Cancer Risk Factors

Do you know people who’ve smoked their whole lives and thrived well into old age without any sign of lung cancer? Or someone who never seemed to go near fruits and veggies but lived a long, full life? When you think of them, you might decide that cancer will come when it comes and there’s nothing you can do about it. That’s where you’d be wrong.

There will always be someone you know whose health flies in the face of conventional medical wisdom. But clinical studies of cancer risks can involve thousands of people and last several years. They give scientists a far broader perspective on cancer risk and prevention than you could ever get yourself.

You might also believe there’s little you can do to lower your cancer risk because you’ve heard that genes play a role in many cancers. It’s true that people who have certain versions of particular genes can be more susceptible to some cancers and the factors in the environment that trigger them. While you can’t change the genes you inherited from your parents, you can change factors in the environment.

Not all people are equally susceptible to a given type of cancer, and different people will get different benefits from cancer prevention strategies. But there are several general lifestyle changes that researchers have proven lower your risk of cancer. There are others they suspect may lower your risk. Researchers are studying those further. So why not make some changes now and lower the chance you’ll have to go through a rough, costly and potentially fatal battle with cancer?

“On average, about 30 to 35% of cancers relate to smoking,” says Dr. John A. Milner of NIH’s National Cancer Institute. “About 30 to 35% relate to diet. Overall, it’s estimated that about 90% of cancers are due to factors in the environment. Something other than our genes are triggers.”

So what are the environmental factors? Milner explains, “The air we breathe, the water we drink and the food we eat are all environmental factors.”

The greatest cancer risk factor through the air comes from cigarette smoke. Cigarette smoking is the leading preventable cause of death in the United States. It leads to an estimated 438,000 deaths—or about 1 out of every 5 deaths—each year. Some people are particularly susceptible to lung cancer from smoking. A recent NIH-funded study found that both African Americans and Native Hawaiians had significantly greater risks of lung cancer related to smoking than whites, Hispanics and Japanese Americans. So don’t smoke, and avoid second-hand smoke, too.

People who have a poor diet, don’t get enough physical activity or are overweight may be at increased risk of several types of cancer. Studies suggest that people who eat high-fat diets with few fruits and vegetables have an increased risk of cancers of the colon, uterus and prostate. Be sure to eat 5 to 9 servings of fruits and vegetables every day along with whole-grain breads and cereals. Limit foods that are high in fat, such as butter, whole milk and fried foods.

Lack of physical activity and being overweight are risk factors for cancers of the breast, colon, esophagus, kidney and uterus. Some studies have also reported links between obesity and cancers of the gallbladder, ovaries and pancreas. Physical activity can help control your weight and reduce body fat. Most scientists agree that adults should engage in moderate physical activity (such as brisk walking) for at least 30 minutes on 5 or more days each week.

Ultraviolet (UV) radiation, which comes from the sun, sunlamps and tanning booths, causes skin damage that can lead to skin cancer. Limit your time in the sun, use sun protection and avoid other sources of UV radiation.

Some chemicals and other substances can raise your risk of getting cancer. People who have certain jobs—such as painters, construction workers and those in the chemical industry—have an increased risk of cancer. You can be exposed to hazardous chemicals in your home as well. Follow instructions and safety tips to avoid or reduce contact with harmful substances such as pesticides, used engine oil, solvents and other chemicals.

Some bacteria and viruses may also increase the risk of developing cancer. If you have a stomach ulcer, it could be a sign that you have bacteria that can also cause stomach cancer. Human papillomaviruses (HPVs) are the main cause of cervical cancer and may also be a risk factor for other types of cancer. Hepatitis B or C infections can lead to liver cancer. HIV, the virus that causes AIDS, raises the risk of certain cancers. Don’t have unprotected sex or share needles, and consider getting the vaccines for hepatitis B and HPV.

It’s important to talk to a health professional about your specific cancer risks and what you can do to lower them. Make sure to discuss the cancers that people in your family have had. Your doctor can also help you figure out if you have particular risks because of your lifestyle. Together, you can put together a plan to lower your risk of getting cancer.

