By Mayo Clinic Staff

There are lots of myths about causes of cancer that can be scary because they involve items or foods you may use every day. From putting on deodorant to eating sugar, these myths may cause you to worry about your health and the health of your family when you don’t need to.

Take a look at the reality behind these common myths.

Fact: There’s no conclusive evidence that using underarm antiperspirants or deodorants causes breast cancer.

Some reports have suggested that these products contain harmful substances, such as aluminum compounds and parabens, that can be absorbed through the skin or enter the body through nicks caused by shaving. No clinical studies have yet given a certain answer to the question of whether these products cause breast cancer. But the evidence to date suggests these products don’t cause cancer.

If you’re still worried that your underarm antiperspirant or deodorant could raise your risk of cancer, choose products that don’t have chemicals that worry you.

Fact: Plastic containers and wraps labeled as safe for use in the microwave should be safe when used as directed.

Not all plastic containers are meant for use in the microwave. There is some evidence that plastic containers that don’t have a microwave-safe label could melt and potentially leak chemicals into your food. Avoid microwaving plastic containers that are not meant for the microwave, such as margarine tubs, takeout containers or whipped topping bowls.

Check to see that any container you use in the microwave has a microwave-safe label. If it doesn’t, consider moving the food or liquid into a glass or ceramic container.

Fact: More research is needed to understand the relationship between sugar in the diet and cancer. All kinds of cells, including cancer cells, depend on blood sugar, also called glucose, for energy. But giving more sugar to cancer cells doesn’t make them grow faster. And keeping sugar from cancer cells doesn’t make them grow more slowly.

This misconception may be based in part on a misunderstanding of positron emission tomography (PET) scans. These scans use a small amount of radioactive tracer that’s usually a form of glucose. All tissues in your body absorb some of this tracer. But tissues that are using more energy, such as cancer cells, absorb greater amounts. For this reason, some people mistakenly believe that cancer cells grow faster on sugar. But this isn’t true.

There is some evidence that eating large amounts of sugar may raise the risk of certain cancers, including esophageal cancer. Eating too much sugar also can lead to weight gain and increase the risk of obesity and diabetes, which may raise the risk of cancer.

Fact: There’s no need to avoid someone who has cancer. You can’t catch it. It’s OK to touch and spend time with someone who has cancer. In fact, your support may never be more valuable.

Though cancer itself isn’t contagious, sometimes viruses, which are contagious, can cause cancer to develop. Examples of viruses that can cause cancer include:

• Human papillomavirus (HPV). HPV is a common virus that’s passed through sexual contact. It can cause cervical cancer and other forms of cancer.
• Hepatitis B and hepatitis C. Hepatitis B and hepatitis C are viruses that can be passed through unprotected sex and sharing needles. These viruses can cause liver cancer.

Talk to your healthcare professional about vaccines and other ways to protect yourself from these viruses.

Scary claims circulate on the internet that everyday objects and products, such as plastic and deodorant, cause cancer. Beyond being wrong, many of these myths may cause you to worry unnecessarily about your own health and the health of your family.

Before you panic, take a look at the reality behind these common myths.

Fact: There’s no conclusive evidence linking the use of underarm antiperspirants or deodorants with breast cancer.

Some reports have suggested that these products contain harmful substances such as aluminum compounds and parabens that can be absorbed through the skin or enter the body through nicks caused by shaving. No clinical studies have yet given a definitive answer to the question of whether these products cause breast cancer. But the evidence to date suggests these products don’t cause cancer.

If you’re still concerned that your underarm antiperspirant or deodorant could increase your risk of cancer, choose products that don’t contain chemicals that worry you.

Fact: Plastic containers and wraps labeled as safe for use in the microwave don’t pose a threat.

There is some evidence that plastic containers that aren’t intended for use in the microwave could melt and potentially leak chemicals into your food. Avoid microwaving plastic containers that were never intended for the microwave, such as margarine tubs, takeout containers or whipped topping bowls.

Check to see that any container you use in the microwave is labeled as microwave-safe.

Fact: More research is needed to understand the relationship between sugar in the diet and cancer. All kinds of cells, including cancer cells, depend on blood sugar (glucose) for energy. But giving more sugar to cancer cells doesn’t make them grow faster. Likewise, depriving cancer cells of sugar doesn’t make them grow more slowly.

This misconception may be based in part on a misunderstanding of positron emission tomography (PET) scans, which use a small amount of radioactive tracer — typically a form of glucose. All tissues in your body absorb some of this tracer, but tissues that are using more energy — including cancer cells — absorb greater amounts. For this reason, some people have concluded that cancer cells grow faster on sugar. But this isn’t true.

There is some evidence that consuming large amounts of sugar is associated with an increased risk of certain cancers, including esophageal cancer. Eating too much sugar can also lead to weight gain and increase the risk of obesity and diabetes, which may increase the risk of cancer.

Fact: There’s no need to avoid someone who has cancer. You can’t catch it. It’s OK to touch and spend time with someone who has cancer. In fact, your support may never be more valuable.

Though cancer itself isn’t contagious, sometimes viruses, which are contagious, can lead to the development of cancer. Examples of viruses that can cause cancer include:

• Human papillomavirus (HPV) — a sexually transmitted infection — that can cause cervical cancer and other forms of cancer
• Hepatitis B or C — viruses transmitted through sexual intercourse or use of infected IV needles — that can cause liver cancer

Talk to your doctor about vaccines and other ways to protect yourself from these viruses.