How to Choose the Best Greens Powder, According to Experts

With a plant-based lifestyle, we’d like to think we’re always getting in our recommended amount of fruits and vegetables every day. However, even with many of us working from home – cutting boards nearby just waiting for fresh produce to be sliced upon them – intake can still be lacking. To fill that gap, there are a variety of greens powders which claim to boost energy, enhance digestion, and support immunity just as effectively as whole foods.

The wellness world is full of these types of promises. So why have greens powders become so popular? Convenience, according to Stacy Kennedy, registered dietitian and co-founder of The Wellness Guides.

Only one out of every 10 Americans eats the recommended servings of fruits and vegetables per day. The rest of us? More likely to get ambitious at the grocery store, only to watch the cart full of fresh produce eventually wilt in the fridge.

“There are a lot of reasons why [intake] is so low,” Kennedy said. “It can be pricey, time-consuming, and require skills in cooking, so many people turn to powders for a quick, easy, and portable way to get their nutrients that's shelf-stable and reduces food waste.”

Greens powders, or superfood powders, are considered a dietary supplement by the Food and Drug Administration. They are typically a blend of leafy greens, grasses, seaweed, and/or herbs, with fruit, stevia, or other flavor additives to make them taste more palatable, and are a fine texture in order to easily blend with liquid.

You might think the powder is just whole produce dehydrated and thrown in a Vitamix, but it can be more complicated than that and manufacturing differs with each brand.

Not all ingredients are processed the same way — some are indeed dehydrated and ground, while others are extracted in other ways, such as juicing before dehydrating and separating from their fiber. This is different than juicing, however, as the living enzymes in a fruit or vegetable juice are not present in the shelf-stable powder.

Convenience aside, many brands claim their blends also benefit the immune system, support digestion, improve energy, and help the body detox.

There is little research focusing specifically on greens powders to support these claims. The studies that do exist are often funded by the manufacturers themselves, which adds potential bias to the results. To judge the benefits then, we can look to research on the ingredients.

The main ingredients in quality greens powders are those hailed as superfoods such as kale, spinach, wheatgrass, alfalfa, and algae like spirulina and chlorella. Nutritional content varies by product, though all of these green foods are highly nutritious and packed with vitamins, minerals, antioxidants, and phytonutrients.

Some star nutrients include:

How does the science stack up with the health claims?

Vitamins A and C are known for their role in reducing inflammation and supporting immune health. In particular, Vitamin A supports the development of the immune system and regulates immune response. It also protects your mucus membranes — the eyes, mouth, nasal passages, and digestive tract — which are one of the body’s first lines of defense against viruses and infections.

Vitamin C is a strong antioxidant that has been found to improve immune cell function and reduce the length of the common cold and other respiratory infections. Humans cannot make or store this nutrient, so it’s important to get it in through the diet.

The body utilizes Vitamin C to cope with stress, which is why you may find yourself getting sick more easily when you’re emotionally or physically burnt out.

Plant fiber is essential to healthy digestive function. Kennedy suggests looking for greens powders that contain at least three grams of fiber per serving. Fiber may not be easy to find, however, as greens powders tend to be low on this type of nutrient. Because of this, the digestive benefits that brands claim may primarily come from additives.

Make sure to look at the ingredient label to know where that fiber is coming from. A 2015 study published in Nutrition Today exploring potential benefits of fiber supplementation noted that isolated fiber supplements don’t necessarily provide the same health benefits as the fiber contained within whole foods. Researchers found that only a gel-forming type of fiber was beneficial for digestion — not the type you’ll usually find in superfood powders.

Other additives may include probiotics and digestive enzymes. Probiotics are well known to support healthy gut flora (which is also a bonus for immune health, since 70 percent of the immune system lives in the gut).

The nutrients in food help our bodies generate energy — calories convert into energy and the vitamins and minerals in our food help with that process.

Green powders are mostly low-calorie, however, so any energy boost may be attributed to other sources.

Iron, for instance, is an essential mineral for energy production that helps carry oxygen to the cells, and magnesium is a key element of the conversion from food to fuel. The deficiency of both of these nutrients is linked to fatigue.

Some greens powders also include matcha, which has a modest amount of caffeine. Hydration also supports your energy levels as well, so blending your powder with water or adding it to a smoothie can increase the energy-boosting benefits of its mineral or caffeine content.

The body does a pretty great job of detoxifying on its own, primarily through the liver, kidneys, and digestive tract. We don’t typically need supplements to help this process along, although the nutrients from our food do support this natural process.

What you may see in the marketing for greens powders is that they will help your pH levels to be more alkaline. What does that actually mean? Brands aren’t too specific about this promise, so whether they’re referring to the alkalinity of your blood or urine is unclear. Blood pH is pretty strictly controlled, so it’s unlikely your green smoothie will alter that number, but greens can have a slight impact on the pH of your pee.

The idea is that disease proliferates in an acidic environment, so theoretically the more you can lead towards alkalinity, the better. These claims have not been proven in human studies, however.

One noted benefit that research, although limited, does support is that green powder supplements promote heart health. In a small study of 40 participants, researchers found that consuming 12 grams twice a day resulted in reduced both systolic and diastolic blood pressure.

The mechanism of action behind this benefit is not well established, but here’s what we know. Leafy greens and grasses are high in Vitamin K, which is essential for blood and cardiovascular health. Nutrients like calcium and potassium, found in smaller quantities in green vegetables, are known to help decrease blood pressure as well.

Consuming vegetables in powder form may seem like a dream to picky eaters, but is it really a suitable replacement? Not exactly. You may be missing out on some important benefits of the whole-food versions.

“Consumption of whole foods offers hydration and additional nutrients that may not be preserved in the drying process,” Kennedy said. “While relying on a powder when traveling or for some of your veggie needs can be a smart strategy, eating vegetables remains important for the majority of your daily goal.”

It’s also important to note that certain nutrients like Vitamins A and K are fat-soluble, meaning they are best absorbed when consumed with some form of fat. Because greens powders are typically mixed with water, you may not be absorbing as much nutrition as you think.

To get the most out of your blend, add it to a smoothie recipe that contains beneficial fat like nut butter, coconut, avocado, or chia seeds.

Beyond the health claims listed on the packaging, to figure out which brand is best for you, turn the label around and go straight to the ingredients.

There will likely be a list of different blends, from greens to superfoods to herbs and probiotic mixes, but both Kennedy and Brook Wyatt, a registered dietitian at Long Game Nutrition, note that there may be additional ingredients unaccounted for on the label.

“Supplements are unregulated and often contain heavy metals if they are not tested by a third party,” Wyatt said.

Heavy metals are toxins that can negatively impact your health at relatively low concentrations. In 2016, Consumer Labs found that four out of 13 products it tested were contaminated with lead, with others containing arsenic and cadmium.

These contaminants can accumulate in the body over time and become destructive to human biological function and lead to organ damage and even cancer.

To avoid this, you may want to research different brands to see whether their products are third-party tested (meaning the studies available haven't been funded by the brand or manufacturer themselves).

“You want to ensure what you are buying is actually what is printed on the label, and it isn’t full of contaminants,” Wyatt said. “NSF International, Informed Choice, and USP are top companies that test for supplement safety. If a greens powder has been tested, you should be able to locate one of these certifications on the package.”