Lifestyle and Health

Do lifestyle choices affect health outcomes?

HCP 2011 Lifestyle and Health video still

Key Messages

  • In Canada, tobacco consumption has fallen steadily since the 1960s, but mortality rates due to lung cancer began to drop only in the 1990s—reflecting the lag between exposure to smoking and the point at which cancer develops or is detected.
  • The already high and growing obesity rates in the U.S., Australia, the U.K., and Canada are a serious health concern because obesity is a risk factor for cardiovascular diseases, diabetes, cancer, and hypertension.
  • As obesity rates in Canada and the U.S. have increased, so have mortality rates due to diabetes.

Health outcomes are improving in Canada and its peer countries, aren’t they?

Over the past five decades, the OECD average life expectancy has grown by more than 10 years—from 68.2 years to 79.2 years. Cancer mortality rates have fallen, infant mortality rates are significantly lower, and a deadly disease (smallpox) has been eradicated. These improvements in health outcomes can in large part be attributed to increased prosperity and better education—and consequently, advancements in technology and health care.

However, the fact that mortality rates due to cancer and chronic diseases are falling does not mean that the incidence of chronic diseases is on the decline. Data on cancer incidence for both 1998 and 2008 are available for 11 of the 17 peer countries. For each of the 11 countries, the cancer incidence rate was higher in 2008. Both diabetes incidence and mortality rates due to diabetes are increasing at an alarming rate. A rising proportion of the population has high blood pressure or hypertension. Hypertension is a condition often linked to heart disease and diabetes, and is a risk factor that can lead to a host of health complications.

Data for Canada show that in just six years—from 2003 to 2009—the proportion of the population reporting having diabetes grew by a third, from 4.6 to 6 per cent, as diagnosed by a health-care professional.1 In the same six years, the proportion of the population reporting having high blood pressure grew from 14.4 to 16.9 per cent.2 The actual numbers are likely even higher, given that many people living with these conditions have not yet been diagnosed.

North Americans and Europeans continue to be plagued by a number of chronic diseases that are often linked to lifestyle choices. Smoking, over-consumption of alcohol, poor diet, and inactivity all greatly increase the risk of developing heart disease, hypertension, diabetes, and cancer.

What impact has tobacco consumption had on lung cancer deaths in Canada?

Smoking is the main preventable risk factor for respiratory diseases like lung cancer and chronic obstructive pulmonary disease. The link between smoking and cancer is well documented. Smoking is the single most preventable cause of lung cancer, which is the number one cause of deaths from cancer in the country, and the second most common cancer in Canada for both men and women (prostate cancer for men and breast cancer for women being the most common).3 In Canada, tobacco consumption has fallen steadily since the 1960s. In fact, Canada has one of the lowest smoking rates among its peer countries. Lung cancer mortality rates in Canada, however, rose from the 1960s through to the 1980s and began to decline only in the 1990s—a reflection of the lag between exposure to risk factors such as smoking and the point at which cancer develops or is detected.

Gender-disaggregated data for Canada are particularly revealing.

As seen in the chart, tobacco consumption by men started to fall in the early 1960s. Mortality rates due to lung cancer in males began to level off in the mid-1980s and have been falling ever since—there has been an average annual decrease in lung cancer mortality in males of 2 per cent every year since 1989. Lung cancer incidence rates for men also began to level off in the mid-1980s, according to the Canadian Cancer Society.

Tobacco consumption by women remained steady through the 1960s and did not begin to drop until the 1980s. The mortality rate due to lung cancer for women continued to rise, however, as did the lung cancer incidence rate, which was on an upward trend of 1.2 per cent per year between 1997 and 2006. But the incidence rate in females is finally beginning to level off.4 Given the lag of 20 years or more between the drop in smoking rates and the decline in lung cancer mortality rates, it is likely that mortality rates in females will begin to drop as well over the longer term.

How have tobacco consumption rates and lung cancer deaths changed for Canada’s peers?

Canada’s peer countries have also experienced a large drop in the proportion of smokers since the 1960s, as well as a resulting drop in the mortality rates due to lung cancer. The U.K. experienced a notable drop in its proportion of smokers over the past few decades—from 51.5 per cent in 1960 to 22 per cent in 2008. The U.K. had the highest tobacco consumption rate among the peer countries for which data were available in 1960.5 Given the delay between smoking and the onset of lung cancer, the lung cancer mortality rate in the U.K. remains high—but it has fallen markedly and will likely continue to do so. The Netherlands saw the proportion of smokers fall like other OECD countries over the past few decades. But it still has the highest proportion of smokers and continues to have one of the highest mortality rates due to lung cancer.

