Cancer
Supplements studied for cancer.
Overview
Cancer supplement evidence in this database is broad but condition-specific effects differ sharply. Melatonin has the largest trial base (22 studies) and may improve survival or tumor response when added to chemotherapy in some advanced cancers, though cancer type and regimen matter.
Vitamin D supplementation does not clearly lower overall cancer incidence, though some research suggests a modest effect on advanced or fatal cancers at certain doses. Vitamin E does not appear to reduce cancer risk in most populations. Reishi combined with chemotherapy showed more tumor shrinkage in some Asian trials but not improved survival. See the heatmap and evidence reviews below for outcomes by cancer type and supplement.
Effect graph
Relevant supplements
Relevant supplements sorted by DEX Score.
| Melatonin | ★★★★★ | Medium |
| Magnesium | ★★★★★ | Medium |
| Vitamin D | ★★★★★ | Low |
| Panax Ginseng | ★★★★★ | Low |
| Olive Oil | ★★★★★ | Low |
| Reishi | ★★★★★ | Low |
| Alpha-Linolenic Acid | ★★★★★ | Low |
| Vitamin K | ★★★★★ | Low |
| Vitamin B9 (Folate) | ★★★★★ | Low |
| Red Yeast Rice | ★★★★★ | Low |
| Multivitamin | ★★★★★ | Very Low / None |
| Kava | ★★★★★ | Low |
| Vitamin E | ★★★★★ | Very Low / None |
| Vitamin B3 (Niacin) | ★★★★★ | Low |
| Selenium | ★★★★★ | Very Low / None |
| Apigenin | ★★★★★ | Low |
| Yerba Mate | ★★★★★ | Very Low / None |
| Resveratrol | ★★★★★ | Very Low / None |
Studies
Find individual evidence reviews for supplements sorted by DEX Score.
18 supplements for , and rated at least stars. All purchase bands. No minimum star filter.
MagnesiumView supplement →
Consider purchase·★★★★★
How we scored this▸
- There is not enough evidence to determine if magnesium has any benefit for colorectal (bowel) cancer.
Browse 4 studies·4 meta-analyses
MetaDietary Intakes of Calcium, Iron, Magnesium, and Potassium Elements and the Risk of Colorectal Cancer: a Meta-Analysis2019
A meta-analysis of 29 studies found higher dietary magnesium intake associated with 20% lower colorectal cancer risk in cohort studies (HR 0.80) and 20% lower odds in case-control studies.
- Effect
- Benefit
MetaNonlinear association between magnesium intake and the risk of colorectal cancer2013n=510
An analysis showing a nonlinear inverse relationship between magnesium intake and colorectal cancer risk, suggesting protective effects beyond certain intake thresholds. A meta-analysis of 7 prospective cohort studies including 333 510 participants and 7435 cases of colorectal cancer found that when comparing the highest vs. the lowest dietary magnesium intake, there was a 19% reduction in colorectal cancer (RR: 0.81, 95% CI: 0.70-0.92), a 24% reduction in colon cancer (RR: 0.76, 95% CI: 0.64-0.88) and an 18% reduction in rectal cancer risk (RR: 0.82, 95% CI: 0.58-1.06).
- Effect
- Benefit
- Dose
- 270 mg/day
- Population
- Adults
- Participants
- 510
MetaMagnesium intake and colorectal tumor risk: a case-control study and meta-analysis2012
A combined case-control study and meta-analysis found each 100 mg/day increase in dietary magnesium associated with 13% lower colorectal adenoma risk and 12% lower colorectal cancer risk.
- Effect
- Benefit
- Dose
- 100 mg/day
MetaMagnesium intake and risk of colorectal cancer: a meta-analysis of prospective studies2012n=338,979
A meta-analysis of prospective cohort studies showing an inverse association between dietary magnesium intake and colorectal cancer risk. A meta-analysis of 8 large prospective studies found that the summary relative risk for the highest vs lowest category of magnesium intake for colorectal cancer was 0.89 (95% CI, 0.79-1.00). There was a greater reduction in risk of colon cancer (Pooled relative risk of 0.81; 95% CI, 0.70-0.93) compared to rectal cancer (0.94; 95% CI, 0.72-1.24) from higher magnesium intake. Dose-response analyses showed that increased magnesium intake of 50 mg/day reduced co
- Effect
- Benefit
- Dose
- 50 mg/day
- Participants
- 338,979
MelatoninView supplement →
Consider purchase·★★★★★
How we scored this▸
- Research suggests that melatonin, when taken along with cancer treatments such as chemotherapy, may help improve survival and reduce tumor growth in some cancers, including breast, lung, kidney, liver, pancreatic, stomach, and colon cancer. In patients with advanced cancers, adding melatonin to chemotherapy improved survival rates compared to chemotherapy alone. Melatonin has also been reported to reduce side effects of chemotherapy, such as tiredness, nerve pain, poor appetite, and blood-related complications.
- Some smaller studies suggest that melatonin on its own may help slow down disease progression in people with certain hard-to-treat cancers, including lung, liver, pancreatic, breast, colon, or brain cancers. In patients with brain tumors such as glioblastoma, melatonin given with radiation was found to extend survival, although this benefit was not seen in patients with brain metastases.
- Most studies used melatonin doses between 10–40 mg daily. In one study, patients received melatonin by injection for two months, then switched to oral use.
Browse 22 studies·5 meta-analyses
MetaInfluence of melatonin supplementation on cancer-related fatigue: a meta-analysis of randomized controlled trials2024
A meta-analysis of 9 RCTs found melatonin modestly reduced cancer-related fatigue (SMD −0.23), with significant benefit only in studies lasting ≥13 weeks.
- Effect
- Benefit
- Population
- Cancer patients
RCTMelatonin Aids in Treating Mood and Sleep Problems Resulting from Hormonal Therapy in Breast Cancer Patients: A Randomized, Double-Blinded, Placebo-Controlled Trial2024n=60
A 4-week RCT of 60 breast cancer patients on hormonal therapy found 6 mg/day melatonin significantly improved PSQI sleep quality scores but did not significantly reduce depression or mood disorder scores.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 6 mg
- Population
- Adults
- Participants
- 60
RCTThe Effect of Melatonin Supplementation on Cancer-Related Fatigue during Chemotherapy Treatment of Breast Cancer Patients: A Double-Blind, Randomized Controlled Study2024n=26
A 3-month RCT of 49 breast cancer patients on chemotherapy found 1 mg/day melatonin plus Mediterranean diet reduced cancer-related fatigue and BMI vs placebo, though between-group CRF differences were not significant.
