In processed or pre-cooked foods, substances are often added as a preservative and/or to enhance color, flavor, and texture. In addition, the more processing or handling a product goes through before reaching your shelf, the more chance there is for exposure to harmful chemicals and substances that are either a by-product of the processing or are from agricultural use and not necessarily meant for human consumption (such as pesticides or antibiotics). We know that overconsumption of foods, especially calorie dense processed foods, contributes to weight gain, but what’s happening to us when we ingest all these artificial ingredients, preservatives, or even pesticides?
Berti et al. (2015) came out with one of the most comprehensive dietary studies investigating the effect of nutrients on Alzheimer’s and declining brain health in otherwise cognitively normal individuals. By looking at a variety of different dietary patterns, the researchers found that a diet focused on processed meats and butter, high-fat dairies, fried potatoes, and sweets (particularly high in saturated and trans fats, cholesterol, and sodium) is negatively associated with grey matter volume, a marker of brain atrophy. Individuals consuming this type of diet therefore would be more at risk for Alzheimer’s and/or cognitive decline (Berti et al., 2015).
Sodium, an infamous mineral, is lurking even in unexpected places like frozen meals, which can be packed with upwards of 1,000 mg of sodium or more. The dietary reference intake (DRI) for sodium is 2,300 mg/day, which is found in just one teaspoon of table salt. New research shows us that there appears to be a direct relationship between a high salt diet and impaired spatial memory, possibly due to oxidative stress in the hippocampus region of the brain (Liu et al., 2014).
Trans-fats, another well-known health offender, are strongly linked to cardiovascular disease, heart attacks, and strokes. Your brain relies on a steady flow of blood from the heart for essential nutrients (think oxygen), and any disruption in this blood flow could cause serious damage. Also, the same risk factors for heart disease and stroke (like diabetes) have been shown to be risk factors for serious conditions such as dementia, Alzheimer’s, and cognitive decline (Sridhar, Lakshmi, & Nagamani, 2015). This heart–brain connection may also be the reason a high sodium diet was found to impair cognitive functioning in an elderly population (Fiocco et al., 2012).
Fortunately, trans fats, introduced in the 1950s, are starting to disappear from foods, thanks to tighter regulations from the FDA. However, sodium and other additives remain prevalent and don’t appear to be decreasing any time soon.
Even seemingly innocent products such as smoked salmon can pose serious threats to brain health. Fresh fish have the risk of contamination by sea pollution, but processes such as smoking can introduce polycyclic aromatic hydrocarbons to the product, which when broken down, react with DNA to cause cancer, among other problems.
Regardless of body weight, a healthy diet for your brain is beneficial to your whole body. Avoid highly processed foods such as sodas, frozen dinners, and sweets and you may drastically improve your quality of life as you get older.
Berti, V., Murray, J., Davies, M., Spector, N., Tsui, W. H., Li, Y., … Mosconi, L. (2015). Nutrient patterns and brain biomarkers of Alzheimer’s disease in cognitively normal individuals. The Journal of Nutrition, Health & Aging, 19(4), 413-423.
Liu, Y. Z., Chen, J. K., Li, Z. P., Zhao, T., Ni, M., Li, D. J., … Shen, F. M. (2014). High-salt diet enhances hippocampal oxidative stress and cognitive impairment in mice. Neurobiology of Learning and Memory, 114, 10-15.
Sridhar, G. R., Lakshmi, G., & Nagamani, G. (2015). Emerging links between type 2 diabetes and Alzheimer’s disease. World Journal of Diabetes, 6(5), 744-751.
Fiocco, A. J., Shatenstein, B., Ferland, G., Payette, H., Belleville, S., Kergoat, M. J., … Greenwood, C. E. (2012). Sodium intake and physical activity impact cognitive maintenance in older adults: the NuAge Study. Neurobiology of Aging, 33(4), 829.e21-28.