Use the bubble diagram to view the relationship between tobacco consumption and lung cancer mortality. Follow these steps:

  1. Under “Color,” choose “Country.” That way, each colour will represent a specific country. (When you scroll over each different coloured bubble, the country name will pop up.)
  2. Under “Size,” we recommend you choose “Population” or “GDP per capita” as the variable to track based on the size of the bubble. That way, you will be able to see at a glance how bigger countries are doing compared with smaller ones, or how richer countries are doing compared with poorer ones.
  3. Choose “Tobacco consumption” as the variable to track on the horizontal axis.
  4. Choose a health outcome such as “Lung cancer mortality” as the variable to track on the vertical axis.
  5. If you want to see a trail for a particular country, click in the “Trails” box, and then click in the box of the country (or countries) you want to trail. Each country will be represented by a trail of bubbles in its unique colour.
  6. Finally, click the play button in the bottom left to begin the show.

Overall, the data reveal a strong relationship between smoking and lung cancer mortality rates. Using a 20-year lag for tobacco consumption, we found a very strong correlation between tobacco consumption and mortality rates due to lung cancer (correlation coefficient = 0.96), based on a fixed effects panel analysis for the 17 peer countries using data from 1960 to 2008. The 20-year lag was used to reflect the time between smoking and the development of lung cancer.

Is obesity the latest epidemic?

Obesity has taken centre stage as a major risk factor for chronic diseases. Obesity rates around the world have grown over the past few decades. By 2015, more than 700 million people worldwide will be obese, according to World Health Organization estimates.6 Half or more of the adult population is overweight or obese today in many OECD nations.

The commonly used measure of being overweight or obese is the body mass index (BMI). A person with a BMI between 25 and 30 is considered to be overweight, and a person with a BMI over 30 is defined as obese.

Two sets of BMI measurements are available: self-reported and measured. Estimates based on self-reported height and weight are available for most countries. BMI estimates derived from actual measurements of height and weight are sparse and only available for a select number of countries—these data are generally higher and more reliable than BMI estimates based on self-reports. According to calculations based on self-reported data, in 2008, 47 per cent of Canada’s population was considered to be either overweight or obese and 16 per cent was considered to be obese, compared with 60 per cent and 24 per cent, respectively, using measured data.7

The U.S., Australia, the U.K., and Canada have high obesity rates that continue to trend upwards. Growing obesity rates are a serious health concern. Obesity is a risk factor for cardiovascular diseases, diabetes, cancer, and hypertension.

The U.S. has the highest obesity rate among OECD countries. Over 33 per cent of the U.S. population is obese—more than twice the obesity rate 30 years ago. An estimated 81,100,000 American adults have one or more types of cardiovascular disease. More than one in three American adults suffers from one or a combination of the following conditions: coronary heart disease, heart failure, stroke, high blood pressure, and congenital cardiovascular defects.8 Cardiovascular disease is the leading cause of death in the United States. Among the types of cardiovascular disease, coronary heart disease is the biggest killer, accounting for 51 per cent of cardiovascular disease deaths in 2006.

Why have mortality rates due to heart disease fallen if obesity rates have increased?

The bubble chart shows how the relationship between obesity rates and mortality rates due to heart disease for Canada and other OECD countries has changed over time. Paradoxically, as obesity rates have grown over the past few decades, the mortality rates due to heart disease have fallen.