- Effect
- Benefit
- Duration
- 3 months
- Dose
- 1 mg/day
- Population
- Women
- Participants
- 26
- Avg age
- ~52
RCTA Randomized, Controlled, Parallel-Group, Trial on the Long-term Effects of Melatonin on Fatigue Associated With Breast Cancer and Its Adjuvant Treatments2023n=34
A 2-year RCT of 92 breast cancer patients found 18 mg/day melatonin significantly reduced fatigue scores (5.72 to 1.99 vs 5.56 to 2.93 on placebo) during and after adjuvant treatment.
- Effect
- Benefit
- Dose
- 18 mg/day
- Population
- Women
- Participants
- 34
MetaEffect of melatonin on quality of life and symptoms in patients with cancer: a systematic review and meta-analysis of randomised controlled trials2022n=2,101
A meta-analysis of 19 RCTs (2,101 cancer patients) found melatonin significantly reduced stomatitis rate (RR 0.47) and eased depression with >14 days of use, but showed no significant overall effect on QoL, sleep, or fatigue.
- Effect
- Benefit
- Population
- Adults
- Participants
- 2,101
RCTEffects of melatonin on physical fatigue and other symptoms in patients with advanced cancer receiving palliative care: A double-blind placebo-controlled crossover trial2015n=72
A crossover RCT of 72 palliative cancer patients found 20 mg/day melatonin for 1 week did not significantly improve physical fatigue or other symptom measures vs placebo.
- Effect
- No Benefit
- Duration
- 1 week
- Dose
- 20 mg/day
- Population
- ALL patients
- Participants
- 72
- Ages
- 18+
RCTMelatonin as adjuvant cancer care with and without chemotherapy: a systematic review and meta-analysis of randomized trials2012
A systematic review and meta-analysis found melatonin improved 1-year survival and tumor response in solid cancers with and without chemotherapy, while reducing treatment toxicity.
- Effect
- Benefit
RCTThe efficacy and safety of melatonin in concurrent chemotherapy or radiotherapy for solid tumors: a meta-analysis of randomized controlled trials2012
A meta-analysis of RCTs found melatonin alongside chemotherapy or radiotherapy improved tumor response rates and reduced treatment-related side effects without significant safety concerns.
- Effect
- Benefit
RCTRandomized phase II trial of high-dose melatonin and radiation therapy for RPA class 2 patients with brain metastases (RTOG 0119)2007
A phase II RCT in brain metastases patients (RPA class 2) found high-dose melatonin added to whole-brain radiotherapy did not improve survival vs radiotherapy alone, though it was well tolerated.
- Effect
- No Benefit
- Population
- Cancer patients
RCTMelatonin in the treatment of cancer: a systematic review of randomized controlled trials and meta-analysis2005
A systematic review and meta-analysis of randomized trials found melatonin improved 1-year survival, enhanced tumor remission rates, and reduced chemotherapy side effects across several solid tumor types.
- Effect
- Benefit
RCTDecreased toxicity and increased efficacy of cancer chemotherapy using the pineal hormone melatonin in metastatic solid tumour patients with poor clinical status1999
An RCT in metastatic solid tumor patients with poor performance status found adding melatonin to chemotherapy improved response rates and reduced toxicity vs chemotherapy alone.
- Effect
- Benefit
- Population
- Cancer patients
RCTBiotherapy with the pineal immunomodulating hormone melatonin versus melatonin plus aloe vera in untreatable advanced solid neoplasms1998
A randomized study in advanced untreatable solid tumors found melatonin plus aloe vera extract improved tumor stabilization and survival more than melatonin alone.
- Effect
- Benefit
RCTA randomized study of chemotherapy with cisplatin plus etoposide versus chemoendocrine therapy with cisplatin, etoposide and the pineal hormone melatonin as a first-line treatment of advanced non-small cell lung cancer patients in a poor clinical state1997
An RCT in advanced NSCLC patients with poor performance status found adding melatonin to cisplatin-etoposide improved tumor response, 1-year survival, and reduced chemotherapy toxicity.
- Effect
- Benefit
- Population
- Cancer patients
Clinical trialA phase II study of tamoxifen plus melatonin in metastatic solid tumour patients1996n=25
A phase II study of 25 metastatic solid tumor patients found tamoxifen plus 20 mg/day melatonin produced partial responses in 12% and stable disease in 52%, with improved performance status.
- Effect
- Benefit
- Dose
- 20 mg/day
- Population
- Cancer patients
- Participants
- 25
- Ages
- 38–81
RCTIncreased survival time in brain glioblastomas by a radioneuroendocrine strategy with radiotherapy plus melatonin compared to radiotherapy alone1996n=30
An RCT of 30 glioblastoma patients found melatonin plus radiotherapy increased 1-year survival (6/14 vs 1/16) and was well tolerated vs radiotherapy alone.
- Effect
- Benefit
- Dose
- 30 g/day
- Population
- Cancer patients
- Participants
- 30
Controlled trialModulation of cancer endocrine therapy by melatonin: a phase II study of tamoxifen plus melatonin in metastatic breast cancer patients progressing under tamoxifen alone1995n=11
A phase II study of 14 metastatic breast cancer patients progressing on tamoxifen found adding 20 mg/day melatonin restored partial responses in 4/14 (28%) and lowered IGF-1 levels.
- Effect
- Benefit
- Dose
- 20 mg/day
- Population
- Women
- Participants
- 11
RCTA randomised study with subcutaneous low-dose interleukin 2 alone vs interleukin 2 plus the pineal neurohormone melatonin in advanced solid neoplasms other than renal cancer and melanoma1994n=41
An RCT of 41 advanced solid tumor patients found IL-2 plus 40 mg/day melatonin achieved 27% objective response vs 2.6% with IL-2 alone, with higher 1-year survival (19/41 vs 6/39).
