Product Reviews and Information for Cancer Prevention

11/17/2013

Latest Supplement Recommendations

New draft recommendations on vitamin and mineral supplement use were published this week by the U.S. Preventive Services Task Force. The recommendations apply only to healthy adults without nutritional deficiencies. They focus only on the use of supplements for the prevention of cardiovascular disease and cancer at doses not exceeding tolerable upper intake levels. The recommendations are based on existing science and are generally consistent with information already presented in ConsumerLab.com's Product Reviews.  We have summarized the recommendations below, with links to more information in ConsumerLab.com's reports:

4/14/2025

Vitamin D for Diabetes Prevention?

Did taking vitamin D for more than 5 years reduce the risk of type 2 diabetes among healthy older people in a major U.S. study? Find out in the Diabetes, insulin resistance and glucose control section of our Vitamin D Supplements Review.

Also see our Top Picks for vitamin D.

And see our article: Which supplements and foods can help lower or control blood sugar?

5/05/2025

Vitamin D & Cold Prevention

Does taking vitamin D during winter months reduce colds and other respiratory infections? Find out what a recent study showed in the Respiratory infection, colds, and influenza section of our Vitamin D Supplements Review, which includes our Top Picks for vitamin D.

Also see our article: Do any supplements help prevent or treat a cold?

11/07/2024

Supplements for Parkinson’s?

Find out if taking CDP-choline (a.k.a., citicoline) or PEA (palmitoylethanolamide) help people with Parkinson’s disease in our article: Do supplements help with Parkinson’s disease treatment or prevention?

12/05/2024

Remineralizing Tooth Powder?

Is Remineralizing Tooth Powder by Living well With Dr. Michelle better than a toothpaste? Find out what research suggests in the Toothpaste vs. tooth powder vs. toothpaste tablets section of our article about finding the best toothpaste, which includes our Top Picks for cavity prevention, desensitization, bleeding gums, whitening surface stains, dry mouth, and bad breath.

7/18/2024

Black Currant for Osteoporosis Prevention?

Does supplementing with black currant fruit extract improve bone mineral density in peri- and postmenopausal women? Find out what a recent study showed in our article about supplements and diets for osteoporosis.

8/08/2023

Theodent for Cavities?

Can Theodent toothpaste, which contains theobromine instead of fluoride, help remineralize teeth and prevent cavities? Find out what research suggests in our article about toothpastes and other dental products, which includes our Top Pick for cavity prevention.

10/04/2022

Problem With a Preventive Drug

EVUSHELD (tixagevimab with cilgavimab) is the only product authorized for the pre-exposure prevention of COVID-19, but evidence shows it may provide less protection against Omicron variants compared to earlier strains. Get the details in our CL Answer about treatments for COVID-19.

2/11/2022

Omega-3s for Fall Prevention?

Can omega-3 supplementation help reduce falls in older men and women? See what a study found in the Muscle, Strength and Falls section of our Fish Oil/Omega-3 Fatty Acid Supplements Review. Also, see our Top Picks among fish oil supplements.

7/10/2021

Niacin for Parkinson's?

Can niacin supplementation improve symptoms or slow decline in people with Parkinson's disease? See what a new study found in the Niacin section of our B Vitamin Supplements Review.

Also see our answer to the question: Do supplements help with Parkinson's disease treatment or prevention?

8/24/2021

Parkinson's Disease: 5-HTP for Sleep?

Can supplementation with 5-HTP reduce sleep disturbances in people with Parkinson's disease? See what a recent study found in the What It Does section of our L-Tryptophan and 5-HTP Supplements Review.

Also see our answer to the question: Do supplements help with Parkinson's disease treatment or prevention?

6/09/2019

Vitamin D for Diabetes Prevention

Does high-dose vitamin D help prevent people with pre-diabetes from progressing to type 2 diabetes? See the results of a major new study in the What It Does section of the Vitamin D Supplements Review. Also see our Top Picks for vitamin D.

5/09/2011

Does folic acid affect the risk of colon cancer?

Supplementation with higher amounts of folic acid (vitamin B-9) has been shown to increase the risk of prostate cancer, but its effect on the risk of colon cancer has been unclear. A new study found no increase in colon cancer due to folic acid supplementation. But if you supplement with folic acid, be careful. See the B Vitamin Supplements Review for more >>

1/17/2015

Vitamin D and Colorectal Cancer

Higher blood levels of vitamin D are associated with a reduced risk of colon cancer, and a new study shows this association to be strongest with a particular subtype of colon cancer. The risk of this cancer in those with higher vitamin D levels is only 10% of that in those with low levels. For details about this and the uses of vitamin D, as well as our ratings of vitamin D supplements, see the Vitamin D Supplements Review >>   

7/21/2013

Soy Protein to Prevent Prostate Cancer?

Prostate cancer occurs less frequently in parts of the world where people eat more soy. So researchers recently gave a soy protein drink, or a placebo drink, to men who previously had prostate cancer to see if it reduced the risk of the cancer recurring. Learn what they found in the updated Protein Powders and Drinks Review >>

4/01/2017

Vitamin D and Cancer

Although studies have shown that sufficient vitamin D in the blood is associated with lower risk of developing and dying from cancer, a new study among women found no cancer benefit from taking vitamin D supplements. However, the study had a major weakness. For details, see the "What It Does -- Cancer" section of the Vitamin D Supplements Review >>

1/16/2021

Coffee and Prostate Cancer Risk

Is drinking coffee associated with prostate cancer risk? Find out what a recent study suggests in our updated answer to the question: Does drinking coffee increase or decrease the risk of cancer? Can it slow cancer progression?

1/08/2019

B Vitamins & Breast Cancer

A reduced risk of breast cancer was associated with supplementing with certain amounts of folic acid and vitamin B12 for women predisposed to breast cancer in a new study. See the details in the "Breast cancer" section of the B Vitamin Supplements Review.

2/29/2020

Breast Cancer & Milk Consumption

Is drinking milk – dairy or soy – associated with breast cancer risk? Find out what a new study found in our answer to the following question: Are there vitamins or supplements that can reduce my risk of breast cancer? Do any increase cancer risk?

