10 Best Ways to Prevent Cancer: Evidence Based Guide (2023 Edition)
Information related cancer prevention has been overwhelming and confusing as well. Information is all over the place and various groups are giving conflicting statements. How do you make sense from all these fragmented information?
New studies are being added almost every day. We have organised and summarised relevant and salient research information in one place. Below, we look at the most published and studied categories.
- Don't use tobacco
- Healthy diet and Cancer Fighting Foods
- Olive Oil
- Turmeric (Curcumin)
- Tomato (Lycopene)
- Citrus Fruits
- Cancer and supplements
- Vitamin D3, K2 and Magnesium
- Omega-3 Fatty Acids
- EGCG (Green tea)
- Allicin (Garlic)
- Curcumin (Turmeric)
- Molecular Hydrogen
- Vitamin C
- Vitamin B6
- Maintain a healthy weight and be physically active
- Avoid risky behaviors
- Protect yourself from the sun
- Get regular medical care and Health Screening
- Avoid unnecessary exposure to radiation.
- Avoid exposure to environmental toxins and infections that contribute to cancer
- Sleep Quality and Reduce Stress
Below, we look at the best prevention strategies for cancer and summaries of the rationale and evidence for each category.
1. Don't use tobaccoSmoking has been linked to many types of cancer, including cancer of the lung, mouth, throat, voice box, pancreas, bladder, cervix and kidney. Even being around secondhand smoke might increase the risk of lung cancer.
But it's not only smoking that's harmful. Chewing tobacco has been linked to cancer of the mouth, throat and pancreas.
Staying away from tobacco — or deciding to stop using it — is an important way to help prevent cancer. For help quitting tobacco, ask a health care provider about stop-smoking products and other ways of quitting.
2. Healthy diet and Cancer Fighting FoodsAlthough eating healthy foods can't ensure cancer prevention, it might reduce the risk. Consider the following in general:
- Eat plenty of fruits and vegetables. Base your diet on fruits, vegetables and other foods from plant sources — such as whole grains and beans. Eat lighter and leaner by choosing fewer high-calorie foods. Limit refined sugars and fat from animal sources.
- Drink alcohol only in moderation, if at all. Alcohol increases the risk of various types of cancer, including cancer of the breast, colon, lung, kidney and liver. Drinking more increases the risk.
- Limit processed meats. Eating processed meat often can slightly increase the risk of certain types of cancer. This news comes from a report from the International Agency for Research on Cancer, the cancer agency of the World Health Organization.
Do take note that we are talking about foods to prevent your risk of cancer and not about treating cancer with foods. Cancer treatments will be something that you will need to discuss with your cancer specialist.
We will delve into the research and look at a list of foods that may lower your risk of cancer.
One test-tube study showed that sulforaphane reduced the size and number of breast cancer cells by up to 75% (Clin Cancer Res. 2010).
Similarly, an animal study found that treating mice with sulforaphane helped kill off prostate cancer cells and reduced tumor volume by more than 50% (Carcinogenesis. 2004).
Some studies have also found that a higher intake of cruciferous vegetables like broccoli may be linked to a lower risk of colorectal cancer.
Including broccoli with a few meals per week may come with some cancer-fighting benefits.
However, keep in mind that the available research hasn’t looked directly at how broccoli may affect cancer in humans.
Instead, it has been limited to test-tube, animal and observational studies that either investigated the effects of cruciferous vegetables, or the effects of a specific compound in broccoli. Thus, more studies are needed.
In one human study, 25 people with colorectal cancer were treated with bilberry extract for seven days, which was found to reduce the growth of cancer cells by 7% (Source).
Another small study gave freeze-dried black raspberries to patients with oral cancer and showed that it decreased levels of certain markers associated with cancer progression (Source).
One animal study found that giving rats freeze-dried black raspberries reduced esophageal tumor incidence by up to 54% and decreased the number of tumors by up to 62% (Source).
Similarly, another animal study showed that giving rats a berry extract was found to inhibit several biomarkers of cancer (Source).
Based on these findings, including a serving or two of berries in your diet each day may help inhibit the development of cancer. Keep in mind that these are animal and observational studies looking at the effects of a concentrated dose of berry extract, and more human research is needed.
For instance, a study looked at the diets of 19,386 people and found that eating a greater amount of nuts was associated with a decreased risk of dying from cancer (Br J Nutr. 2015).
Another study followed 30,708 participants for up to 30 years and found that eating nuts regularly was associated with a decreased risk of colorectal, pancreatic and endometrial cancers (Source).
