Feb. 3, 2011 -- Obesity rates across the globe have nearly doubled since 1980, but there have been slight declines in high blood pressure and high cholesterol, two major risk factors for heart disease and stroke, according to three new studies in TheLancet.
The three papers took a global look at blood pressure, cholesterol, and body mass index (BMI) trends between 1980 and 2008. Taken together, they show that obesity, high blood pressure, and cholesterol are not just problems in high-income countries; some low- and middle-income countries have similar health concerns.
More than half a billion adults were obese in 2008, according to the new reports.
“The good news is that there have been impressive declines in blood pressure in many high-income countries and in cholesterol in many Western high-income countries,” says study researcher Majid Ezzati, PhD, of the Harvard School of Public Health in Boston and the Imperial College London, in an email.
“The bad news is the rise in BMI in most places, by large amounts in some, especially in many middle income countries.” BMI takes both height and weight into account.
The U.S. had the highest average BMI of all high-income countries, and the sharpest increase in BMI levels among all high-income countries from 1980 to 2008. Average BMI in the U.S. in 2008 was more than 28 for men and women. A BMI of 25 to 29.9 is considered to be overweight and a BMI above 30 is considered obese. New Zealand had the second highest average BMI, while people in Japan had the lowest, according to the new reports.
Global Blood Pressure Trends
Systolic blood pressure levels (the upper number in a blood pressure reading) were highest in Baltic countries and East and West African countries. Levels were equally high in some Western European countries in the 1980s before they began to dip. Of all countries, South Korea, Cambodia, Australia, Canada, and the U.S. had the lowest blood pressures. In addition, men had higher blood pressure levels than women in most countries.
“We are certainly doing better here and around the world in terms of blood pressure control in spite of getting fatter,” says George Bakris, MD, president of the American Society of Hypertension. Bakris is also a professor of medicine and director of the Hypertension Center at the University of Chicago. “At least a major factor that would contribute to worsening cardiovascular risk, high blood pressure, is actually being controlled far better."
Global Cholesterol Trends
When it comes to cholesterol, certain Western European countries, including Greenland, Iceland, Andorra, and Germany, had the highest cholesterol levels, while African countries had the lowest cholesterol, the new report showed.
Suzanne Steinbaum, MD, director of women and heart disease at Lenox Hill Hospital in New York City, is concerned that the increase in obesity rates may lead to an increase in blood pressure and cholesterol levels across the globe.
Our bad habits appear to be contagious, she says “We gave the Japanese and Chinese McDonalds and their cholesterol is going up,” she says. “The impact of Western diet on risk factors is so critical.”
“Even though obesity is increasing, we are making progress in some of the risk factors for heart disease, which are leading to a decrease in cardiovascular disease morbidity and mortality,” says David Frid, MD, a staff cardiologist at the Cleveland Clinic in Ohio. “The bad news is that obesity is increasing and is leading to an increase in diabetes and may ultimately offset the benefits we are seeing in other risk factors.”
Multi-pronged community-based efforts are needed to buck these trends. These include increasing physical activity in schools, making healthy foods as accessible as unhealthy choices, and aggressively identifying and treating risk factors for heart disease and stroke.
Call for Healthier Diets
Nancy Copperman, RD, the director of public health initiatives in the office of community health at the North Shore Long Island Jewish Health System in Great Neck, N.Y., agrees.
“The findings underscore the need for Americans to take action and adopt the changes recommended by the recently released 2010 Dietary Guidelines," she says. “Balance your calories, increase fruits and vegetables, switch to low-fat dairy products, and reduce sodium and sugars in foods and beverages.”
In addition to eating a healthier diet, she says, “We need to be sitting less and moving more, and building up to an hour of physical activity per day.”