11/14/2018

Vitamin D May Prevent Cancer Deaths

A major 5-year study in which a cross-section of Americans were given high-dose vitamin D daily found no overall reductions in cardiovascular disease or cancer or death from these causes. However, when excluding the first two years of the study, the rate of death from cancer was 25% lower with vitamin D than with placebo — a finding consistent with other studies. See the details in the Cancer section of the Vitamin D Supplements Review. (Also see our Top Picks for vitamin D.)

8/13/2019

Vitamin D for Breast Cancer?

Some evidence suggests that having higher blood levels of vitamin D lowers the risk of breast cancer. Can very high-dose vitamin D slow tumor growth in women with breast cancer? See what a new study found in the Cancer section of the Vitamin D Supplements Review. Also see our Top Picks for vitamin D supplements.

6/28/2022

Vitamin D & Cancer

Does vitamin D decrease the risk of cancer or cancer mortality? See the latest evidence in the Cancer section of our Vitamin D Supplements Review.

1/05/2024

Vitamin K2 & Breast Cancer

Does supplementing with vitamin K2, which can be derived from fermented soy (natto), increase the risk of breast cancer? Find out in the Concerns and Cautions section of our Vitamin K Supplements Review, which includes our Top Picks for vitamin K.

Also see: Are there vitamins or supplements that can reduce my risk of breast cancer? Do any increase cancer risk?

3/22/2022

Multivitamins & Cancer Risk

Did a popular multivitamin for seniors reduce the risk of cancer diagnosis in a three-year-study? Find out in the Cancer Risk section of our Multivitamin and Multimineral Supplements Review. Also see our Top Picks among multivitamins.

4/30/2012

Cancer Findings with Natural Vitamin E

Clinical studies have raised doubts, and even concerns, about the relationship between vitamin E supplements and cancer. However, recent studies in animals suggest the tocopherols found in natural forms of vitamin E may help prevent cancer -- although the results are preliminary. For more about this, and our tests of vitamin E supplements, see the updated Vitamin E Supplements Review. More >>

3/05/2016

Vitamin D and Prostate Cancer

A recent study looked at the association between vitamin D blood levels and the risk of advanced prostate cancer. Based on the findings from this and related studies, there seems to be a reasonable approach with vitamin D to potentially lower prostate cancer risk. Get the details (as well as our tests of products) in the Vitamin D Supplements Review >>

4/20/2016

Vitamin D and Cancer

Several studies, including one published this month, show that sufficient levels of vitamin D in the body are associated with decreased risk of various forms of cancer. What's the best level? See "Cancer" in the What It Does section of the Vitamin D Supplements Review >>

9/14/2016

Raising Vitamin D Levels May Reduce Risk Factor For Breast Cancer

A study among postmenopausal women showed that raising vitamin D blood levels helps reduces blood estrogens, which are a known risk factor for breast cancer. And there's something that reduces estrogen levels even more! For more details, see the "What It Does - Cancer" section of the Vitamin D Supplements Review >>

5/13/2015

Fish Intake and Breast Cancer Risk

Women with breast cancer who consumed the most fish had a lower risk of death compared to women who did not eat fish, a new study reports. Get the details, plus evidence for the use of fish oil supplements to reduce the risk of breast and prostate cancer, and our tests of popular products in the Fish Oil and Omega-3 Fatty Acids Supplements Review >>

10/24/2015

Niacin Helps Prevent Skin Cancers

A study published this week showed that taking a form of niacin daily significantly lowered the rate of new basal-cell and squamous-cell skin cancers in patients with a history of such cancers. For details about the supplement and dose, see the B Vitamins Review >>

2/19/2012

Curcumin and Cancer

Curcumin (from turmeric) can suppress cancer cells in the laboratory, but how about in people? A new study in smokers showed that taking curcumin for a month significantly reduced the number of precancerous lesions that could lead to cancer of the colon. Find out more (including the dose used) in the Turmeric and Curcumin Supplements Review, which includes our recent product tests and reviews. More >>

1/08/2012

Vitamin D and Pancreatic Cancer

A lower risk of developing pancreatic cancer was recently associated with higher levels of vitamin D in the body. See the update to the Vitamin D Supplements Review for the vitamin D levels associated with decreased pancreatic cancer risk, as well as our ratings of vitamin D supplements.

11/26/2019

Fish Oil & Colon Cancer

There is new evidence that taking fish oil may reduce the risk of colorectal cancer for certain people. For details see the Cancer section of the Fish Oil Supplements Review. Also see our Top Picks among fish oil supplements and other marine sources of omega-3s.

10/01/2019

Vitamin D and Risk of Cancer Death

Are you more likely to survive colorectal cancer if you have higher blood levels of vitamin D? Find out in the Cancer section of the Vitamin D Supplements Review. Also see our Top Picks for vitamin D.

3/27/2018

Green Tea and Ovarian Cancer

Drinking green tea was associated with a reduced risk of developing ovarian cancer in a recent analysis. Get the details about this and green tea's relationship to other types of cancer in the What It Does section of the Green Tea Review. (Also see our test results for various types of green tea, including matcha, bagged tea, loose tea, and supplements.)

7/21/2018

Cancer & High-Dose Vitamin D

Does taking high-dose vitamin D reduce the risk of cancer? Find out what a major new study found in the Cancer section of the Vitamin D Supplements Review. (Also see our Top Picks for vitamin D.)

1/24/2021

Aspirin and Colorectal Cancer Risk

Regular use of aspirin may reduce or increase the risk of colorectal cancer depending on when it is initiated, according to observational studies and clinical trials. Get the details in our updated answer to the question: Which supplements help reduce the risk of colorectal cancer?

3/19/2021

Melatonin and Cancer

Can high-dose melatonin increase survival time or improve symptoms in people with advanced lung cancer? See what a new study found in the What It Does section of our Melatonin Supplements Review.

Also see results of a study in which melatonin was given during breast cancer treatment.

See our Top Picks among melatonin supplements.

