Protein Powders, Shakes, and Drinks Review
Initial Posting: 6/10/16 Last Update: 9/25/18
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Summary: What You Need to Know About Protein Powders, Drinks and Shakes
- Do they help? Extra protein (typically about 30 to 50 grams per day) from a powder or drink can help athletes build muscle and older people prevent or reverse age-related loss of muscle and strength when used in conjunction with resistance-type exercise. It may also help people with diabetes maintain blood sugar levels and even reverse diabetes if taken as part of low calorie diet. (See "What It Does").
- What type? Protein products vary based on the source of protein (e.g., whey, casein, soy, rice, pea, egg, and hemp). In general, whey is most popular as it is a complete protein and rather quickly digested. Casein is digested more slowly — which is why it is sometimes taken in the evening — to counter loss of muscle at night. Vegans may be more interested in plant sources, such soy, pea, rice, and hemp. See ConsumerTips, Protein for more about each type of protein.
- Which brand? 28% of the protein products which ConsumerLab.com selected for review failed to pass tests. (See "What CL Found"). Among products which were Approved, the lowest cost to obtain an equivalent amount (20 grams) of protein was 67 cents from a whey protein powder, while it was over $5 for some products listing many additional ingredients. See which products were CL's Top Picks for value. You can also compare all of the products in the Results Table.
- How to Use? Protein powders are typically mixed with water or other liquids, but be aware of what you are adding. (See What to Consider When Using).
- Cautions: Also be aware that you may need to increase your fluid intake when consuming higher amounts of protein -- (See Concerns and Cautions).
What It Is:
To increase protein in the diet, one can turn to meats, which are complete protein sources because they provide all the essential amino acids. The downside to meats, especially red meat, is that they can also provide significant amounts of saturated fat and cholesterol. Another way to increase protein intake is by combining large servings of incomplete proteins such as legumes and grains, but this increases carbohydrate and calorie intake. Powders and drinks offer a protein alternative without significantly increasing consumption of fats, carbohydrates, cholesterol, or calories.
Unlike nutrition bars (see Nutrition Bar Product Review), which need to contain a good amount of carbohydrates to give them a reasonable texture, feel and taste, protein powders and drinks do not. Consequently, makers of protein powders and drinks have a great deal of flexibility in the nutritional content of these products. For example, it is quite possible to find powders and drinks with half the fat and carbohydrates of most nutrition bars, while often offering twice the protein. Of course, the nutrition numbers can change significantly depending on the type of liquid with which you choose to mix the powder (see ConsumerTips™ for the nutrient content of milks and juices). For people seeking a powder or drink as a meal replacement, it is important to understand overall nutritional needs, as also discussed in the ConsumerTips™ section.
Protein powders typically come in canisters or packets ready to be mixed with water, milk, juice, or other beverage. Protein drinks often come in ready-to-use cans or bottles. These products are marketed as dieting aids, meal replacements, energy boosters, endurance/recovery products, and as concentrated sources of protein -- typically for athletes seeking to build muscle and strength.
What It Does:
Protein is necessary to build, maintain, and repair muscle. The Academy of Nutrition and Dietetics (AND) -- formerly the American Dietetic Association (ADA) -- currently recognizes a daily protein requirement of about 0.40 gram/pound of bodyweight for sedentary individuals, 0.55 to 0.65 gram/pound for endurance athletes and 0.65 to 0.80 gram/pound for strength athletes. Based on a body weight of 150 lbs., this works out to about 60 grams for sedentary individuals, 90 grams for endurance athletes, and 109 grams for strength athletes. As you can see, a person's need for protein can more than double depending on their level of activity. The AND also states that the daily maximum usable amount of protein for adults is 1 gram/pound, or 150 grams for a 150 lb. person.
Building and maintaining muscle mass:
Combined with regular resistance exercise, protein supplementation can help to increase muscle mass and strength gains in both younger and older adults. A review of 22 studies in both young and older individuals found that after training two to five times a week over periods of ranging from 6 to 24 weeks, subjects getting supplemental protein gained an additional 1.5 lbs. of muscle and could leg press an additional 30 lbs. compared to subjects not getting the extra protein. The reviewed studies involved various types of supplements -- most of which included whey protein -- given immediately before, during, and/or after the exercise session (Cermak, Am J Clin Nutr 2012). (See ConsumerTips for information about the forms of protein: whey, casein, soy, and rice.) Similarly, a subsequent review of 49 studies found that increasing total daily protein intake up to 0.73 grams per pound of bodyweight (109.5 grams per day for a 150 lb adult), significantly enhanced changes in muscle strength and size during prolonged resistance exercise training in both younger and older adults. Consuming more than this amount of protein per day provided no additional benefit. All sources of protein were beneficial, including protein supplements (whey, soy, casein, pea) or whole foods (i.e. beef, yogurt, eggs) (Morton, Br J Sports Med 2017). It has been suggested that to optimally stimulate muscle growth, it is best to divide the daily protein intake over three meals (Padden-Jones, Curr Opin Clin Nutr Metab Care 2009).
