There are many risk factors to health in the world, some of which are more dangerous than others. There are environmental factors that affect our health, along with genetic and dietary factors. Some of these are unavoidable — you can’t exactly change your family history — but others are distinctly preventable.

Ranging from poor diet to unsafe environmental factors like air pollution, risk factors that aren’t inevitable have huge effects on health around the world, and it’s getting worse. According to a new analysis on risk utilizing data from 188 countries, avoidable risk factors account for a growing number of deaths and disease burdens.

The Study

The Global Burden Of Disease, Injuries, and Risk Factor Study 2013 (GBD 2013) examined 79 different risk factors that accounted for 30.8 million global deaths in 2013. The study estimated attributable deaths, years of life lost, years lived with disability, and disability-adjusted life years (DALYS) for each of the risks to compile a hierarchy. Compared to the previous GBD study, completed with data from 2010, the latest analysis included six new factors that had not previously been examined—hand washing practices, occupational exposure to trichloroethylene, childhood wasting, childhood stunting, unsafe sex, and low glomerular filtration rate.

The study aims to identify which risks (mostly modifiable ones) are threatening to the population, and identify opportunities for prevention.

What Are The Biggest Risks?

The top risks for combined for both men and women were, in order, high blood pressure, smoking, high body mass index (BMI) and high fasting plasma glucose. Cumulatively, though, it was poor diet that had the biggest impact on health, with 14 dietary risk factors contributing to the highest number of deaths worldwide through conditions like stroke, diabetes, and ischemic heart disease. Twenty-one percent of the total global deaths in 2013 were attributed to these ailments, which can arise from risk factors including a diet low in fruits, whole grains and vegetables, and diets high in red meat and sugar.

Apart from these major risks, the risks affecting different demographics vary. Smoking, for example, is a larger problem in males, ranking as the No. 2 risk factor in men, and No. 6 in women. Alcohol is also a top 10 risk factor for male deaths, but it is not a leading cause for females. Children are at risk for different things than adults — children under the age of 5 suffered from undernutrition as the No. 1 cause of death worldwide.

Regional variations also contributed to differences in risk factors. In the Middle East and Latin America, a high body mass index is the No. 1 risk associated with health loss. South and Southeast Asia face indoor air pollution as a leading risk, and India sees a lot of trouble because of unsafe water and childhood undernutrition. Smoking is a leading cause of death in some high-income countries, including the United Kingdom, where it is the No. 1 leading risk. Sub-Saharan Africa suffers from a uniquely toxic combination of risk factors — the region sees high levels of child undernutrition, unsafe water and sanitation, and unsafe sex.

A New Era Of Risk

Since 1990, the mix of leading risk factors has changed significantly. Gone are child undernutrition and unsafe water sources from the global top 10 list, while alcohol use and high cholesterol have replaced them as a major contributors to poor health and death. Though this is hard to see as good news, the fact that these risks are preventable gives researchers hope for effective prevention.

"There's great potential to improve health by avoiding certain risks like smoking and poor diet as well as tackling environmental risks like air pollution," said Institute for Health Metrics and Evaluation (IHME) Director Dr. Christopher Murray, in a press release. "The challenge for policymakers will be to use what we know to guide prevention efforts and health policies."

Of course, regional differences remain a problem, and different areas require different prevention strategy.

"While we have seen a tremendous growth in risk factors that contribute to non-communicable diseases like heart disease, pulmonary diseases, and diabetes, childhood undernutrition remains a huge challenge for some countries," said Dr. Mohammad Hossein Forouzanfar, assistant professor of Global Health at IHME and the paper's lead author.

The IHME has made their findings widely available so policymakers have the information and evidence they need to make decisions about allocating resources to improve health.

Source: Forouzanfar M, Murray C, Vos T. Global, regional, and national comparative risk assessment of 79 behavioral, environmental and occupational and metabolic risks or clusters of risks in 188 countries, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013. The Lancet. 2015.