Source: NIH News in Health (NIH)1

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In two disorders in which patients display DNA repair-deficiencies, Xeroderma pigmentosa (XP) and Cockayne's syndrome (CS), patients are extremely sensitive to UV light and exhibit an increased incidence of skin cancer.

XP patients have a defect in nucleotide excision repair (NER) but display no neurologic sequelae.

CS patients show defects in transcription-coupled repair (TCR) and the repair of oxidative base damage, and intriguingly, bear neurologic pathologies, including an ataxic gait and demyelination.

In the two helicase deficiencies discussed, Bloom's and Werner's syndromes, patients have an increased cancer predisposition but no neurologic disease is evident.

Source: NINDS (NIH)2

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Risk Factors

Key Points

Factors That are Known to Increase the Risk of Cancer

Factors That May Affect the Risk of Cancer

Scientists study risk factors and protective factors to find ways to prevent new cancers from starting. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.

Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Risk factors that a person can control are called modifiable risk factors.

Many other factors in our environment, diet, and lifestyle may cause or prevent cancer. This summary reviews only the major cancer risk factors and protective factors that can be controlled or changed to reduce the risk of cancer. Risk factors that are not described in the summary include certain sexual behaviors, the use of estrogen, and being exposed to certain substances at work or to certain chemicals.

Source: NCI (NIH)3

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Environmental Risk Factors

Being exposed to chemicals and other substances in the environment has been linked to some cancers:

  • Links between air pollution and cancer risk have been found. These include links between lung cancer and secondhand tobacco smoke, outdoor air pollution, and asbestos.
  • Drinking water that contains a large amount of arsenic has been linked to skin, bladder, and lung cancers.

Studies have been done to see if pesticides and other pollutants increase the risk of cancer. The results of those studies have been unclear because other factors can change the results of the studies.

Source: NCI (NIH)4

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Does someone who inherits a cancer-predisposing mutation always get cancer?

No. Even if a cancer-predisposing mutation is present in a family, it does not necessarily mean that everyone who inherits the mutation will develop cancer. Several factors influence the outcome in a given person with the mutation.

One factor is the pattern of inheritance of the cancer syndrome. To understand how hereditary cancer syndromes may be inherited, it is helpful to keep in mind that every person has two copies of most genes, with one copy inherited from each parent. Most mutations involved in hereditary cancer syndromes are inherited in one of two main patterns: autosomal dominant and autosomal recessive.

With autosomal dominant inheritance, a single altered copy of the gene is enough to increase a person’s chances of developing cancer. In this case, the parent from whom the mutation was inherited may also show the effects of the gene mutation. The parent may also be referred to as a carrier.

With autosomal recessive inheritance, a person has an increased risk of cancer only if he or she inherits a mutant (altered) copy of the gene from each parent. The parents, who each carry one copy of the altered gene along with a normal (unaltered) copy, do not usually have an increased risk of cancer themselves. However, because they can pass the altered gene to their children, they are called carriers.

A third form of inheritance of cancer-predisposing mutations is X-linked recessive inheritance. Males have a single X chromosome, which they inherit from their mothers, and females have two X chromosomes (one from each parent). A female with a recessive cancer-predisposing mutation on one of her X chromosomes and a normal copy of the gene on her other X chromosome is a carrier but will not have an increased risk of cancer. Her sons, however, will have only the altered copy of the gene and will therefore have an increased risk of cancer.

Even when people have one copy of a dominant cancer-predisposing mutation, two copies of a recessive mutation, or, for males, one copy of an X-linked recessive mutation, they may not develop cancer. Some mutations are “incompletely penetrant,” which means that only some people will show the effects of these mutations. Mutations can also “vary in their expressivity,” which means that the severity of the symptoms may vary from person to person.

Source: NCI (NIH)5

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Risk Factors for Cancer

It is usually not possible to know exactly why one person develops cancer and another doesn’t. But research has shown that certain risk factors may increase a person’s chances of developing cancer. (There are also factors that are linked to a lower risk of cancer. These are sometimes called protective risk factors, or just protective factors.)

