Modern nutrition determines the healthiness of a food by isolating its vitamins, proteins, minerals, fats, and other constituents. Choosing your foods based on the results of nutritional analysis, while it may help you become aware of your health needs, does not help you to know food intimately, which is where true health lies. It is not the beta-carotene found in squash or carrots that makes these vegetables important food choices. Vitamin C is not a valid reason to eat citrus fruits, nor should lycopene be the reason for eating tomatoes. For a medical professional or other dietary professional to prescribe or suggest to someone an isolate nutrient like those just mentioned is quite a shame, for it helps no one.