Chemo brain. This is the common term used to describe a decline in mental function following conventional cancer treatments. Chemotherapy drugs such as cisplatin, which is used to treat bladder, lung, ovarian cancers, etc, are commonly associated with chemo brain.
The medical name for chemo brain is cancer-related cognitive decline (CRCD). Estimates are that up to 75% of cancer patients experience chemo brain and 35% of people have it after their treatment has ended.
Treatment for chemo brain currently centers on “cognitive rehabilitation,” in which people are taught to learn and remember in new ways. Additionally, people are encouraged to exercise regularly and eat a healthy diet. Beyond these suggestions people are left to simply cope with their decreased cognitive function.
As with most things in medicine, prevention is typically the most successful course of action. This may be true with chemo brain as well. A newer study published in December of 2022 reported on the effect of diet on the changes in cognition during chemotherapy. This study included 96 people (69% female) with an average age of 59 years old. Diet questionnaires were used to assess participant’s eating habits. The study found that a higher pre-treatment ratio of monounsaturated to saturated fat was associated with less decline in cognitive abilities. The authors concluded that “Results suggest greater monounsaturated fat and less saturated fat intake could be protective against CRCD during chemotherapy.”
From this it seems that people would be wise to consume higher amounts of monounsaturated fats before their cancer treatments if they want to preserve their cognitive abilities. These results also, and likely more importantly, suggest that people may want to pay attention to the saturated fats they are consuming.
Monounsaturated fats can be found in foods such as olive oil, peanut and canola oil (although I tend not to recommend consuming peanut or canola oil), avocados, almonds, hazelnuts, and pumpkin and sesame seeds. Saturated fats, on the other hand, are most frequently found in the US in food such as pizza and cheese, fast food, cookies, grain-based desserts, and meat products. Roughly 90% of the saturated fats consumed by Americans are of the nutritionally deficient junk food variety.
While impossible to conclude from this study, a question that arises is how much the nutritional quality of food may be contributing to the neuroprotective effect. Certainly, people consuming high levels of pizza, cookies, and fast food would be less nutritionally fit and their bodies would have less healing potential than those following a healthier diet. Additionally, dietary indexes and questionnaires rarely assess a person’s consumption of organic and grass-fed foods vs commercially produced foods.
Humans have been consuming saturated fats for as long as there have been humans. And, there are some healthier sources of saturated fats such as nuts, avocados, fish, etc. Modern day humans, however, do tend to consume more saturated fats than our ancestors. For example, modern commercially raised meat can have up to 4x the amount of fat that game meat contains.
The takeaway from this study echos numerous other studies investigating the effects of diet on cancer and cancer-related problems. Consuming a healthy diet not only helps to prevent cancer, but also helps to maximize effectiveness of treatment and reduce treatment-related adverse effects. We can now add a preservation of cognitive ability to the long list of things that a healthy diet can positively affect.