It is no secret fruits and vegetables carry innumerable nutritional benefits. Chief among them: vegetables are high in fiber, vitamins, minerals, and phytochemicals. The most recent Dietary Guidelines for Americans recommends Americans consume 4-5 cups of vegetables and fruits daily.1 No doubt, this is partly why we strongly suggest filling half of your meal plate with fruits and vegetables. As Registered Dietitians, we are often asked about the nutritional value of ubiquitous “greens powders” (dehydrated fruit and vegetable-based powders used to mix into water and other liquids), and if we recommend them for the various health benefits they claim. In this month’s Wellness Read, we explain what greens powders are, what the research says about their health effects, as well as how and when to incorporate into your diet.
What are greens powders?
Greens powders are dietary supplements formed by dehydrating and crushing whole vegetables, fruits, and their juices. Most greens powders contain a blend of a variety of green vegetables, grasses, herbs, and other plants. Like all supplements, greens powders are not subject to FDA regulations that ensure safety or efficacy. As such, it is paramount to seek out brands that third parties test for potency and purity (see Recommended Brands list below).
While greens powders are designed as a vegetable alternative, it is important to highlight notable differences between greens powders and whole vegetables.
While abundant in whole vegetables, dietary fiber is largely, if not completely, removed in the process of making greens powders. Research shows fiber intake is linked to lower LDL cholesterol levels2, improved GI health3, better stabilized blood sugar levels4, reduced risk of mortality from CVD and cancers5, and maintenance of a healthy weight6. Some manufacturers add fiber into the greens powder, usually in the form of rice bran, inulin, apple fiber, and other additives, to make up for the loss of natural fiber. However, we cannot assume that benefits seen in foods naturally rich in fiber are tantamount to those where fibers have been added in processing; thus, greens powders and whole vegetables are not necessarily “equal” when it comes to fiber content.
Greens powders, in general, are high in certain vitamins, minerals, antioxidants, and other elements containing anti-inflammatory properties. We already know cooking vegetables can deplete vitamin and mineral content while simultaneously enhancing the bioavailability of others7, so we recommend a diet that includes raw vegetables as well as cooked vegetables. The vegetables in greens powders are raw, which generally preserves nutrient content, however some nutrients may also be lost during processing. Micronutrient richness is a main benefit of vegetables, so factors that influence vitamin and mineral concentration are worth noting.
Greens powders and fresh vegetables are drastically different in cost. Typically, greens powders cost $2-3 per serving whereas fresh vegetables cost an average of $0.15 per serving8, depending on the type of vegetable. This price difference is significant when considering the recommendations for vegetable servings for Americans (~35 servings per week).
Despite notable differences between greens powders and vegetables, greens powders are marketed as a health “superfood,” touting several desirable outcomes. It is important to consider the body of research when evaluating the credibility of such claims.
Is there research-based evidence to support the use of greens powders?
As mentioned, there are several well-established benefits of fruit and vegetable intake, from lower coronary artery disease risk (CAD)9 to reduced incidence of cancers.10 Regular intake of green, leafy vegetables11 in particular is associated with reduced cancer, osteoporosis, cardiovascular disease and better weight management and blood sugar control. Do these health benefits extend to greens powders containing dehydrated vegetables? Current research on greens powders is novel and limited. However, early studies† show these benefits:
- Enhanced anti-oxidative properties12 – A four-week study following 10 subjects showed lower blood levels of oxidatively damaged proteins by 30%.
- Reduced blood pressure13 – A 90-day study showed 8% reduction in blood pressure among 40 participants after taking a greens supplement daily.
- Increased energy14 – A 12-week research trial showed improved energy among women who took a green supplement during the study period. Of note, the greens powder used contains green tea extract, which contains caffeine.
- Improved immunity – Greens powders contain significant amounts of vitamin A15 and C16, both of which are important to healthy immune function. However, there are no studies at present that evaluate the effect greens powders have on immune function directly.
Early research shows possible promising outcomes, but the body of scientific evidence is too limited to draw definitive conclusions about the health benefits of greens powders in general and relative to those known to exist from including vegetables in our diet. As ever, because studies on dietary supplements often have confounding variables that are not always accounted for in study design, conclusions drawn from supplement-based research should always be taken within the broader context of health until more is known through controlled analysis.
Should you incorporate greens powders into your routine?
Unless and until more is known, greens powders should never serve as a replacement for whole vegetables. When increasing vegetable intake, first and foremost aim to incorporate whole-food versions. Try adding vegetables into your diet in creative ways, such as adding to soups, sauces, smoothies, pastas, and egg breakfasts. However, if you believe you are falling short of your fruit and vegetable intake, greens powders could be a convenient way to bridge the gap. Whether traveling or just navigating a hectic week, greens powders can provide vegetable-based nutrients when eating whole vegetables is not possible.