Resistance exercise and protein supplementation can be particularly beneficial in older adults, since aging is associated with a progressive loss of skeletal muscle mass and strength (known medically as sarcopenia). Sarcopenia may increase the risk of falls in older adults (Clynes, Calcif Tissue Int 2015). Protein supplementation after resistance-type exercising has been shown to increase muscle protein synthesis and inhibit muscle protein breakdown, helping muscle to build during the post-exercise recovery period. For example, a three-month study in Brazil among older women (average age 67) who normally participated in regular resistance exercise (about 3 days per week) found that, compared to placebo, 35 grams of whey protein consumed immediately after exercise significantly increased lean soft tissue (muscle, tendons, etc.) (3.8% vs. 2%) and muscle strength as measured by volume load (45.4% vs 35.4%). Women who consumed whey protein also had a greater reduction in a cardiovascular risk measure (ratio of total cholesterol to high density lipoprotein), which decreased 11.8% versus 2.9% in the placebo group. There was no significant change in body fat in either group (Fernandes, Exp Gerontol 2018).
However, studies show that simply eating extra protein, without exercise, does not help build muscle or increase strength. A large, 2-year placebo-controlled study in healthy women ages 70 to 80 in Australia who did not perform regular resistance exercise found that a daily drink providing 30 grams of whey protein did not increase or preserve muscle mass, nor improve muscle strength, compared to placebo (Zhu, J Nutr 2015). In fact, both the protein and placebo groups experienced a decrease in upper arm and calf muscle mass, as well as a decrease in hand-grip strength -- although skeletal muscle mass remained stable for both groups. Most of the women already had adequate protein intake (averaging 76 grams daily) at the beginning of the study -- well above recommendations for protein intake. Similarly, a 6-month study in Boston among older men (average age 73 years) with physical limitations found that simply adding about 45 grams of protein (from a casein and whey mix) beyond the recommended daily intake, without any added exercise, did not increase muscle mass or strength compared to adding an equal amount of carbohydrates. The study found that adding a weekly testosterone injection (100 mg), with or without the extra protein, had no effect on muscle mass or strength but was associated with a 4.4 lb. reduction in fat (Bhasin, JAMA Int Med 2018). Along the same lines, a five-month study among women in Japan aged 65 to 80 years who were already getting adequate protein from their diet found that consuming 22.3 grams of whey protein twice weekly after resistance exercise significantly increased muscle mass and hand grip strength compared to exercise alone — but consuming the same amount of whey protein without resistance exercise resulted in little increase in muscle mass and no improvement in hand grip strength (Mori, Geriatr Gerontol Int 2018).
Also, if you already consume ample protein from your diet, extra protein won't help, even with exercise. A study of older men who completed 12 weeks of resistance exercise training (3 sessions per week) and consumed supplementary protein (21 grams) or a non-protein placebo after exercise and each night before sleep found no greater improvement in muscle strength or size with the protein supplement than with the placebo. The lack of benefit of protein supplementation was likely due to the fact that the men were already consuming amounts of protein considered adequate for their moderate training: Those receiving the placebo, for example, were naturally consuming an average of about 93 grams of protein daily (0.53 grams per pound of body weight) (Holweda, Nutr Physio Metab 2018).
Maintaining muscle and improving fat loss during dieting:
A study among obese young men found that giving extra protein during a 4-week period of dieting (40% fewer calories than normal) and intense exercise (6 days per week) caused them to lose more fat (2.9 lbs. more) and gain more muscle (2.4 lbs. more) than men to whom additional protein was not provided. All participants ate similar prepared meals and consumed 3 to 4 drinks per day of a dairy beverage which, for some, contained added whey protein isolate (about 34 extra grams per drink) but also less fat to offset the calories of the extra protein. Although the protein-supplemented group gained more muscle, their increase in strength was the same as that of the group receiving the lower amount of protein -- a finding which surprised the researchers (Longland, AJCN 2016).
Diabetes, blood sugar and insulin response:
A small, one-day study in people with type 2 diabetes found that drinking whey protein before a high glycemic meal resulted in improved insulin response compared to those who did not receive the protein. In the study, 15 men and women (whose diabetes was well controlled with the medications sulfonylurea or metformin) drank either 50 g whey protein (in 250 ml water) or plain water before a high glycemic meal. Over a three hour period following the meal, glucose levels were 28% lower, early insulin response was 96% higher, and overall insulin response was 105% higher after ingestion of whey protein compared to placebo (Jakubowicz, Diabetologia 2014).