7/27/2021

Fish Oil and Colon Cancer

Does fish oil supplementation decrease the risk of abnormal colorectal growths or other changes associated with colorectal cancer? See what a new study found in the Cancer section of our Fish Oil Supplements Review.

8/07/2021

Vitamin D and Palliative Cancer Care

Can high-dose vitamin D supplementation in palliative care cancer patients reduce pain and fatigue? Find out what a recent study showed in the Cancer section of our Vitamin D Supplements Review. Also see our Top Picks for vitamin D.

9/26/2023

Melatonin During Breast Cancer Treatment?

Can taking melatonin reduce fatigue or other side effects of breast cancer therapy? Find out what a recent study showed in the Cancer Treatment Side Effects section of our Melatonin Supplements Review, which includes our Top Picks for melatonin.
 

11/21/2023

Green Tea for Blood Cancer?

Does supplementing with green tea improve biomarkers in patients with leukemia, lymphomas or other blood cancers? Find out what research has shown in the Cancer Treatment section of our Green Tea Supplements Review, which includes our Top Picks for brewable tea and green tea supplements.

8/25/2023

Vitamin D for GI Cancers

Taking high-dose vitamin D greatly improved the outcomes of a large subgroup of people with gastrointestinal cancers (colorectal, gastric, esophageal). Get the details in the Cancer section of our Vitamin D Supplements Review. Also see our Top Picks for vitamin D.

11/01/2022

Soy & Breast Cancer?

Supplementing with soy isoflavones prior to menopause was shown to reduce dense breast tissue, which is associated with breast cancer, according to a recent study. Get the details in the Soy isoflavone section of our Menopause Supplements Review.

Also see our CL Answer about vitamins or supplements that may reduce breast cancer risk.

11/15/2022

NAD Booster & Cancer Risk

The NAD booster, nicotinamide riboside, increased the spread of certain aggressive cancers in a recent laboratory study, adding to existing concerns. Get the details in the Concerns and Cautions section of our NAD Booster Supplements Review.

Also, see our CL Answer about vitamins and cancer risk.

12/19/2024

Fish Oil for Prostate Cancer?

Did taking fish oil slow the progression of prostate cancer? Find out what a recent study showed in the Cancer section of our Fish Oil Supplements Review, which includes our Top Picks for fish oil.

3/20/2025

Vitamin D & Cancer

Find out if taking vitamin D reduced the risk of cancer among older people in a recent study and if it improved breast cancer prognosis in another study in our Vitamin D Supplements Review, which includes our Top Picks for vitamin D.

3/29/2024

Vitamin D & Prostate Cancer-Related Bone Loss

Taking high-dose vitamin D during androgen deprivation therapy for prostate cancer may help some men prevent bone loss, according to a recent study. Get the details in the Prostate Cancer section of our Vitamin D Supplements Review, which includes our Top Picks for vitamin D.

6/12/2025

Saccharin & Cancer

Does saccharin cause cancer? A link between saccharin and bladder cancer has been debunked. Interestingly, preliminary research suggests saccharin may have anticancer effects. Get the details, and learn more about the pros and cons of saccharin in our article about sweeteners, which includes our Top Picks.

Some people being treated for cancer may benefit from three, rather than two, initial vaccine doses, according to a recent study.

11/29/2022

Cancer Pain

Does CBD reduce cancer pain? Find out in the What It Does section of our Review of products.

1/31/2023

Canned Fish & Cancer?

Is there a link between canned fish and cancer, as there is for some other processed meats? Find out in the Concerns and Cautions section of our Tuna, Salmon, Sardines & Herring Review. Also see our Top Picks for canned fish.

2/03/2023

Niacin & Cancer?

The NAD booster, nicotinamide riboside, might promote growth of existing cancers. Is there similar risk with niacin and niacinamide (nicotinamide)? Find out what evidence suggests in the Concerns and Cautions section of our NAD Booster Supplements Review.

Also, see our Top Pick among niacin supplements in our B Vitamin Supplements Review.

2/07/2023

Smoked Fish & Cancer?

Can eating smoked or salted fish increase the risk of cancer? Find out in the Concerns and Cautions section of our Canned Tuna, Salmon, Sardines & Herring Review. Also see our Top Picks among products.

12/09/2022

Supplement Linked with Stroke

DIM (diindolylmethane), a supplement promoted for treating cancer, has been linked with reports of clots and stroke. Get the details in our updated CL Answer, "Does I3C (from broccoli) or DIM (a related chemical) reduce the risk of cancer?”

4/21/2023

Aspartame & Cancer?

Another study has found a link between use of aspartame (in Equal and NutraSweet) and increased cancer risk. Learn more in our article about sweeteners (which covers more than 20 types of sweeteners).

2/21/2024

Lumbrokinase for Cancer, Infection?

Can lumbrokinase help slow cancer progression or treat chronic infections such as Lyme disease? Find out in our article about lumbrokinase.

7/12/2024

Glucosamine & Cancer Risk?

Is the use of glucosamine associated with the risk of developing cancer? See what a recent study found in the What It Does section of our Joint Health Supplements Review. Also see our Top Picks for glucosamine and other joint health supplements.

10/13/2023

Berberine & Cancer

Does berberine reduce the risk of colon cancer recurrence? Find out what research has shown in the Other uses section of our Berberine Supplements Review, which includes our Top Picks for berberine.

10/20/2023

Vitamin E & Cancer Risk

Supplementing with vitamin E might increase the risk of recurrence of bladder cancer, according to a recent study. Get the details in the Cautions and Concerns section of our Vitamin E Supplements Review.

9/22/2023

Cat’s Claw for Cancer Symptoms?

Does cat’s claw supplementation reduce cancer-related symptoms such as fatigue, insomnia, or gastrointestinal side effects? Find out in our article about the potential benefits and side effects of cat’s claw.

9/12/2023

Vitamin D for Cancer?

Does supplementing with vitamin D improve survival for people with solid tumors and low levels of vitamin D? See what a recent study showed in the Cancer section of our Vitamin D Supplements Review. Also see our Top Picks for vitamin D.

