Poor diets and obesity stall CVD rates from declining, Australian study finds

06 Aug 2019 --- Heart disease and stroke mortality rates have stopped declining in many high-income countries and are even increasing in some. This is according to Australian researchers, who have analyzed trends in cardiovascular disease (CVD) mortality in 23 high-income countries since 2000. The researchers found that CVD mortality rates for people aged 35 to 74 are now barely declining – and are increasing in 12 of the 23 countries. This phenomenon is potentially a result of obesity and poor diet, the researchers note, and they call for investment in public health policies and industry reformulations to avoid a future increase in CVD-related mortality.

In the US and for Canadian females, CVD mortality rates have increased in this year. In Australia, UK and New Zealand annual declines in deaths from CVD are now only 20 to 50 percent of what they were in the 2000s, the study showed. 

“We have all taken for granted that the factors driving the 50-year decline in CVD death rates would continue, perhaps at a slower pace. That has not happened,” Professor Alan Lopez from the University of Melbourne and Rowden-White Chair of Global Health and Burden of Disease Measurement, tells NutritionInsight.

Poor diets boost CVD mortality rates
Lopez who co-authored the research, says that the results suggest that obesity, or at least poor diet, may have been a significant contributor to the slowdown in the decline of cardiovascular disease deaths. “Each of these countries has very high levels of obesity. In Australia, close to one-third of adults are obese.” 

“These increases in obesity levels mean that a significant portion of the population has been exposed to the CVD risks associated with being overweight for several decades,” he adds. 

In the US and for Canadian females, CVD mortality rates have increased in this year.However, obesity is only one of many risk factors for CVD mortality – others include smoking, high blood pressure, high cholesterol and diabetes. A healthier lifestyle seems to be as important as proper nutrition in curbing CVD. Recently, a German study found that nearly half of premature CVD deaths in Europe could be prevented by better nutrition. The researchers evaluated data provided by the Global Burden of Disease Study (GBD), which were collected between 1990 and 2016. They analyzed the prevalence of CVD in the 51 countries that the World Health Organization (WHO) has designated as the “European region.” 

In the new study, however, the researchers found that obesity levels are low in Italy and France where the slowdown in CVD mortality in recent years is among the most notable of all countries.

“To our knowledge, increasing overweight and obesity rates, which carry significant excess risks of death from CVD, are the only major risk factors that have been increasing over the past few decades in countries where the change is most pronounced, such as Australia, US, Canada, UK,” Lopez says.

Earlier this year, an American Heart Association (AHA) Heart and Stroke Statistics report showed that 48 percent of Americans suffer from some type of CVD. The AHA report’s release coincided with a Cleveland Clinic survey, which noted that while 90 percent of Americans understand that regulating body weight is beneficial to heart health, they do nothing to actively tackle weight issues. The root of the issue, according to the survey, may also be that Americans do not know what to eat for better heart health.

The relationship between obesity and CVD is also supported by previous research. Last month, another Australian study discovered that restricting calorie intake moderately can significantly reduce the risk of heart attack in people who are only marginally overweight. In addition to significantly improving conventional cardiometabolic risk factors and reducing the risk of CVD by about a factor of 13, the trial participants also enjoyed major improvements on a range of risk factors linked to problems such as Type 2 diabetes, stroke, inflammation and some forms of cancer.

Policy and industry can tackle CVD?
The cause of the stalling rates in CVD-related mortality may be a public health policy issue or one that can still be amended by industry reformulations. Less sugar, less salt and healthier food options are some of the measures that industry can take according to the researchers.

The cause of the stalling rates in CVD-related mortality may be a public health policy issue or one that can still be amended by industry reformulations.“A greater dialogue is needed between the food industry and public health authorities to reduce the high-calorie components of commercial food products and reduce prices on healthy food options to make them more accessible. Additionally, we need to increase efforts and policies to reduce consumption of fast foods and a vast reduction in sugar content of soft drinks,” Lopez notes.

University of Melbourne researcher and study co-author Tim Adair says the research shows that the effect of successful public health interventions on CVD mortality over the past 50 years is diminishing. “In order to combat this, significant investment in preventive health measures is needed, particularly those aimed at increasing physical activity, improving diet and reducing obesity.” 

“Failure to address these issues could confirm the end of the long-term decline in cardiovascular disease deaths and threaten future gains in life expectancy,” he adds.

However more research on the link between obesity and the stalling CVD rates is warranted, the authors say. “It is likely that increasing obesity is the primary cause of the slowdown, but that needs to be confirmed in a rigorous, well designed, multi-country epidemiological research study,” Lopez concludes. 

By Kristiana Lalou