Food appears to be more symbiotic than biologists realize. Why is fructose sweeter than glucose? Because taste buds selected for fructose, while glucose needed to be more controlled and physiologically regulated as the primary energy source for muscles and cell metabolism. Fructose gets channeled into energy storage as fat, which was a good thing during earlier evolution. Monkeys benefited from storing some fat, since their diet was extremely lean.

About twenty years ago, I developed a reaction against swallowing in response to some types of food. The reaction would start as hiccups, and water would usually be a cure, but blockage would get so extreme that water could not be swallowed. So I theorized; if it is a reaction to food, try optimizing the food. That meant eating some sugar. A small amount of sugar ends the reaction in about ten seconds. The reaction starts in response to bad food and fixes in response to good food.

An interesting twist to the reaction is that it always starts with hiccups, which only occur when there is a shortage of water while eating. It means there is a cross reaction involved. The hiccup reaction is connected to the food reaction.

Modern evolution is that way. Physiological process are borrowed and tacked onto more basic reactions. Older evolution is not that way, in part because time sorts out the differences. But also, recent evolution is getting so specialized that adaptations cannot be adequate. All biology would differentiate out of existence within ten million years, if no artificial influences existed, because biology is at an extreme of specialization (differentiation), where functions are so interdependent that they will not tolerate change.

Farther back in evolution, change was much easier to produce. The clamp connections on mold mycelium evolved about 200-300 million years ago and were extremely frivolous. Residues of clamp connections still exist, since evolution discards nothing without a significant selective advantage.

So the relationship between humans and their food supply would have been quite adaptable when deciding what to eat in the jungles. For example, youngsters have more simplistic preferences for taste than adults. Youngsters don't like such things as mushrooms or avocados. They prefer sugary foods. The reason is that they needed to be more conservative in what to eat in a jungle, until they learned the complexities with age. This shows how complex the adaptation of evolution to the food supply was.

Which gets to medicinal plants. Humans in the jungles have always been highly dependent upon medicinal plants, which means, over time, human physiology will adapt to the plant cures that are available. This would be why aspirin is effective—human physiology adapted to it's properties in nature.

This is why scientists are continually finding small benefits from endless natural products. The benefits aren't the major cures that people expect now days, but the cumulative effects in the jungles were significant enough to influence the evolution of human physiology in adapting to exotic plant nutrients.