The Truth About Greens Powders
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This article was written by Associate Registered Nutritionist (ANutr) Sophie Gastman, and reviewed by Registered Dietitian Maeve Hanan.
If you’re on social media, the likelihood is that you’ve seen at least one influencer or celebrity promoting powdered greens as the go-to solution for health enthusiasts everywhere. With so many different brands and a lengthy list of wild marketing claims including energy-boosting, immune-supporting and hormone-balancing benefits, it’s easy to wonder if greens powders are something we really need to add to our diets.
This article will breakdown the evidence and explore whether greens powders truly live up to the hype.
What Are Greens Powders?
Greens powders (aka superfood powders/blends), as the name would suggest, are a dietary supplement that typically consist of a blend of dehydrated or powdered fruit and vegetables. Whilst the specific contents of these powders will vary from brand to brand, the majority of them contain around 25-40 different ingredients including added extracts, vitamins, minerals, probiotics, natural sweeteners and other plant-based ingredients. It might seem like a no-brainer toget all of our veggie fix for the day from one convenient powder mixed into a drink – but are they actually any good for us, and should we be relying on them?
Do Greens Powders Really Work?
With some popular greens powders costing close to £100, you’d like to believe that all of the product’s claims are true, but it’s actually very difficult to prove that they work. Let’s look beyond the marketing and dive into the scientific evidence to see if the claims hold up under scrutiny.
Energy Boosting
Along with claims of boosting energy, most greens powders also claim to be low calorie – so where is this source of energy coming from? A lot of these powders are formulated with compounds that make you feel more alert, such as green tea extract, which contains caffeine and can therefore have an energy boosting effect.
One small study of 63 healthy women investigating the effects of a greens powder with green tea extract on vitality, energy and perception of well-being found that those who were given the greens powder daily for 12 weeks reported significantly higher energy levels than those who received a placebo. However, this is just one study and the overall findings were not conclusive that the greens powder increased energy, so a lot more research needs to be done in this area first (1).
If you find yourself in need of an energy boost, you’re better of relying on some actual food or perhaps a cup of coffee for a quick (and cheaper) caffeine fix!
Improves Blood Pressure
Research has suggested that greens powders may have a positive impact on blood pressure. This is because many of the minerals found in these supplements, such as magnesium and calcium, are known to help regulate blood pressure levels.
For instance, a small study involving 40 students showed that taking a greens supplement for 90 days led to a significant decrease in both systolic and diastolic blood pressure, whereas the control group experienced no improvements (2). Another study on individuals with hypertension found that taking a greens powder called “NanoGreens” for 90 days resulted in a significant reduction in both systolic and diastolic blood pressure. It’s worth noting, however, that this study was funded and authored by Biopharma Scientific, the manufacturer of the product, which could potentially introduce bias to the results.
Again, while there is some evidence to support the claims about blood pressure improvements, there is a lot more research that needs to be done in this area, such as in larger groups and different populations, before we can definitively say greens powders are beneficial for blood pressure management.
It’s also important to acknowledge that there are more scientifically proven and cost-effective methods of reducing blood pressure, such as engaging in regular physical activity, managing stress levels, consuming a balanced diet and decreasing sodium intake.
‘Immune Boosting’
It’s no secret that many health supplements claim to boost the immune system, but this marketing tactic can be misleading. In fact, an overstimulated immune system can actually do more harm than good.
While some greens powders do contain vitamins that support immunity, such as Vitamins A, C, and D, these same nutrients can be obtained through eating whole foods or a regular vitamin supplement.
And if you aren’t deficient in these nutrients taking extra doesn’t usually ‘boost’ the immune system further.
Furthermore, research on other popular ‘immune-boosting’ ingredients found in greens powders, such as echinacea, is often limited and the amount of these ingredients included is not always disclosed, making it difficult to determine their effectiveness. As a result, it’s important to be aware of the potential limitations of relying solely on greens powders for immune support.
Digestion and Gut Health
Gut health has been a hot topic in recent years, and powdered greens have jumped on the bandwagon by adding a variety of digestive enzymes, prebiotics, probiotics and fibre to promote gut health. A little bit of extra care for our gut can benefit everyone, and consuming gut-friendly bacteria from greens powders can be an easy and effective way to do so.
However, not all probiotics are created equal, and the strains included in these powders may not be the right fit for you. The unique makeup of your microbiome can determine how a specific strain of bacteria affects your gut health, with one strain potentially aiding gut health for one person, but causing bloating for another (3).