Cancer risk factors include exposure to chemicals or other substances, as well as certain behaviors. They also include things people cannot control, like age and family history. A family history of certain cancers can be a sign of a possible inherited cancer syndrome. (See the Hereditary Cancer Syndromes section for more information about inherited genetic mutations that can cause cancer.)

Most cancer risk (and protective) factors are initially identified in epidemiology studies. In these studies, scientists look at large groups of people and compare those who develop cancer with those who don’t. These studies may show that the people who develop cancer are more or less likely to behave in certain ways or to be exposed to certain substances than those who do not develop cancer.

Such studies, on their own, cannot prove that a behavior or substance causes cancer. For example, the finding could be a result of chance, or the true risk factor could be something other than the suspected risk factor. But findings of this type sometimes get attention in the media, and this can lead to wrong ideas about how cancer starts and spreads. (See the Common Cancer Myths and Misconceptions page for more information.)

When many studies all point to a similar association between a potential risk factor and an increased risk of cancer, and when a possible mechanism exists that could explain how the risk factor could actually cause cancer, scientists can be more confident about the relationship between the two.

The list below includes the most-studied known or suspected risk factors for cancer. Although some of these risk factors can be avoided, others—such as growing older—cannot. Limiting your exposure to avoidable risk factors may lower your risk of developing certain cancers.

Source: NCI (NIH)6

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Cancer-Causing Substances in the Environment

Cancer is caused by changes to certain genes that alter the way our cells function. Some of these genetic changes occur naturally when DNA is replicated during the process of cell division. But others are the result of environmental exposures that damage DNA. These exposures may include substances, such as the chemicals in tobacco smoke, or radiation, such as ultraviolet rays from the sun.

People can avoid some cancer-causing exposures, such as tobacco smoke and the sun’s rays. But others are harder to avoid, especially if they are in the air we breathe, the water we drink, the food we eat, or the materials we use to do our jobs. Scientists are studying which exposures may cause or contribute to the development of cancer. Understanding which exposures are harmful, and where they are found, may help people to avoid them.

Source: NCI (NIH)7

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A person who receives an organ or tissue from a donor who had cancer in the past may be at increased risk of developing a transplant-related cancer in the future. However, that risk is extremely low—about two cases of cancer per 10,000 organ transplants. Doctors avoid the use of organs or tissue from donors who have a history of cancer.

In some people, cancers may be caused by certain viruses (some types of human papillomavirus, or HPV, for example) and bacteria (such as Helicobacter pylori). While a virus or bacterium can spread from person to person, the cancers they sometimes cause cannot spread from person to person. For more information about cancer-causing viruses and bacteria, see the NCI fact sheets on Helicobacter pylori and Cancer, HPV and Cancer, and Cancer Vaccines.

Source: NCI (NIH)8

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Most cancers in children, like those in adults, are thought to develop as a result of mutations in genes that lead to uncontrolled cell growth and eventually cancer. In adults, these gene mutations are often the result of exposure to environmental factors, such as cigarette smoke, asbestos, and ultraviolet radiation from the sun. However, environmental causes of childhood cancer have been difficult to identify, partly because cancer in children is rare, and partly because it is difficult to determine what children might have been exposed to early in their development.

Many studies have shown that exposure to ionizing radiation can damage DNA, which can lead to the development of childhood leukemia and possibly other cancers. For example, children and adolescents who were exposed to radiation from the World War II atomic bomb blasts had an elevated risk of leukemia (10), and children and adults who were exposed to radiation from accidents at nuclear power plants had an elevated risk for thyroid cancer (11). Children whose mothers had x-rays during pregnancy (that is, children who were exposed before birth) and children who were exposed after birth to diagnostic medical radiation from computed tomography scans also have an increased risk of some cancers (12).

Studies of other possible environmental risk factors, including parental exposure to cancer-causing chemicals, prenatal exposure to pesticides, childhood exposure to common infectious agents, and living near a nuclear power plant, have so far produced mixed results. Whereas some studies have found associations between these factors and risk of some cancers in children, other studies have found no such associations (8,13-15). Higher risks of cancer have not been seen in children of patients treated for sporadic cancer (cancer not caused by an inherited mutation) (16).

