A person’s intake of ultra-processed foods may increase their risk for stroke and cognitive impairment.
Varun M. Bhave, of Harvard Medical School, recently presented data at the American Heart Association/American Stroke Association’s 2024 International Stroke Conference that showed that greater intake of ultra-processed foods (UPFs) was associated with these increased risks regardless of other risk factors.
To look at food intake, the researchers used the NOVA food classification system to group foods based on the level of processing. In this classification system, Group 1 (NOVA 1) includes foods that are unprocessed or minimally processed (fruit, vegetables, meat, milk). Group 2 (NOVA 2) are foods processed in the kitchen with the aim of extending shelf life (fats, aromatic herbs). Group 3 (NOVA 3) are processed goods obtained by combining food groups 1 and 2 to obtain food products for domestic use (bread, jam, etc.).
Finally, Group 4 (NOVA 4) are UPFs that use many ingredients including food additives that improve how they taste, processed raw materials, and ingredients rarely used in home cooking.
The study included participants from the REGARDS (REasons for Geographic and Racial Differences in Stroke) cohort who had self-reported baseline dietary data available and looked at two outcomes:
incident stroke identified through medical records
cognitive impairment.
The NOVA system was used to classify items taken from a baseline food frequency questionnaire obtained from participants without previous stroke. The researchers quantified intake in grams for each NOVA category and normalized it to total grams consumed over the course of a day. Participants were also scored for a Mediterranean, DASH, or Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet.
Greater intake of UPFs considered NOVA 4 was associated with an increased risk for stroke (hazard ratio[HR] per SD=1.10; 95% CI, 1.03-1.18; P=4.77x10-3) in a model adjusted for age, race, sex, age-by-race interaction as well as vascular risk factors including smoking, atrial fibrillation, hypertension, diabetes, cardiovascular disease, and left ventricular hypertrophy.
In contrast, greater intake of foods in NOVA 1 was associated with a decreased risk for stroke (HR=0.87; 95% CI, 0.81-0.93; P=5.56x10-5).
“Importantly, the effect of UPFs on stroke risk was actually higher among Black participants,” Bhave said.
Increased intake of UPFs (NOVA 4) was also associated with increased risk for cognitive impairment, even after adjusting for age, race, sex, total caloric intake, income, educational attainment, physical activity, BMI, hypertension, diabetes, cardiovascular disease, smoking status, alcohol consumption, and depressive symptoms. Again, in contrast, intake of unprocessed NOVA 1 items was associated with a lower risk of incident cognitive impairment.
Bhave pointed out that the association between UPFs and stroke and cognitive impairment was also independent of adherence to the recommended health dietary patterns examined.
“We need to better understand what specific food items play the most role in conferring risk of these neurological outcomes because this analysis was dietary pattern based and relatively broad,” Bhave said.
According to Mary Ann Bauman, MD, current American Heart Association president for the Western States region board of directors and a primary care physician, the evidence continues to mount that UPFs are not healthy. They increase the risk of heart disease, diabetes, cancer, and stroke.
“That’s a pretty compelling list,” she said. “PCPs advise patients every day to make healthier eating choices, even though changing behavior is hard. Having more proof helps us make the case, but we also know that barriers exist that make it difficult, and sometimes impossible, for some to adopt healthier habits.”
Disclosures: Bhave and Dr. Bauman report no conflicts of interest.