Exercise and diet advice misses the mark in improving heart health around the globe

A leading cardiovascular disease researcher from Simon Fraser University is ringing the alarm on universal recommendations intended to improve heart health around the globe.

Exercise and eat your veggies: For most of the world, privileged prescriptions like these don’t always reduce risk of heart disease. 

Cardiovascular disease (CVD) is the leading cause of death worldwide, with 80 per cent of deaths occurring in low- and middle-income countries. However, international heart-health guidelines are primarily based on research from high-income countries and often overlook upstream causes of CVD, says Scott Lear, a health sciences professor at SFU and the Pfizer/Heart & Stroke Foundation Chair in Cardiovascular Prevention Research.

"The world extends beyond high-income countries when we think about universal recommendations like 75 minutes of exercise each week or getting five servings of fruit and vegetables every day," says Lear, the lead author of a new review examining the impact of social, environmental, and policy factors on cardiovascular disease globally.

"There's a stark contrast between a daily sidewalk stroll in Vancouver's West End and walking to work in New Delhi, the world's most polluted city, where many people cannot afford to drive and public transit is lacking," he says. "We cannot assume that life is the same everywhere. The environments in which people live and the kind of work they do makes a huge difference to their health."

The review paper examined the causes behind the causes of CVD, using data from the ongoing collaborative Prospective Urban Rural Epidemiology (PURE) study. This study has been collecting data from high-, middle- and low-income countries since 2002, and now includes over 212,000 participants from 28 countries across five continents.

PURE study data is collected every three years and includes a core survey, physical measurements (such as height, weight, blood pressure, waist-hip circumference, and lung capacity), and additional questionnaires targeting specific research interests, including CVD.

In addition to physical activity environments, Lear's review study identified several other causes behind the causes of CVD worldwide, including nutrition, education, tobacco use, air pollution, climate change, social isolation and access to medication, treatment and health care. 

About 87 per cent of PURE participants live in low- or middle-income countries, uniquely positioning the study to examine individual risk factors related to urbanization, says Lear. Although these review findings are based on global data, they also reflect the microcosms of different regions within a single city, or region.

Privilege shapes exercise 

Lack of exercise is a major risk factor for cardiovascular disease, but the type and context of physical activity people do get also plays a role.

According to Lear's review, self-reported physical activity was highest in high-income countries, despite over 22 per cent of participants sitting for more than eight hours a day. By contrast, only 4.4 per cent of participants in low-income countries reported sitting for more than eight hours a day, yet their overall physical activity levels were lower.

The difference lies in the nature of the activity. In low-income countries, physical activity is often tied to work, transportation, and domestic tasks rather than leisure, explains Lear.

Priced out of produce

A healthy diet containing fruits, vegetables, legumes, nuts, fish and dairy can reduce the risk of cardiovascular disease. Lear reported that regardless of country income, fruits and vegetables were more readily available and more affordable in urban areas. 

But he was also surprised to find that consumption of fruits and vegetables is lower in low-income countries because farmers can't afford to eat their own produce.

This is a real eye opener. For many of these farmers, getting the recommended minimum of five servings of fruits and vegetables a day would eat up 50 per cent of their household income."

Scott Lear, health sciences professor at SFU