Other studies have found that specific types of nuts may be linked to a lower cancer risk. For example, Brazil nuts are high in selenium, which may help protect against lung cancer in those with a low selenium status (Trusted Source).
Similarly, one animal study showed that feeding mice walnuts decreased the growth rate of breast cancer cells by 80% and reduced the number of tumors by 60% (Trusted Source).
These results suggest that adding a serving of nuts to your diet each day may reduce your risk of developing cancer in the future.
Still, more studies in humans are needed to determine whether nuts are responsible for this association, or whether other factors are involved.
2.4. Olive Oil
Research has found that eating nuts may be linked to a lower risk of certain types of cancer. There are more than 1,000 search results on olive oil and cancer on PubMed.
One massive review made up of 19 studies showed that people who consumed the greatest amount of olive oil had a lower risk of developing breast cancer and cancer of the digestive system than those with the lowest intake (Source).
Another study looked at the cancer rates in 28 countries around the world and found that areas with a higher intake of olive oil had decreased rates of colorectal cancer (Source).
Swapping out other oils in your diet for olive oil is a simple way to take advantage of its health benefits. You can drizzle it over salads and cooked vegetables, or try using it in your marinades for meat, fish or poultry.
Though these studies show that there may be an association between olive oil intake and cancer, there are likely other factors involved as well. More studies are needed to look at the direct effects of olive oil on cancer in people.
2.5. Tomato (Lycopene)It has long been known that tomato consumption reduces the risk of developing cancer and cardiovascular disease, due to its high lycopene content (Ratto 2022).
For example, an analysis looked at the results of five studies and concluded that eating carrots may reduce the risk of stomach cancer by up to 26% (Source).
Another study found that a higher intake of carrots was associated with 18% lower odds of developing prostate cancer (Source).
One study analyzed the diets of 1,266 participants with and without lung cancer. It found that current smokers who did not eat carrots were three times as likely to develop lung cancer, compared to those who ate carrots more than once per week (Source).
Try incorporating carrots into your diet as a healthy snack or delicious side dish just a few times per week to increase your intake and potentially reduce your risk of cancer.
Still, remember that these studies show an association between carrot consumption and cancer, but don’t account for other factors that may play a role.
One study followed 1,905 people with a history of colorectal tumors, and found that those who consumed more cooked, dried beans tended to have a decreased risk of tumor recurrence (Source).
According to these results, eating a few servings of beans each week may increase your fiber intake and help lower the risk of developing cancer.
2.8. Turmeric (Curcumin)
For the best results, aim for at least 1/2–3 teaspoons (1–3 grams) of ground turmeric per day. Use it as a ground spice to add flavor to foods, and pair it with black pepper to help boost its absorption.
2.9. Citrus Fruits
One large study found that participants who ate a higher amount of citrus fruits had a lower risk of developing cancers of the digestive and upper respiratory tracts (Source).
A review looking at nine studies also found that a greater intake of citrus fruits was linked to a reduced risk of pancreatic cancer (Trusted Source).
Finally, a review of 14 studies showed that a high intake, or at least three servings per week, of citrus fruit reduced the risk of stomach cancer by 28% (Trusted Source).
These studies suggest that including a few servings of citrus fruits in your diet each week may lower your risk of developing certain types of cancer.
Keep in mind that these studies don’t account for other factors that may be involved. More studies are needed on how citrus fruits specifically affect cancer development.
lower risk of breast cancer. Tofu (bean curd), is a popular food derived from soy in Asia.
A review of 35 studies (Plos One. 2014) found that soy intake could lower the risk of breast cancer for both pre- and post-menopausal women in Asian countries. However, for women in Western countries, pre- or post-menopausal, there is no evidence to suggest an association between intake of soy isoflavone and breast cancer.
3. Cancer and supplements
For reasons other than cancer prevention, some vitamin and/or mineral supplements may be beneficial for some people to prevent nutrient deficiency, such as in pregnant women, women of childbearing age, and people with restricted dietary intakes. Dietary supplementation may also be indicated to correct a documented clinical deficiency or insufficiency, such as supplementation with vitamin D in those with low circulating concentrations or vitamin B12 supplementation in those with vitamin B12-associated anemias.
