Life expectancy is increasing around the globe as advances are made in medical care and research; however, the more the medical world investigates, the more we learn new risk factors that can lead to death. Today, the majority of deaths worldwide can be attributed to non-communicable diseases, like cardiovascular diseases and cancer. However, in developing countries, such as Kenya, the leading cause of death is diarrheal disease, which can often be prevented with adequate water filtration and sanitation facilities.
Our World in Data collected statistics from the Global Burden of Disease, and authored an extensive paper on the world’s leading causes of death, considering behavioral, environmental, occupational, and metabolic risk categories. The risk factors were measured across all ages and genders, and refer to deaths from 2016.
The contribution of risk factors varies based on country, with high-income countries reporting more deaths related to diet, smoking and alcohol intake, and lower-income countries reporting more deaths related to malnutrition, poor sanitation and pollution-related illness.
Stacker compiled the 26 top factors that lead to the most deaths, and examined the effects each factor can have on a person’s health. Readers should note that many of these factors can be avoided or remedied through a change in diet, or treatment by a medical professional. However, in developing countries, risk factors are often unavoidable, and medical facilities scarce.
Stopping breastfeeding an infant suddenly can lead to a number of health problems, which is why health organizations emphasize the importance of weaning young children slowly and gradually introducing other foods. In 2016, discontinued breastfeeding was the 11th most common risk factor leading to deaths in children under the age of five.
Left untreated, an iron deficiency—also known as anemia—can result in death. Inherited anemia, like sickle cell anemia, can lead to complications. People with anemia who lose large amounts of blood quickly may experience acute anemia, which can result in death. To avoid an iron deficiency, people should eat a vitamin-rich diet. Those who live in regions where malaria is a problem should take extra precautions, as the disease can sometimes result in anemia as a complication.
Zinc is an essential mineral that’s crucial for immune function, healing and growth. Because the body has no specialized zinc storage system, people must ingest the mineral daily, whether through food or supplements. A zinc deficiency is difficult to diagnose, because many of the symptoms, such as weight loss, hair loss, and diarrhea, can also be associated with other illnesses.
Vitamin A deficiency increases the chance of disease and death from severe infections, and is also the leading cause of preventable blindness in children. The issue is a problem in more than half of the world’s countries, particularly in Africa and southeast Asia. The best way to protect children from vitamin A deficiency is through breastfeeding, since breast milk naturally contains a high amount.
Non-exclusive breastfeeding is when an infant younger than six months old is given other foods or fluids in addition to breast milk. Across the world, 60 percent of infant deaths are caused by inappropriate infant feeding practices. Non-exclusive breastfeeding can also limit the full absorption of nutrients from breast milk, as well as increase the risk for diarrhea and acute respiratory infections.
Stunting is impaired growth and development caused by improper nutrition and infection. Stunting during childhood can cause poor cognition, educational impairments, lost productivity, and an increased risk of nutrition-related chronic illnesses.
Low bone mineral density, also called osteoporosis or osteopenia, creates weak bones and increases the risk for breakage. People with low bone mass can help slow down density loss by eating calcium- and vitamin D-rich foods, as well as doing light to medium weight-bearing exercises. Medical professionals may also be able to prescribe medications, including annual calcium infusions, to prevent low bone mass.
More than 72,000 Americans died from drug overdoses in 2017, representing a two-fold increase within the past decade. The largest increase occurred among deaths related to opioids— particularly fentanyl, a potent opioid. From 2002 to 2017, there was more than a sevenfold increase in the total number of heroin-related deaths in the United States. Between 2010 and 2017, there was a more than a threefold increase in cocaine-related deaths.
People with low access to sanitation facilities—including hand-washing facilities and flushing toilets—experience an increase in diarrheal disease deaths. In 2015, Kenya had the most deaths from diarrheal disease due to lack of sanitation, with only 30 percent of the population having access to facilities.
Low-weight newborns face an increased risk of death until they reach adolescence. Maternal smoking and poor nutrition during pregnancy are two factors known to cause a lower birth weight in babies.
Even short periods of exposure to secondhand smoke can be harmful to one’s health, and living with a smoker can increase someone’s chance of getting lung cancer by 20 to 30 percent. Secondhand smoke can cause other serious health problems as well, like heart disease and respiratory illness.