5/22/2025

Niacin for Skin Cancer

Some research suggests that taking high-dose niacin (as nicotinamide, also called niacinamide) can reduce skin cancer risk. Learn more about this (and an observational study of its safety) in the Niacin section of our B Vitamins Review, which includes our Top Picks for niacinamide supplements and other B vitamins.

8/08/2024

Apricot Seeds for Cancer?

A CL Member stated they have a friend who has been eating apricot seeds after being diagnosed with colon cancer and asked if this could be harmful. Find out in our article about supplements and chemotherapy.

9/18/2024

Creatine & Prostate Cancer Treatment

Androgen deprivation therapy (ADT) is a common treatment for prostate cancer, but it can lead to muscle loss. Did taking creatine along with regular exercise increase muscle mass or strength among men undergoing ADT? See what a recent study found in the Creatine section of our Muscle & Workout Supplements Review, which includes our Top Picks among creatine and BCAA supplements.

9/14/2021

NAC and Lung Cancer

Was there a study that showed that animals given NAC developed lung cancer? Find out what research in animals suggested in the Concerns and Cautions section of our NAC supplements Review.

10/14/2022

Do Prebiotics Cause Liver Cancer?

Some CL readers expressed concern over recent headlines suggesting that prebiotic fiber may cause liver cancer. Learn if this should be of concern in the Concerns and Cautions section of our Prebiotics Review.

10/14/2022

Cancer-Causing Sweetener?

Acesulfame potassium is a sweetener in some of the products that we have tested. A CL member asked if it can cause cancer. Find out in the Sweetening agents section of our Inactive Ingredients/Excipients in Supplements Review Article.

5/17/2022

Supplements Reduce Invasive Cancer Risk

Supplementing with vitamin D and omega-3 reduced the risk of invasive cancer in older men and women, according to a recent analysis. Adding resistance exercise further decreased this risk. Get the details in our Vitamin D Supplements and Fish and Marine Oil Supplements Reviews. 

11/18/2020

Vitamin K and Breast Cancer Risk

Can eating foods high in vitamin K affect the risk of breast cancer? Learn what a recent study showed in the What It Does section of our Vitamin K Supplements Review. Also see our Top Picks for vitamin K supplements.

3/23/2021

Folic Acid and Colorectal Cancer

Do higher intakes of folic acid and other sources of folate increase or decrease the risk of colorectal cancer? It may depend on time, according to a new study discussed in the Folate section of our B Vitamin Supplements Review. Also see our Top Picks among B vitamin supplements.

3/27/2021

Curcumin & Prostate Cancer

Does curcumin benefit men undergoing chemotherapy for prostate cancer? See what a new study found in the What It Does section of our Turmeric and Curcumin Supplements & Spices Review. Also see our Top Picks among turmeric and curcumin products.

4/23/2021

Collagen and Breast Cancer?

Does supplementing with collagen increase the risk of breast cancer recurrence? Learn what the evidence shows in the Concerns and Cautions section of our Collagen Supplements Review.

6/01/2021

Citrus And Skin Cancer Risk?

Does consuming citrus fruits and juices increase your risk of skin cancer? See what a recent study found in our update to our answer about supplements, foods, and sun damage.

9/15/2020

Olive Oil & Breast Cancer Risk

Is olive oil consumption associated with a lower risk of breast cancer in women? See what a recent analysis found in the What It Does section of the Extra Virgin Olive Oil Review. Also see our Top Picks for olive oil.

8/06/2020

Chocolate and Cancer

Can eating more chocolate reduce cancer risk? Find out what a recent study showed in the What It Does section of the Dark Chocolates, Cocoa & Cacao Powders, Nibs, and Supplements Review. Also see our Top Picks for dark chocolate, chocolate chips and cocoa powders.

9/22/2018

Vitamin C and Prostate Cancer

Does taking vitamin C reduce the chance of developing prostate cancer? Find out what studies are showing, including one reported this month, in the What It Does section of the Vitamin C Supplements Review. (Also learn about vitamin C and cataracts and see our Top Picks for vitamin C.)

11/12/2016

Vitamin D & Breast Cancer Survival

A new study making headlines this week found that women with "the highest" levels of vitamin D had better survival rates from breast cancer than women with the "lowest rates." What was left out of news stories — and may surprise you — is what these levels are. Find out in the "What It Does" section of the Vitamin D Supplements Review >>

2/18/2017

Selenium and Ovarian Cancer

A recent study found that women with the highest intakes of selenium from supplements had a much lower risk of ovarian cancer than those not getting selenium from supplements. Get the details in the "What It Does" section of the Selenium Supplements Review (which includes our tests of products) >>

9/10/2017

Olive Oil and Prostate Cancer

Another possible benefit of olive oil within a Mediterranean diet is a reduced risk of aggressive prostate cancer, according to a new study. For details about this and other benefits of olive oil, see the updated "What It Does" section of the Extra Virgin Olive Oils Review, which includes our Top Picks among products.

3/06/2019

Soy Isoflavones & Breast Cancer Risk

Soy isoflavones, which have estrogen-like effects, are used by women hoping to reduce menopausal symptoms. A new study suggests this use may raise the risk of breast cancer in some women but lower it in others. For details, see the What It Does section of the Soy Isoflavone Supplements Review.

3/08/2019

CBD & Cancer

Preliminary evidence suggests that CBD (cannabidiol) may have anti-cancer properties, and a dramatic reduction in tumor size was recently reported in a person taking low-dose CBD. For details, see the What It Does section of the CBD Oils and Hemp Extracts Review.

8/29/2017

High-Dose B Vitamins & Lung Cancer Risk

A recent study found that taking high doses of vitamins B6 and B12 was associated with an increased risk of lung cancer among men, particulary among those who smoke. For details, see the "ConsumerTips" section of the B Vitamin Supplements Review >>

6/22/2019

Yogurt and Colorectal Cancer

Does regular consumption of yogurt affect the risk of colorectal polyps and colorectal cancer? Find out what studies are showing in the Fermented Dairy Foods section of the Probiotic Supplements Review.

