A new study may offer the biggest clues yet.
Name a common condition — heart disease, Type 2 diabetes, cancer, dementia, irritable bowel syndrome — and chances are good that following a diet high in ultraprocessed foods has been linked to it.
But the ultraprocessed food category is large and wide-ranging. It makes up an estimated 73 percent of the U.S. food supply, and contains stereotypically “unhealthy” products like sodas, candies and hot dogs as well as seemingly “healthy” ones like whole grain breads, breakfast cereals, flavored yogurts and plant milks.
It’s a “hodgepodge of foods,” some of which are likely more harmful than others, said Josiemer Mattei, an associate professor of nutrition at the Harvard T.H. Chan School of Public Health.
On Monday, Dr. Mattei and her colleagues published one of the largest and longest studies on ultraprocessed foods and heart health to date. In it, they analyzed the risks of consuming these foods, and teased out the worst offenders.
An Overall Risk of Ultraprocessed Foods
The new study, published in a Lancet journal, included more than 200,000 adults in the United States. They filled out detailed diet questionnaires beginning in the 1980s and early 1990s, and completed them again every two to four years for about 30 years. Most of the participants in the study were white and worked as health professionals. The researchers looked at how the participants’ ultraprocessed food consumption related to their chances of developing cardiovascular disease.
After adjusting for risk factors like smoking, family health history, sleep and exercise, the researchers found that those who consumed the most ultraprocessed foods were 11 percent more likely to develop cardiovascular disease and 16 percent more likely to develop coronary heart disease during the study period, compared with those who consumed the least ultraprocessed foods. The highest consumers also had a slightly, but not significantly, elevated risk of stroke.