Are protein powders safe?
The following article from a Kaplan Univ Professor is probably the most concise and clear article I came across for this question
Protein Supplements: The Good, The Bad, and & The Ugly...
It was not until my older brother asked me a couple of weekends ago whether protein supplements were safe for consumption that I became interested in researching for this article. My brother is a well-built man in his early 40s who eats right and exercises regularly, besides running around after my 2-year-old niece. Protein supplements cannot hurt, right?
Grocery and health food stores are packed with a variety of protein supplements, mostly carrying pictures of buff, tan men on their labels. Maybe my brother wants to look like one of these men, but I am a gal in my 30s and I certainly do not want to have a big pair of python arms and giant, muscular thighs. People all around the world spend billions of dollars on nutrition, or-as they are often called-"ergogenic aids" (from the Greek ergon, meaning work). These substances can allegedly "enhance athletic performance, decrease fatigue, change body composition, and improve looks."
Commercial protein supplements may consist of whey, casein, soy, egg albumin, goat or cow milk, wheat, beef, pea, hemp, or brown rice. Protein supplements can be in the form of isolates (a pure protein source), concentrates (which are not as pure as the isolate form), hydrolysates (which are chemically and/or enzymatically digested resulting in a product that is quickly absorbed), and blends (a combination of various protein sources and purity levels). Supplements can be in the form of ready-to- drink shakes, bars, bites, oats, and gels and powders, and come in a variety of flavors. What follows is a review of the scientific literature on the good, the bad ,and the ugly regarding protein supplements.
Proteins have an overall benefit on physical activity and on overall health. In a study with healthy male US Marines, "the protein supplemented group had an average of 33% fewer total medical visits, 28% fewer visits due to bacterial/viral infections, 37% fewer visits due to muscle/joint problems, and 83% fewer visits due to heat exhaustion" than the control, unsupplemented group.
Furthermore, protein may help reduce blood pressure. A protein mixture, consisting of 20% pea, 20% soy, 30% egg, and 30% milk-protein isolate, reduced systolic and diastolic blood pressure in overweight individuals (BMI = 25-35). This research suggests that protein intake might help manage blood pressure and prevent complications associated with elevated blood pressure.
Animal and human studies have shown that soy protein consumption is beneficial to cardiovascular health. The consumption of soy protein can lower triglyceride levels as well as total and LDL cholesterol levels, and increases HDL levels and HDL/LDL ratios.
While an optimal soy protein intake is in the range of 15 to 20 g/day, an intake of 25 g/day of soy protein can be specifically used to reduce cholesterol levels.
Furthermore, supplementation with soy protein can help reduce the markers of prostate cancer development, such as the prostate-specific antigen (PSA), "in patients with prostate cancer or in men at high risk for developing advanced prostate cancer."
Whey proteins have the capacity to modulate adiposity, enhance immune function and anti-oxidant activity, and improve cardiovascular health.
Furthermore, whey protein appears to have a blood glucose and/or insulin lowering effect. Some clinical studies have also shown that taking whey protein in combination with strength training can increase lean body mass, strength, and muscle size.
Under the Dietary Supplement Health and Education Act of 1994 (DSHEA), protein supplements, like any other supplement, are not regulated by the Food and Drug Administration (FDA). This means that supplement manufacturers do not need to register their products with FDA and they do not need FDA approval before producing or selling dietary supplements.
Unfortunately, this lack of a regulation might result in products with contaminants, as it occurred in 2010 with two protein supplements containing unwanted levels of lead, cadmium, mercury, and arsenic.
The recommended daily intake of protein for healthy adults is 0.75 g of protein/kg body weight, which translates into approximately 45 to 56 g of protein a day.
The daily intake for adult athletes is about 1.5 g/kg body weight, with a range of 1-2 g/kg body weight.
But excessive protein intakes can cause a buildup of ketones bodies. When there is an excessive accumulation of ketone bodies, an abnormal but not necessarily harmful state called ketosis results. With progressively higher levels of ketone bodies, the body's pH is lowered to dangerously acidic levels, leading to a state called ketoacidosis. As your kidneys rid your body of these toxic ketones, you can lose a significant amount of water, which puts you at risk of dehydration, particularly if you exercise heavily. And dehydration from a ketogenic diet can make you feel weak and dizzy, give you bad breath, and lead to other health problems.
While there is no evidence that high protein intake per se would be detrimental for bone mass, it appears reasonable to avoid high protein diets (i.e., more than 2 g/kg body weight/day) when associated with low calcium intake (i.e., less than 600 mg/day).
According to an article in the Journal of Nutrition:
Excessive soy intake has been reported to be responsible for the development of goiter, including thyroid enlargement, in both iodine-deficient rodents and infants fed soy-flour–based formula without iodine fortification. Animals fed a soy diet require almost twice as much iodine compared with animals not fed soy. . . [Studies] suggest that intake of soy may reduce the efficiency of thyroid hormone function and that soybeans may contain goitrogens that can interfere with the utilization of iodine or functioning of the thyroid gland and cause thyroid problems. However, it appears that the consumption of soy could cause goiter only in animals or humans consuming diets marginally adequate in iodine or who were predisposed to develop goiter, and in most cases dietary supplementation with adequate iodine can reverse the disorders.
Protein supplements for a healthy, noncompetitive adult who participates in recreational sports are usually not warranted.
If you are an active person, chances are you do not need a protein supplement and using one will be counterproductive because of the extra calories (remember, 1 gram of protein provides as many kilocalories as 1 gram of sugar!). Athletes and vegetarians are special populations that may require supplements. Athletes, especially those who train with weights and burn a significant amount of calories from cardiovascular and aerobic training, may require additional supplementation. However, their need for extra protein could be easily obtained through the diet, thereby negating the use of protein supplements.
Vegetarian diets are often very low in protein and supplementation may be appropriate.
Therefore, my brother does not need to consume any protein supplements. As far as I know, he won't be participating in the Olympic Games any time soon unless, of course, running after energetic toddlers becomes a new sport sensation.
Paz Etcheverry, Ph.D.
Paz Etcheverry is an adjunct professor at Kaplan University's School of Health Sciences. Paz received her Bachelor of Science in Food Science at Cornell University in Ithaca, New York, and her Master of Science in Food Science and Nutrition at North Carolina State University in Raleigh, North Carolina. She then pursued a PhD in Food Technology with minors in nutrition and biochemistry at Cornell University. Currently, she is a research instructor at Baylor College of Medicine in Houston, Texas, and a member of the American Society for Nutrition.