4/02/2019

Green Tea and Breast Cancer

Drinking green tea has been associated with a reduced risk of breast cancer recurrence. But what effect does high-dose green tea extract have? See what a major study found in the What It Does section of the Green Tea Review. Also see our Top Picks among green tea products.

1/11/2020

Risk With Supplements During Chemotherapy

The risk of cancer recurrence and risk of death were shown to be higher when certain supplements were used by women being treated for breast cancer, according to a recent study. We’ve add details about this to our answer to the question: Do any supplements reduce side of effects of chemotherapy?

10/21/2015

Men's Health Supplements Don't Help Prostate Cancer

While there is some evidence that certain supplements may help relieve symptoms of prostate enlargement (BPH), a recent study shows no benefit with regard to prostate cancer treatment. Details are in the Prostate Supplements Review >>

6/15/2018

Vitamin D & Colorectal Cancer Risk

What level of vitamin D is associated with the lowest risk of colorectal cancer according to a recent study? Find out in the What It Does section of the Vitamin D Supplements Review. (Also see our Top Picks among vitamin D supplements.)

11/25/2017

How Hot Should Green Tea Be?

Drinking green tea may reduce the risk of certain cancers, but its effect on gastric (stomach) cancer may depend on the temperature at which you drink it, according to a new study. Find out what the best temperature seems to be in the "What It Does" section of the Green Tea Review >> (Also see how brands of green tea, including matcha, stack up in our tests.)

7/17/2018

Lower Cancer Risk With High Vitamin D?

A recent analysis suggests that breast cancer risk is lowest with vitamin D blood levels at or above 60 ng/mL -- an unusually high level. Before you try this at home, be sure to read our commentary in the What It Does section of the Vitamin D Supplements Review. (Also see our Top Picks for vitamin D.)

10/24/2018

B Vitamin Cancer Risk?

Giving high-dose vitamin B12 along with a modest amount of folic acid to older people was found to significantly increase the risk of colorectal cancer. See the B12 section of the B Vitamins Review for details. (Also see our Top Picks for B12 and other B vitamins.)

3/20/2019

Hot Tea & Cancer

Drinking very hot tea increases the risk of developing esophageal cancer. How long should you wait after brewing to drink tea? Find out what recent studies are showing in the What It Does section of the Green Tea Review. Also see other tips for the best way to prepare brewable green tea, and our Top Picks among green tea products.

8/06/2019

Vitamin A and Skin Cancer

A study showed that people with higher intakes of vitamin A have a lower risk of developing squamous cell cancer of the skin. Does mean that taking a vitamin A supplement will help? Find out in the What It Does section of the Vitamin A Supplements Review, where we also discuss the risk of melanoma. (Also see our Top Picks for vitamin A supplements.)

8/13/2019

Folic Acid and Colon Cancer

Several studies have evaluated whether folate from food and/or folic acid from supplements affect cancer risk. Find out what a recent report suggests about long-term, high-dose folic acid supplementation in the Folate section of the B Vitamin Supplements Review. Also see our Top Picks for folic acid and other B vitamin supplements.

5/09/2011

Did you hear that DHA (an omega-3 fatty acid in fish oil) might raise the risk of prostate cancer?

This was recently in the news. Higher levels of DHA in the blood were associated with increased risk of high-grade prostate cancer. However, the findings do not mean that you should stop taking fish oil or eating fish. We talked with the researcher of this study and learned more. Get the facts in our Fish Oil Supplements Review. More >>

8/18/2013

Ginseng Reduces Cancer-Related Fatigue

A well-controlled clinical trial recently showed reduced fatigue among cancer patients given a particular type and dose of ginseng. Get the details, as well as our test results for 16 ginseng supplements, in the updated Ginseng Supplements Review >> 

10/13/2013

Multivitamins May Improve Breast Cancer Survival

A study of women with invasive breast cancer found that those who took multivitamins were 30% less likely to die of the disease during the study than women who did not take multivitamins, suggesting a possible role for supplementation. For more information about the study, as well as tests of popular multivitamins, see the updated Multivitamin and Multimineral Supplements Review >> 

12/22/2013

More Evidence of What Multivitamins Don't Do

Several new studies about multivitamins were published this week. The bottom line: In well-nourished people, multivitamins don't reduce the risk of cardiovascular disease or overall-mortality, nor improve cognition and memory. Although some studies have suggested a modest benefit in reducing the risk of certain cancers, no clear cancer benefit for multivitamins has been established. For more information, see the updates to the Multivitamins and Multimineral Supplements Review >>  

3/08/2014

Vitamin D and Breast Cancer Survival

A new analyses of clinical studies found that women with the highest blood levels of vitamin D had a much higher rate of survival from breast cancer than women with the lowest levels. Details on what may be the most beneficial levels, as well as our test results for vitamin D supplements, are found in the updated Vitamin D Supplements Review >>  

5/03/2014

Vitamin D Deficiency May Predict Advanced Prostate Cancer

According to a new study, prostate biopsies in men who are deficient in vitamin D are more likely to show a higher grade and stage of cancer than biopsies in men with higher levels of vitamin D. For more details, as well as our tests of vitamin D supplements, see the Vitamin D Supplements Review >> 

9/01/2013

Calcium During Breast Cancer Treatment

A recent analysis of clinical studies concluded that supplementation with calcium and vitamin D during breast cancer treatment does not help maintain bone mineral density, although often given for this purpose. Calcium and vitamin D may certainly play other important roles. For more details, as well as test results and comparisons for 33 calcium supplements, see the updated Calcium Supplements Review >>

3/01/2015

Selenium and Prostate Cancer

A new study suggests that men who have prostate cancer should not take supplements providing high-dose selenium. Earlier research has similarly advised against high-dose selenium for people with already adequate selenium intake. For details and more about selenium, see the Selenium Supplements Review >> 

4/15/2015

Muscle Supplements and Testicular Cancer

A study of men who have used muscle-building supplements shows a disturbing increase in the risk of testicular cancer. More information is in the Muscle Enhancers (Creatine and Branched-chain Amino Acids) Review >>

