Author: Patricia Nicholson

When we think of medicine, we think of drugs and treatments performed in hospitals and clinics. But growing evidence suggests that it’s what we do outside of the doctor’s office that may be the best medicine.

‘Number one in every guideline about every single chronic disease is lifestyle,’ said Dr. Paul Oh, medical director of the Cardiac Rehabilitation and Secondary Prevention Program at the Toronto Rehabilitation Institute.

But sometimes lifestyle factors can get sidelined in favour of pharmaceutical and clinical treatments.

‘We move very quickly on to writing a prescription,’ Dr. Oh explained during a presentation at Women’s College Hospital. But large-scale studies in diabetes care and cardiovascular disease are highlighting the importance of lifestyle interventions. For cardiac patients, for example, many studies have shown that exercise actually saves lives.

‘There is a mortality advantage of about 20 per cent for those who do cardiac rehab versus those who don’t, for overall survival,’ Dr. Oh said, adding that the evidence for this is irrefutable. ‘This evidence is as good as anything else that’s out there: as good as the evidence for aspirin or lowering cholesterol or smoking cessation.’

The power of feet

While some lifestyle factors have shown huge improvements in recent trends, such as sharp decreases in smoking rates, others have deteriorated. There is a growing preponderance of physically inactive people in our society, and that rate goes up with age. The rate at which physical inactivity increases in a society very closely mirrors the increases in the burden of chronic diseases.

But even for those people who have no health issues or major risk factors, the relationship between activity and health is important.

‘We all have a chronic disease that’s called aging,’ Dr. Oh says, describing what he calls a fertile soil of aging, inactivity and genetic predisposition, where chronic health problems can easily take root. ‘That’s what we all need to defend our bodies against.’

Large studies have shown a clear gradient linking fitness levels with long-term survival over several decades.

‘If we can only do one test on you today to determine how you’re going to do over the next 10 years, it wouldn’t be a cholesterol profile, and it wouldn’t necessarily be a blood pressure profile,’ Dr. Oh says. ‘We could just put you on a treadmill and see how long you can go. The longer you can go on that treadmill, that’s probably the tightest correlation with how well and how long you’re going to live. So that’s the power that’s in your feet.’

Exercise, diet and other lifestyle habits really can shape the future of your heart. Dr. Oh notes that there is a common set of nine risk factors that predict heart disease.

‘These nine factors relate a lot to lifestyle, and these nine factors are indeed modifiable and can explain 90 per cent of the risks that we carry,’ Dr. Oh said.

• abdominal obesity
• cholesterol
• daily fruits and vegetables (lowers risk)
• diabetes
• hypertension
• physical inactivity
• regular alcohol consumption (lowers risk)
• smoking
• stress and psychosocial factors

In large studies, when cardiovascular risk is weighted against the number of these nine risk factors that are modified – such as quitting smoking, improving diet, being more active, having a healthy weight and healthy alcohol consumption – risk drops dramatically.

‘As we mitigate each of these risks in turn, we can actually reduce our risk by 70 to 80 per cent,’ Dr. Oh says. ‘So that’s a very exciting thing: the power of lifestyle. We’re actually not very good at it, but that’s the promise of what we can actually achieve.’

Strong medicine

Because they are so fundamental to almost every chronic medical condition, lifestyle interventions and rehabilitation programs need to be thought of more as core medical therapies, not something that would be nice to do as an add-on.

Using the example of cardiac rehabilitation, Dr. Oh illustrates the relationship between completion of a cardiac rehab exercise program and survival. Not only do patients in rehab programs have a survival advantage, that advantage increases with their level of participation.

‘There is a dose response gradient,’ he says, describing a U.S. study of patients in a 12-week cardiac rehab program. Patients who only attended one session had almost half the survival rate of those who attended all 36 sessions (three times per week over 12 weeks). Patients who attended 12 sessions were 22 per cent less likely to survive than those who attended all the sessions, and those who only attended 24 sessions were 14 per cent less likely to survive.

Those findings are mirrored in studies of diabetes patients. In the Nurses’ Health Study, women living with diabetes who exercised more had a significantly lower risk of heart disease. Again, there was a dose response – more exercise was associated with an increasingly lower risk.

‘If we get up to five hours of exercise per week, we can cut the risk of heart disease by about half,’ Dr. Oh says of diabetes patients.

Other diabetes studies have shown that exercise can actually lower levels of hemoglobin A1c (a marker of blood glucose) by about 10 per cent, with no other medical interventions.

At the physiological level, there are good reasons why exercise improves health. It improves blood flow and reduces inflammation (which is implicated in many diseases).

Walking an hour per day not only improves these markers, but also makes your blood less sticky, improves your metabolic environment, makes you more sensitive to insulin, improves good cholesterol levels, lowers bad cholesterol levels and improves nitric oxide levels, which is important for healthy blood flow.

A simple recipe

So how can people get better? Dr. Oh says it’s a simple recipe: some cardio, and then some weights. Start slowly and gradually build up. Dr. Oh says a good place to start is walking 1.5 miles per day in about 25 to 30 minutes.

‘Start moderately and go from there. It’s never a good idea to take a running start – literally,’ he says. Starting out with something too ambitious, like running, usually means giving up quickly.

Gradually build up walking duration slowly over a period of several weeks, and then start to work on intensity: walking faster. Then introduce weight training a couple of times a week, starting with one-pound weights.

‘Get up to a dose of about three or four miles in 45 to 60 minutes,’ Dr. Oh says. ‘Why? Because that’s the dose that we say is evidence-based – that can impact positively on risk factors and impact on mortality. There actually is science behind this.’

If you get fast enough, you might wish to go from walking to jogging. If you like, you can also mix in other activities such as cycling or swimming.

For some people – particularly those who have a chronic disease or who have cardiac risk factors – a chat with your family doctor before starting is recommended. In some cases, testing might be in order, such as cholesterol testing or a stress test.

Dr. Oh notes that it would be considered poor treatment if a doctor failed to recommend a proven medical therapy, such as aspirin for heart patients. But few patients expect a prescription for exercise, despite its proven benefits.

‘It’s more difficult to take a walk a day than a pill a day. Ideally, it should be both,’ Dr. Oh says. ‘We have high quality evidence that engaging in regular exercise has a real impact on how well and how long we live.’

In that light, a prescription for fitness makes a great deal of sense.

‘Wouldn’t it be great if instead of focusing on disease, we could focus on health?’ Dr. Oh asks. ‘That’s where we would love to be.’