IN TOMORROW’S IRISH DAILY MAIL

BODY CLOCK TIPS FOR A HAPPIER MARRIAGE

so taking aspirin at that time of day, just as they’re being formed, ensures the new platelets are ‘deactivated’ long before the dangerous window for strokes the following morning.

The downside is that taking aspirin before bed may increase the chances of damaging the stomach lining, leading to ulcers or reflux – although drugs called proton pump inhibitors (PPIs) can resolve this. See panel below.

Another risk factor for heart attacks or stroke is raised levels of ‘bad’ cholesterol. To address this, many people are prescribed statins which slow down cholesterol production in the liver.

Of course, there’s an optimum time to take statins, too.

Cholesterol levels in the blood follow a circadian rhythm, with cholesterol normally produced between midnight and 6am. The best time to take statins depends on what type you use: some remain effective in the blood for four to six hours, but others work for 20 or even 30 hours.

So if you’re on a short-acting statin such as simvastatin, take it around bedtime to ‘hit’ the night-time production in cholesterol.

But if you’re on statins that are effective for 20 to 30 hours, (such as atorvastatin) take them any time because their effectiveness will always overlap with higher levels of cholesterol production at night.

Harnessing knowledge of the body clock could make a significant difference to cancer treatment, too.

Increasingly, research is identifying the role of circadian rhythms, and their disruption, in cancer developments and how we can use time to our advantage when treating tumours.

Laboratory studies show that tumours grow much faster if the circadian system is disrupted.

In experiments, mice with simulated jet lag show much faster tumour growth. And similar effects have been demonstrated in humans. Night-shift workers, including nurses, and those with rapidly changing work schedules, such as pilots and air crew, have significantly higher rates of cancer. So sleep and circadian rhythm disruption (SCRD) increases our vulnerability to getting cancer.

In addition, cancer progression is worse in those individuals with SCRD. As a result, one holistic approach often recommended alongside cancer treatments involves trying to stabilise a patient’s circadian rhythms.

This science is relevant to everyone’s attempts to stay healthy.

We should all make sure that our circadian system – specifically, the master clock in our brain – is ‘reset’ daily to be in sync with our 24-hour world. This will enable us to deliver the correct materials to the right organs at the correct concentration at the right time of day to defend ourselves against disease.

Keeping our body clock in sync involves eating at regular times, getting enough exposure to light around both dawn and dusk, and having a consistent sleep/wake routine, getting up and going to bed at the same time each day.

As for cancer treatment, while chemotherapy and radiotherapy both attack fast-growing cancer cells, they also affect healthy cells that are undergoing division, and this can produce traumatising sideeffects. But there is normally a circadian time window during the day when healthy cells grow, and this is often very different from that of cancerous cells, which divide and grow much faster.

This means that if treatment is given at times of the day when our healthy cells are ‘quietest’ – when they’re dividing and growing the least – the toxicity of the treatment to the healthy cells can be reduced. And so higher doses can be given to ‘blast’ the bad, cancerous cells without having such terrible side-effects.

Studies have shown the benefits of timing drugs to treat ovarian cancer, leukaemia, colorectal cancer and brain tumours, with the optimum delivery window depending on the area affected by cancer.

However, despite all this valuable knowledge, patients are usually given anti-cancer drugs at times convenient for those treating them.

Admittedly, there are important logistical problems delivering toxic drugs in busy hospitals.

Yet modern equipment such as ambulatory medical pumps, which give chemotherapy via a drip at a particular time, could be used at low cost and potentially in patients’ own homes.

Practicalities aside, another major hurdle is a failure to understand the importance of circadian timing.

Most doctors are given very little training in the importance of circadian rhythms, and until this becomes a serious topic for study in medical schools, there will always be a barrier between exciting laboratory findings, medical application and new drug discovery. This has to change.