"Green foods" is a general marketing term introduced decades ago that remains popular today. It can refer to products that are made from fruit and vegetable extracts, typically in the form of capsules, tablets, wafers or powders. Marketers typically represent them to be the nutritional equivalents of the fresh produce that you should consume daily but, perhaps, don't. There are also so-called green "superfoods," such as chlorella, spirulina, and wheat and barley grass that are often promoted as a way to improve digestion or absorption. A newer marketing term is "food grown," referring to ingredients that are whole foods, rather than extracts or laboratory products.
Green foods, particularly the grass and algae "superfoods," have never been part of my nutritional recommendations. While I certainly don't object to people using "green food" products as part of a supplement program, the science that addresses their positive contribution to human nutrition is scant at best. The supplement line I designed is evidence-based, and includes ingredients proven to be safe, effective, and beneficial. I share and support the general philosophy of the "food grown" concept, in that I believe supplements should reflect natural nutritional profiles as closely as possible. For example, I recommend mixed carotenoids rather than isolated beta-carotene, and vitamin E as the full complement of tocopherols and tocotrienols found in nuts and seeds. Interestingly enough, while research clearly demonstrates the health benefits of consuming generous amounts of fruits and vegetables, scientists tend to study the effects of isolated components found in them. They have not looked critically at most of the green foods on the market.
The "food grown" products, especially those made from organic, freeze-dried raw materials, sound good on paper as concentrated versions of whole foods, but I still prefer to get my micronutrients from fruits and vegetables, and use supplements only as insurance against dietary gaps. Not only is that a more pleasurable way to get the nutrients you need, it also supports the spiritual and social aspects of eating. I'm also concerned that if your diet doesn't include vegetables and fruits because you're using a green supplement, superfood, or food-grown supplement, you may be filling up on lower quality foods that are high in calories, bad fats, and quick-digesting carbohydrates.
I consider food-grown products to be mostly suitable for young children and seniors who don't eat enough produce. But I wonder whether youngsters who become accustomed to getting their vegetables and fruits through supplements are less likely to develop the eating habits they need for good health throughout their lives.
The only green drink that I consume regularly is matcha, the Japanese powdered green tea. It provides trace minerals and vitamins (A, B-complex, C, E, and K) and is rich in catechin polyphenols compounds with high antioxidant activity that offer protection against many kinds of cancer, cardiovascular disease, and other age-related diseases. Matcha has a significant amount of dietary fiber and practically no calories, and, because I enjoy preparing and drinking it, I have no interest in taking green tea in a pill.
Andrew Weil, M.D.