Although a diet rich in vegetables, fruits, and other plant-based foods may reduce the risk of cancer, there is limited and inconsistent evidence that dietary supplements can reduce cancer risk (R). Whereas 2 RCTs showed reductions in cancer risk among men taking low-dose antioxidants or low-dose multiple micronutrients, evidence for women is lacking. Furthermore, evidence exists that some high-dose supplements containing nutrients such as β-carotene and vitamins A and E can increase the risk of some cancers (R). For individual nutrients, an exception may be calcium, in which supplemental calcium may reduce the risk of colorectal cancer. However, people who have excessive calcium intake (mostly from supplements) may have a higher risk of death from all cancer types combined compared with those who have a recommended level of dietary calcium. The same study also reported no overall benefit to longevity from all dietary supplements considered together. Nonetheless, more than one-half of US adults use one or more dietary supplement(s).
Many healthful compounds are found in vegetables and fruits, and it is likely that these compounds work synergistically to exert their beneficial effect. There are likely to be important, but as yet unidentified, components of whole food that are not included in dietary supplements. Some supplements are described as containing the nutritional equivalent of vegetables and fruits. However, the small amount of dried powder in such pills frequently contains only a small fraction of the levels contained in the whole foods, and there is a lack of evidence supporting a role of these products in cancer prevention. Food is the best source of vitamins, minerals, and other bioactive food components.
3.1. Vitamin D3, K2 and MagnesiumVitamin D can absorb calcium and help the immune, muscle, and nervous systems function properly. There are more than 13,000 search results on vitamin D and cancer on PubMed.
The cancers for which the most human data are available are colorectal, breast, prostate, and pancreatic cancer. Numerous epidemiologic studies have shown that higher intake or blood levels of vitamin D are associated with a reduced risk of colorectal cancer (R). In contrast, the Women’s Health Initiative randomized trial found that healthy women who took vitamin D and calcium supplements for an average of 7 years did not have a reduced incidence of colorectal cancer (NEJM 2006). Some scientists have pointed out that the relatively low level of vitamin D supplementation (10 μg, or 400 IU, once a day), the ability of participants to take additional vitamin D on their own, and the short duration of participant follow-up in this trial might explain why no reduction in colorectal cancer risk was found.
- fatty fish
- egg yolks
- fortified milk
3.2. EGCG (Green tea)
3.3. Curcumin (Turmeric)The spice turmeric can be extremely helpful when it comes to fighting cancer. There are more than 7,000 search results on curcumin and cancer on PubMed and more than 50 clinical trials with curcumin and cancer, most of which are still ongoing.
- blocking cancer cells from multiplying
- killing colon, breast, prostate, and melanoma cancer cells
- slowing tumor growth
"Curcumin blocks the formation of reactive-oxygen species, possesses anti-inflammatory properties as a result of inhibition of cyclooxygenases (COX) and other enzymes involved in inflammation; and disrupts cell signal transduction by various mechanisms including inhibition of protein kinase C.
These effects may play a role in the agent's observed antineoplastic properties, which include inhibition of tumor cell proliferation and suppression of chemically induced carcinogenesis and tumor growth in animal models of cancer."
3.4. Omega-3 Fatty Acids
There are more than 4,000 search results on Omega 3 and cancer on PubMed. Most people use fish oil supplements to
enhance the amount of omega-3’s in their
Findings from a study performed in mice, research from
Harvard Medical School’s Beth Israel Deaconess Medical
Center in Boston demonstrated omega-3 fat could reduce
tumor growth by 67% (R).
The research was presented April 4, 2022 at the annual
Experimental Biology meeting in Philadelphia. The animal
model showed that omega-3 fatty acids helped promote the
cancer-fighting activities of immunotherapy and
Many governments recommend eating omega-3 containing
fatty fish, two times per week. But that is often not
enough. Ideally, people would need to eat fatty fish
four times per week, while also supplementing with
omega-3 fatty acids, at least 1,000 mg of pure omega-3
(DHA and EPA) per day.
However, fish oil was shown
one study on mice (2015) to possibly reduce the effectiveness of
chemotherapy, and for that reason ground flax seed
is a worthy alternative.
Flax seed is rich in omega-3 fatty acids,
which may reduce the risk of certain cancers. When supplementing, try to avoid flaxseed
oil because it lacks the nutrients of
ground flax seed. Ground flax seed can be
purchased online or found in many larger grocery store
chains. Simply sprinkle some ground flax seed on your
food and enjoy.
Make sure you buy
high-quality omega-3 fatty acid supplements, meaning
that the omega-3 fatty acids are pure and have not
oxidized much (having low “TOTOX” value).
