DR MICHAEL MOSLEY: The simple steps I’m taking to help ward off cancer 

As anyone who has seen a friend or loved one die from cancer knows, it can be a terrible disease.

Half of us will develop cancer at some point in our lives, so most will be affected in some way.

Over the past couple of years, I have lost two friends to cancer, both relatively young. My dad discovered he had prostate cancer at around my age (I am 65), so I know that I am at greater risk. I have regular PSA (prostate specific antigen) tests and I have also recently had a bowel scope (an examination of the bowel using a tiny camera).

Other things I do to keep cancer at bay include short bursts of high-intensity interval training (HIIT) and following a healthy, relatively low-carb diet.

So it was reassuring to see new research showing that both these approaches can impact cancers, by starving them of their preferred energy source, glucose in your blood. This seems not only to stop cancer cells spreading, but also prevent the disease recurring in people who’ve had it.

While there are drugs being trialled that can also do this, they are some way off reaching patients. Meanwhile, changes to diet and activity levels are things you can implement immediately.

Cancers arise because of a mutation in the DNA in certain cells. If these mutant cells grow and manage to elude your immune system, then they can spread throughout your body.

If you catch cancer early enough then the usual options are to cut it out (i.e. surgery) and/or destroy it using radiotherapy and/or chemotherapy. Increasingly there has been a lot of success using immunotherapy, an approach where the immune system is switched on to fight the cancer.

However, there’s also mounting evidence that you can weaken a cancer by starving it of the fuel it needs to grow — blood glucose.

H ow can you reduce a cancer’s fuel supply without damaging other cells? That’s where two relatively simple approaches come in.

The first is HIIT: we’ve known for some time that exercise can cut your risk of cancer, by up to 35 per cent for some forms.

Analysis of data from 3,000 people over a 20-year period showed that those who did intense aerobic exercise were 72 per cent less likely to develop metastatic cancer (cancer that had spread) than those who did no exercise

Now a study by Tel Aviv University has shown that doing high-intensity aerobic exercise (i.e. running or cycling) is particularly effective. Analysis of data from 3,000 people over a 20-year period showed that those who did intense aerobic exercise were 72 per cent less likely to develop metastatic cancer (cancer that had spread) than those who did no exercise.

To find out what was going on, researchers injected mice that had run on treadmills with cancer cells. They discovered that the running caused muscles and organs, such as the lungs and liver, to grow more glucose receptors on their surface.

In other words, they could ‘suck in’ more glucose from the blood, depriving the cancer cells of the fuel they needed to spread. Any regular exercise should help, but the scientists say for the most benefits it has to be intense, pushing your heart rate up to at least 80 per cent of its maximum.

To work out your maximum heart rate, subtract your age from 220. So my maximum heart rate is 155 beats per minute — to count as ‘intense’ I would need to push it up to over 120 beats per minute.

Dr Michael Mosley: I do it on my bike, by cycling hard for short bursts up the hill. The scientists suggest alternating a couple of minutes of brisk walking with a one-minute sprint, followed by more walking, then another sprint

But it doesn’t have to be for long. I do it on my bike, by cycling hard for short bursts up the hill. The scientists suggest alternating a couple of minutes of brisk walking with a one-minute sprint, followed by more walking, then another sprint.

If you can’t do this, don’t be discouraged. A review published in October in the International Journal of Cancer concluded that women with breast cancer benefit from simply walking (though the more intense, the better), and from keeping to a healthy weight.

Why does weight matter? A recent study of people with type 2 diabetes and obesity concluded it’s mainly to do with keeping your blood sugar levels down.

Researchers at the University of Gothenburg in Sweden found that the patients who lost lots of weight and got their blood sugar levels down to a normal level were 60 per cent less likely to develop cancer over the following ten years than those who didn’t. I find this study personally encouraging because, ten years ago, I was diagnosed with type 2 diabetes, lost 9kg by following a rapid weight-loss diet and managed to get my blood sugar levels back to normal.

This new research suggests that not only has this reduced my risk of heart disease and dementia, but it’s cut my risk of getting cancer by 60 per cent, too.

More controversial than exercise or weight loss are claims a ketogenic diet, where you eat more fat and protein but cut right back on carbs, can reduce your cancer risk.

Dr Michael Mosley: The downside of going keto is you may cut out foods known to prevent cancer, such as wholegrains, fruits and vegetables. Keto can also lead to weight loss at a time when people are struggling to maintain their weight. So it is not to be undertaken lightly

This diet has been used for more than 100 years to treat epilepsy, but studies into its impact on cancer are more recent. Like exercise, the idea is that by following a keto diet, you weaken cancer by depriving it of glucose.

And you are not replacing cancer treatments, but complementing them.

Earlier this year researchers at Princeton University in the U.S. published a study which showed that in mice with pancreatic cancer, combining a keto diet with chemotherapy tripled their chance of survival. The researchers are now enrolling patients to take part in a clinical trial to see if the same approach works in humans.

The downside of going keto is you may cut out foods known to prevent cancer, such as wholegrains, fruits and vegetables. Keto can also lead to weight loss at a time when people are struggling to maintain their weight. So it is not to be undertaken lightly.

If you are being treated for cancer then you should discuss with your doctor whether doing intense exercise or trying a low-carb diet would be safe or suitable to add to whatever treatment regimen you’re on.

If, like me, you are just keen to stay fit and reduce your risk of developing cancer, then sticking to a low-ish carb, Mediterranean-style diet and doing some HIIT is sensible. But if you are not reasonably fit and healthy, be cautious.