The U.S. government spends billions of dollars each year on subsidies to farmers, but consuming too much food made from those subsidized farm products can boost people's risk for heart disease, researchers say.
The more people eat of foods made with subsidized commodities, the more likely they are to be obese, have abnormal cholesterol and high blood sugar, according to a report in JAMA Internal Medicine.
Current federal agricultural subsidies help finance the production of corn, soybeans, wheat, rice, sorghum, dairy and livestock, which are often converted into refined grains, high-fat and high-sodium processed foods, and high-calorie juices and soft drinks (sweetened with high-fructose corn syrup), the authors write.
"We know that eating too many of these foods can lead to obesity, cardiovascular disease and type 2 diabetes," said lead author Karen R. Siegel of the Centers for Disease Control and Prevention in Atlanta.
But the subsidies help keep the prices of those products down, making them more affordable.
"Among the justifications for the 1973 U.S. Farm Bill was to assure consumers a plentiful supply of food at reasonable prices," Siegel told Reuters Health by email. "Subsidized food commodities are foods made from federally funded crops to ensure the American population has an adequate supply of food, thus they tend to be non-perishable, or storable, e.g., corn, wheat, rice, to reduce the risk of spoiling."
The researchers used National Health and Nutrition Examination Survey responses obtained from more than 10,000 adults between 2001 and 2006. Each person reported everything they had eaten in one 24-hour period.
The researchers gave each individual a "subsidy score" based on the percentage of their total calories than had come from subsidized foods.
At the same time, participants had their body mass index, abdominal fat, C-reactive protein (a marker of inflammation), blood pressure, cholesterol and blood sugar levels measured.
On average, people were getting about 56 percent of their calories from subsidized food commodities. When the total group was divided into four smaller groups based on their subsidy score, those with the highest scores were more likely to be obese, have a larger waist circumference, more C-reactive protein, more "bad" cholesterol and higher blood sugar than those in the lowest subsidy score, as reported in JAMA Internal Medicine.
The study itself can't prove that a diet higher in subsidized foods causes poor health, Siegel said. But foods that are high in fat, sugar and sodium are known to increase the risk for chronic health problems, particularly when paired with other factors such as smoking and inactivity, she added.
In a separate study in the same journal, a team led by Dr. Frank B. Hu of the Harvard T.H. Chan School of Public Health in Boston found that over a 32-year period, eating more saturated fat and trans-fat, found in fatty meat and dairy, rather than polyunsaturated and monounsaturated fatty acids, found in sunflower oil and olive oil, was associated with higher rates of death.
U.S. dietary guidelines recommend emphasizing fruits, vegetables, whole grains, and fat-free or low-fat milk products, lean meats, poultry, fish, beans, eggs, and nuts, Siegel said.
The government subsidies were a strategy to support rural communities and to manage hunger in the 1970s, said Raj Patel of the University of Texas at Austin, who wrote a commentary on Siegel's report.
But "we rarely buy these foods raw," Patel told Reuters Health by email. "These commodities are grown to be processed."
It's easy to tell people to eat fresh fruits and vegetables instead of subsidized commodities in processed foods, "but affording healthy food is a challenge for millions of Americans - around 50 million Americans are food insecure - and it makes little sense to blame the working poor for their inability to afford to eat fewer subsidized foods and more fresh fruit and vegetables, when our modern food system is geared toward encouraging everyone to eating these commodity crops," Patel said.