This may be because changes in other lifestyle choices have played a role. Smoking has decreased significantly since the 1960s, as discussed above. Also, better diet may be a contributing factor—fewer saturated fats are being consumed and this, in turn, along with the drop in smoking, has resulted in lower cholesterol levels.9

Also, better treatments for heart disease have had an impact. A study on the decrease in deaths in the U.S. due to heart disease found that between 1980 and 2000, “about 47 per cent of the decrease was attributable to evidence-based medical therapies.”10 Prescription drugs such as beta blockers, antiplatelet drugs, ACE inhibitors, and lipid-lowering drugs are being increasingly used to treat conditions such as hypertension and high cholesterol and have proven to be effective in lowering heart disease mortality rates.11

Use the bubble diagram to view the relationship between obesity and mortality rates due to heart disease. Follow these steps:

  1. Under “Color,” choose “Country.” That way, each colour will represent a specific country. (When you scroll over each different coloured bubble, the country name will pop up.)
  2. Under “Size,” we recommend you choose “Population” or “GDP per capita” as the variable to track based on the size of the bubble. That way, you will be able to see at a glance how bigger countries are doing compared with smaller ones, or how richer countries are doing compared with poorer ones.
  3. Choose “Obesity: self-reported” as the variable to track on the horizontal axis.
  4. Choose “Mortality: heart disease” as the variable to track on the vertical axis.
  5. If you want to see a trail for a particular country, click in the “Trails” box, and then click in the box of the country (or countries) you want to trail. Each country will be represented by a trail of bubbles in its unique colour.
  6. Finally, click the play button in the bottom left to begin the show.

Historical data on the incidence of heart disease, rather than mortality rates, would shed more light on the relationship between heart disease and obesity. Unfortunately, comparable data for the 17 peer countries are not available. However, the data available for Canada show that compared to the 1990s, more surgical treatments like angioplasties and coronary bypass surgeries are now being performed—a reflection of the increase in the prevalence of heart disease.

The number of coronary bypass surgeries performed in Canada grew between 1995 and 2001 and has since levelled off because angioplasties are increasingly being done as an alternative procedure.12 Between 1995 and 2005, the total number of angioplasties performed in Canada nearly doubled.13

In spite of the effectiveness of medical treatments and the reduction of risk factors such as smoking, mortality rates due to heart disease will likely increase in the future, given the growing obesity epidemic. Also, as mentioned earlier, heart disease is not the only chronic condition linked to obesity. So are hypertension and diabetes. They are also both closely related to heart disease. Hypertension or high blood pressure, also known as the “silent killer,” “doubles or triples the risk for stroke, ischemic heart disease, peripheral vascular disease, and heart failure.” 14 In Canada, between 1994 and 2007, hypertension prevalence grew by 8 percentage points, from 10 per cent to 18 per cent. While this increase was in part due to more screening and diagnosis of high blood pressure, increased obesity also likely played a role. Risk factors for high blood pressure include being overweight or obese, heavy alcohol consumption, physical inactivity, and high salt intake.

Are the growing rates of obesity leading to more deaths due to diabetes?

Diabetes, another chronic disease associated with obesity, cardiovascular disease, and hypertension, is also on the rise. Between 2000 and 2005, the proportion of Canadian men and women diagnosed with diabetes increased by 29 per cent and 27 per cent, respectively.15 Being overweight or obese greatly increases the risk of developing Type 2 diabetes. About 90 to 95 per cent of all diabetes cases are Type 2.16 Disturbingly, there is a growing incidence of Type 2 diabetes among children, not just in Canada and the U.S., but around the world. According to the International Diabetes Federation, Type 2 diabetes in children is becoming a global health issue.17

Mortality rates due to diabetes have also increased in Canada since the 1980s. The U.S. and Canada have two of the highest mortality rates due to diabetes among the peer countries. They also have two of the highest obesity rates. Surprisingly, the U.K., which also has a high obesity rate, has a low mortality rate due to diabetes. The number of deaths due to diabetes in the U.K. is likely hugely underestimated, though, because other diseases caused by diabetes—namely cardiovascular disease—are usually recorded as the cause of death in death certificates of people with diabetes.18

Poor health outcomes are not just about lifestyle choices, are they?

Lifestyle clearly affects health outcomes, but it’s not the only thing that does. Socio-economic factors—like poverty, income inequality, crime, education, and the environment—also affect the health of the population.19 For example, a Statistics Canada study found that the onset of Type 2 diabetes in women is linked to household income and education. Low-income women and those with lower education levels are more likely to develop Type 2 diabetes—independent of whether or not they are overweight. 20

Socio-economic status also plays an indirect role in health outcomes by affecting lifestyle choices. The prevalence of lifestyle-related risk factors is often higher for socio-economically disadvantaged groups. The OECD notes that, in Canada, “women with poor education are almost twice as likely as more educated women to be overweight.”21

