction but did not reach statistical significance. The trial found no significant increase in fat mass. Talk with your clinician before starting any supplement, including creatine.
How long do the benefits of diet and exercise last during hormone therapy?
In the reviewed trials, follow-up averaged 6 months, with a range of 3 to 12 months. Some improvements in cardiovascular and metabolic risk factors faded over time, so the durability of benefits varied from study to study. This suggests that ongoing support, such as continued coaching, may be needed to maintain improvements. Long-term effects remain unknown.
What does it mean that 11 studies had 'some overall risk of bias'?
It means the trials had concerns that could affect how results were measured, often due to deviations from the intended intervention. One reason was blinding: exercise and diet interventions cannot be double-blinded, so patients knew which program they were in. This knowledge may have influenced some measurements. No study had a high overall risk of bias, but the concern limits certainty.
Should I ask my doctor about a multidisciplinary team for my care?
Yes. Trials that used multidisciplinary care and community involvement reported better accountability and more durable outcomes. Multidisciplinary care means a team of different health professionals working together with the patient. For patients, this means dietitians, exercise specialists, and other clinicians may all play a role. Ask your care team about a Mediterranean-style or low-carbohydrate eating pattern combined with physical activity.
I'm starting hormone therapy for prostate cancer and want to try a Mediterranean diet or supplements like creatine — when should I get a second opinion?
A second opinion can help when you are weighing diet, nutrition, or supplement programs alongside androgen deprivation therapy. The evidence covers 13 randomized trials with 23 to 96 men each and about 6 months of follow-up; Mediterranean-style and low-carbohydrate diets combined with exercise reduced cardiovascular and metabolic risk factors, though benefits varied in durability, and creatine's lean-mass increase was not statistically significant. No trial tested GLP-1 receptor agonists. Discuss supplements with your clinician first. Diagnostic Detectives Network provides independent expert second opinions.
Source Information
Original article title: Diet, nutrition, and hormone therapy for prostate cancer: a systematic review with implications for future interventions.
Article type: Systematic Review
Authors: Pahulu I, Calumpit M, Tominez P, Shih JJ, Ebrahimi S, Deville NV, Samoa R, Moin T, Sedrak MS, Valle LF, Steinberg M, Kishan AU, Ganz PA, Taparra K.
Publication: JNCI Cancer Spectrum, 2026, volume 10, issue 2, article pkag014
DOI: https://doi.org/10.1093/jncics/pkag014
Advance access publication date: February 17, 2026
Author affiliations: Stanford University; University of Pennsylvania; Tripler Army Medical Center; University of California, San Francisco; David Geffen School of Medicine at UCLA; University of Nevada, Las Vegas; City of Hope; Greater Los Angeles Veterans Affairs Healthcare System; and the Fielding School of Public Health at UCLA.
Note: This patient-friendly article is based on peer-reviewed research. The original article is an Open Access publication distributed under the terms of the Creative Commons Attribution License.
