What you've heard
A scoop of greens powder covers your vegetables
Verdict
Expensive vitamins, and no substitute for vegetables
Can a greens powder replace vegetables?
Expensive vitamins, and no substitute for vegetables.
The best evidence is a systematic review of commercial mixed fruit and vegetable concentrates. They raised blood levels of beta-carotene, vitamins C and E and folate, and lowered some laboratory markers of oxidation, with no serious side effects. But the studies measured blood markers, not illness, the products varied widely, and there is no evidence that the powders improve outcomes such as heart disease.10 The fiber findings in this chapter, and the links to lower death rates, come from eating plants themselves.
Where the book tests it
What the book recommends instead
Eat more fiber, from many kinds of plant
ProbableEvidence grade: Probable. Good observational evidence with a plausible mechanism, or small or few trials.How: beans or lentils most days (Chapter 5's third of a cup counts), whole grains instead of white, and a fruit or vegetable at every meal; frozen vegetables and canned beans count. A medium apple carries about 4 grams, so together these moves take a typical day from about 17 grams toward 25 or more. Build up slowly to limit gas. Why: it feeds the colon's bacteria, and high intakes are consistently linked to lower death rates.
Sources
- 10.Esfahani, A., Wong, J.M.W., Truan, J., Villa, C.R., et al. (2011). "Health effects of mixed fruit and vegetable concentrates: a systematic review of the clinical interventions." Journal of the American College of Nutrition, 30(5), 285-294. https://doi.org/10.1080/07315724.2011.10719971 (22 reports of commercial concentrates)
Note numbers are those of Chapter 6, The Gut That Expects Dirt.
This verdict is one of the "What you've heard" boxes in Chapter 6, The Gut That Expects Dirt, where the book tests the claims people repeat against the studies behind them.
Educational content, not medical advice. Disclaimer.