Are greens powders good for you?

Greens powders, made with greens such as kale and algae, are hugely popular on social media.

The big question is about the ingredients. Many of these formulas are proprietary, meaning we don’t fully know what’s in them. What we do know is that they’re heavily processed: Greens powders are at very least freeze dried, powdered and often mixed with additives and sweeteners.

Ask yourself this: Does your greens powder taste good mixed in water? You probably couldn’t stomach fresh broccoli and water. So what was added to that powder to make it tolerable to you?

Eating fresh vegetables is always going to be more beneficial than taking greens powders. And greens powders may give you a false sense of security that your diet is balanced and doesn’t require any fresh fruits and vegetables. For the record, you still do: One analysis from Consumer Lab found that at best only 1/5 of the recommended adult daily intake of fruits and vegetables could be met with a daily serving of greens powders.

How to shop for greens powders

I recently perused the ingredient list of several greens powders at my local store. The companies selling these products don’t actually have to disclose every ingredient - supplements are not regulated by the Food and Drug Administration the way medications are. So I’d skip the ones that skimp on details and go for a brand that has been vetted, at least somewhat, by third parties that test for lead or heavy metals, which have worked their way into greens powders before.

Here are some greens powders ingredients you may not have been expecting:

Digestive enzymes:

• Lipase: Unless you have a major disorder, like pancreatic insufficiency, diagnosed by a physician, you don’t need a little sprinkle of extra lipase in your water. It’s a common enzyme added to greens powders for unclear reasons - your pancreas will make plenty, and we don’t have good data to show they’re beneficial otherwise.

• Cellulase: Humans don’t make cellulase, unlike cows, allowing our ruminant friends to digest the cellulose contained in the cell walls of many plants. But adding cellulase is totally missing the target. A key benefit of cellulose is precisely in our inability to digest it: In humans, cellulose reaches our colonic microbiome and gets fermented to produce beneficial metabolites like short-chain fatty acids.

• Lactase: Some greens powders I looked at casually slipped in lactase, which can certainly be helpful to those with lactose intolerance. But this would be a weird way to find that out about yourself.

• Food allergens: I often saw several possible allergens buried in the dense ingredient paragraphs, including soy and pineapple. Many products also contain wheat grass or barley grass, which could be an issue for people who have gluten intolerance or celiac disease (the grasses themselves are not problematic per se, but there may be cross-contamination).

• Extra sweeteners: “Stevia leaf” extract, present in many greens powders, sounds in touch with nature and allows a company to say “no artificial sugars,” but it’s 200 to 400 times sweeter than table sugar. Plus, the World Health Organization has advised people to stop using sweeteners such as stevia, since studies have found an association between non-sugar sweeteners and an increased risk of Type 2 diabetes and cardiovascular disease.

• Random extra stuff: For example, ashwagandha? This was a prominent feature of many of the greens powder I perused. For the record, the strongest data on ashwagandha supports a sedative effect, so double check if that’s how you want to start your morning.

What I want my patients to know

Greens powders are expensive. I appreciate that fresh vegetables are often not cheap, but once you’re dropping $50 to $100 on a month’s supply of powdered greens, maybe your money is better spent on interventions with proven benefit.

Overall, I tend to be wary of most supplements without a medical reason and of anything that adds overly processed foods into our diets. The risks of taking greens powders are not absurdly high - but as with any supplement, don’t mistake them for zero. I’d run any new supplements by your physician to make sure you’re not at higher risk of a bad outcome. This is especially important if you are on a blood thinner called warfarin, which is sensitive to levels of vitamin K (check how much is present in any powder you purchase), and also if you’re a cancer patient, are pregnant or are breastfeeding.