02-08-2025
Six ways to reduce your cancer risk according to an oncologist
As a consultant haematologist, I spend my working life treating patients with blood cancers at The Christie NHS Foundation Trust in Manchester, but like many, I also have my own personal history with cancer.
My dad was diagnosed with prostate cancer in his 60s, and while he went through a number of lines of treatments over more than a decade, he eventually died from the disease in his late 70s.
Now at the age of 54, which is very close to when my dad was diagnosed, I have had a PSA test done, and seemingly so far I'm all right, but knowing my family background certainly has played on my mind a little bit. One of the things we know is that if you have prostate cancer in your family, you're at greater risk of getting it yourself.
But given that one in two people will develop cancer in their lifetime, the burden of disease risk through family history is also the reality for many of us. One of the most common questions I find myself being asked by patients is: 'I've got cancer, what can I do now? Can I change my diet or what about some supplements?' But without wanting to sound too cynical, to some extent the horse has already bolted. If cancer has already developed, the outlook is more difficult.
This means that prevention is key. If we look at relative cancer outcomes in the UK compared with other high-income nations, research consistently shows that we lag behind, even though we have excellent cancer doctors and nurses, and largely speaking, we have access to most drugs.
The differences are down to a combination of lifestyle factors – if everybody's diet was better and we reduced obesity rates for example, we would see less cancer – and our ability to detect more cancers at an early stage.
Improving this comes down to decisions taken by policymakers, but also us as individuals and the choices we make. There are some things in terms of cancer risk which are out of our control, for example we cannot change our genetic makeup or our family history. We are also exposed all the time to environmental risk factors such as UV radiation and pollution which are hard to avoid.
But there are other things that are very much within our remit. Here are six lifestyle choices that we can all make to limit our cancer risk.
1. Stop smoking and cut down on alcohol
Not smoking is just a no-brainer. There is nothing good that can be said about it. As the NHS highlights, if you smoke 25 cigarettes a day, you are 25 times more likely than a non-smoker to get lung cancer due to the amount of toxins they contain.
Alcohol is also linked to a number of different cancers and, as with smoking, there is a clear reason. It's metabolised into a toxin which damages DNA, and the more you damage your cells, the more you risk creating an abnormality which leads to cancer.
The major factor that drives cancer is still ultimately chance. Things can randomly go wrong in the process of cell replication, which creates cancer cells, and there's not a lot any of us can do about that. But it's all about trying to keep the odds more in your favour, and if you're doing less damage to your body through not smoking and not drinking to excess, you are improving your chances of avoiding cancer.
2. Avoid unnecessary antibiotics
Another key player in reducing cancer risk is your immune system. Your body is continually dealing with damaged cells with the potential to become cancerous, but they are spotted and dealt with by the immune system before that happens. Because of this, it's important to take steps towards keeping your immune system healthier for longer.
In recent years, studies have repeatedly shown that the intestinal flora in our guts plays a key role in immune health, which is why a dysregulated gut microbiome has been linked to a variety of cancers.
One of the biggest things that can adversely affect your gut health is unnecessary antibiotics. In recent years, large studies in both the UK and Sweden have linked antibiotics to proximal colon cancer or tumours which occur in the first section of the colon. This association was found to be highest for antibiotics that wipe out anaerobic bacteria, such as penicillin and cephalosporin-based drugs. Other studies have found possible associations between excessive antibiotic use and lung cancer, pancreatic cancer, lymphoma and multiple myeloma.
Researchers are still trying to untangle those links, but the message is clear: messing with your gut health can tip the balance towards greater risk of cancer development.
3. Eat enough antioxidants and limit nitrites
Our bodies are all continuously exposed to something called oxidative stress, or toxins created within our body which damage the genetic material in our cells.
As well as avoiding things like smoking, alcohol or ingesting carcinogens like nitrites which are found in processed meats, factors which all exacerbate the effects of oxidative stress, we can also mitigate it by consuming whole foods rich in antioxidants which are capable of neutralising oxidative stress.
There are many foods like blueberries, raspberries, blackberries, kale, spinach and others that contribute to an antioxidant-rich diet which again over time can help protect your body and lower cancer risk.
4. Have the right vaccines
We know that there is an increased risk of cancer from various infections. We can't prevent all of them, but there are some like human papillomavirus (HPV) where certain strains are known to be the main cause of cervical cancer. One particular strain, HPV16, is also linked to up to 90 per cent of all head and neck cancers in both genders.
Because of this, having the HPV vaccine – which is available to all women under 25 on the NHS – is hugely important in terms of reducing cervical cancer risk. With the vaccine also available for free to all 12 and 13-year-olds of both genders, having it could play a big role in future when it comes to reducing risk of oral cancers.
5. Get tested early
One of the biggest drivers of cancer mortality is late diagnosis. While there are some cancers that are very slow growing and it makes little difference if you are diagnosed now or in five years' time, for the most part, early detection makes a huge difference when it comes to the outcome.
Again there are things we can all do, whether it's taking part in screening programmes that we are eligible for, being aware of our family history of certain cancers, or simply not ignoring symptoms. With this, it is about listening to your body. We all get symptoms and if you pulled a muscle and you've now got backache, that's obviously fine. But if you have had a strange backache that is really severe, doesn't go away after more than a few weeks or is associated with other symptoms such as weight loss, then that could be a problem.
Most of the time it is about not sitting on stuff, and asking yourself the question: 'Is this symptom something I have had for longer than I should have done?'
6. Sleep duration and regularity
Some studies have found that irregular sleeping patterns, including variable bedtimes and waking times, are linked to a greater risk of cancer over time, compared with people with more regular sleep schedules.
Again a lot of this is probably related to immune-system health. Sleep is restorative and consistent sleeping patterns help regulate immune cell production and function, making the body more effective at healing itself. Your body is constantly under stress from the environment, some of which you can't change, and therefore sleep is a useful chance for it to repair.
We still need to know more about the link between sleep and cancer risk because some of the research is a little inconsistent, but overall, the more sleep you can get, and the more regular your sleeping pattern, the better it probably is for your overall cancer risk.
