Understanding Cancer Prevention

When it comes to cancer prevention, what are the lifestyle habits that really matter? What could we all be doing today to lower our cancer risk? And what does the latest science tell us about the things that matter most?

How Cancer Develops

Our bodies are made up of hundreds of millions of cells, all responding to chemical signals. Usually, the number of cells in our body is kept in a fine balance, as some cells die and others divide and reproduce. If these cells become damaged over time, the signals that control their growth can become faulty, leading to uncontrolled growth and the development of cancer. As cancers grow, they affect the health of everything around them. Cancer survival in the UK has doubled in the last 40 years, which is amazing, but overall survival is still just 50% at 10 years. Preventing cancer in the first place is a huge win.

The Role of Lifestyle in Cancer Prevention

A 2018 study looking at 26 different cancer types in adults estimated that 42% of all cancers, excluding lower-risk skin cancers, were due to avoidable risk factors. By making small changes to lifestyle and avoiding these risks, it is possible to reduce cancer risk by almost half.

Tobacco and Smoking Cessation

Tobacco avoidance and smoking cessation play a crucial role in cancer prevention. Cancer Research UK reports that 33% of cancers are due to smoking, making it the leading cause of cancer. Smoking harms nearly every organ and organ system in the body and increases the risk of various diseases. Of the 5000 chemicals released into the body through cigarette smoke, at least 70 are known to cause cancer. Once they enter the lungs, they spread throughout the body, damaging cells and allowing them to develop into cancer. Second-hand smoke is also a major risk, as living with a smoker increases a non-smoker’s chance of developing lung cancer by 20-30%. The best advice is to stop smoking completely. While vaping and e-cigarettes are healthier alternatives, they still keep users addicted to nicotine, and their long-term effects are unknown. Various treatments such as nicotine gums, patches, and prescription medications can help reduce cravings, and health apps can support those trying to quit.

The Impact of Diet on Cancer Risk

Diet also plays a key role in cancer prevention. The media frequently links food to cancer, leading to ongoing debates. For example, concerns about artificial sweeteners like aspartame have circulated for years, yet studies have found no strong evidence linking them to cancer. Similarly, while antioxidants in food are beneficial, antioxidant supplements do not appear to provide cancer protection. However, evidence is strong regarding processed meats, which the World Health Organization has classified as a definite cause of cancer, particularly bowel and prostate cancer. Red meat also likely contributes to cancer, though the evidence is not as strong. A simple way to reduce risk is to cut down on processed and red meats, perhaps by introducing meat-free days or swapping bacon and sausages for chicken, fish, or plant-based alternatives.

The Importance of Fibre

Fibre is another key factor in cancer prevention. It is not absorbed by the body but helps digestion by reducing the time harmful chemicals spend in the gut. Studies suggest that meeting the recommended fibre intake can lower bowel cancer risk by 20%. Incorporating fibre-rich foods, such as beans, lentils, nuts, dried fruit, and whole grains, can be an effective way to improve health.

Sun Protection and Skin Cancer Prevention

Protecting the skin from harmful UV radiation is another important step. UV rays damage DNA in skin cells, leading to skin cancer. Melanoma, the most serious type, can spread rapidly if untreated. In the UK, it is the fifth most common cancer, and the Skin Cancer Foundation estimates that having five or more sunburns doubles the risk of melanoma. However, up to 86% of cases are preventable with proper sun protection. Staying out of the sun is the best protection, but using sunscreen is crucial when exposure is unavoidable. SPF ratings measure protection against UVB, which causes burns, while star ratings measure UVA protection, which contributes to ageing. Sunscreen with at least SPF 30 and a four-star rating is recommended. Seeking shade during peak sunlight hours, protecting children, and monitoring moles for changes are also important measures.

The Link Between Alcohol and Cancer

Alcohol is linked to 12% of cancers. It is broken down in the body into acetaldehyde, a chemical believed to cause cancer. Additionally, alcohol generates free radicals, which can damage DNA. Heavy drinkers have a fivefold increase in the risk of mouth, throat, and oesophageal cancers and double the risk of liver cancer. Red wine, often debated in the media, does not prevent cancer despite containing resveratrol, which has some health benefits. There is no completely safe level of alcohol, but reducing intake is beneficial. Simple steps include having alcohol-free days, tracking intake with apps, and avoiding triggers such as keeping alcohol at home or social drinking. Support services and medications can help those struggling to cut down.

Weight Management and Cancer Risk

Maintaining a healthy weight is another critical factor. Excess weight increases the risk of at least 13 types of cancer. A study found that nearly 1 in 20 cancers in men and 1 in 10 cancers in women were caused by excess weight. Fat tissue can produce hormones such as oestrogen, which fuel hormone-sensitive cancers like breast and womb cancer. Excess weight also affects blood sugar control and inflammation, leading to cell damage. Research suggests that weight loss of 5% or more reduces cancer risk in postmenopausal women, with weight loss from bariatric surgery reducing cancer risk by a third. While weight loss can be challenging due to psychological and hormonal factors, diet and physical activity remain key. Mobile apps can provide valuable support for those on a weight loss journey.

The Role of Cancer Screenings

Regular health check-ups and screenings are essential for early cancer detection. In the UK, there are three main cancer screening programmes. Boys and girls aged 12 to 13 are offered the HPV vaccine to prevent cervical cancer. Women, trans men, and non-binary people with cervixes are invited for cervical screening from age 25. Women, as well as some trans and non-binary individuals, are invited for breast cancer screening every three years from ages 50 to 70. Bowel cancer screening kits are sent to people in their 50s, 60s, and 70s every two years. Attending these screenings can significantly improve survival rates by detecting cancer early.

Aspirin and Cancer Prevention

Finally, aspirin has been discussed as a possible cancer prevention tool. A 2021 study analysing over 100 research studies found a 20% reduction in cancer deaths associated with aspirin use. However, the benefits are unclear for specific cancers and certain groups. In adults over 70, aspirin may not be helpful and could even increase the risk of advanced cancers. It can also cause side effects such as stomach ulcers and asthma attacks, making it unsuitable for everyone. More research is needed to determine its overall effects.

Conclusion

Nearly half of all cancers are preventable through lifestyle changes. Avoiding smoking, maintaining a healthy diet, staying sun-safe, limiting alcohol, managing weight, and attending regular screenings can significantly reduce cancer risk. For more information, visit the Skin Cancer Foundation, Cancer Research UK, or the American Cancer Society.