The World Health Organization says cancer is a "major contributor to global mortality." It projects that the global cancer burden will increase by about 77% by 2050. But at least some forms of cancer can be avoided.

Destiny is in your hands: Don't smoke

Being diagnosed with cancer is a shock that hits you hard. And yet almost half of all cancer cases could be prevented. Smoking alone triggers about every fifth tumor.

The toxic cigarette smoke does not only cause lung cancer but many other kinds of tumors as well. Smoking is the most frequent self-imposed cause for cancer, but not the only one.

Regarding vaping, the science is a bit thin. But a decade-long study published in 2024 suggested that ex-cigarette smokers who vaped were at a greater risk of lung cancer than those who did not vape. 

Being overweight increases cancer risk

In second place of cancer-causing agents: obesity. Why does obesity cause cancer? Enhanced insulin levels increase the risk of almost all sorts of cancer, especially when it comes to kidney, gall bladder, and esophagus cancer.

Overweight women produce increasing amounts of female sex hormones in their fat tissue and hence have a higher risk for uterine or breast cancer.

Get off the couch, get active!

People who don't move enough are especially likely to get cancer.

Long-term studies show that exercising prevents tumors. Working out lowers insulin levels and prevents you from gaining weight. It doesn't have to be high-performance sport. Even just going for a walk or a bike ride makes a big difference.

Avoiding consuming too much alcohol

Alcohol promotes tumors in the oral cavity, the throat and the esophagus.

The combination of smoking and drinking alcohol is especially dangerous and increases the risk of cancer up to a hundredfold.

While drinking one glass of wine a day is healthy and supports the cardiovascular system, you shouldn't drink more than that.

Avoid red meat, eat fish instead

Long-term studies suggest there's a correlation between the consumption of red meat and intestinal cancer. Beef is especially dangerous, and pork is thought to cause cancer to a minor degree.

Barbecuing meat can release carcinogenic substances, such as polycyclical aromatic hydrocarbons.

Fish, on the other hand, is said to prevent cancer.

Use sunscreen to avoid skin cancer

Sunscreens protect against ultraviolet (UV) radiation from the sun. UV rays can damage skin cells and cause different types of cancer, including melanoma.

The higher the "sun protection factor" the better. Some health bodies recommend using at least factor 30. But the protection you need will depend on your personal skin tone and where you are in the world, so it's best to consult a doctor. 

Cancer triggered by modern medicine

X-rays harm genomes. With an ordinary radiogram the exposure is only minor. But it's a different story for computed tomography, which you should only undergo when necessary. Magnetic resonance imaging is harmless. But did you know that you're even exposed to cancer-causing radiation when you're on an airplane?

Cancer triggered by infection

Human papillomaviruses can cause cervical cancer.

Hepatitis B and C can cause hepatocytes to degenerate. The bacterium helicobacter pylori settles in your stomach and can cause stomach cancer.

But you can get vaccinated against many of these pathogens and antibiotics help fight helicobacter pylori.

The pill: Better than its reputation

The oral contraceptive pill can increase the risk of breast cancer, but it can also decreases the risk of ovarian cancer. Consult your personal doctor to find out what is best for you. 

Some cancer can't be avoided

But even if you do everything right, you're never completely immune from getting cancer. Half of all cancer cases are caused by the wrong genes or age. Brain cancer is particularly likely to be inherited.

This article was originally published March 12, 2018. It was updated July 12, 2024.