While they don't appear to have tested any of the 3-4 green powdered drink products I am familiar with, here is the list of products that failed quality control testing--and why:
- All Day Energy Greens (lead)
- Gary Null's Green Stuff (lead)
- InnerLight Super Greens (lead)
- Now Spirulina (failure of tablets to disintegrate after 60 minutes)
- The Ultimate Meal (>2x the USP limit for aerobic bacteria)
- Vibrant Green Health (arsenic)
The antioxidant activity of greens powders is reported in terms of the value obtained from a laboratory test known as ORAC (Oxygen Radical Absorbance Capacity). Consumer Labs notes that this ORAC score is observed in test tubes and may not (or likely does not) correlate to what happens in the human body.
Similarly, CL sort of challenges the entire "alkalinizing" argument for green drinks--something I have often wondered about. They argue, quite convincingly, that:
The blood of the human body maintains a pretty strict pH range, just slightly alkaline, from 7.35 to 7.45. Since the typical (western) diet is more acidic, goes the alkaline diet theory, this tilts the famed acid-alkaline balance to the acidic end of the range, promoting the loss of essential minerals (add reference here please!), and is thought to make people prone to illness.
"Alkalinizing" greens are purported to help restore this balance, improve overall health and prevent many chronic diseases.
There is little evidence, however, to suggest that an acid-producing diet is the foundation of chronic illness or that food consumption will easily change the pH of one's blood. The human body has a complex system of checks and balances to keep the pH of blood tightly within the range of 7.35-7.45. Food choices can temporarily increase or decrease the pH of one's urine or saliva, but will have little to no effect on the pH of blood.* Alkaline diets may, however, help prevent the formation of calcium kidney stones, osteoporosis, and age-related muscle wasting.
Greens products tested and passed by CL testing:
- AmaZing Grass Greens
- American Health More Than A Greens
- Barlean's Organic Oils Greens Organic
- Garden of Life Perfect Food RAW Organic Super Food
- Health To Go Greens
- Juice Plus Garden Blend
- Puritan's Pride Life's Greens
- Rainbow Light Immuno-Build Greens
- Solgar Earth Source Greens & More
- Swanson GreenFoods Green Max Powder
* GIven that even a 0.01 shift in the pH of the blood would seem significant, I would like to hear more about CL's apparent equivocation between "little" and "no" effect. This matter might warrant further scrutiny, and I am not yet entirely convinced that the alkalinizing hypothesis is total bunk.