Recommendations for adding greens powders to your diet
- Choose a high-quality product. When choosing a greens powder, aim for an ingredient list that is recognizable, and a product that contains minimal to no added sugar, dyes, etc. Recommended brands include, but are not limited to, the following:
- Amazing Grass® Greens Superfood
- Athletic Greens®
- Garden of Life® Raw Organic Green Superfood
- Aim for Balance. Be sure to always include greens powders as a part of a balanced meal (pair with a lean protein and complex carbohydrate) or balanced snack (pair with a lean protein or healthy fat).
- Get Creative. If you would rather not drink your greens powder, try adding to your diet in other ways, such as:
- Add to a protein smoothie
- Sprinkle atop roasted vegetables or salad veggies
- Incorporate into a salad dressing
- Stir into a vegetable dip
- Add to a soup, stew, or casserole
Questions about greens powders and if they might be right for you? Reach out to our Registered Dietitian, Lauren Munson (firstname.lastname@example.org) for a more individualized approach.
In Real Health,
SHIFT Registered Dietitian
- 2020-2025 Dietary Guidelines for Americans. US Department of Agriculture, December 2020. https://www.dietaryguidelines.gov/sites/default/files/2021-03/Dietary_Guidelines_for_Americans-2020-2025.pdf.
- Mayo Clinic Staff. Cholesterol: Top foods to improve your numbers. Mayo Clinic, 2018. https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/cholesterol/art-20045192
- Gill, S., Rossi, M., Bajka, B. & Whelan, K. Dietary fibre in gastrointestinal health and disease. Nat Rev Gastroenterol Hepatol. 2021;18:101-116. https://www.nature.com/articles/s41575-020-00375-4
- Riccardi, G. & Rivellese, A. Effects of dietary fiber and carbohydrate on glucose and lipoprotein metabolism in diabetic patients. Diabetes Care. 1991; 14(12):1115-25, doi: 10.2337. https://pubmed.ncbi.nlm.nih.gov/1663443/
- Kim Y, et al. Dietary fibre intake and mortality from cardiovascular disease and all cancers: A meta-analysis of prospective cohort studies. Archives of Cardiovascular Disease. 2016;109:39. https://pubmed.ncbi.nlm.nih.gov/26711548/
- Ma, Y., et al. Single-Component Versus Multicomponent Dietary Goals for the Metabolic Syndrome: A Randomized Trial. Ann Intern Med. 2015;162(4):248-257. https://www.acpjournals.org/doi/pdf/10.7326/M14-0611
- Lee S, Choi Y, Jeong HS, Lee J, Sung, J. Food Sci Biotechnol. 2018 Apr; 27(2): 333–342. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6049644/
- How Much do Americans Pay for Fruits and Vegetables. Economic Research Service, USDA. https://www.ers.usda.gov/webdocs/publications/42549/15151_aib790d_1_.pdf?v=42061#:~:text=The%20weighted%20average%20price%20for%20all%20fresh%20vegetables%20was%20%240.64,item%20was%20%242.67%20per%20pound.
- Dauchet L, Amouyel P, Dallongeville J. Fruits, vegetables and coronary artery disease. Nat Rev Cardiol. 2009 Sep;6(9):599-608. doi: 10.1038/nrcardio.2009.131
- Vainio H & Weiderpass E. Fruit and vegetables in cancer prevention. Nutr Cancer. 2006;54(1):111-42. doi: 10.1207/s15327914nc5401_13.
- Yan L. Dark Green Leafy Vegetables. USDA Agricultural Research Service. Last Modified 2016. https://www.ars.usda.gov/plains-area/gfnd/gfhnrc/docs/news-2013/dark-green-leafy-vegetables/
- Rao V, et al. In vitro and in vivo antioxidant properties of the plant-based supplement greens+™. Int J Mol Sci. 2011;12(8):4896-908. https://pubmed.ncbi.nlm.nih.gov/21954333/
- Zhang J, Oxinos G, Maher J. The effect of fruit and vegetable powder mix on hypertensive subjects: a pilot study. J Chiropr Med. 2009;8(3):101-106. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2732245/
- Boon H, Clitheroe J & Forte T. Effects of greens+: a randomized, controlled trial. Can J Diet Pract Res. 2004;65(2):66-71. https://pubmed.ncbi.nlm.nih.gov/15217524/
- Vitamin A: Fact Sheet for Health Professionals. National Institutes of Health – Office of Dietary Supplements. Updated March 2021. https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/
- Vitamin C: Facto Sheet for Consumers. National Institutes of Health – Office of Dietary Supplements. Updated March 2021. https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/
† Results vary based on brand and supplement formulation.