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 40 mg/day
- Population
- Cancer patients
- Participants
- 41
RCTA randomized study with the pineal hormone melatonin versus supportive care alone in patients with brain metastases due to solid neoplasms1994n=50
An RCT of 50 brain metastases patients found 20 mg/day melatonin significantly improved 1-year survival and neurological symptom control vs supportive care alone.
- Effect
- Benefit
- Dose
- 20 mg/day
- Population
- Cancer patients
- Participants
- 50
Efficacy of the concomitant administration of the pineal hormone melatonin in cancer immunotherapy with low-dose IL-2 in patients with advanced solid tumors who had progressed on IL-2 alone1994n=14
An RCT of 14 IL-2-resistant advanced cancer patients found adding 40 mg/day melatonin to IL-2 produced partial remission in 21% and stable disease in 43%, with improved 1-year survival.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 40 mg/day
- Population
- Cancer patients
- Participants
- 14
Clinical trialBiological and clinical results of a neuroimmunotherapy with interleukin-2 and the pineal hormone melatonin as a first line treatment in advanced non-small cell lung cancer1992n=20
A clinical study of 20 advanced NSCLC patients found IL-2 plus 10 mg/day melatonin produced 20% partial response and 50% stable disease as first-line neuroimmunotherapy.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 10 mg/day
- Population
- Cancer patients
- Participants
- 20
RCTRandomized study with the pineal hormone melatonin versus supportive care alone in advanced nonsmall cell lung cancer resistant to a first-line chemotherapy containing cisplatin1992n=32
An RCT of 63 advanced NSCLC patients post-cisplatin failure found 10 mg/day melatonin improved 1-year survival and performance status vs supportive care alone.
- Effect
- Benefit
- Dose
- 10 mg/day
- Population
- Cancer patients
- Participants
- 32
Clinical trialClinical results with the pineal hormone melatonin in advanced cancer resistant to standard antitumor therapies1991n=54
A clinical study of 54 advanced treatment-resistant cancer patients given 20 mg/day IM melatonin found 1 partial response and 21 stable disease cases, with 33% reporting improved performance status.
- Effect
- Benefit
- Duration
- 2 months
- Dose
- 20 mg/day
- Population
- Cancer patients
- Participants
- 54
Vitamin DView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Vitamin D does not seem to reduce the overall risk of getting cancer.
- Some research shows people with higher vitamin D levels may have a lower chance of cancer, but most studies giving vitamin D supplements do not find a big effect on cancer risk.
- However, vitamin D might slightly lower the chance of cancer spreading or dying from cancer.
- One large study found that taking 2000 IU of vitamin D daily for about 5 years reduced advanced or fatal cancers a little bit.
- Other research shows vitamin D may lower the risk of dying from cancer by 12-13% when taken daily in doses between 400 and 4000 IU for 1 to 7 years.
- Taking very high doses occasionally doesn't seem to help.
- It's not clear if vitamin D helps people already diagnosed with cancer live longer.
- Some studies suggest a small improvement in overall survival but no clear effect on stopping cancer from growing or coming back.
- Different doses have been tested, but it’s still unknown which kinds or stages of cancer might benefit the most from vitamin D supplements.
Browse 13 studies·6 meta-analyses
MetaEfficacy of vitamin D3 supplementation on cancer mortality: Systematic review and individual patient data meta-analysis of randomised controlled trials2023n=104,727
An IPD meta-analysis of 14 RCTs (104,727 participants) found vitamin D did not significantly reduce overall cancer mortality, though daily dosing lowered mortality 12%.
- Effect
- No Benefit
- Dose
- 3 g/day
- Population
- Adults
- Participants
- 104,727
- Ages
- 70+
MetaVitamin D Intake, Serum 25-Hydroxyvitamin-D (25(OH)D) Levels, and Cancer Risk: A Comprehensive Meta-Meta-Analysis Including Meta-Analyses of Randomized Controlled Trials and Observational Epidemiological Studies2023
A meta-meta-analysis of 35 meta-analyses found higher vitamin D intake and 25(OH)D associated with lower overall cancer incidence and mortality, with colorectal and lung benefits.
- Effect
- Benefit
RCTEffects of Vitamin D3 Supplementation on Cardiovascular and Cancer Outcomes by eGFR in VITAL2022n=15,917
A VITAL secondary analysis in 15,917 participants found vitamin D 2000 IU/day did not differ in cardiovascular or cancer outcomes across eGFR subgroups over 5.3 years.
- Effect
- No Benefit
- Dose
- 2000 IU/day
- Population
- Women
- Participants
- 15,917
- Avg age
- ~68
MetaPost-Diagnosis Vitamin D Supplement Use and Survival among Cancer Patients: A Meta-Analysis2022
A meta-analysis found post-diagnosis vitamin D supplement use associated with improved overall survival (SRR 0.87) but not progression-free or cancer-specific survival.
- Effect
- Benefit
- Population
- Cancer patients
RCTEffect of Vitamin D3 Supplements on Development of Advanced Cancer: A Secondary Analysis of the VITAL Randomized Clinical Trial2020n=25,871
VITAL secondary analysis in 25,871 adults found 2000 IU/day vitamin D reduced advanced/metastatic cancer incidence (HR 0.83), strongest in those with normal BMI.
- Effect
- Benefit
- Duration
- 5.3 years
- Dose
- 2000 IU/day
- Population
- Obese patients
- Participants
- 25,871
- Avg age
- ~50
RCTEffect of High-Dose vs Standard-Dose Vitamin D3 Supplementation on Progression-Free Survival Among Patients With Advanced or Metastatic Colorectal Cancer: The SUNSHINE Randomized Clinical Trial2019n=70
In 139 patients with metastatic colorectal cancer given high- versus standard-dose vitamin D3 with chemotherapy, high dose improved progression-free survival (HR 0.64).
- Effect
- Benefit
- Population
- Women
- Participants
- 70
- Ages
- 56+
RCTEffect of Vitamin D Supplementation on Relapse-Free Survival Among Patients With Digestive Tract Cancers: The AMATERASU Randomized Clinical Trial2019n=166
In 417 Japanese patients with digestive tract cancers given 2000 IU/day vitamin D for median 3.5 years post-surgery, relapse-free survival improved (HR 0.76) versus placebo.