TOTOX value stands for total oxidation value. The omega
3 fatty acids EPA and DHA from fish oil are highly
sensitive to oxidation. This means that they are rapidly
affected by contact with oxygen. Oxidised fatty acids
are not beneficial to our health. For this reason, a
good fish oil supplement has a low TOTOX value. The
maximum TOTOX value is set at 26 by the Global
Organization for EPA and DHA omega-3.
Related: Researchers Showed Omega-3 Could Cut Tumor Growth
The research was presented April 4, 2022 at the annual Experimental Biology meeting in Philadelphia. The animal model showed that omega-3 fatty acids helped promote the cancer-fighting activities of immunotherapy and anti-inflammatory therapy.
Make sure you buy high-quality omega-3 fatty acid supplements, meaning that the omega-3 fatty acids are pure and have not oxidized much (having low “TOTOX” value).
Related: Researchers Showed Omega-3 Could Cut Tumor Growth by 67%
Garlic is a great choice when it comes to
giving your body a little extra protection. To
reap the benefits of garlic, you should eat one
clove per day, or
300 to 1,000 milligrams (mg) of garlic extract.
Protective effects may include:
The active component in garlic is allicin, a
compound that has been shown to kill off cancer
cells in multiple test-tube studies (Source, Source, Source).
- antibacterial properties
blocking and halting the activation of
- enhanced DNA repair
- a reduction in cancer cells spreading
There is evidence demonstrating garlic can kill
cancer cells in vitro. Several studies have analyzed
the effects that dietary garlic may have on the
development of colorectal cancer.
Several clinical studies have found an
association between garlic intake and a lower
risk of certain types of cancer.
One study of 543,220 participants found that those
who ate lots of Allium vegetables, such as garlic,
onions, leeks and shallots, had a lower risk of
stomach cancer than those who rarely consumed
A study of 471 men showed that a higher intake of
garlic was associated with a reduced risk of
prostate cancer (Source).
A meta-analysis of 11 studies, published
in January 2020, did find evidence that garlic could reduce
the risk of ColoRectal Cancer.
Another study published in the Asia Pacific Journal of Clinical
Oncology (2019) revealed the odds of getting
ColoRectal Cancer were 79% lower in those who
a diet high in allium vegetables, which
include garlic, leeks and onions.
Based on these findings, including 2–5
grams (approximately one clove) of fresh
garlic into your diet per day can help you
take advantage of its health-promoting
Despite the promising results showing an
association between garlic and a reduced
risk of cancer, more studies are needed to
examine whether other factors play a
- antibacterial properties
- blocking and halting the activation of cancer-causing substances
- enhanced DNA repair
- a reduction in cancer cells spreading
Several clinical studies have found an association between garlic intake and a lower risk of certain types of cancer.
One study of 543,220 participants found that those who ate lots of Allium vegetables, such as garlic, onions, leeks and shallots, had a lower risk of stomach cancer than those who rarely consumed them (Source).
A study of 471 men showed that a higher intake of garlic was associated with a reduced risk of prostate cancer (Source).
Despite the promising results showing an association between garlic and a reduced risk of cancer, more studies are needed to examine whether other factors play a role.
3.6. Molecular Hydrogen and Cancer
Published in the Asian Pacific Journal of Cancer Prevention in 2023, this systematic review is the first to summarise effects associated with the use of molecular hydrogen for cancer. Out of the 677 articles retrieved from Cochrane, PubMed and Google Scholar, 27 articles were included for this systematic review. Based on the authors' analysis, "H2 plays a promising therapeutic role as an independent therapy as well as an adjuvant in combination therapy, resulting in an overall improvement in survivability, quality of life, blood parameters, and tumour reduction."
3.7. QuercetinQuercetin is an antioxidant flavonol that's found in foods such as red grapes, green tea, elderflower and onions, to name a few. As the health benefits of the supplement become more widely known, the market has grown rapidly (R). According to market research, quercetin market was worth $261.12 million in 2020 and is expected to reach $406.58 million in 2027.
2022 - A paper published in August 2022 in Nutrition Research analyzed the pro-apoptotic effect that quercetin has on aging cells. The paper reviewed preclinical and early phase data using quercetin as a senolytic agent and found the data showed it was effective in “preventing or alleviating cancer formation.”
The authors reviewed the importance of cellular aging in the development of cancer cells and the effect that quercetin may have on the suppression of cancer cell proliferation.
Cellular senescence is a dynamic and multi-step process that is associated with alterations in metabolic activity and gene expression. This can compromise tissue regeneration and contribute to aging. On the other hand, by removing senescent cells, age-related dysfunction can be attenuated and potentially extend the lifespan.
