Yunzhi QianNavigating through a modern US grocery store is a journey of culinary choices. But, deciding what to have for dinner can present challenges. Aisles brimming with frozen pizzas, pre-packaged pasta, and frozen orange chicken might draw your focus away from other foods like fresh vegetables and unprocessed meats. If you find yourself drawn to these processed meal options, you’re in good company. Ultra-processed foods (UPFs), defined by their inclusion of rarely-used home cooking ingredients like high-fructose corn syrup, hydrogenated oils, protein isolates, and chemical additives, are crafted to be extraordinarily tasty and encourage overconsumption.
Approximately 60 percent of calories in an average American diet are derived from highly processed foods. The dependence on UPFs is a multifaceted problem, influenced by factors including brain reward systems, the tastiness of the food, convenience, and cost-effectiveness. Numerous studies have confirmed that UPFs elevate the risk of obesity, cardiovascular disease, and diabetes. However, only in recent years have scientists begun revealing the detrimental impacts of UPFs on the human brain.
Recent research has indicated that individuals who consume diets rich in UPFs, may be more prone to experiencing depression and anxiety compared to those who consume fewer of these items. These individuals may also face a heightened risk of cognitive decline. One cross-sectional study demonstrated a correlation between high consumption of UPFs and elevated stress levels. A separate cohort study conducted by Harvard T.H. Chan School of Public Health explored the relationship between specific dietary patterns and the risk of depression. This study included 31,712 women and revealed that the consumption of artificial sweeteners is linked with a heightened risk of depression. Women who consumed the highest amount of UPF — up to nine servings per day — were 50% more likely to develop depression compared to those who ate the least amount of UPF, capped at no more than four servings per day. While the mechanism that connects UPF with depression remains unidentified, one possible explanation is that UPFs negatively impact gut microbiota health, which could, in turn, affect the brain. Researchers are also looking into how the timing of what we eat might be linked to depression.
If you’re looking to reduce your intake of UPFs, there’s positive news! Achieving a balanced diet doesn’t require entirely eliminating UPFs. Opt for adding more whole foods, like raw fruits, into your diet instead of reaching for pre-packaged options. Choose water over sugary drinks, and limit how often you dine out. This approach may be particularly beneficial for individuals experiencing depression – curtailing UPF consumption could enhance brain health and potentially prevent more severe issues down the line.
Peer Editor: Jeanne-Marie Ellen McPherson