- Effect
- No Benefit
- Dose
- 2000 IU/day
- Population
- Colorectal cancer patients
- Participants
- 166
- Ages
- 30–90
MetaVitamin D supplementation and total cancer incidence and mortality: a meta-analysis of randomized controlled trials2019
An updated meta-analysis of 10 cancer RCTs found vitamin D did not reduce cancer incidence but significantly lowered cancer mortality (RR 0.87), mainly with daily dosing.
- Effect
- Benefit
- Dose
- 1100 IU/day
- Ages
- 3–10
RCTVitamin D Supplements and Prevention of Cancer and Cardiovascular Disease2019n=25,871
In VITAL (25,871 adults, 2000 IU/day, median 5.3 years), vitamin D did not reduce invasive cancer or major cardiovascular events versus placebo.
- Effect
- No Benefit
- Dose
- 2000 IU/day
- Population
- Healthy adults
- Participants
- 25,871
- Ages
- 50+
RCTEffect of Vitamin D and Calcium Supplementation on Cancer Incidence in Older Women: A Randomized Clinical Trial2017n=109
In 2,303 postmenopausal women given 2000 IU/day vitamin D3 plus calcium for 4 years, supplementation nonsignificantly reduced cancer incidence (HR 0.70).
- Effect
- No Benefit
- Duration
- 4 years
- Dose
- 2000 IU/day
- Population
- Postmenopausal women
- Participants
- 109
- Ages
- 65+
MetaThe effect of vitamin D supplementation on skeletal, vascular, or cancer outcomes: a trial sequential meta-analysis2014n=3,853
Trial sequential meta-analysis concluded vitamin D supplementation is unlikely to reduce skeletal or non-skeletal outcomes by >15% in community-dwelling adults.
- Effect
- No Benefit
- Population
- Adults
- Participants
- 3,853
MetaVitamin D supplements and cancer incidence and mortality: a meta-analysis2014
A meta-analysis of vitamin D RCTs found no effect on total cancer incidence but a significant 12% reduction in cancer mortality with 400–833 IU/day over 2–7 years.
- Effect
- Benefit
- Dose
- 833 IU/day
- Ages
- 2–7
RCTVitamin D and calcium supplementation reduces cancer risk: results of a randomized trial2007
In 1,179 postmenopausal Nebraska women given 1100 IU/day vitamin D3 plus calcium for 4 years, combined supplementation reduced all-cancer risk (RR 0.40 vs placebo).
- Effect
- Benefit
- Duration
- 4 years
- Dose
- 1100 IU/day
- Population
- Postmenopausal women
- Ages
- >55
Olive OilView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It’s not clear whether eating olive oil lowers the risk of getting cancer or dying from cancer.
- Some research shows people who eat more olive oil have about a 30% lower chance of getting cancer, but other studies show no benefit.
- Big studies also do not agree on whether eating olive oil helps people live longer after a cancer diagnosis.
- More research is needed to know if olive oil protects against cancer.
Browse 5 studies·3 meta-analyses
ObservationalConsumption of Olive Oil and Risk of Total and Cause-Specific Mortality Among U.S. Adults2022n=60,582
In 92,383 US adults followed 28 years, olive oil intake >7 g/day was associated with 19% lower all-cause mortality (HR 0.81) vs rarely consuming olive oil.
- Effect
- Benefit
- Dose
- 7 g/day
- Population
- Adults
- Participants
- 60,582
MetaEffect of olive oil consumption on cardiovascular disease, cancer, type 2 diabetes, and all-cause mortality: A systematic review and meta-analysis2022n=806,203
A meta-analysis of 806,203 participants found each olive oil increment associated with 16% lower cardiovascular disease risk and reduced all-cause mortality.
- Effect
- Benefit
- Dose
- 25 g/day
- Participants
- 806,203
MetaOlive oil intake and cancer risk: A systematic review and meta-analysis2022n=929,771
A meta-analysis of 929,771 subjects found highest vs lowest olive oil consumption associated with 31% lower overall cancer likelihood, including breast and gastrointestinal cancers.
- Effect
- Benefit
- Participants
- 929,771
Olive oil intake and mortality within the Spanish population (EPIC-Spain)2012n=40,622
In 40,622 Spanish EPIC participants followed 13.4 years, highest olive oil intake quartile had 26% lower all-cause mortality and 44% lower cardiovascular mortality vs nonconsumers.
- Effect
- Benefit
- Dose
- 10 g/day
- Participants
- 40,622
- Ages
- 29–69
MetaOlive oil intake is inversely related to cancer prevalence: a systematic review and a meta-analysis of 13,800 patients and 23,340 controls in 19 observational studies2011n=13,800
A meta-analysis of 19 observational studies (13,800 cancer patients) found highest vs lowest olive oil intake associated with lower odds of any cancer (OR 0.59) and breast cancer.
- Effect
- Benefit
- Population
- Adults
- Participants
- 13,800
Panax GinsengView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is unclear if taking Panax ginseng can prevent cancer.
- Some studies suggest people who take ginseng might get cancer less often, but large studies found no lower cancer risk with taking ginseng regularly.
- Some research shows Panax ginseng may help slow cancer or improve quality of life in people already diagnosed.
- Taking a special form of ginseng called sun ginseng daily improved quality of life in some cancer patients, and giving ginseng through an IV might slow lung cancer in some people.
Browse 9 studies
RCTEffects of a polyherbal formulation on the quality of life and survival of patients with common upper gastrointestinal cancers: A randomized placebo-controlled trial2021n=20
A 12-week RCT in 40 upper GI cancer patients found a polyherbal syrup with ginseng improved quality of life versus placebo syrup.