A longer-term study of 30 men and women with type 2 diabetes in the U.K. found that following a very low calorie diet reversed diabetes (fasting plasma glucose fell below 7 mmol/L) in 40% of patients (87% if based on those who had been diabetic for less than four years). Participants in the study were taken off all antidiabetic medication and, for the first 8 weeks, consumed a very low calorie daily diet of just 3 shakes (OPTIFAST from Nestle -- which was not involved in the study) consisting of 43% carbohydrate, 34% protein, and 19.5% fat, and providing 624 kcal per day, as well as up to 240 grams of nonstarchy vegetables providing up to 76 additional kcal, and at least 2 liters of calorie-free beverages. Normal physical activity was maintained and one-to-one weekly counseling support was provided. Over the next two weeks, shakes were gradually replaced with solid foods and a diet providing adequate calories for weight maintenance. The reversal of diabetes was sustained for the next 6 months during which participants continued with an individualized weight maintenance diet and physical activity was encouraged. On average, participants lost 31 lbs. during the first 8 weeks and remained close to the lower weight for the duration of the study (Steven, Diabetes Care 2016). (Note: OPTIFAST in the UK differs from that in the U.S., having a higher fat concentration and serving size.)
Quality Concerns and What CL Tested for:
Neither the U.S. Food and Drug Administration (FDA), nor any other federal or state agency, routinely tests nutrition powders and drinks for quality prior to sale. Some labeling discrepancies can be spotted by calculating the expected calories in a product, based on the protein, fat and carbohydrate contents on the label and seeing if the total calories match the calories actually listed on the label (see ConsumerTips™). However, most problems, and the magnitude of such problems, can be determined only with laboratory testing.
As pointed out in an article in the Journal of Nutrition about the quality of protein supplements (Maughan, J of Nutr 2013), other potential issues include the absence of active ingredients, inclusion of unwanted or harmful substances, and poor manufacturing practices. The article cites ConsumerLab.com's 2010 review in which one protein powder was found to contain excess sugar and two were contaminated with lead -- which is always of concern with products made from plant-based materials or containing minerals. The article concludes that risks associated with protein powders can be reduced by using only products that have been tested by quality assurance programs such as ConsumerLab.com's.
Arsenic is a toxic heavy metal and known carcinogen which can damage organs. Arsenic contamination can be a concern with products made from rice, including protein powders made from rice. In 2012, FDA tests found arsenic levels in twelve rice protein supplements (product names were not provided) to range between 0.1 mcg and 5.7 mcg per serving (See the Warning for more about this.) The cancer-warning threshold of the State of California is 10 mcg of arsenic per daily serving, meaning that if someone consumed more than one serving of some of these products in one day, they could exceed this amount.
Several years ago, a quality concern specific to protein products was contamination with melamine. Melamine has been illegally used in place of protein in some products because it is cheaper than protein but can make poor quality or diluted material appear to be higher in protein by elevating the total nitrogen content detected by simple protein tests. Kidney stones, kidney failure and death were reported in 2007 and 2008 due to melamine used in place of protein in pet foods, milk, and infant formulas. However ConsumerLab.com's tests of protein products in 2010 did not find melamine in any products and no cases of melamine contamination have been reported in recent years. Consequently, products in the current review were not tested for melamine.
A study of contaminants in popular protein powders published in 2018 indicated that the majority contained detectable amounts of arsenic (83.5%), cadmium (73.7%), and lead (71.4%), and 28.6% contained mercury (Clean Label Project, 2018). Egg- and milk-based proteins contained the smallest amounts of metals. Review of the published data (which lacked product names) by ConsumerLab, however, showed that, based on a 35 gram serving, none of the 133 samples exceeded reasonable safety limits for arsenic or mercury, but 10 exceeded limits for cadmium and three for lead. The average detectable amount of cadmium per serving was only 1.6 mcg (well below the 4.1 mcg daily safe limit), but ten samples contained between 4.6 mcg and 10.7 mcg. In ConsumerLab's experience, elevated cadmium in protein powder tends to be due to chocolate flavoring with cocoa powder (a known source of cadmium), not the protein ingredient itself. The average detectable amount of lead was 0.66 mcg per 35 g serving (well below the 2.5 mcg safe limit applied by ConsumerLab), but four samples contained between 2.7 mcg and 4.3 mcg. Not surprisingly, "organic" products contained about twice the concentration of heavy metals as other products — an issue ConsumerLab has noted in its reviews over the years. Twenty-one percent of samples contained more than 3 mcg per serving of BPA (bisphenol A, which can leach from containers made of polycarbonate plastic), the limit for dermal contact in California without a label warning of potential reproductive harm to women.
To see which problems might exist with current protein/nutrition powders and drinks, and as part of its mission to independently evaluate products that affect health, wellness, and nutrition, ConsumerLab.com again purchased a variety of these products (see How Products were Evaluated). The products were first evaluated to make sure that their listed ingredients and claims were in compliance with FDA labeling regulations. Products were then tested for the accuracy of their label claims regarding total calories, total carbohydrates, total sugars, total protein, total fat (including a breakout of saturated fat and trans fat), sodium and cholesterol. Products that contain whole herb(s) and/or more than 250 mg of minerals daily were tested for lead, arsenic, cadmium and mercury. Products claiming to be gluten-free were tested for gluten levels. (For details, see Testing Methods and Passing Score).