As for digestive enzymes, while our bodies produce digestive enzymes naturally to aid in food breakdown, some individuals with conditions such as IBS, pancreatitis, and lactose intolerance may benefit from digestive supplements. It’s worth noting, however, that the digestive enzyme typically found in greens powders is bromelain, which is a naturally occurring enzyme in pineapple. Despite bromelain being a popular digestive aid, the National Centre for Complementary and Integrative Health (NCCIH) states there’s not enough evidence to claim that bromelain effectively treats digestive issues (4).
Therefore, if you are experiencing digestive issues, it’s wise to consult a healthcare professional first rather than relying solely on a greens powder with added digestive enzymes. Otherwise, for healthy individuals these types of supplements are absolutely not necessary.
We all know that fibre is great for gut-health but with a serving of powdered greens typically only providing 2g of fibre per serving where the recommended daily intake is 30g, it’s clear that greens powders are not a replacement for high-fibre foods like fruits, vegetables, nuts and whole grains.
It’s also important to keep in mind that not all of the seemingly gut-friendly ingredients in these powders are suitable for everyone. Those with digestive sensitivities like IBS, IBD, or FODMAP sensitivities may experience bloating and other negative digestive symptoms from certain ingredients like inulin, chicory root extract, and asparagus powder, which are high in FODMAPs
Reducing Risk of Chronic Disease
Greens powders are believed to contain significant amounts of antioxidants, particularly Vitamin C and K, which may reduce the risk of chronic diseases. In a study examining the antioxidant properties of Greens+ powder, researchers found that taking 6 teaspoons daily for four weeks resulted in lower levels of oxidative stress, suggesting that it could protect against diseases like Alzheimer’s (5). It’s important to note, however, that this study had a limited sample size of just 10 participants, and further large-scale research is needed to verify these findings.
Detoxifying/Alkalising
Potentially the most concerning claim seen on powdered greens is that they will help to ‘detoxify’ the body and increase its alkalinity. The issue with this claim is that it is completely false and not based on any scientific evidence.
For background, it’s vital that the pH of our blood remains constant as if something were to happen where our blood pH fell outside of the normal range, you would die very quickly if left untreated. Thankfully, our bodies tightly regulate blood pH within a narrow range of 7.35-7.45, which is almost impossible to change through the foods we eat (6).
In terms of ‘detoxification’, a nutrient dense diet might aid the body’s natural detoxification process, but a daily dose of greens powders certainly won’t ‘cleanse’ your body.
Issues With Greens Powders
While greens powders can be a convenient way to add nutrients to your diet and may have some health benefits, there are also some potential issues to consider.
Lack of Regulation
The supplement industry is not as tightly regulated as the food industry, and some greens powders may contain questionable ingredients or as discussed earlier, have misleading health claims attached.
Possible Contaminants
Due to the lack of regulation, greens powders may also be at risk of contamination with heavy metals or other harmful substances. If you decide to include a greens powder in your diet, it’s important to choose one from a reputable brand that has been third-party tested for quality and purity.
Not Equal or Superior to Whole Foods
Whilst some ingredients in green powders sound really healthy, they are not necessarily better than the nutrients found in whole foods.
In fact, eating the whole food with the fibre intact and complex combination of nutrients found naturally in food (known as the ‘whole food effect’) is usually much better than consuming it in the form of a powder where the fibre has been removed and other nutrients have potentially been lost in the process.
It’s also worth noting that as of 2018, Public Health England declared that fruit and vegetable powders do not count towards your ‘5 a day’. The reason for this is that these powders are too far removed from the original product and there isn’t enough evidence that they have equal health benefits to consuming the whole product (7).
Risks Associated with Overconsumption of Supplements
Taking too many supplements can lead to nutrient imbalances and other health problems. For example, regularly exceeding the safe upper limits of iron or fat-soluble vitamins like Vitamin A can cause serious health issues. One large meta-analysis concluded that high doses of Vitamin A, Vitamin E and beta-carotene in the form of a supplement was actually associated with an increased mortality (8).
Additionally, if powdered greens are combined with other supplements containing Vitamin A, it could be risky for bone health if this exceeds 1500 micrograms per day, as The Scientific Advisory Committee on Nutrition (SACN) found that this could increase risk of bone fractures later in life (9).
Not Advised in Pregnancy/Breastfeeding
Pregnant and breastfeeding women should be cautious about taking greens powders, as the effects of some ingredients are not well known and could pose certain risks for the developing fetus.