4/22/2015

Green Tea Extract and Prostate Cancer

A new study, funded by the National Institutes of Health, showed that fewer men with pre-cancerous lesions developed prostate cancer if given a daily green tea extract supplement, although the results were not statistically significant due, in part, to the small size of the study. However, a somewhat similar study found a significant benefit. Learn more about these studies, and see our test results for green tea supplements, teas, and drinks, in the Green Tea Review >>

5/16/2015

Niacin Reduces Skin Cancer

A recent study suggests that high-dose niacin (vitamin B-3) may reduce the risk of developing certain types of skin cancer. A closer look at the study, however, raises questions about its relevance to people in North America. Get the details, as well as more information about niacin and our product test results & comparisons, in the B Vitamin Supplements Review >> 

2/27/2014

Vitamin E, Selenium Can Increase Cancer Risk

In some men, taking high doses of vitamin E or selenium may double the risk of developing high-grade prostate cancer, according to a recent analysis. For details, including the dose, see the updates to the Vitamin E Supplements Review >> and the Selenium Supplements Review >>   

7/23/2016

Vitamin C and Breast Cancer

Higher intakes of vitamin C from foods are linked to lower risk of postmenopausal breast cancer in women, but getting vitamin C from supplements on top of that may increase the risk, says a new study. Get the details in the Vitamin C Supplements Review >>

4/13/2019

Does Vitamin D Improve Cancer Survival?

Does giving high-dose vitamin D to people with cancer of the colon or other parts of the digestive tract improve survival rates? Find out what recent studies are showing in the What It Does section of the Vitamin D Supplements Review. Also see our Top Picks for vitamin D supplements.

4/19/2017

Niacin & Skin Cancer

People who don't get enough niacin each day may be able to lower their risk of developing squamous cell skin cancer by getting a bit more niacin from their food or supplements suggests a recent analysis. However, this doesn't mean you should overdo it. For details, see the "Niacin" section of the B Vitamin Supplements Review. You can also find foods high in niacin using the food table in the report.

8/23/2017

Curcumin for Cancer?

Curcumin (from turmeric) has shown potentially beneficial biological effects with regard to cancer, although it has not been shown to cause clinical improvements. Nevertheless, a case was recently reported of a woman with myeloma who was stabilized with curcumin treatment. For details, see the "What It Does" section of the Turmeric/Curcumin Review >>

11/04/2017

Cereal Fiber Reduces Risk of Death from Colorectal Cancer

Higher intakes of dietary fiber are associated with a lower risk of colorectal cancer. A new study suggests that higher intakes of fiber from cereal may reduce the risk of dying among those who have the disease. How much is needed for a benefit? Get the details in the "What It Does" section of the Oat Cereals Review >> [Also see our Top Picks for oat cereals in the Review.]

4/21/2013

Does Ginkgo Cause Cancer?

According to a new study from the government, animals given an extract of Ginkgo biloba for two years developed cancers of the thyroid and liver. Should you be concerned? See the "Concerns and Cautions" section of the Ginkgo Biloba Supplements Review for more information, as well our assessment of ginkgo's usefulness, and our tests of ginkgo supplements

7/14/2013

Fish Oil Linked to Prostate Cancer?

Headlines this week about a study showing an association between the fatty acids in fish oil and the development of prostate cancer have stirred concerns about consuming fish and fish oil supplements. For details about this study and studies of other effects of fish oil and omega-3 fatty acids, as well as test results and comparisons for 74 fish and other marine oil supplements, see the updated Fish/Marine Oil (Omega-3) Supplements Review >>

11/04/2012

Vitamin D and Bladder Cancer

A new study looked at vitamin D levels and the risk of developing bladder cancer. Find out which levels were best, as well as which vitamin D supplements pass our tests, in the updated Vitamin D Supplements Review. More >>

10/21/2012

Multivitamin Reduces Cancer Risk in Some

You may have heard that a new study found reduced rates of cancer among men taking a specific daily multivitamin. But there's more to this story... Certain types of men were much more likely to benefit than others. Several multivitamins like the one studied have been tested by ConsumerLab.com, and some Quality Approved products cost as little as 3 cents a day -- a very reasonable investment if it can help you! For details, see the update in the Multivitamin Supplements Review.  More >>

8/02/2012

Vitamin E and Liver Cancer

A study has shown a dramatic decrease in the risk of liver cancer among people taking vitamin E supplements or getting higher amounts of vitamin E from their diets. But don't necessarily rush out to get vitamin E. Read the details in the update to the Vitamin E Supplements Review. More >>

10/13/2023

Fenugreek Safety

Do fenugreek supplements pose a breast cancer risk? Find out in the Side Effects section of our article about fenugreek.

9/08/2023

Starbucks Decaf

Does Starbucks decaffeinate its coffee with chemical solvents? Find out in our article about coffee and cancer risk.

12/20/2022

Supplements While On Chemotherapy

Certain supplements should be used cautiously or avoided by people undergoing chemotherapy due to possible interactions, toxicity, or worsening of cancer status, as discussed in our updated CL Answer about supplements and chemotherapy.

7/18/2023

Aspartame & Cancer

A group of experts recently classified aspartame as "possibly carcinogenic." Learn what evidence was used to support this classification, and find out if all experts agree with it, in the Aspartame section of our article about sugar substitutes.

5/16/2023

Concerning Chemical in Soap

A recent study found that some personal care products, including hand soaps, contain an ingredient known to the State of California to cause cancer. Get the details, including what to look for on the label if you want to avoid it, in our article about soaps that won’t irritate the skin.

Also, see our Top Picks for body wash and bar soap.

8/29/2023

Dunkin’, Nespresso & Decaf

Does Dunkin’ Donuts or Nespresso decaffeinate its coffee with chemical solvents? Find out in our article about coffee and cancer risk.

9/01/2023

Green Tea Interactions

Drinking green tea can affect the absorption of many drugs, as was most recently shown with raloxifene (Evista), a medication used to treat osteoporosis and reduce breast cancer risk. Learn about these interactions (including those with certain statins, beta-blockers, and blood thinners) in the Concerns and Cautions section of our Green Tea Review. Also see our Top Picks among green tea products.

