Cancer is a complex disease with many causes—and sometimes none. For some patients, getting cancer is down to plain bad luck.

As an oncology consultant, I see many cases where patients are otherwise perfectly healthy and have followed a healthy lifestyle.

Nevertheless, research has shown there are several ways to reduce your risk. Here are five evidence-based strategies to help lower your chances of developing cancer:

1. Quit smoking and avoid tobacco

Tobacco use is the single largest preventable cause of cancer.

Smoking not only increases the risk of lung cancer but also contributes to the development of oral, throat, kidney, bladder, pancreatic, stomach and cervical cancers to name a few.

The harmful chemicals in cigarette smoke affect the entire body, not just the lungs.

If you currently smoke, quitting is the most important step you can take to reduce your cancer risk.

Around 30% of all cancer deaths in the US and Europe are thought to be caused by cigarette smoking. It’s never too late to quit—and the benefits begin immediately after stopping.

Consider joining a tobacco treatment program or asking your doctor about products that can help you quit smoking, but sometimes the best way to quit is just to “do it.”

Even if you don’t smoke, it’s crucial to avoid second-hand smoke, which is also a risk factor for cancer, so-called passive smoking, so keep your home and environment smoke-free to protect yourself and others.

2. Maintain a healthy weight and stay physically active

Maintaining a healthy weight is one of the most important factors in cancer prevention after not smoking.

Excess body fat triggers the release of certain hormones that can promote cancer growth and we know that obesity is linked to a higher risk of breast, colorectal, endometrial, esophageal, kidney and pancreatic cancers.

To help with this, everyone should engage in regular physical activity, which not only helps with weight management but also independently lowers cancer risk.

The American Cancer Society recommends at least 150 minutes of moderate exercise or 75 minutes of vigorous exercise each week for cancer prevention.

Regular physical activity has been linked to a reduced risk of so many different cancers like colon and breast cancer.

Even if you don’t lose weight, exercise will still help protect you against cancer so some advise trying to incorporate movement throughout your day, such as taking short walking breaks during work or using standing desks while working on a computer.

3. Adopt a healthy diet

While there’s no guaranteed way to prevent cancer through diet alone, certain eating habits can significantly lower your risk.

An anti-cancer diet primarily consists of plant-based foods, including a variety of fruits, vegetables, whole grains and beans.

It was recently reported that King Charles is cutting out red meat to keep his cancer at bay. In general, we should all aim to limit processed foods and sugar, reduce intake of saturated fats and consider adopting a Mediterranean-style diet, which has been associated with a lower risk of some cancers. All of this is linked to maintaining a healthy weight.

4. Limit alcohol consumption

Alcohol consumption is tied to several types of cancer, including oral, throat, breast, liver and colorectal cancers, and may explain why so many younger people are developing certain cancers.

The risk increases with the amount of alcohol consumed regularly over time and this is called a dose-response, so the more you drink, the greater your risk.

Just like for smoking, quitting alcohol really helps decrease risk, though at this time of year with office parties and going out that’s not always easy—perhaps aim to drink a little less. There’s now lots of research that shows that there’s no safe level of alcohol consumption when it comes to cancer prevention.

If you don’t drink, don’t start, and if you do drink, less is better. But, at the same time, it’s important to enjoy life, so focus on moderation.

5. Protect against sun exposure and get vaccinated

If you’re going somewhere hot for the winter, sun protection is crucial in preventing skin cancer, including the most dangerous type called melanoma, one of the most common and preventable types of cancer.

The sun’s UV rays can damage the DNA of skin cells, potentially leading to cancerous growths so to protect yourself from harmful sun exposure, use sunscreen in ample quantities with an SPF of 30 or higher, seek shade, especially between ten in the morning and four in the afternoon, when the sun’s rays are strongest.

Be sure to wear protective clothing, including wide-brimmed hats and sunglasses.

In addition to sun protection, getting vaccinated against certain viruses can help prevent some types of cancer. Examples include the human papillomavirus (HPV) vaccine recommended for all teenage girls, with new data showing this dramatically reduces the risk of cervical and other genital cancers. The NHS has pledged to eradicate cervical cancer by 2040 due in large part to the vaccine’s success.

While it’s impossible to completely eliminate cancer risk, these five strategies can significantly reduce your chances of developing the disease. By quitting smoking, maintaining a healthy weight, staying physically active, eating a balanced diet, limiting alcohol consumption, protecting yourself from sun exposure and getting vaccinated, you can take control of many modifiable risk factors for cancer.

Remember that small changes can make a big difference over time. Perhaps even start by incorporating one or two of these strategies into your daily routine and gradually build on them. Regular medical check-ups and cancer screenings are also essential for early detection and prevention.

By adopting healthy lifestyle choices, you’re not only reducing your cancer risk but also improving your overall health and well-being, and you’ll probably be happier with your new self too. It’s never too late to start making positive changes that can have a lasting impact on your health.

If you care about cancer, please read studies about vitamin D and bowel cancer, and a cautionary note about peanuts and cancer.

For more health information, please see recent studies about the link between ultra-processed foods and cancer, and everyday foods to ward off pancreatic cancer.

Written by Justin Stebbing, The Conversation.