If I want my memory system to be as strong as possible, what should I avoid? Right? We can talk about what to do, but what should a person clearly avoid? Besides alcohol, head injuries, opioids, and methamphetamine, I think we all agree that these things are bad for memory.
When I started studying the effects of diet on neural cognition and memory function, we were working with adult animals and using what we call the "Western diet." It's a diet where maybe 35% of calories come from fat, 15% from sugar, and a large part of it is simple sugar. I mean simple carbohydrate sugars, not complex starchy carbohydrates. And in animal models, this can lead to impairment in hippocampus-dependent memory if the animals follow this diet for just a week, though the studies generally take a few months. And it seems that hippocampus-dependent memory processes are more susceptible to the negative effects of this diet than other types of memories that don't depend on the hippocampus. So the hippocampus is like a canary in a coal mine (an early warning indicator). And when I started my lab here in Los Angeles, we were looking at aspects of development.
Moving away from adult models and looking at whether, if you give animals individual components of a diet during the developmental stage in adolescence, is there a long-term effect on their memory systems? And the first model we studied was the high-sugar model. The animals had free access to a sugar solution, at the same percentage of calories as found in the sodas we consume. And other than that, they had healthy food and water. And with this model, the animals showed a deficit in hippocampus-dependent memory when they got older. And it seems that this deficit persists into later stages of life, even if they no longer consume sugar. So we ran a few studies using that model. There may be a role for the microbiome (gut bacteria). There are some changes in gut bacteria resulting from the sugar model that may have a functional relationship with memory impairment. We also looked at models where the animals consume a fast-food diet entirely in an attempt to study the mechanisms. But again, the same thing. So if the animals consumed a fast-food diet, like cups of chocolate peanut butter, potato chips, and a high-fat, high-sugar rodent diet, they show a memory deficit that persists even after being switched to a healthy diet. Um, this doesn't mean that we can't reverse this memory deficit with some other type of intervention besides just returning them to a healthy diet. Um, but at least in rodents and during this developmental window, these types of foods have a long-term effect on neural cognition.
We have a research draft that hasn't undergone peer review yet. It's in the process of becoming that, hopefully one day. Where we were trying to look at food processing from a mechanistic perspective of a single variable. So food processing is a term we all hear, and it's ultra-processed foods. The way this is studied in humans is through the "NOVA" classification system, where there are four different categories of food processing, and where ultra-processed foods are essentially just junk food. On the other end of the spectrum, there are the ideal raw vegetables and completely unprocessed foods. And this isn't really mechanistic in terms of the types of processing that concern us. Because food processing involves many processes that happen to food in modern food manufacturing. So we wanted to try to address one variable at a time. And we ended up with thermal processing of food. So this is healthy food originally, and we baked it for an hour at high temperature. And the idea behind this is that it triggers something called the "Maillard reaction." The Maillard reaction is used in cooking because it enhances the flavor of food. So this is something we do for a reason. It's a chemical reaction that occurs depending on the food composition, acidity level, and many other factors. But when you heat food, you can get this Maillard reaction.
...and ate it as is, most people know what it tastes like. But if you took that carrot, cut it, spread some butter on it, maybe a little olive oil, some salt, put it in the oven, and cooked it until it was tender, it would come out with a quality almost like meat, tasting a little bitter but appetizing. Is that what you're referring to?
Yes. Yes, I mean the actual flavor components resulting from the Maillard reaction aren't well understood. So we can't point to specific flavonoid compounds and say that this is what makes it taste that way. But in general, if you bake a dish in the oven, it will taste better than it did before baking, right?