9/01/2023

Decaf Coffee Brands

Do decaffeinated coffees from Seattle's Best or San Fransisco Bay use the solvent methylene chloride? We’ve added information about these to our article about coffee and cancer risk that covers more than 20 coffee brands.

8/01/2023

Chemical in Coffee

Some forms of decaffeinated coffee may contain potentially dangerous residual solvents used to remove the caffeine. See how selected brands compare and how you can avoid solvents in coffee, in our updated article about coffee and cancer.

8/08/2023

Decaf Coffee & Chemical Solvents

Find out which brands of coffee do not use chemical solvents to decaffeinate their coffee in the “Does coffee contain toxic heavy metals or solvents?" section of our article about coffee & cancer.

8/08/2023

CoQ10 During Chemotherapy?

Can CoQ10 be taken during cancer chemotherapy? Find out in the Concerns and Cautions section of our Coenzyme Q10 Supplements Review.

Also see: Do any supplements reduce the side effects of chemotherapy? Should any be avoided?

9/12/2023

Solvent in Instant Decaf?

Does decaf instant coffee contain less solvent than decaf ground coffee? Find out in our updated article about coffee and cancer.

9/15/2023

Early Puberty from Sweetener?

A common sweetener was linked with early puberty in girls in a recent study. An increased risk of cancer has also been reported. See the details in our article about sugar substitutes.

8/22/2023

Maxwell House Decaf

Does Maxwell House decaffeinated coffee contain chemical solvent? Find out what the company told ConsumerLab in our updated article about coffee and cancer.

11/28/2023

DIM for Acne?

Can supplementing with diindolylmethane (DIM) reduce acne? Find out what research has shown in our article about supplements for acne.

Also see: Does I3C (from broccoli) or DIM (a related chemical) reduce the risk of cancer?

3/12/2024

Low-Acid Coffee for Reflux?

Are “low-acid” coffees easier on the stomach or less likely to cause reflux than regular coffee? Find out now in our article about coffee.

Also find out how coffee affects:

• Heart attack risk
• Cholesterol levels
• Blood pressure
• Atrial fibrillation
• Dementia risk
• Cancer risk

3/26/2024

Arsenic in Edible Seaweed

A popular type of edible seaweed was found to contain very high amounts of arsenic, posing a cancer risk. See the details in our Seaweed Snacks & Foods Review. Also see what our tests of popular products showed and our Top Picks among seaweed snacks and foods.

1/23/2024

Is Manuka Honey Safe?

Concerns have been raised that a compound in manuka honey might increase the risk of cancer, but is this true? See what research suggests in our article about manuka honey.

8/01/2024

Cancer-Causing PAH in Olive Oil?

A limit on PAH compounds in oils was recently set in Europe. Should you be concerned about PAH in olive oils? Get the facts in the Concerns and Cautions section of our Extra Virgin Olive Oil (EVOO) Review, which includes our Top Picks for EVOO.

6/18/2024

Mouthwash Caution

A popular alcohol-containing mouthwash increased the abundance of cancer-related bacteria in the mouth. Get the details in the Mouthwash section of our article about toothpaste and other dental products, which includes our Top Pick mouthwash for bleeding gums.

5/14/2024

Chlorophyll Supplements: Benefits and Risks

Do chlorophyll supplements reduce body odor, help prevent cancer, or have other health benefits, and are there adverse effects? Find out in our answer to the question: What are the health benefits of chlorophyll and chlorophyllin, and are they safe?

5/21/2024

Andrographis Health Effects

Find out if andrographis helps with conditions such as cancer, COVID-19, and multiple sclerosis in our article about the health benefits and safety of andrographis.

Also see: Do any supplements reduce symptoms or relapse of multiple sclerosis?

Also see: Do any supplements help with COVID-19?

3/25/2022

Some Potatoes Form Less Toxin

When fried, roasted, or baked, potatoes can contain relatively large amounts of acrylamide – a neurotoxin and potential cancer-causing agent – but the amount depends on the type of potato, according to a recent study. Get the details in our updated answer about acrylamide in foods.

3/11/2022

Green Tea and Colon Polyps

Can taking green tea extract reduce the recurrence colon polyps? See what a recent study found in the What It Does section of our Green Tea Review. Also see our Top Picks among green tea extracts, tea bags, loose tea, and matcha powders.

See our answer to the question: Which supplements help reduce the risk of colorectal cancer?

2/11/2022

Reducing Acrylamide in Cookies

Acrylamide is a neurotoxin and probable cancer-causing agent that can form when cooking or baking certain foods at high temperatures. Find out how to reduce acrylamide formation when baking cookies in our updated article about Acrylamide in Foods, which also includes information about acrylamide in coffee, chocolate, potatoes and other foods.

2/01/2022

Olive Oil Lowers Risk of Death

Regular consumption of olive oil was associated with reduced risk of death from heart disease, cancer, and Alzheimer’s disease in a large, long-term study – but only if replacing certain other foods. Get the details in the What It Does section of our Extra Virgin Olive Oil Review. Also see our Top Picks among extra virgin olive oils.

3/11/2012

When Not to Take Selenium

A researcher has advised not to take selenium if your selenium level is already adequate. Supplementation in people with adequate to high serum levels of selenium may increase the likelihood of developing type 2 diabetes. For details, see the update to the Concerns and Cautions section of the Cancer Supplements Review. More >>

10/23/2011

Vitamin E Risk

A study of healthy men who had taken a high-dose vitamin E supplement for several years showed a 17% increase in the risk of prostate cancer compared to men who took a placebo. See the Vitamin E Supplements Review for details, extensive information about vitamin E, and our quality ratings of vitamin E supplements.  More >>

3/09/2011

Fish Oil Helps in Chemotherapy

A recent study in lung cancer patients showed that those using fish oil supplementation during initial chemotherapy tended to maintain their muscle and total weight while those who did not lost 5 lbs of weight on average (2.2 lbs of which was muscle). See the Fish Oil (Omega-3) Product Review for more details, including the dosage used. More >>

10/17/2015

Headlines Saying "Vitamin D and Calcium Don't Prevent Colon Cancer" Are Not Quite Right