- Effect
- Benefit
- Duration
- 12 weeks
- Population
- Patients with common upper gastrointestinal cancers
- Participants
- 20
Case series of non-small cell lung cancer treated with mountain Ginseng pharmacopuncture2011
A case series in 6 non-small cell lung cancer patients found mixed responses to mountain ginseng pharmacopuncture by intravenous or acupoint routes over 28-day cycles.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 20 mL/day
- Population
- Patients with non-small cell lung cancer treated with mountain g
ObservationalAdvanced cancer cases treated with cultivated wild ginseng phamacopuncture2010
A pilot study of 7 advanced cancer patients given cultivated wild ginseng pharmacopuncture (20 mL/day IV for 2 weeks) reported 1-year survival 57.1% and median survival 544 days.
- Effect
- Benefit
- Duration
- 2 weeks
- Dose
- 20 mL/day
- Population
- Cancer patients
RCTNon-organ-specific preventive effect of long-term administration of Korean red ginseng extract on incidence of human cancers2010
A randomized trial of 643 Chinese adults with chronic atrophic gastritis found 1 g/week red ginseng for 3 years (followed 8 years) did not significantly lower overall cancer risk versus placebo (relative risk 0.54, P=0.13).
- Effect
- No Benefit
- Duration
- 3 years
- Dose
- 1 g
- Population
- Adults
RCTNon-organ-specific preventive effect of long-term administration of Korean red ginseng extract on incidence of human cancers2009
A randomized trial of 643 Chinese adults with chronic atrophic gastritis found 1 g/week red ginseng for 3 years (followed 8 years) did not significantly lower overall cancer risk versus placebo (relative risk 0.54, P=0.13).
- Effect
- No Benefit
- Duration
- 3 years
- Dose
- 1 g
- Population
- Adults
RCTEffects of sun ginseng on subjective quality of life in cancer patients: a double-blind, placebo-controlled pilot trial2006n=32
In 53 cancer patients, sun ginseng 3000 mg/day for 12 weeks improved psychological quality of life (WHOQOL-BREF, P=0.02) and general health scores (GHQ-12, P<0.01) versus placebo.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 3000 mg/day
- Population
- Cancer patients
- Participants
- 32
ObservationalThe cancer-preventive potential of Panax ginseng: a review of human and experimental evidence2000
A review of human and animal studies concluded Panax ginseng shows cancer-preventive potential, with Korean cohort and case-control data suggesting lower cancer risk with regular intake.
ObservationalNon-organ specific cancer prevention of ginseng: a prospective study in Korea1998n=4,634
A prospective cohort of 4634 Koreans over 40 found ginseng consumers had 60% lower cancer risk than non-consumers (RR 0.40, 95% CI 0.28–0.56), with strongest effects for fresh extract and red ginseng.
- Effect
- Benefit
- Population
- Adults
- Participants
- 4,634
- Ages
- 40+
ObservationalPreventive effect of ginseng intake against various human cancers: a case-control study on 1987 pairs1995
A Korean case-control study of 1987 pairs found ginseng intakers had half the cancer odds of non-intakers (OR 0.50), with dose-response by frequency and duration and lower risk across many cancer sites.
- Effect
- Benefit
- Population
- Patients with ovarian cancer
Alpha-Linolenic AcidView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Studies show that eating a lot of alpha-linolenic acid may be linked to a slightly higher risk of dying from cancer, but this does not prove it causes cancer deaths.
Browse 2 studies·2 meta-analyses
MetaDietary intake and biomarkers of alpha linolenic acid and risk of all cause, cardiovascular, and cancer mortality: systematic review and dose-response meta-analysis of cohort studies2021n=26
Meta-analysis of 41 cohort studies in 1.2 million participants linked higher ALA intake to lower all-cause, CVD, and CHD mortality, but slightly higher cancer mortality.
- Effect
- Benefit
- Dose
- 1 g/day
- Participants
- 26
Systematic reviewDietary Intake and Biomarkers of α-Linolenic Acid and Mortality: A Meta-Analysis of Prospective Cohort Studies2021n=58,634
Meta-analysis of 34 cohorts in 658,634 participants linked ALA intake to lower CVD mortality, with mixed associations for all-cause and other disease mortality.
- Participants
- 58,634
ReishiView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Research combining reishi mushroom with chemotherapy found more patients had tumor shrinkage compared to chemotherapy alone, but there was no improvement in overall survival.
- The studies varied a lot and were all done in Asia, so the results are not conclusive.
Browse 2 studies·1 meta-analysis
Systematic reviewCoriolus Versicolor and Ganoderma Lucidum Related Natural Products as an Adjunct Therapy for Cancers: A Systematic Review and Meta-Analysis of Randomized Controlled Trials2019
A systematic review and meta-analysis found Coriolus versicolor and Ganoderma lucidum products may improve survival and quality of life as adjunct cancer therapy, though evidence varied by cancer type.
- Effect
- Benefit
- Population
- Cancer patients
Clinical trialEffects of ganopoly (a Ganoderma lucidum polysaccharide extract) on the immune functions in advanced-stage cancer patients2003n=30
In 30 advanced cancer patients over 12 weeks, Ganopoly polysaccharide extract 1,800 mg/day modulated immune markers including increased natural killer cell activity.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 800 mg/day
- Population
- Patients with cancer
- Participants
- 30
KavaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Research looking at populations suggests that people who consume more kava tend to have lower rates of cancer.
Browse 2 studies
RCTKava-Kava administration reduces anxiety in perimenopausal women2003n=19
In perimenopausal women, kava 100–200 mg/day for 3 months reduced anxiety and climacteric symptoms more than calcium alone, with significant anxiety decline versus controls (P<0.009).
- Effect
- Benefit
- Duration
- 3 months
- Dose
- 100 mg/day
- Population
- Women
- Participants
- 19
The correlation between cancer incidence and kava consumption2000
Ecological comparison across Pacific Island nations suggested higher traditional kava consumption correlates with lower age-standardized cancer incidence, though causality was not established.
MultivitaminView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if taking multivitamins helps prevent or treat cancer. Experts say there isn’t enough good evidence to know if multivitamins reduce the chance of getting cancers like lung, breast, or prostate cancer, or if they help people live longer after a cancer diagnosis.
- One large study found men who took multivitamins daily might have a slightly higher chance of getting cancer, but this was not seen in women. Another study found no benefit from a specific multivitamin for preventing invasive cancer in older adults.