It is not just waistlines that are expanding—health spending continues to rise with increasing obesity rates. Obesity-related health-care spending is twice what it was nearly a decade ago. Medical spending for an obese person is 42 per cent higher per year, on average, than for a normal weight person.22 The growing incidence of obesity-related Type 2 diabetes will increase future health spending. According to the International Diabetes Federation, between 2010 and 2030, global health-care spending for diabetes will grow by 30 to 34 per cent.23

Use the bubble diagram to compare lifestyle factors (such as tobacco and alcohol consumption and obesity) with health outcomes (such as mortality rates due to cancer, heart disease, and diabetes) over time. Follow these steps:

  1. Under “Color,” choose “Country.” That way, each colour will represent a specific country. (When you scroll over each different coloured bubble, the country name will pop up.)
  2. Under “Size,” we recommend you choose “Population” or “GDP per capita” as the variable to track based on the size of the bubble. That way, you will be able to see at a glance how bigger countries are doing compared with smaller ones, or how richer countries are doing compared with poorer ones.
  3. Choose a lifestyle factor such as “Alcohol consumption” as the variable to track on the horizontal axis.
  4. Choose a health outcome such as “Mortality: heart disease” as the variable to track on the vertical axis.
  5. If you want to see a trail for a particular country, click in the “Trails” box, and then click in the box of the country (or countries) you want to trail. Each country will be represented by a trail of bubbles in its unique colour.
  6. Finally, click the play button in the bottom left to begin the show.

Footnotes

1  Statistics Canada, “Diabetes, by Sex, Provinces, and Territories,” (accessed May 9, 2011). Data are for the population 12 and over who reported that they have been diagnosed by a health professional as having diabetes.

2  Statistics Canada, “High Blood Pressure, by Sex, Provinces, and Territories,” (accessed May 9, 2011). Data are for the population 12 and over who reported that they have been diagnosed by a health professional as having high blood pressure.

3  Canadian Cancer Society, “Canadian Cancer Statistics 2010,” 11, (accessed May 9, 2011).

4  Ibid.

5  Data for 1960 are not available for Netherlands.

6  World Health Organization, “Obesity and Overweight, Fact Sheet No. 311.”

7  OECD Health Data 2010.

8  Data are for 2006. American Heart Association, Heart Disease and Stroke Statistics: 2010 Update At-A-Glance (Dallas: American Heart Association, 2010), 6.

9  Annika Rossingren, “Declining Cardiovascular Mortality and Increasing Obesity: A Paradox,” Canadian Medical Association Journal (August 2009), 127–128.

10  New England Journal of Medicine, 2007, as cited in American Heart Association, Heart Disease and Stroke Statistics: 2010 Update At-A-Glance, 12.

11  D. Mukherjee, J. Fang, S. Chetcuti, M. Moscucci, E. Kline-Rogers, and K.A. Eagle, “Impact of Combination Evidence-Based Medical Therapy on Mortality in Patients With Acute Coronary Syndromes,” Circulation, Journal of the American Heart Association 19, 6 (February 2004), 746.

12  Public Health Agency of Canada, Tracking Heart Disease and Stroke in Canada (2009), 83.

13  Ibid., 85.

14  Ibid., 49.

15  Ibid., 47.

16  International Diabetes Federation, “Types of Diabetes,” (accessed May 9, 2011).

17  Ibid.

18  British Heart Foundation, “Heart Statistics,” (accessed May 9, 2010).

19  D. Munro, Healthy People, Healthy Performance, Healthy Profits: The Case for Business Action on Socio-Economic Determinants of Health (Ottawa: The Conference Board of Canada, 2008).

20  Statistics Canada, “Study: The Role of Socio-Economic Status in the Incidence of Diabetes,” (accessed May 23, 2011).

21  OECD, “Obesity and the Economics of Prevention: Fit not Fat—Canada Key Facts,” (accessed May 23, 2011).

22  Eric A. Finkelstein, Justin G. Trogdon, Joel W. Cohen, and William Dietz, “Annual Medical Spending Attributable to Obesity: Payer- and Service-Specific Estimates,” Health Affairs, 28, 5 (July 27, 2009), w828.

23  International Diabetes Federation, “Economic Impact of Diabetes,” Diabetes Atlas (Fourth Edition), 2009, 6, (accessed May 23, 2011).