Used with permission from Superfoods: The Healthiest Foods on the Planet by Tonia Reinhard, $24.95 paperback, Firefly Books, 2010. The following excerpt can be found on Page 10.
The meaning of the word “superfood” has evolved over time and taken on specific connotations in different parts of the world. According to the Oxford English Dictionary (OED), the term dates back to two early usages in print media in 1915 and 1949. The OED entry provides an adequate general definition: “food considered especially nutritious or otherwise beneficial to health and well-being.” In recent years, however, some more specific definitions have had to be created, partly to protect consumers against unscrupulous marketing practices.
A concept that has been widely employed to help better define the meaning of “superfood” is that of the “nutrient density” of foods, whereby foods are described as either “nutrient-dense” (or “nutrient-rich”) or “nutrient-poor.” The so-called essential nutrients are compounds that we need to grow and maintain our bodies and can only obtain from food; they include protein, carbohydrates, fat, minerals, and vitamins. A nutrient-dense or nutrient-rich food is one that provides significant levels of these nutrients in a reasonable number of calories. A useful way to get to grips with this concept is to think of your optimal daily calorie level, a level that does not promote weight gain, as money. When we buy things, we all want to get the best product for our dollars; likewise, we have a limited number of calories that we can use each day, so we want to obtain the highest possible levels of essential nutrients for those limited calories.
And it’s certainly true that many superfoods are nutrient-rich foods—dark, leafy vegetables, for example, are high in vitamin A and other essential nutrients, and low in calories. But superfoods also include foods that are high in other compounds that are not essential nutrients but may still offer health benefits—most notably, the compounds collectively known as phytochemicals.
According to current scientific understanding, the potential benefits of eating foods that are high in either nutrients or phytochemicals, or both, include the fact that they may help lower our risk of developing certain chronic diseases, including cancer, cardiovascular disease, and type 2 diabetes. In the majority of Western countries, these are the leading causes of death. So, by incorporating the foods in this book into your eating plan, you might well increase your likelihood of living longer.