Consumption of Ultraprocessed Foods Associated with Cognitive Decline

Researchers in Brazil have found that higher consumption of ultraprocessed foods was associated with a higher rate of global and executive function decline after a median follow-up of 8 years.

The prevalence of dementia is estimated to increase from 57 million cases in 2019 to 153 million in 2050 owing to the increase in life expectancy worldwide. It is the most important cause of disability in high-income countries, and it is among the 10 most important causes in low-income and middle-income countries. The limited efficacy of available treatments for dementia highlights the importance of identifying interventions that are capable of preventing or delaying dementia onset to decrease the burden caused by this disorder. Lifestyle modifications, such as physical activity, healthy dietary habits, and smoking cessation, have been related to dementia prevention. Healthy eating habits, which include a high intake of whole grains, vegetables, fruit, nuts, and fish, have been linked to increased brain volume and decreased risk of cognitive decline over time.

In the last 40 years, the food supply industries have increased the commercialization of ultraprocessed foods (UPFs). Such UPFs are formulations of processed food substances (oils, fats, sugars, starch, and protein isolates) that contain little or no whole foods and typically include flavorings, colorings, emulsifiers, and other cosmetic additives. Examples of UPFs are sweet and savory snacks, confectionery, breakfast cereals, ice cream, sugar-sweetened beverages, processed meats, and ready-to-eat frozen meals. Fifty-eight percent of the calories consumed by US citizens, 57% of the calories consumed by British citizens, and 48% of the calories consumed by Canadian citizens come from UPFs.Consumption of UPFs has been linked to an increased risk of cardiovascular disease, metabolic syndrome, and obesity.

Goncalves et al conducted a multicenter, prospective cohort study with a total of 10 775 participants whose data were analyzed. They found that during a median follow-up of 8 years, individuals with ultraprocessed food consumption above the first quartile showed a 28% faster rate of global cognitive decline and a 25% faster rate of executive function decline. A higher percentage of daily energy consumption of ultraprocessed foods was associated with cognitive decline among adults from an ethnically diverse sample.

Consumption of UPF greater than 19.9% of total daily calories was associated with a faster decline in global cognitive performance and executive function compared with consumption less than 19.9% of total daily calories. They also found that the percentage of daily energy from UPF was associated with cognitive decline in participants younger than 60 years, which suggested the importance of preventive interventions in middle-aged adults. Additionally, the percentage of daily energy from UPF was associated with cognitive decline in participants with a low healthy diet score, whereas there was no association in those with a high healthy diet score.

Neuroimaging studies found that high consumption of a Western dietary pattern was related to a reduction in the left hippocampus and gray matter volume in cognitively healthy individuals. Another possible biological mechanism for the decline in executive function and global cognition seen in our study may be related to systemic inflammation caused by the consumption of UPF, because increased levels of circulating proinflammatory cytokines have been associated with cognitive decline. On the other hand, healthy dietary patterns were associated with higher gray and white matter volume, total brain volume, and Aβ42/40 ratio, as well as lower oxidative stress and inflammation.

The authors recommend limiting UPF consumption, particularly in middle-aged adults, to prevent cognitive decline. Future studies investigating the mechanism by which UPF may lead to cognitive decline are needed, as well as confirmation of these findings in other longitudinal studies and randomized clinical trials.

Reference:

Association Between Consumption of Ultraprocessed Foods and Cognitive Decline Natalia Gomes Gonçalves, PhD; Naomi Vidal Ferreira, PhD; Neha Khandpur, ScD; et al JAMA Neurol. Published online December 5, 2022. doi:10.1001/jamaneurol.2022.4397