June 3, 2010 -- Popular protein drinks with names like Muscle Milk and EAS Myoplex -- favorites of teens, gym rats, boomers, and pregnant women -- can contain potentially unsafe levels of heavy metals and other harmful substances, according to an investigation by Consumer Reports.
''Consuming these kinds of protein drinks on a regular basis can in some cases create the risk of chronic exposure, even at low levels, to heavy metals such as cadmium and lead that can pose health problems, particularly to vulnerable people," says Andrea Rock, the Consumer Reports editor for the investigation. Among vulnerable people are children under age 18, pregnant women, and people with diabetes or chronic kidney conditions, she says.
Makers of protein drinks disagreed and said there were flaws in the investigation.
While the protein drinks are marketed as convenient, Rock says, "Most people can meet their protein needs through diet. And that can be better for both your health and your wallet.''
The full report will be in the July issue of Consumer Reports.
Lab Tests on Protein Drinks
For the study, Consumer Reports had an independent laboratory test 15 protein drinks, including ready-to-drink formulas and powders meant to be mixed with milk, juice, or water. Three servings of the products tested provide from 27 to180 grams of protein.
Testing for contaminants -- including arsenic, cadmium, lead, and mercury -- found most products to be in the low to moderate range. But three products cause concern, Rock says, because people who have three servings a day could be exposed to higher levels of three substances -- arsenic, cadmium and lead. Some products surpass the maximum limit proposed by the U.S. Pharmacopeia (USP). The USP sets voluntary standards for health products.
Excess cadmium can accumulate and gather in the kidneys, and excess protein can also damage the kidneys.
Protein drinks are considered dietary supplements, so the makers are not required to test the products before sale to ensure they are safe and effective, according to the report.
Consumer Reports says these three products are of special concern:
- EAS Myoplex Original Rich Dark Chocolate Shake has an average of 16.9 micrograms of arsenic in three servings -- more than the 15 micrograms a day that is the proposed USP limit. It has an average of 5.1 micrograms of cadmium for three servings -- above the USP limit of 5 micrograms a day.
- Muscle Milk chocolate powder, at three servings, contained all four of the metals, and three metals were found at a level that was among the highest of all 15 products tested. Cadmium levels were 5.6 micrograms -- above the 5-microgram limit. Lead was 13.5 micrograms -- above the USP limit of 10 micrograms. The arsenic averaged 12.2 micrograms -- near the 15-microgram daily USP limit.
- Muscle Milk vanilla crème had 12.2 micrograms of lead per three servings -- above the 10-microgram daily limit. It has 11.2 micrograms of arsenic -- close to the 15-microgram daily limit.
Just one of the products, Six Star Muscle Professional Strength Whey Protein, specifies a maximum daily intake, Rock found. Other makers use vague language, the researchers say, which could promote high consumption levels.
The industry took exception to the report for a number of reasons. The substances tested in the report ''are naturally occurring in the environment," according to a statement issued by Greg Pickett, founder of CytoSport, which makes Muscle Milk. ''It would be uncommon, if not impossible, not to detect the trace amounts reportedly found in any agricultural product, such as dairy products, fruits and vegetables."
In the statement, Pickett notes that the two Muscle Milk products that Consumer Reports says have high levels of contaminants were both analyzed by NSF International, an independent organization that sets product standards, and found to pass.
Michelle L. Zendah, a spokeswoman for Abbott Nutrition, which makes Myoplex protein shakes, issued this statement: "There is no safety risk from the trace levels of cadmium and arsenic in our Myoplex protein shakes. Our quality testing shows the level of these elements is below all current, well-established safety standards, including those from the U.S. Environmental Protection Agency (EPA) and the World Health Organization (WHO). Consumers can continue to use Myoplex shakes with confidence."
A Nutrition Expert's Perspective
Protein is important in the diet, but you don’t need the protein drinks to get enough, says Jeannie Gazzaniga-Moloo, PhD, RD, a spokeswoman for the American Dietetic Association.
She recommends people turn to natural food sources primarily. "Don't rely on these [protein drinks] heavily to be your primary protein source in your diet. Look to dairy, meats, and beans and some whole grains to provide protein."
Turning to food rather than protein drinks is easier on your health and your wallet, according to Consumer Reports.
To get a rough idea of daily protein needs, the researchers say, multiply your body weight by 0.4. Athletes generally are advised to eat a gram of protein per pound of body weight daily.
So a 120-pound person in general would need about 48 grams and a 180-pound person would need 72 grams. Most Americans surpass that, getting 82 grams a day, according to government surveys.
Good sources of protein include half a chicken breast (27 grams), three scrambled eggs (20 grams), or three 8-ounce glasses of milk (23 grams). A scoop of Nitro-Tech powder, in comparison, has 25 grams.