- For people who have had cancer, taking multivitamins doesn’t seem to lower the risk of dying overall but might slightly reduce the risk of dying from certain cancers or heart disease in some groups. Based on current knowledge, multivitamins are not proven to prevent or treat cancer.
Browse 12 studies·3 meta-analyses
ObservationalMultivitamin use and all-cause and cause-specific mortality in cancer survivors2024
An observational study of cancer survivors found multivitamin use was not associated with lower all-cause or cause-specific mortality.
- Effect
- No Benefit
- Population
- ALL patients
RCTMortality after multivitamin supplementation: Nearly 35-year follow-up of the randomized Linxian Dysplasia Nutrition Intervention Trial2022
Nearly 35-year follow-up of the Linxian trial found multivitamin supplementation did not reduce long-term mortality in the original cohort.
- Effect
- No Benefit
- Duration
- 6 years
- Population
- Adults
- Ages
- 40–69
ObservationalMultivitamin Use and Overall and Site-Specific Cancer Risks in the National Institutes of Health-AARP Diet and Health Study2022n=489,640
An analysis of 489,640 participants in the NIH-AARP cohort found multivitamin use was not linked to lower overall or site-specific cancer risk.
- Effect
- No Benefit
- Population
- Adults
- Participants
- 489,640
- Ages
- 50–71
RCTMultivitamins in the prevention of cancer and cardiovascular disease: the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial2022n=535
The COSMOS RCT of 535 older adults found daily multivitamin supplementation did not significantly reduce cancer or cardiovascular disease incidence versus placebo.
- Effect
- No Benefit
- Population
- Adults
- Participants
- 535
- Ages
- ≥60
ObservationalRegular, Long-Duration Multivitamin Use and Risk of Overall and Aggressive Prostate Cancer in the Health Professionals Follow-Up Study2022n=48,137
A prospective study of 48,137 men found regular long-duration multivitamin use was not associated with reduced overall or aggressive prostate cancer risk.
- Effect
- No Benefit
- Population
- Older adults
- Participants
- 48,137
ObservationalThe Associations of Multivitamin and Antioxidant Use With Mortality Among Women and Men Diagnosed With Colorectal Cancer2022n=534
An observational study of 534 women found multivitamin and antioxidant use was not associated with lower mortality over follow-up.
- Effect
- No Benefit
- Population
- ALL patients
- Participants
- 534
GuideVitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer: US Preventive Services Task Force Recommendation Statement2022
A USPSTF evidence review found insufficient evidence that multivitamin or mineral supplementation prevents cardiovascular disease or cancer in healthy adults.
- Effect
- No Benefit
- Population
- Adults
MetaDietary supplement use and colorectal cancer risk: a systematic review and meta-analyses of prospective cohort studies2015
A meta-analysis found no clear evidence that dietary supplement use, including multivitamins, reduces colorectal cancer risk.
- Effect
- No Benefit
- Dose
- 100 mg/day
MetaMultivitamin supplement use and risk of breast cancer: a meta-analysis2011n=355,080
A meta-analysis of 355,080 women found no significant association between multivitamin use and breast cancer risk over 3–10 years of follow-up.
- Effect
- No Benefit
- Population
- Women
- Participants
- 355,080
- Ages
- 3–10
MetaThe effect of supplemental vitamins and minerals on the development of prostate cancer: a systematic review and meta-analysis2011
A meta-analysis found supplemental vitamins and minerals did not significantly reduce prostate cancer incidence in pooled trial data.
- Effect
- No Benefit
- Population
- Men with prostate cancer
ObservationalIntakes of vitamins A, C, and E and use of multiple vitamin supplements and risk of colon cancer: a pooled analysis of prospective cohort studies2010n=676,141
A prospective study of 676,141 women found higher vitamin C and E intake and multivitamin use were not associated with lower lung cancer risk.
- Effect
- No Benefit
- Dose
- 1000 mcg/day
- Population
- Adults
- Participants
- 676,141
- Ages
- 7–20
Intakes of vitamins A, C and E and folate and multivitamins and lung cancer: a pooled analysis of 8 prospective studies2006
A pooled analysis found intakes of vitamins A, C, E, folate, and multivitamins were not consistently associated with reduced lung cancer risk.
- Effect
- No Benefit
- Ages
- 6–16
Red Yeast RiceView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Taking red yeast rice (1.2 grams daily) for about 4.5 years may lower the chance of dying from cancer in people who have had a heart attack.
- However, it's unclear if it helps prevent cancer from starting or coming back.
- More research is needed.
Browse 2 studies
RCTBeneficial impact of Xuezhikang on cardiovascular events and mortality in elderly hypertensive patients with previous myocardial infarction from the China Coronary Secondary Prevention Study (CCSPS)2009n=772
In 772 elderly hypertensive post-MI patients over 4.5 years, Xuezhikang reduced coronary events by 38% and coronary death by 29% versus placebo.
- Effect
- Benefit
- Population
- Older adults
- Participants
- 772
RCTEffect of Xuezhikang, an extract from red yeast Chinese rice, on coronary events in a Chinese population with previous myocardial infarction2008
In ~5000 post-MI Chinese patients over 4.5 years, Xuezhikang cut major coronary events from 10.4% to 5.7%, reduced CV and total mortality ~30%, and improved lipids.
- Effect
- Benefit
- Population
- Surgical patients
Vitamin B9 (Folate)View supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is unclear if taking folic acid supplements helps prevent cancer.
- Research in children born to mothers with epilepsy who took high doses of folic acid during pregnancy found a higher risk of cancer compared to children of mothers with epilepsy who did not take high doses.
- Mothers without epilepsy did not have this risk with high folic acid intake.
- Studies in large groups of people have shown that folic acid supplements do not clearly change the overall risk of getting cancer, though there might be a slightly higher risk for some types, like prostate cancer.
- Some studies suggest moderate folate intake might help protect against certain cancers.
- Mothers with epilepsy are advised not to take more than 4 mg of folic acid daily during pregnancy.
- More research is needed to understand how folic acid affects cancer risks in different people.
Browse 3 studies
Benefits and Risks of Periconceptional Folic Acid Supplementation2023
A study found that benefits and Risks of Periconceptional Folic Acid Supplementation..