This study published in 2017 in Oncology Reports took things a step further, finding that quercetin induced cancer cell death in nine types of cancer, including prostate cancer, colon cancer, and breast caner.
In another 2017 study, researchers gave quercetin to mice with tumors. Researchers found that mice in the quercetin-treated group showed delayed tumor growth, no significant changes in daily behavior, significantly better survival ratings, and increased rates of cell death.
Lab studies (2011) have also demonstrated that quercetin is a strong antioxidant and has pro-apoptotic effects on tumor cells, with the ability to block growth at different phases of the cell cycle.
3.8. MelatoninMelatonin is one of the most important antioxidant molecules. In the human body — aside from having direct antioxidant effects — it also stimulates the synthesis of glutathione and other important antioxidants like superoxide dismutase and catalase.
3.9 - 3.10. Vitamin C and B6
Sally Norton, author of “Toxic Superfoods: How Oxalate Overload Is Making You Sick — and How to Get Better,” explains:
By the third time, I became harder and harder to stab for the IV needle because now my veins were ropier and rollier and would run away from the needle. That's fibrosis ... I only had IV vitamin C maybe 10 times. But the doctor and the nurse took no notice of this side effect of the treatment — that I was becoming more fibrotic and harder to puncture ...
It's hubris to say, ‘Oh, well, it's fine. All my patients are doing great on my vitamin C IVs when you're not open to seeing the side effects. One of the studies demonstrated that just with oral supplementation, for not all that long, once they stopped the vitamin C, the level of oxalate in the urine went way up.
So, while the body's being assaulted by too much vitamin C, it's busy sequestering the oxalate that's forming and holding onto it and protecting the kidneys from devastation, from excessive oxalate load. Once you stop producing or eating too much oxalate, this holding pattern can let go, and now you see much higher oxalate levels in the blood and the urine.”
For these reasons, if you take vitamin C on a regular basis, Norton recommends limiting it to 250 mg a day. This is enough to meet your nutritional requirements and is unlikely to cause oxalic acid-related trouble. The exception would be if you are septic, in which case large doses of IV ascorbic acid can save your life.
4. Maintain a healthy weight and be physically activeBeing at a healthy weight might lower the risk of some types of cancer. These include cancer of the breast, prostate, lung, colon and kidney.
Physical activity counts too. Besides helping control weight, physical activity on its own might lower the risk of breast cancer and colon cancer.
Doing any amount of physical activity benefits health. But for the most benefit, strive for at least 150 minutes a week of moderate aerobic activity or 75 minutes a week of hard aerobic activity.
You can combine moderate and hard activity. As a general goal, include at least 30 minutes of physical activity in your daily routine. More is better.
5. Avoid risky behaviors
Another effective cancer prevention tactic is to avoid risky behaviors that can lead to infections that, in turn, might increase the risk of cancer. For example:
Practice safe sex. Limit the number of sexual partners and use a condom. The greater the number of sexual partners in a lifetime, the greater the chances of getting a sexually transmitted infection, such as HIV or HPV.
People who have HIV or AIDS have a higher risk of cancer of the anus, liver and lung. HPV is most often associated with cervical cancer, but it might also increase the risk of cancer of the anus, penis, throat, vulva and vagina.
- Don't share needles. Injecting drugs with shared needles can lead to HIV, as well as hepatitis B and hepatitis C — which can increase the risk of liver cancer. If you're concerned about drug misuse or addiction, seek professional help.
6. Protect yourself from the sun
Skin cancer is one of the most common kinds of cancer and one of the most preventable. Try these tips:
- Avoid midday sun. Stay out of the sun between 10 a.m. and 4 p.m. when the sun's rays are strongest.
- Stay in the shade. When outdoors, stay in the shade as much as possible. Sunglasses and a broad-brimmed hat help too.
- Cover your skin. Wear clothing that covers as much skin as possible. Wear a head cover and sunglasses. Wear bright or dark colors. They reflect more of the sun's harmful rays than do pastels or bleached cotton.
- Don't skimp on sunscreen. Use a broad-spectrum sunscreen with an SPF of at least 30, even on cloudy days. Apply a lot of sunscreen. Apply again every two hours, or more often after swimming or sweating.
- Don't use tanning beds or sunlamps. These can do as much harm as sunlight.
7. Get regular medical care and Health ScreeningDoing regular self-exams and having screenings for cancers — such as cancer of the skin, colon, cervix and breast — can raise the chances of finding cancer early. That's when treatment is most likely to succeed. Ask a health care provider about the best cancer screening schedule for you.