Protein powders, a rich protein source, are used by fitness enthusiasts to help them build muscle and increase strength. Research has also found there are added benefits for certain proteins like whey, which are used extensively in powders retailed in the market. For instance, whey protein is believed to be antibacterial, antiviral, antihypertensive, antioxidant, hypolipidemic, and possibly even has antitumor properties.1 Unfortunately, protein powders are not without their side effects. Knowing the side effects of different kinds of powders can help you minimize potential problems.
Side Effects If You Have Too Much
Remember, just having too much of a protein powder could cause problems for you. Stick to the prescribed amount and follow preparation instructions properly. Having a couple of scoops a day is usually fine for those who are heavily engaged in sports or physical training. Have too much and you will be taking in more protein than you need. You then end up experiencing a range of digestive side effects from nausea and cramps to flatulence and diarrhea. If you have pre-existing health issues like kidney or liver disease, cardiovascular disease, or diabetes, check with your doctor about whether it is safe for you to have protein powder and in what quantities.
Lactose Intolerance To Whey-Based Protein Powder
Lactose, the sugar found in milk products and milk, is also present in whey-based protein powders. If you have lactose intolerance and consume protein powder that contains lactose, you are likely to experience digestive symptoms. You may experience bloating or flatulence, or have a bout of diarrhea – just as you would after you consume milk/milk products. Abdominal pain and nausea may also affect you.2 If you’re lactose intolerant, you could try lactose-free protein powders to avoid these side effects.
Intestinal Discomfort And Flatulence From Pea Protein Powder
If you have lactose intolerance or are vegan, you are likely on pea protein powder. But you should know that, while rare, it is possible to be sensitive to pea protein too. Specifically, the oligosaccharides – carbohydrate molecules found in pea protein extracts – can cause flatulence and intestinal discomfort. However, a process called ultrafiltration can be done to reduce levels of oligosaccharides and, consequently, side effects too.3 Look for protein powders of this category if you do experience these side effects.
Endocrine Disruption From Soy Protein Powder
Phytoestrogens like the isoflavones found in soy protein can disrupt hormonal balance in the body. They could either reduce estrogen activity because they block the actual estrogen in the body from binding. Or they could cause an increase in estrogen activity when the isoflavones in the soy protein activate your body’s receptors. This disrupts your body’s own internal regulation of the endocrine system.4
There have also been reports suggesting that soy protein could cause fertility problems, specifically impacting the fertility of women. Animal studies seem to indicate a connection, and some experts are already concerned about the effect of having a lot of soy protein on humans.5
Upset Stomach From Sweeteners In Protein Powders
Most protein powders contain sweeteners of some form to make them more palatable. Always check what kind of sugar or sweetener is used in your go-to protein powder. Sugar alcohols like maltitol and sorbitol, as well as isolated fructose, can cause stomach upsets if they don’t agree with you. Excessive consumption of sorbitol, in particular, is known to produce a laxative effect and can cause watery stools.6
Gut Microbiota Imbalance From Sweeteners In Protein Powders
Regularly consuming very highly sweetened protein powders could disrupt the careful balance of gut flora. Research has shown that continuously exposing your system to either fructose or sugar substitute can reduce the diversity of gut microbiota. This in turn can potentially compromise immunity as well.7 If you are alright with consuming a few extra calories, you may be better off having an unsweetened protein powder with whole fruit or even honey to add flavor.
Toxic Waste Buildup Due To Excess Protein In Liver Disease Patients
If your liver is badly damaged, healthcare professionals advise against consuming too much protein. While small amounts through food may be fine, loading up on protein in the form of protein powders may not be wise. With a damaged liver, proteins aren’t processed properly. Which means harmful toxic waste products could build up in your body.8 Whether or not you are better off avoiding protein powders or can have them in moderation will depend on your medical history and is best decided in consultation with your doctor.
Heavy Metal Toxicity From Certain Protein Powders
An investigation into samples of various brands of protein powders revealed that trace amounts of toxic heavy metals were present in each of the varieties tested. The heavy metals found included lead, mercury, arsenic, and cadmium. All of these can cause a range of side effects including constipation, fatigue, muscular and joint pain, as well as headaches. Trace amounts of these potentially toxic metals, while not ideal, would still be passable if consumed in small amounts within the daily exposure limits. Unfortunately, just three servings a day of some protein powders would cause you to exceed maximum permissible daily exposure limits for lead, cadmium, and arsenic. And that’s reason enough to be cautious.9
Risk Of Cancer, Diabetes, And Heart Disease: Is There A Connection To Protein Powders?
High intake of phytoestrogens in soy protein powder may be linked to increased risk of breast cancer. Animal studies have found that soy isoflavones can cause breast cancer tumors to grow.10 However, human studies are limited at best. Which is why it may be better to wait for more conclusive studies before worrying on this front. You could still cut down consumption of soy proteins as a precaution or use a protein powder made from an alternative source.
Some research does indicate that milk proteins could contribute to Type 1 diabetes. In addition, because these powders do contain saturated fats and cholesterol, they may also be linked to an increased risk of heart disease. Further research is needed before widespread recommendations can be made on avoiding or allowing the use of these powders in this context. But considering the composition of the powders and the potential issues from the fat and milk proteins, you may want to moderate intake or consult a doctor if you are at risk of or already diagnosed with any of these conditions.11
|↑1||Keri Marshall, N. D. “Therapeutic applications of whey protein.” Alternative Medicine Review 9, no. 2 (2004): 136-156.|
|↑2||Lactose Intolerance. The National Institute of Diabetes and Digestive and Kidney Diseases.|
|↑3||Fredrikson, Mattias, Pierre Biot, Marie Larsson Alminger, Nils-Gunnar Carlsson, and Ann-Sofie Sandberg. “Production process for high-quality pea-protein isolate with low content of oligosaccharides and phytate.” Journal of agricultural and food chemistry 49, no. 3 (2001): 1208-1212.|
|↑4||Hwang, Chang Sun, Ho Seok Kwak, Hwa Jae Lim, Su Hee Lee, Young Soon Kang, Tae Boo Choe, Hor Gil Hur, and Ki Ok Han. “Isoflavone metabolites and their in vitro dual functions: they can act as an estrogenic agonist or antagonist depending on the estrogen concentration.” The Journal of steroid biochemistry and molecular biology 101, no. 4 (2006): 246-253.|
|↑5||Could Eating Too Much Soy Be Bad for You? Scientific American.|
|↑6, ↑7||Payne, A. N., C. Chassard, and C. Lacroix. “Gut microbial adaptation to dietary consumption of fructose, artificial sweeteners and sugar alcohols: implications for host–microbe interactions contributing to obesity.” obesity reviews 13, no. 9 (2012): 799-809.|
|↑8||Diet – liver disease. U.S. National Library of Medicine.|
|↑9||Health risks of protein drinks. Consumer Reports.|
|↑10||Allred, Clinton D., Kimberly F. Allred, Young H. Ju, Suzanne M. Virant, and William G. Helferich. “Soy diets containing varying amounts of genistein stimulate growth of estrogen-dependent (MCF-7) tumors in a dose-dependent manner.” Cancer research 61, no. 13 (2001): 5045-5050.|
|↑11||Casein Protein for Sports & Fitness. University of Michigan Health System.|