Food chemistry is complex and involves both chemicals intrinsic to food and chemicals added to and contaminating food. The food supply in any region of the world involves sampling the chemistry of the agricultural environment. In the good old days, food originated close to home and consumer sampled the local environment.

There are many complicated issues influencing proper food selection. Food choices have been changing rapidly and will continue to change for personal health reasons, but also in the next decades, we will change collec­tively. Some changes will be voluntarily and oth­ers will well be imposed on us by shifting economics, political upheavals, climate changes, population growth, and crop failures. Food choices in affluent coun­tries already involve new and unusual combinations of food chemistry that has never been experienced before in the history of life on earth.  Thousands of new chemicals have entered the food chain as additives and contaminants. Immune-mediated (allergic) diseases are increasing and create expensive, chronic and debilitating illnesses.

Each person interacts with food, home and work environments that determine his or her biological fate. In industrialized countries, the microenvironment of each person is controlled by human constructions and is generally polluted by toxic substances. The extent of this chemical contamination is seldom measured and the effects are poorly understood. As environmental problems multiply, new ill-defined illnesses will increase.

If your premise is that foods in common uses are good foods, healthy for everyone to eat, you will be disappointed. On the other had, if you premise is that foods are too dangerous to eat; you will lead an unhappy and malnourished life.

A balanced point of view is developed in the Alpha Nutrition Program. The most reliable rule is that people should eat plant foods that have been in common use for centuries. Vegetables and fruits provide good nutrition and have additional benefits. Non-nutrient chemicals in plants can add unexpected benefits when included in the diet. These non-nutrient substances are now referred to as "phytochemicals" which just means, "plant chemicals".