Source: NCI (NIH)9

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Many factors play a role in the development of cancer. The importance of these factors varies depending on the type of cancer. A person's risk of developing a particular cancer is influenced by a combination of factors that interact in ways that are not fully understood. Some of the factors include:

  • Personal characteristics such as age, sex, and race
  • Family history of cancer
  • Diet and personal habits such as cigarette smoking and alcohol consumption
  • The presence of certain medical conditions or past medical treatments, including chemotherapy, radiation treatment, or some immune-system suppressing drugs.
  • Exposure to cancer-causing agents in the environment (for example, sunlight, radon gas, air pollution, and infectious agents)
  • Exposure to cancer-causing agents in the workplace

Source: CDC NIOSH10

Risk Factors for Cancer

Fiber: Scientists have also looked into links between fiber and different types of cancer, with mixed results. Much research has focused on colorectal cancer, the second-leading cause of cancer death nationwide. Protection against colorectal cancer is sometimes stronger when scientists look at whole-grain intake rather than just fiber. One NIH-funded study of nearly 500,000 older adults found no relationship between fiber and colorectal cancer risk, but whole-grain intake led to a modest risk reduction.

Source: NIH News in Health (NIH)11

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Smoking: Cigarette Smoking and Tobacco Use

Tobacco use is strongly linked to an increased risk for many kinds of cancer. Smoking cigarettes is the leading cause of the following types of cancer:

Not smoking or quitting smoking lowers the risk of getting cancer and dying from cancer. Scientists believe that cigarette smoking causes about 30% of all cancer deaths in the United States.

Source: NCI (NIH)12

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Infections: Infections

Certain viruses and bacteria are able to cause cancer. Viruses and other infection -causing agents cause more cases of cancer in the developing world (about 1 in 4 cases of cancer) than in developed nations (less than 1 in 10 cases of cancer). Examples of cancer-causing viruses and bacteria include:

Two vaccines to prevent infection by cancer-causing agents have already been developed and approved by the U.S. Food and Drug Administration (FDA). One is a vaccine to prevent infection with hepatitis B virus. The other protects against infection with strains of human papillomavirus (HPV) that cause cervical cancer. Scientists continue to work on vaccines against infections that cause cancer.

Source: NCI (NIH)13

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Dietary Risk Factors: Diet

The foods that you eat on a regular basis make up your diet. Diet is being studied as a risk factor for cancer. It is hard to study the effects of diet on cancer because a person’s diet includes foods that may protect against cancer and foods that may increase the risk of cancer.

It is also hard for people who take part in the studies to keep track of what they eat over a long period of time. This may explain why studies have different results about how diet affects the risk of cancer.

Some studies show that fruits and nonstarchy vegetables may protect against cancers of the mouth, esophagus, and stomach. Fruits may also protect against lung cancer.

Some studies have shown that a diet high in fat, proteins, calories, and red meat increases the risk of colorectal cancer, but other studies have not shown this.

It is not known if a diet low in fat and high in fiber, fruits, and vegetables lowers the risk of colorectal cancer.

Source: NCI (NIH)14

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Alcohol: Alcohol

Studies have shown that drinking alcohol is linked to an increased risk of the following types of cancers:

Drinking alcohol may also increase the risk of liver cancer and female colorectal cancer.

Source: NCI (NIH)15

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Inactivity: Physical Activity

Studies show that people who are physically active have a lower risk of certain cancers than those who are not. It is not known if physical activity itself is the reason for this.

Studies show a strong link between physical activity and a lower risk of colorectal cancer. Some studies show that physical activity protects against postmenopausal breast cancer and endometrial cancer.

Source: NCI (NIH)16

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Obesity: Obesity

Studies show that obesity is linked to a higher risk of the following types of cancer:

Some studies show that obesity is also a risk factor for cancer of the gallbladder.

It is not known if losing weight lowers the risk of cancers that have been linked to obesity.

Source: NCI (NIH)17

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Diabetes: Diabetes

Some studies show that having diabetes may slightly increase the risk of having the following types of cancer:

Diabetes and cancer share some of the same risk factors. These risk factors include the following:

Because diabetes and cancer share these risk factors, it is hard to know whether the risk of cancer is increased more by diabetes or by these risk factors.