- Effect
- Benefit
Benefits and Risks of Periconceptional Folic Acid Supplementation-Reply2023
A study found that benefits and Risks of Periconceptional Folic Acid Supplementation-Reply..
- Effect
- Benefit
ObservationalCancer Risk in Children of Mothers With Epilepsy and High-Dose Folic Acid Use During Pregnancy2022n=784
An observational study of 784 pregnant women found that 1 mg/day cox proportional hazards models were used to calculate adjusted hazard ratios with corresponding 95% CIs, adjusted for potential confounders.
- Effect
- No Benefit
- Duration
- 1997–2017
- Dose
- 1 mg/day
- Population
- Pregnant women
- Participants
- 784
- Avg age
- ~20
Vitamin KView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if eating vitamin K lowers the chance of getting cancer or dying from it.
- One large study in healthy German people found that eating more than 42 to 46 micrograms of vitamin K2 daily was linked to a 27% lower chance of dying from cancer, but it did not affect how often cancer happened.
- Eating vitamin K1 was not linked to cancer risk or death.
- Another study in Mediterranean people at high risk for heart disease found those who ate more vitamin K1 (about 630 micrograms daily) had a 46% lower risk of dying from cancer compared to those who ate less (about 171 micrograms).
Browse 2 studies
RCTDietary intake of vitamin K is inversely associated with mortality risk2014n=7,216
In an RCT of 7,216 participants, energy-adjusted baseline dietary phylloquinone intake was inversely associated with a significantly reduced risk of cancer and all-cause mortality after controlling for potential confounders (HR: 0.54; 95% CI: 0.30, 0.96; and HR: 0.64; 95% CI: 0.45, 0.90, respectively).
- Effect
- Benefit
- Participants
- 7,216
ObservationalDietary vitamin K intake in relation to cancer incidence and mortality: results from the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Heidelberg)2010n=24,340
In an observational study of 24,340 participants, multivariate-adjusted hazard ratios (HRs) and 95% CIs were estimated by using Cox proportional hazards models.
- Effect
- Benefit
- Population
- Cancer patients
- Participants
- 24,340
- Ages
- 35–64
ApigeninView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Some studies suggest that eating foods high in apigenin may lower the risk of certain cancers like breast, digestive, prostate, and blood cancers.
- But this evidence mainly comes from observation, and there aren't enough clinical studies in people yet.
- More research is needed to confirm if apigenin really helps prevent cancer.
Browse 1 study
Apigenin: a promising molecule for cancer prevention2010
A review notes epidemiologic links between higher dietary apigenin/flavone intake and lower cancer risk, but no human clinical trials of apigenin supplementation for cancer prevention have been conducted.
- Effect
- Benefit
SeleniumView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Taking selenium supplements does not appear to lower cancer risk for most people.
- Studies show no overall benefit from selenium supplements taken for several years.
- However, selenium might help some groups, such as men and people who have low selenium levels.
- Getting the recommended amount of selenium through diet or supplements may be linked to a lower chance of cancer, especially for men.
- But overall, the evidence is not strong enough for health authorities to say selenium definitely prevents cancer.
Browse 8 studies·4 meta-analyses
MetaDoes dietary intake of selenium protect against cancer? A systematic review and meta-analysis of population-based prospective studies2020
A meta-analysis of 37 prospective studies found dietary selenium ≥55 mcg/day associated with modestly lower cancer risk, especially from supplements in men.
- Effect
- Benefit
- Dose
- 55 mcg/day
- Population
- Adults
MetaSelenium for preventing cancer2018n=183,863
An updated Cochrane review found selenium supplementation did not clearly prevent cancer and evidence from observational and trial data remained inconsistent.
- Effect
- No Benefit
- Population
- Adults
- Participants
- 183,863
MetaDietary Supplements and Risk of Cause-Specific Death, Cardiovascular Disease, and Cancer: A Systematic Review and Meta-Analysis of Primary Prevention Trials2017n=287,304
A meta-analysis of 49 primary-prevention trials found vitamin E reduced cardiovascular mortality, folic acid reduced CVD risk, and most other supplements including selenium showed no clear mortality benefit.
- Effect
- No Benefit
- Participants
- 287,304
- Ages
- 18+
MetaSelenium Exposure and Cancer Risk: an Updated Meta-analysis and Meta-regression2016
An updated meta-analysis of 69 studies found higher selenium exposure associated with lower overall cancer risk, though selenium supplements did not show clear preventive efficacy.
- Effect
- No Benefit
MetaEffects of selenium supplements on cancer prevention: meta-analysis of randomized controlled trials2011n=8
A meta-analysis of 9 cancer-prevention RCTs (152,538 participants) found selenium supplementation alone associated with lower overall cancer incidence, especially in low-selenium and high-risk populations.
- Effect
- Benefit
- Participants
- 8
RCTThe nutritional prevention of cancer: 400 mcg per day selenium treatment2008n=424
In 424 high-risk patients, 400 mcg/day selenium did not reduce total cancer incidence, unlike the NPC trial's 200 mcg/day dose which lowered lung, colon, and prostate cancer risk.
- Effect
- No Benefit
- Dose
- 400 mcg/day
- Population
- High-risk dermatology patients
- Participants
- 424
Systematic reviewThe efficacy and safety of multivitamin and mineral supplement use to prevent cancer and chronic disease in adults: a systematic review for a National Institutes of Health state-of-the-science conference2006
A systematic review for NIH found multivitamin/mineral supplements had fair-to-poor evidence for preventing cancer and chronic disease in generally healthy adults.
- Effect
- No Benefit
- Population
- Pregnant women
RCTThe SU.VI.MAX Study: a randomized, placebo-controlled trial of the health effects of antioxidant vitamins and minerals2004n=7,876
In 13,017 French adults followed 7.5 years, daily antioxidant vitamins plus 100 mcg selenium did not reduce total cancer or ischemic cardiovascular disease versus placebo.
- Effect
- No Benefit
- Dose
- 20 mg
- Population
- Adults
- Participants
- 7,876
- Ages
- 35–60
Vitamin B3 (Niacin)View supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear whether eating more niacin or taking niacin supplements helps prevent cancer or improves survival.
