Nutritional science has undergone a profound revolution in that time For most of the 20th century it aimed to define an adequate diet It determined our body’s minimal requirements for chemical building blocks (protein, minerals, fatty acids), for essential cogs in its machinery (vitamins), and for the energy it needs to run and maintain itself from day to day Toward the end of the century, it became clear from laboratory studies and comparisons of health statistics in different countries that the major diseases of the adequately nourished developed world — cancer and heart disease — are influenced by what we eat Nutritional science then began to focus on defining the elements of an optimal diet So we discovered that minor, nonessential food components can have a cumulative effect on our long-term health And plants, the planet’s biochemical virtuosos, turn out to be teeming with trace phytochemicals — from the Greek phyton, meaning “leaf” — that modulate our metabolism Antioxidants Oxidative Damage: The Price of Living One major theme in modern nutrition is the body’s need to cope with the chemical wear and tear of life itself Breathing is essential to human life because our cells use oxygen to react with sugars and fats and generate the chemical energy that keeps the cellular machinery functioning Unfortunately, it turns out that energy generation and other essential processes involving oxygen generate chemical by-products called “free radicals,” very unstable chemicals that react with and damage our own complex and delicate chemical machinery This damage is called oxidative because it usually originates in reactions involving oxygen It can affect different parts of the cell, and different organs in the body For example, oxidative damage to a cell’s ... metabolism Antioxidants Oxidative Damage: The Price of Living One major theme in modern nutrition is the body’s need to cope with the chemical wear and tear of life itself Breathing is essential... life because our cells use oxygen to react with sugars and fats and generate the chemical energy that keeps the cellular machinery functioning Unfortunately, it turns out that energy generation and other essential processes involving oxygen generate chemical... unstable chemicals that react with and damage our own complex and delicate chemical machinery This damage is called oxidative because it usually originates in reactions involving oxygen It can affect different parts of the