A study released this week found that vitamin D and calcium supplements did not reduce the risk of developing colorectal polyps in people prone to them. A closer look at the study, however, suggests that this may not be true for everyone. Get the details in the update in the Vitamin D Supplements Review >> and the Calcium Supplements Review >>

11/09/2017

Curcumin Drug Interaction

Curcumin, from turmeric, can affect many prescription drugs. The most recent report involves an immunosuppressive drug also used in cancer treatment. For details about this interaction and other drug interactions of curcumin and turmeric, see the "Concerns and Cautions" section of the Turmeric & Curcumin Supplements Review >>

10/06/2017

Green Tea & Prostate Cancer

A recent study investigated the effects of green tea extract in men with pre-cancerous changes of the prostate. Find out if it helped in the "What It Does" section of the Green Tea Supplements and Drinks Review >>

4/12/2019

Food vs. Supplements for Getting Vitamins & Minerals

We've added new information to our answer to the question Is it better to get vitamins from foods or supplements, and are natural vitamins better than synthetic vitamins? The new information is based on an investigation of the association between nutrient intakes and the risk of dying from cancer and/or other causes.

9/29/2015

Melatonin Helps Post-Op Sleep

A study found that giving melatonin to women significantly improved their sleep time during the weeks after breast cancer surgery. For details, including our tests of products, see the Melatonin Supplements Review >>

7/06/2016

Lower Risk of Death With Green Tea

A long-term study of men in China found that those who regularly drank green tea — particularly larger amounts — were less likely to die during the study and had lower risks of dying from cardiovascular disease or cancer, compared to non-green tea drinkers. Get the details in the "What It Does" section of the Green Tea Review >>

3/15/2017

Anti-Inflammatory Effect of Juice Plus+?

Chronic systemic inflammation is a risk factor for cardiovascular disease, diabetes, and cancer. A recent clinical trial assessed the product Juice Plus+ for its ability to reduce this inflammation in obese men and women. The abstract of the published study indicates that it works, but the results tell a different story. For details, see the "What It Does" section of the Greens and Whole Foods Powders, Pills, and Drinks Review (which includes our tests of products) >>

3/29/2017

Vitamin E/Selenium & Alzheimer's

A long-term study among men in the U.S. found that giving high doses of vitamin E and/or selenium did not significantly affect their risk of developing dementia. The study was part of a larger study which found that these supplements increased the risk of prostate cancer, type 2 diabetes, hair loss, and dermatitis. For details, see the "Alzheimer's disease/dementia" section of the Selenium Supplements Review >>

8/31/2021

Chia Seeds and Estrogen

Do chia seeds contain plant estrogens and, if so, should I be concerned as I have a family history of breast cancer? See the answer in the Concerns and Cautions section of our Chia Seeds Review.

6/12/2021

Vitamin D and Melanoma

Can vitamin D supplementation improve outcomes in people with melanoma skin cancer? See what a new study found in the What It Does section of the Vitamin D Supplements Review.

Also see our answer to the question: Do any supplements or foods help prevent sunburn or skin damage from sun exposure? Can any increase your risk of sun-related skin damage?

3/16/2019

Colloidal Silver Concern

Long-term use of colloidal silver may have contributed to the development of bone marrow cancer, according to a new report. We've added details about this to our answer to the question: Is ingesting colloidal silver helpful for any condition and is it safe to use?

4/22/2020

Melatonin During Chemotherapy?

Does melatonin improve sleep quality and have other benefits during chemotherapy for breast cancer? Find out what a recent study showed in the What It Does section of the Melatonin Supplements Review. Also see our Top Picks for melatonin.

2/01/2020

Pomegranate for Memory?

Pomegranate juice and supplements have been promoted for improving cardiovascular health, controlling blood sugar, and inhibiting prostate cancer. Most recently pomegranate juice was tested in a year-long study for its effects on memory. Find out if it helped, and see if it works for other touted uses, in the What It Does section of the Pomegranate Juice and Supplements Review Article.

2/04/2020

Berberine vs. Colon Cancer?

A large study investigated the potential for berberine (promoted for blood sugar control) to prevent precancerous colon polyps. Find out if it worked in the What It Does section of the Berberine & Goldenseal Supplements Review. Also see our Top Pick for berberine.

5/30/2020

Cranberry for Cystitis in Men?

Cystitis (inflammation of the bladder) is common in men undergoing radiation therapy for prostate cancer. A study evaluated whether a cranberry supplement could reduce the incidence of cystitis in these men. Find out if it helped in our updated answer to the question: Are cranberry supplements helpful for men? Can they help with symptoms of prostatitis or urinary tract infections?

2/11/2020

Vinegar Makes Grilling Safer

Grilling food can create cancer-causing compounds, but a study shows that vinegar can help. Find out how in the What to Consider When Using section of the Apple Cider Vinegar Review. Also see our Top Picks for apple cider vinegar.

10/05/2019

Extra Protein During Chemotherapy?

Is taking extra whey protein during chemotherapy helpful to malnourished cancer patients? Learn what a study found in the What It Does section of the Protein Powders, Shakes, and Drinks Review. Also see our Top Picks among protein powders.

6/19/2019

NAD+ and Cancer?

Supplements that raise NAD+ levels in the body have been promoted for anti-aging effects. But there is a theoretical risk that they could stimulate cancerous cells, and a CL member reported this week that a supplement containing such an ingredient, nicotinamide riboside, appeared to increase his PSA level. Learn more in the Niacin section of the B Vitamin Supplements Review.

1/27/2019

Caution With Antioxidants

A new study suggests it might be risky to take antioxidant supplements during cancer treatment. We have added this important information to our answer to the following question: Can supplements with antioxidants like beta-carotene and vitamins A and E cause you to die sooner?

11/11/2018

Mixed Results for EPA/DHA Fish Oil

Concentrated EPA/DHA fish oil given daily to a cross-section of Americans was not found to lower the risk of cancer or cardiovascular disease except for those with low fish intake and for African-Americans. See the details in the What It Does section of the Fish Oil Supplements Review. Also see which supplements are comparable to the fish oil in the study.