- A study found that people with cancer who ate more niacin had a lower risk of dying from cancer or any cause than those who ate less.
- Those who took niacin supplements were also less likely to die from cancer, but their overall death rate was not lower compared to non-users.
- More research is needed to know if taking niacin really helps.
Browse 1 study
ObservationalAssociation between niacin and mortality among patients with cancer in the NHANES retrospective cohort2022n=3,504
An observational study of 3504 found that according to our study, higher dietary niacin intake was associated with lower mortality in cancer patients.
- Effect
- Benefit
- Population
- Cancer patients
- Participants
- 3,504
- Avg age
- ~65
Vitamin EView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Taking vitamin E by mouth does not seem to lower the risk of getting cancer for most people.
- Studies looked at vitamin E combined with other antioxidants and found no clear benefit, though there might be a small effect in men.
- One large, long-term study gave men vitamin E every other day for about 8 years and found it did not reduce cancer risk compared to placebo.
- Reviews of many studies agree that vitamin E does not lower cancer risk overall.
- Health authorities do not recommend vitamin E supplements to prevent cancer because there is no clear benefit.
Browse 5 studies·1 meta-analysis
GuideVitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer: US Preventive Services Task Force Recommendation Statement2022
A USPSTF evidence review found insufficient evidence that multivitamin or mineral supplementation prevents cardiovascular disease or cancer in healthy adults.
- Effect
- No Benefit
- Population
- Healthy adults
RCTVitamin E and C supplementation and risk of cancer in men: posttrial follow-up in the Physicians' Health Study II randomized trial2014
Post-trial follow-up of Physicians' Health Study II found neither 500 mg/day vitamin C nor 400 IU vitamin E every other day affected cancer mortality.
- Effect
- No Benefit
- Dose
- 500 mg/day
- Population
- Men
- Ages
- ≥50
RCTVitamins E and C in the prevention of prostate and total cancer in men: the Physicians' Health Study II randomized controlled trial2009n=1,307
In Physicians' Health Study II (14,641 men, 8 years), 400 IU vitamin E every other day did not reduce prostate cancer (HR 0.97) or total cancer versus placebo.
- Effect
- No Benefit
- Dose
- 400 IU/day
- Population
- Cancer patients
- Participants
- 1,307
- Avg age
- ~50
MetaThe role of vitamin E in the prevention of cancer: a meta-analysis of randomized controlled trials2007n=67,025
A meta-analysis of 12 RCTs (167,025 participants) found vitamin E did not reduce total mortality or overall cancer but lowered prostate cancer incidence (RR 0.85).
- Effect
- No Benefit
- Population
- Adults
- Participants
- 67,025
RCTThe SU.VI.MAX Study: a randomized, placebo-controlled trial of the health effects of antioxidant vitamins and minerals2004n=7,876
In 13,017 French adults followed 7.5 years, daily antioxidant vitamins plus 100 mcg selenium did not reduce total cancer or ischemic cardiovascular disease versus placebo.
- Effect
- No Benefit
- Dose
- 20 mg
- Population
- Adults
- Participants
- 7,876
- Ages
- 35–60
Yerba MateView supplement →
Do not purchase·★★★★★
How we scored this▸
- Evidence is insufficient for this condition.
Browse 2 studies·1 meta-analysis
MetaMaté consumption association with upper aerodigestive tract cancers: A systematic review and meta-analysis2018
In a meta-analysis, consumption of more than one liter of maté per day was associated with increased odds of having UADT cancer compared to an intake of less than one liter per day (OR = 1.72; 95%CI = 1.47-2.01).
- Effect
- No Benefit
- Dose
- >1 L/day maté
ObservationalDrinking of maté and the risk of cancers of the upper aerodigestive tract in Latin America: a case-control study2010n=2,194
In an observational study, our study strengthens the evidence of an association between maté drinking and esophageal cancer; the hypothesis of an association with other UADT cancers remains to be clarified.
- Effect
- No Benefit
- Population
- Adults
- Participants
- 2,194
ResveratrolView supplement →
Do not purchase·★★★★★
How we scored this▸
- It is not clear whether eating foods or supplements containing resveratrol helps prevent cancer.
- Studies in people have not shown a lower risk of cancer with higher resveratrol intake.
- Resveratrol has not been proven in humans for cancer prevention.
Browse 1 study
RCTResveratrol levels and all-cause mortality in older community-dwelling adults2014
In 783 older community-dwelling adults, higher urinary resveratrol metabolites were not associated with lower mortality, inflammation, or cardiovascular disease.
- Effect
- No Benefit
- Population
- Adults
Evidence visualised
Same ratings as above, aggregated so you can see coverage and imbalance.
| Supplement | DEX | Studies | Meta-analyses | Share |
|---|---|---|---|---|
| Melatonin | ★★★★★68% | 22 | 5 | 23% |
| Vitamin D | ★★★★★56% | 13 | 6 | 14% |
| Multivitamin | ★★★★★44% | 12 | 3 | 13% |
| Panax Ginseng | ★★★★★52% | 9 | 0 | 9% |
| Selenium | ★★★★★40% | 8 | 4 | 8% |
| Olive Oil | ★★★★★52% | 5 | 3 | 5% |
| Vitamin E | ★★★★★40% | 5 | 1 | 5% |
| Magnesium | ★★★★★68% | 4 | 4 | 4% |
| Vitamin B9 (Folate) | ★★★★★44% | 3 | 0 | 3% |
| Alpha-Linolenic Acid | ★★★★★48% | 2 | 2 | 2% |
| Kava | ★★★★★44% | 2 | 0 | 2% |
| Red Yeast Rice | ★★★★★44% | 2 | 0 | 2% |
| Reishi | ★★★★★48% | 2 | 1 | 2% |
| Vitamin K | ★★★★★44% | 2 | 0 | 2% |
| Yerba Mate | ★★★★★36% | 2 | 1 | 2% |
| Apigenin | ★★★★★40% | 1 | 0 | 1% |
| Resveratrol | ★★★★★32% | 1 | 0 | 1% |
| Vitamin B3 (Niacin) | ★★★★★40% | 1 | 0 | 1% |