Healthy adults who eat two or more servings of meat a day the equivalent of two burger patties increase their risk of developing metabolic syndrome by 25 percent compared with those who eat meat twice a week, according to research published in Circulation: Journal of the American Heart Association.
Metabolic syndrome is a cluster of cardiovascular disease and diabetes risk factors including elevated waist circumference, high blood pressure, elevated triglycerides, low levels of high-density lipoprotein (HDL or “good”) cholesterol and high fasting glucose levels. The presence of three or more of the factors increases a person's risk of developing diabetes and cardiovascular disease.
But it's not just meat that adds inches to the waist, increases blood pressure and lowers HDL — “it's fried foods as well,” said Lyn M. Steffen, Ph.D., M.P.H., R.D., co-author of the study and an associate professor of epidemiology at the University of Minnesota.
Dairy products, by contrast, appeared to offer some protection against metabolic syndrome.
Steffen said that, “Fried foods are typically synonymous with commonly eaten fast foods, so I think it is safe to say that these findings support a link between fast-food consumption and an increase in metabolic risk factors.”
The findings emerged from an analysis of dietary intake by 9,514 participants in the Atherosclerosis Risk In Communities (ARIC) study. ARIC is a collaborative study funded by the National Heart, Lung, and Blood Institute.
Unlike other researchers who have investigated relationships between nutrients and cardiovascular risk, “we specifically studied food intake. When making recommendations about dietary intake it is easier to do so using the framework of real foods eaten by real people,” Steffen said.
Researchers assessed food intake using a 66-item food frequency questionnaire. From those responses, they categorized people by their dietary preferences into a Western-pattern diet or a prudent-pattern diet.
In general, the Western-pattern diet was heavy on refined grains, processed meat, fried foods, red meat, eggs and soda, and light on fish, fruit, vegetables and whole grain products.
Prudent diet eating patterns, by contrast, favored cruciferous vegetables (e.g., cabbage, radish and broccoli), carotenoid vegetables (e.g., carrots, pumpkins, red pepper, cabbage, broccoli and spinach), fruit, fish and seafood, poultry and whole grains, along with low-fat dairy.
Researchers also assessed associations with individual food items: fried foods, sweetened beverages (regular soda and fruit drinks), diet soda, nuts and coffee.
After nine years of follow-up, 3,782 (nearly 40 percent) of the participants had three or more of the risk factors for metabolic syndrome.
At baseline, participants were 45 to 64 years old — ages at which many people gain weight.
Steffen said that weight gain over the years of follow-up might explain some of the cases of metabolic syndrome. But “after adjusting for demographic factors, smoking, physical activity and energy intake, consumption of a ‘Western' dietary pattern was adversely associated with metabolic syndrome,” she said.