In addition to this, pregnant women also need to be mindful of consuming large amounts of certain vitamins, such as Vitamin A, which could harm the unborn child. The UK Expert Committee on Vitamins and Minerals (EVM) suggest that an intake greater than 1,500 micrograms per day was ‘inappropriate’, based on possible harmful effects (10). The actual recommended daily intake for pregnant women is 800 micrograms a day (11) and with some powders containing up to 1100 micrograms of Vitamin A per serving, it’s important that your daily intake from food and supplements does not exceed this.
Medication Interactions
Some ingredients in greens powders may interact with certain medications and influence the absorption, excretion or activity of prescription drugs. For example, most greens powders are high in Vitamin K, which can interact with blood thinners rendering them ineffective (12).
Conclusion
Greens powders should not be considered a replacement for fruits and vegetables. Ultimately, optimal health and nutrition always boils down to consuming a varied and balanced diet that includes a wide range of fruits, vegetables and whole grains. It’s also worth noting that a less expensive multivitamin and mineral supplement may be a more practical and cost-effective option for some people where nutritional gaps need to be filled. If unsure, it’s always best to seek an individual assessment and advice from a Registered Dietitian.
References
- Boon, H., Clitheroe, J. and Forte, T. (2004) “effects of greens+® a randomized, controlled trial,” Canadian Journal of Dietetic Practice and Research, 65(2), pp. 66–71. Available at: https://doi.org/10.3148/65.2.2004.66.
- Zhang, J. et al. (2006) “Taking nutritional supplements for three months reduced blood pressure but not blood lipid levels in students,” Journal of Chiropractic Medicine, 5(2), pp. 53–59. Available at: https://doi.org/10.1016/s0899-3467(07)60133-5.
- Kothari, D., Patel, S. and Kim, S.-K. (2019) “Probiotic supplements might not be universally-effective and safe: A Review,” Biomedicine & Pharmacotherapy, 111, pp. 537–547. Available at: https://doi.org/10.1016/j.biopha.2018.12.104.
- Bromelain (no date) National Center for Complementary and Integrative Health. U.S. Department of Health and Human Services. Available at: https://www.nccih.nih.gov/health/bromelain (Accessed: April 25, 2023).
- Rao, V. et al. (2011) “In vitro and in vivo antioxidant properties of the plant-based supplement greens+,” International Journal of Molecular Sciences, 12(8), pp. 4896–4908. Available at: https://doi.org/10.3390/ijms12084896.
- Hamm, L.L., Nakhoul, N. and Hering-Smith, K.S. (2015) “Acid-base homeostasis,” Clinical Journal of the American Society of Nephrology, 10(12), pp. 2232–2242. Available at: https://doi.org/10.2215/cjn.07400715.
- Advertising Standards Authority | Committee of Advertising Practice (no date) Racing Greens Nutraceuticals Ltd, ASA. Available at: https://www.asa.org.uk/rulings/racing-greens-nutraceuticals-ltd-a18-443816.html (Accessed: April 25, 2023).
- Bjelakovic, G. et al. (2008) “Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases,” Cochrane Database of Systematic Reviews [Preprint]. Available at: https://doi.org/10.1002/14651858.cd007176.
- England, P.H. (2005) SACN review of dietary advice on Vitamin A, GOV.UK. GOV.UK. Available at: https://www.gov.uk/government/publications/sacn-review-of-dietary-advice-on-vitamin-a (Accessed: April 25, 2023).
- Lay Summary of the Statement on the effects of excess Vitamin A on maternal health (2022) Committee on Toxicity. Available at: https://cot.food.gov.uk/Lay%20Summary%20of%20the%20Statement%20on%20the%20effects%20of%20excess%20Vitamin%20A%20on%20maternal%20health#:~:text=The%20World%20Health%20Organisation%20(WHO,does%20not%20include%20the%20UK) (Accessed: April 25, 2023).
- Bastos Maia, S. et al. (2019) “Vitamin A and pregnancy: A narrative review,” Nutrients, 11(3), p. 681. Available at: https://doi.org/10.3390/nu11030681.
- Booth, S.L. and Centurelli, M.A. (2009) “Vitamin K: A practical guide to the dietary management of patients on warfarin,” Nutrition Reviews, 57(9), pp. 288–296. Available at: https://doi.org/10.1111/j.1753-4887.1999.tb01815.x.