The Goldilocks Effect - A little is not enough, a lot is too much, somewhere in between is just right.

Hormesis is the principle from toxicology that many substances have a biphasic nature - differing effects at differing dosages. It is an obvious part of our medical technology - one aspirin is good, 100 are not.

Researchers have recently begun to look at our diet and even our lifestyles from this viewpoint and PD seems to crop up regularly. No exercise bad. Too much exercise too much. Somewhere between is just right.

That seems obvious. Caloric restriction is a little more subtle. It isn't just that eating too much overloads our system. It is that eating less than we want triggers metabolic changes at the cellular level that benefit us.

The papers below examine this from the aspect of what we eat. In particular, they look at plants such as curcumin. Traditionally considered spices or herbs, these plants were never considered food sources. In fact, those quantities can be toxic, even lethal. Yet, our taste buds have evolved to make us seek them out. The plants evolved them to dissuade insects and we evolved to take advantage of that intra-species conflict. Some interesting reading here:

Hormesis Defined
Mark P. Mattson

Hormetic Dietary Phytochemicals
Tae Gen Son, Simonetta Camandola, and Mark P. Mattson

Viewpoint: Mechanisms of Action and Therapeutic Potential of Neurohormetic Phytochemicals
Mark P. Mattson,a Tae Gen Son,a and Simonetta Camandolaa