Disease can spread quickly without proper sanitation, and can lead to severe health problems, including dehydration and malnutrition. Ringworm and hookworm, which thrive in bacteria-rich environments, can also cause diarrhea. Widespread diarrhea and poor sanitation can lead to dysentery, cholera, giardia and typhoid.
Wasting, defined as a low weight for one’s height, is a strong predictor of mortality for children under the age of five—usually the result of malnutrition. Across the globe, 24 developing countries have a wasting rate of 10 percent
Deaths: 1.1 million
Unprotected sex can transmit diseases like HIV/AIDS, which can lead to recurring infections that shorten the lives of those affected. Other STDs, such as chlamydia and gonorrhea, may not have immediate symptoms and can be treated.
Deaths: 1.16 million
At least two billion people worldwide rely on a drinking water sources that are often contaminated, and this water is estimated to cause 502,000 deaths from diarrheal diseases each year. People who drink untreated water are at risk for cholera, dysentery, typhoid and polio. In developing countries, 35 percent of health facilities lack clean water and soap for hand-washing.
Deaths: 1.37 million
Those who engage in minimal physical activity face a greater risk of developing high blood pressure, heart disease and type 2 diabetes. A sedentary lifestyle may also increase one’s risk for certain cancers and can affect people mentally as well, contributing to anxiety and depression.
Deaths: 1.52 million
Vegetables are an essential source of nutrients, including potassium, fiber, folate, vitamin A, and vitamin C. Potassium-rich diets help to maintain healthy blood pressure, while fiber is important for proper bowel function and folate helps the body form red blood cells. Vegetables are naturally low in calories and fat, as well, and none contain artery-blocking “bad” cholesterol.
Deaths: 2.36 million
Not eating enough fresh produce contributes to about 14 percent of gastrointestinal cancer deaths, 11 percent of ischaemic heart disease deaths and nine percent of stroke deaths worldwide. There is evidence that a diet high in fruits and vegetables can decrease one’s risk for obesity, diabetes and certain cancers.
Deaths: 2.58 million
About three billion people worldwide cook using open fires or stoves fueled by coal or kerosene that can contaminate the air in one’s household. This air pollution can cause conditions like stroke, heart disease, chronic obstructive pulmonary disease and lung cancer. About half of pneumonia-related deaths in children under the age of five are caused by inhaling soot from cooking fires.
Deaths: 2.81 million
Long-term alcohol abuse can have detrimental health effects, not limited to internal bleeding, pancreatic damage, liver damage, and some cancers. Alcohol abuse can also affect cognition and judgement. Long-term abuse use can damage brain cells, causing memory loss and behavioral changes.
Deaths: 4.09 million
People living in countries with high levels of air pollution are at risk for heart disease, stroke, lung cancer, and chronic respiratory diseases. In 2016, 91 percent of the global population lived in areas that did not meet air quality guidelines set by the World Health Organization. In addition, 91 percent of premature deaths due to poor air quality occur in low- and middle-income countries.
Deaths: 4.39 million
While some cholesterol is essential for optimal organ function, high amounts of this waxy substance found in some forms of fat can lead to heart disease. The fatty deposits in blood vessels can block blood flow through arteries, which can cause a heart attack or stroke.
Deaths: 4.53 million
The body mass index is one way to diagnose obesity. People with a higher BMI are at risk for high blood pressure, heart disease, type 2 diabetes, osteoporosis, kidney disease, and metabolic disorder. Pregnant individuals with a high BMI are at increased risk for gestational complications.
Deaths: 5.61 million
Having high blood sugar for a long period of time can damage the vessels that supply blood to the organs, which can lead to kidney disease, heart disease, vision impairment and nerve damage. High blood sugar doesn’t always cause symptoms right away, so it’s important that people who consume large amounts of sugar closely monitor their overall health.
Deaths: 6.32 million
Cigarette smoking is the leading cause of preventable death in the United States, causing nearly one in five deaths. Smoking causes about 90 percent of lung cancer deaths, and about 80 percent of deaths from chronic obstructive pulmonary disease. Smoking is known to increase the risk for multiple types of cancer.
Deaths: 10.46 million
High blood pressure can increase one’s risk of death from heart disease and stroke. Most people with high blood pressure exhibit no symptoms; however, doctors routinely check blood pressure during medical examinations, making it essential for those at risk to schedule regular check-ups.