Studies are being done to see how medicine that is used to treat diabetes affects cancer risk.

Source: NCI (NIH)18

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Age: Age

Advancing age is the most important risk factor for cancer overall, and for many individual cancer types. According to the most recent statistical data from NCI’s Surveillance, Epidemiology, and End Results program, the median age of a cancer diagnosis is 66 years. This means that half of cancer cases occur in people below this age and half in people above this age. One-quarter of new cancer cases are diagnosed in people aged 65 to 74.

A similar pattern is seen for many common cancer types. For example, the median age at diagnosis is 61 years for breast cancer, 68 years for colorectal cancer, 70 years for lung cancer, and 66 years for prostate cancer.

But the disease can occur at any age. For example, bone cancer is most frequently diagnosed among people under age 20, with more than one-fourth of cases occurring in this age group. And 10 percent of leukemias are diagnosed in children and adolescents under 20 years of age, whereas only 1 percent of cancer overall is diagnosed in that age group. Some types of cancer, such as neuroblastoma, are more common in children or adolescents than in adults.

Source: NCI (NIH)19

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Alcohol: Drinking alcohol can increase your risk of cancer of the mouth, throat, esophagus, larynx (voice box), liver, and breast. The more you drink, the higher your risk. The risk of cancer is much higher for those who drink alcohol and also use tobacco.

Doctors advise people who drink to do so in moderate amounts. The federal government’s Dietary Guidelines for Americans defines moderate alcohol drinking as up to one drink per day for women and up to two drinks per day for men.

It has been suggested that certain substances in red wine, such as resveratrol, have anticancer properties. However, there is no evidence that drinking red wine reduces the risk of cancer.

Source: NCI (NIH)20

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Chronic Inflammation: Inflammation is a normal physiological response that causes injured tissue to heal. An inflammatory process starts when chemicals are released by the damaged tissue. In response, white blood cells make substances that cause cells to divide and grow to rebuild tissue to help repair the injury. Once the wound is healed, the inflammatory process ends.

In chronic inflammation, the inflammatory process may begin even if there is no injury, and it does not end when it should. Why the inflammation continues is not always known. Chronic inflammation may be caused by infections that don’t go away, abnormal immune reactions to normal tissues, or conditions such as obesity. Over time, chronic inflammation can cause DNA damage and lead to cancer. For example, people with chronic inflammatory bowel diseases, such as ulcerative colitis and Crohn disease, have an increased risk of colon cancer.

Many studies have investigated whether anti-inflammatory medications, such as aspirin or non-steroidal anti-inflammatory drugs, reduce the risk of cancer. However, a clear answer is not yet available. For more information, see No Easy Answers about Whether Aspirin Lowers Cancer Risk.

Source: NCI (NIH)21

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Alcohol: What is the evidence that alcohol drinking is a cause of cancer?

Based on extensive reviews of research studies, there is a strong scientific consensus of an association between alcohol drinking and several types of cancer (1, 2). In its Report on Carcinogens, the National Toxicology Program of the US Department of Health and Human Services lists consumption of alcoholic beverages as a known human carcinogen. The research evidence indicates that the more alcohol a person drinks—particularly the more alcohol a person drinks regularly over time—the higher his or her risk of developing an alcohol-associated cancer. Based on data from 2009, an estimated 3.5 percent of all cancer deaths in the United States (about 19,500 deaths) were alcohol related (3).

Source: NCI (NIH)22

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Childhood Cancers: Second Cancers

Key Points

  • Childhood cancer survivors have an increased risk of a second cancer later in life.
  • Certain genetic patterns or syndromes may increase the risk of a second cancer.
  • Patients who have been treated for cancer need regular screening tests to check for a second cancer.
  • The kind of test used to screen for a second cancer depends in part on the kind of cancer treatment the patient had in the past.

Source: NCI (NIH)23

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Pregnancy: Does pregnancy affect the risk of other cancers?

