How Safe are Plant Protein Powders?
By Dr. Roopa Chari, M.D.
What are Plant Protein Powders?
Most plant protein powders come from plants (such as soybeans, peas, rice, hemp, potatoes or pumpkin seeds), eggs or milk (including casein or whey protein). The amount of protein per scoop can vary from 10 to 30 grams. Supplements used for building muscle usually contain more protein and supplements used for weight loss contain less protein.
Overall, there are three main processes to turn the types of plants mentioned above into a protein powder:
1. High heat
There are different processes that use high temperature to make protein powder from plants. The problem is the heat destroys the healthy nutrients in the plant and ultimately makes it difficult for your body to digest.
With most soy protein and some other plant products, hexane is used to remove oil from the plants. The problem is that hexane is a chemical neurotoxin that comes from petroleum which can harm your central nervous system.
3. Enzyme processes
Ideally the plant seeds have first been sprouted. Then natural enzymes are added to these plant seeds to remove the protein. This is the best and least processed way to remove the protein from plants and at the same time helps to preserve the most nutrients in the plant.
However, even if you find a plant protein powder that uses the enzyme process, there are still other problems with some plant protein powders that could be harmful to your health.
This problem is other ingredients that have been added to the protein powder.
Some of the protein powders actually contain highly-processed ingredients which includes:
1. "Natural" (artificial) flavors
It is common to find "natural flavors" on so many food labels nowadays. The FDA states that as long as the ingredient originated from a natural source, it can be labeled as a "natural flavor". However, food manufacturers are allowed to add harmful chemicals to their “natural” flavors (which we unfortunately are not aware of).
These are flavoring agents that food manufacturers add to their products to enhance the taste. In addition to their original source for the flavor, these mixtures can contain more than 100 different chemicals, which includes solvents, preservatives and other substances.
Natural flavors are highly processed and contain many chemical additives. "Natural flavors" are not very different from artificial flavors in terms of their chemical composition and the effects on our health.
Some of the ingredients which can be in "natural flavors" include:
- GMO (Genetically Modified Organisms)
- Polypropylene glycol (this is in antifreeze)
- BHA (carcinogen)
2. Soy lecithin and sunflower lecithin (thickeners)
These food additives are used to help thicken protein powders (and other foods). The main issue is that soy lecithin comes from soybean oil which is usually GMO (unless it says “organic” or “non-GMO verified”). On top of this it is extracted from raw soybeans with a chemical solvent such as hexane, and is then both dried and bleached.
Maltodextrin is a food additive that is highly processed and usually is made from genetically modified (GMO) corn. This is used to make mixing the product easier.
The sugar in the ingredients can come from GMO corn and includes what you see on the labels such as fructose, sweeteners, concentrate, juice and syrup. Or artificial sweeteners may be used such as Aspartame (Equal, NutraSweet), Sucralose (Splenda) and Saccharin (Sweet 'N Low).
In addition, in 2018, a nonprofit group called the Clean Label Project released a report about toxins in protein powders. The researchers screened 134 products for 130 types of toxins and found that many protein powders contained heavy metals (lead, arsenic, cadmium, and mercury), bisphenol-A (BPA, which is used to make plastic), pesticides, or other contaminants with links to cancer and other health conditions1.
There were significant levels of some toxins and one protein powder contained 25 times the allowed limit of BPA.
The reason some protein powders contained so many contaminants was from the manufacturing processes we discussed earlier or toxins present in the soil (absorbed by plants that are made into protein powders).
However, not all of the protein powders that were tested had elevated levels of toxins. Please see the results at the Clean Label Project's website (www.cleanlabelproject.org).
Types of Protein powder:
In general, proteins are made of amino acids and there are nine amino acids that are essential in our diets to make a complete protein. However, protein from plant foods can be low in one or more of these nine amino acids.
However, research shows that as long as you eat a variety of protein sources throughout the day, it’s not necessary to consume complete proteins in each meal.
Today we will focus on pea protein powder. Pea protein powder is increasing in popularity and is derived from yellow split peas. Even though the Pea protein contains all of the essential amino acids, the problem with pea protein is that like soy, it contains both lectins and phytates which can limit the absorption of both minerals and protein.
Also, while extracting the protein, some of nutrients in the dry peas may also be removed. In general, split peas contain the nutrients folate, potassium and magnesium. However, labels do not show how much of the nutrients are actually retained in the pea protein powder.
However, isolated pea protein is also missing the important carbohydrate compounds in the pea which can support healthy gut bacteria which helps to decrease inflammation in the body.
In addition, some brands, are high in sodium, (up to 330 mg per scoop). Please read the nutrition facts labels and if you use protein powders, look for brands that have less than 120 mg. of sodium.
If you have a history of gout, pea protein may not be a good source of protein in your diet. The reason is split peas are a source of purines, which can increase the amount of uric acid in your blood which can then lead to a flare up of gout. The University of Pittsburgh Medical Center recommends limiting your intake of legumes (this includes split peas), to two 1/2 cup servings a week (which is approximately 1 1/2 scoops of pea protein powder a week).
What I have personally seen in my practice is that pea protein is causing digestive problems in some of my patients including bloating, gas and constipation or diarrhea along with inflammation. Please discuss nutritional and dietary recommendations with your doctor.
Many years ago, my family and I have stopped using protein powders. Instead for my patients, I highly recommend eating 3 balanced meals a day with whole foods that have good sources of protein, carbs and healthy fats instead of food substitutes.
Plant Based Protein Sources and Extraction (lupinepublishers.com)
Clean Protein or Toxic Blend? The Truth About Protein Powder (cleanlabelproject.org)
The hidden dangers of protein powders - Harvard Health
Pea Protein Side Effects (livestrong.com)
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