Healthy Lifestyle Factors and Diet Linked With Income: PURE

August 26, 2012

August 26, 2012 (Munich, Germany) — Data from the Prospective Urban Rural Epidemiology (PURE) study highlight the disparity between healthy diet and lifestyle behaviors among affluent and underdeveloped nations. The consumption of fruits and vegetables increased among nations with a higher gross domestic product (GDP) and wealth index, but this was offset by an increase in the amount of energy obtained from total and saturated fats, as well as from protein.

Dr Salim Yusuf (McMaster University, Hamilton, ON), the lead researcher of the PURE study, said the study, which describes an "epidemiological transition," might help shift global food policies so that countries subsidize the production of fruits and vegetables rather than meat and dairy. In addition, the study highlights an insufficient policy approach when it comes to increasing physical-activity levels.

"In relation to physical activity, sure, we can tell people to be active 30 minutes a day for five days a week, but it's only a tiny drop in the ocean," Yusuf told heartwire. "We've talked about changing the environment by changing our modes of transportation, but what do you do about somebody like you and me who have sedentary jobs? How do we make our jobs more active?"

Regarding the need for change, Yusuf said there is a need for greater investment to understand the societal determinants of health. Based on data from the INTERHEART and INTERSTROKE studies, approximately 50% to 60% of the risk of cardiovascular disease is attributable to modifiable lifestyle factors. While there are creative solutions, such as eliminating elevators in buildings of a certain height so that able-bodied people are forced to walk upstairs or using balance balls to work on instead of chairs, the key point is the understanding that recreational exercise to overcome the problem will be insufficient and that the entire environment needs to be redesigned.

"That's where policy comes in," said Yusuf. "Our study is really about primordial prevention, to create the right environment to do the right thing."

Income and Health Intrinsically Linked

Presented today at the European Society of Cardiology (ESC) 2012 Congress, the PURE study is a follow-up analysis showcasing the effect of macro- and microeconomic factors on lifestyle and dietary risk factors for cardiovascular disease. First presented last year at the ESC 2011 meeting and published in the Lancet [1], the PURE study has already shown that the use of cardiovascular medications was underused in rural and poor populations. In PURE, one of the most devastating findings was the underuse of proven medical therapy for secondary prevention of cardiovascular diseases.

The PURE survey encompassed 153 996 adults from urban and rural communities in countries categorized as high-income (Canada, Sweden, and United Arab Emirates), upper-middle-income (Argentina, Brazil, Chile, Malaysia, Poland, South Africa, and Turkey), lower-middle-income (China, Colombia, and Iran), and low-income (Bangladesh, India, Pakistan, and Zimbabwe).

In this newest analysis, energy from total fat, saturated fats, and protein increased almost linearly with increasing incomes. Carbohydrate intake, on the other hand, comprised approximately 65% of energy from diets in poor nations, with the percentage declining in wealthier nations. In terms of physical activity, the researchers observed that the amount of recreational physical activity increased with increasing GDP and wealth, but this increase was offset by a reduction in the amount of obligatory physical activity, such as activity required for physical labor. Overall, the net result was a reduction of approximately 2000 METS/minute/week, or 2.7 hours of brisk walking every day, among countries with higher incomes.

"There is no way, unless you're a marathon runner every day, that we're going to overcome the decrease in activity due to the changing environment," said Yusuf. "So the obesity epidemic really requires a change in environment. We can yell at people and say, 'Exercise!' but it is not going to be enough. It's about one-fourth of the difference of lost physical activity."

How Much Physical Activity Is Needed?

Speaking with the media, Yusuf said the researchers and clinicians are still unsure what the ideal level of physical activity is or, more specifically, what level of physical activity significantly reduces cardiovascular events. However, there is a strong correlation between physical-activity levels and obesity. Increased fat consumption and the marked decrease in physical activity are the two main drivers of the obesity epidemic worldwide, but the decrease in physical activity is several orders of magnitude larger than the increase in fat consumption.

To heartwire , Dr Douglas Weaver (Henry Ford Hospital Heart and Vascular Institute, Detroit, MI) applauded the researchers for highlighting the discrepancies in lifestyle and diet between high- and low-income countries but said more research is still needed, particularly research that shows altering some of these variables improves outcomes.

"I think for us to really get behind national efforts to change what the consensus is for us to be healthy, we really need that information," said Weaver. "If we change things, does it really make a difference? What is the magnitude of the difference? It seems intuitive, but a lot of things we think would make a difference don't always do so. As a scientist, or somebody who is trying to set public policy, we need more data."

Regarding smoking, Yusuf explained that the decision to smoke in women depends not only on GDP/wealth but also on cultural factors, such as religion. In men, there is a clear inverse relationship between GDP and wealth and smoking status. Approximately 45% of males in the poorest countries smoke compared with 20% of males in the richest countries. Yusuf said that men begin smoking at approximately the same age in all countries, but that the rate of quitting is higher in higher-income countries.

"This is important, because the focus of smoking should be on quitting," said Yusuf. "It's the people who are alive today, who are smoking today, who will die in the next 40 years from tobacco. And of course, if you can get people to quit, then their children will not start."


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