Research has shown the following with regard to pregnancy and the risk of other cancers:

  • Women who have had a full-term pregnancy have reduced risks of ovarian (27, 28) and endometrial (29) cancers. Furthermore, the risks of these cancers decline with each additional full-term pregnancy.
  • Pregnancy also plays a role in an extremely rare type of tumor called a gestational trophoblastic tumor. In this type of tumor, which starts in the uterus, cancer cells grow in the tissues that are formed following conception.
  • There is some evidence that pregnancy-related factors may affect the risk of other cancer types, but these relationships have not been as well studied as those for breast and gynecologic cancers. The associations require further study to clarify the exact relationships.

As in the development of breast cancer, exposures to hormones are thought to explain the role of pregnancy in the development of ovarian, endometrial, and other cancers. Changes in the levels of hormones during pregnancy may contribute to the variation in risk of these tumors after pregnancy (30).

Source: NCI (NIH)24

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Fertility treatments: Does fertility treatment affect the risk of breast or other cancers?

Women who have difficulty becoming pregnant or carrying a pregnancy to term may receive fertility treatment. Such treatment can include surgery (to repair diseased, damaged, or blocked fallopian tubes or to remove uterine fibroids, patches of endometriosis, or adhesions); medications to stimulate ovulation; and assisted reproductive technology.

Ovarian stimulation and some assisted reproductive technologies involve treatments that temporarily change the levels of estrogen and progesterone in a woman’s body. For example, women undergoing in vitro fertilization (IVF) receive multiple rounds of hormone treatment to first suppress ovulation until the developing eggs are ready, then stimulate development of multiple eggs, and finally promote maturation of the eggs. The use of hormones in some fertility treatments has raised concerns about possible increased risks of cancer, particularly cancers that are linked to elevated levels of these hormones.

Many studies have examined possible associations between use of fertility drugs or IVF and the risks of breast, ovarian, and endometrial cancers. The results of such studies can be hard to interpret because infertility itself is linked to increased risks of these cancers (that is, compared with fertile women, infertile women are at higher risk of these cancers even if they do not use fertility drugs). Also, these cancers are relatively rare and tend to develop years after treatment for infertility, which can make it difficult to link their occurrence to past use of fertility drugs.

Source: NCI (NIH)25

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Carcinogen Exposure: How many cancers are caused by involuntary exposure to carcinogens in the environment?

This question cannot be answered with certainty because the precise causes of most cancers are not known. Some researchers have suggested that, in most populations, environmental exposures are responsible for a relatively small proportion of total cancers (less than 4 percent), whereas other researchers attribute a higher proportion (19 percent) to environmental exposures.

Source: NCI (NIH)26

Non-Risk Factors for Cancer

Dietary Sugar: Will eating sugar make my cancer worse?

No. Although research has shown that cancer cells consume more sugar (glucose) than normal cells, no studies have shown that eating sugar will make your cancer worse or that, if you stop eating sugar, your cancer will shrink or disappear. However, a high-sugar diet may contribute to excess weight gain, and obesity is associated with an increased risk of developing several types of cancer. For more information, see the NCI fact sheet on Obesity and Cancer Risk.

Source: NCI (NIH)27

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Artificial sweeteners: Do artificial sweeteners cause cancer?

No. Researchers have conducted studies on the safety of the artificial sweeteners (sugar substitutes) saccharin (Sweet 'N Low®, Sweet Twin®, NectaSweet®); cyclamate; aspartame (Equal®, NutraSweet®); acesulfame potassium (Sunett®, Sweet One®); sucralose (Splenda®); and neotame and found no evidence that they cause cancer in humans. All of these artificial sweeteners except for cyclamate have been approved by the Food and Drug Administration for sale in the United States. For more information, see the NCI fact sheet on Artificial Sweeteners and Cancer.

Source: NCI (NIH)28

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Negative Emotions: Does my attitude—positive or negative—determine my risk of, or likely recovery from, cancer?

To date, there is no convincing scientific evidence that links a person’s “attitude” to his or her risk of developing or dying from cancer. If you have cancer, it’s normal to feel sad, angry, or discouraged sometimes and positive or upbeat at other times. People with a positive attitude may be more likely to maintain social connections and stay active, and physical activity and emotional support may help you cope with your cancer. For more information, see the NCI fact sheet on Psychological Stress and Cancer.

Source: NCI (NIH)29

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Air: Will cancer get worse if exposed to air?

No. Exposure to air will not make tumors grow faster or cause cancer to spread to other parts of the body. For information about how cancer spreads in the body, see our page on Metastatic Cancer.

Source: NCI (NIH)30

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Cell Phones: Do cell phones cause cancer?

No, not according to the best studies completed so far. Cancer is caused by genetic mutations, and cell phones emit a type of low-frequency energy that does not damage genes. For more information, see the NCI fact sheet on Cell Phones and Cancer Risk.

Source: NCI (NIH)31

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Power Lines: Do power lines cause cancer?

No, not according to the best studies completed so far. Power lines emit both electric and magnetic energy. The electric energy emitted by power lines is easily shielded or weakened by walls and other objects. The magnetic energy emitted by power lines is a low-frequency form of radiation that does not damage genes. For more information, see the NCI fact sheet on Electromagnetic Fields and Cancer.

Source: NCI (NIH)32

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Deodorants: Do antiperspirants or deodorants cause breast cancer?

No. The best studies so far have found no evidence linking the chemicals typically found in antiperspirants and deodorants with changes in breast tissue. For more information, see the NCI fact sheet on Antiperspirants/Deodorants and Breast Cancer.

Source: NCI (NIH)33

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Hair dye: Does hair dye use increase the risk of cancer?

There is no convincing scientific evidence that personal hair dye use increases the risk of cancer. Some studies suggest, however, that hairdressers and barbers who are regularly exposed to large quantities of hair dye and other chemical products may have an increased risk of bladder cancer. For more information, see the NCI fact sheet on Hair Dyes and Cancer Risk.

Source: NCI (NIH)34

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  1. Source: NIH News in Health (NIH): 2008/ February/ docs/ 01features_01.htm
  2. Source: NINDS (NIH): news_and_events/ proceedings/ dna_meeting_2001.htm
  3. Source: NCI (NIH): about-cancer/ causes-prevention/ patient-prevention-overview-pdq
  4. ibid.
  5. Source: NCI (NIH): about-cancer/ causes-prevention/ genetics/ genetic-testing-fact-sheet
  6. Source: NCI (NIH): about-cancer/ causes-prevention/ risk
  7. Source: NCI (NIH): about-cancer/ causes-prevention/ risk/ substances
  8. Source: NCI (NIH): about-cancer/ causes-prevention/ risk/ myths
  9. Source: NCI (NIH): types/ childhood-cancers/ child-adolescent-cancers-fact-sheet
  10. Source: CDC NIOSH: niosh/ topics/ cancer/ 
  11. Source: NIH News in Health (NIH): issue/ aug2010/ feature1
  12. Source: NCI (NIH): about-cancer/ causes-prevention/ patient-prevention-overview-pdq
  13. ibid.
  14. ibid.
  15. ibid.
  16. ibid.
  17. ibid.
  18. ibid.
  19. Source: NCI (NIH): about-cancer/ causes-prevention/ risk/ age
  20. Source: NCI (NIH): about-cancer/ causes-prevention/ risk/ alcohol
  21. Source: NCI (NIH): about-cancer/ causes-prevention/ risk/ chronic-inflammation
  22. Source: NCI (NIH): about-cancer/ causes-prevention/ risk/ alcohol/ alcohol-fact-sheet
  23. Source: NCI (NIH): types/ childhood-cancers/ late-effects-pdq
  24. Source: NCI (NIH): about-cancer/ causes-prevention/ risk/ hormones/ reproductive-history-fact-sheet
  25. ibid.
  26. ibid.
  27. Source: NCI (NIH): about-cancer/ causes-prevention/ risk/ myths
  28. ibid.
  29. ibid.
  30. ibid.
  31. ibid.
  32. ibid.
  33. ibid.
  34. ibid.

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Note: This site is for informational purposes only and is not medical advice. See your doctor or other qualified medical professional for all your medical needs.