Hemp protein's nutty flavor, as well as its fiber, minerals and healthy fats, makes it a boon to power-packed shakes, smoothies and bowls. The risk of hemp protein side effects is low, but some people may be allergic, and its high fiber and mineral contents could be problematic in large doses.
Hemp Protein Powder Facts
The hemp protein powder you find on your store shelves is made from protein-rich hemp seeds from the Cannabis sativa plant. Yes, that's cannabis, but not the cannabis you might be thinking of. Although hemp seed and marijuana are both part of the Cannabis sativa species, they are different varieties with different chemical makeups, according to the Congressional Research Service.
Hemp protein powder is made from whole hemp seeds that that have been pressed to separate the oil and then milled to a fine particle size. Different grades of hemp protein powder may be produced during this process, with each grade differing in protein content and additional nutritional variables, reports the Food and Drug Administration.
Hemp protein powders may contain between 14 and 20 grams of protein per 32-gram serving. One serving also has 125 to 140 calories, 5 to 12 grams of carbohydrates and 3 to 6 grams of fat. The carbohydrates in hemp seed protein are primarily dietary fiber, with one serving providing 3 to 8 grams. The higher the protein content, the lower the fiber content.
The majority of the fat in hemp seeds is polyunsaturated fat, a healthy fat from plant foods that can improve heart health when consumed in place of saturated fats. Additionally, hemp protein powder is a rich source of minerals, including iron, potassium, magnesium, zinc and copper.
Hemp Seed Allergy
Most people can enhance their daily nutrition by adding hemp to a smoothie or a bowl of oatmeal without any hemp protein side effects, besides potentially improved health. But for people with Cannabis sativa allergies, the dietary addition can be dangerous. Although relatively uncommon, reports of allergic reactions to hemp have become more frequent, according to a research review published in the March 2015 volume of the Annals of Allergy, Asthma & Immunology.
Although some foods are known for being common allergens, such as nuts and shellfish, any food can potentially cause an allergic reaction in a susceptible person. Common food allergy symptoms include:
- Nasal congestion
- Difficulty breathing
- Tingling or itchy mouth
- Swelling of lips, tongue, throat, face or other areas of the body
- Abdominal pain
- Nausea and vomiting
- Dizziness, lightheadedness or fainting
One of the rare dangers of hemp allergy is anaphylaxis, a severe immune response that can be life-threatening. Signs of anaphylaxis include:
- Tightening of the airways
- Swollen throat, or the sensation of a lump in the throat that makes breathing difficult
- Shock and a dramatic drop in blood pressure
- Rapid pulse
- Dizziness and lightheadedness
- Loss of consciousness
If you develop any symptoms of anaphylaxis after eating hemp protein powder, you should seek emergency medical attention immediately.
Excess Fiber Side Effects
A more benign, and potentially more common, hemp protein side effect is digestive upset caused by excess fiber intake. Fiber is crucial in a healthy diet, helping to promote healthy bowel movements, lower cholesterol, regulate blood sugar, control weight, and prevent constipation and intestinal cancer, according to the Cleveland Clinic; however, too much of it at one time can cause bloating, cramping, gas and constipation.
One serving contains as much as 8 grams of fiber, which is 32 percent of the recommended daily intake for women and 21 percent of the recommended intake for men, according to the Food and Nutrition Board of the National Academies of Medicine. While this isn't an extraordinary amount, if you have more than one serving at a time, or if you combine hemp protein powder with other fiber-rich foods, such as oatmeal or fruits and vegetables in a smoothie, you could be getting a bigger dose than you planned.
Additionally, if you haven't previously been eating a lot of fiber, even a single serving could cause digestive distress if your body simply isn't used to it. To avoid these unwanted effects, increase your intake gradually over time and stick to a single serving, unless you know your body is able to handle more.
Excess Mineral Intakes
Hemp protein powder is an especially rich source of the minerals iron and copper; as such, there is a risk of side effects and toxicity when consumed in large amounts. The Food and Nutrition Board has set a tolerable upper intake level (UL) for iron of 45 milligrams per day for all adults. One brand of hemp protein powder provides 7.5 milligrams of iron per serving. If you stick to one serving, you don't have to worry; but having six servings per day would put you right at the UL.
At this intake level, you could potentially experience stomach upset, constipation, nausea, abdominal pain, vomiting and faintness. However, the risk of excess iron side effects from protein powder is much lower than from iron pills, because it is ingested along with other macronutrients that help buffer its impact on the GI system, according to the National Institutes of Health (NIH).
One serving of hemp protein powder also provides close to 100 percent of the daily recommended intake of copper for men and women. NIH reports that copper toxicity is rare, but that chronic excessive intake could lead to liver damage and abdominal pain, cramps, nausea, diarrhea and vomiting.
With 0.8 milligrams of copper per serving in some hemp protein powders, you'd have to ingest a lot of the supplement to approach the UL of 10 milligrams daily; however, it's not that uncommon for people to take large doses of supplements for long periods of time.
Dangers of Hemp Supplements
All protein powders are considered supplements, and the FDA doesn't regulate them in the same way as foods. Because of this, you can't always trust that what's on the label is actually in the supplement, warns Harvard Health Publishing. A supplement may contain added sugars, artificial ingredients or other allergenic ingredients that are not easily detectable by the consumer. In some cases, protein powders may even contain toxic chemicals, Harvard reports.
In 2018, the Clean Label Project tested 134 protein powder supplements and found that 70 percent of the products had detectable levels of lead, 74 percent contained cadmium and 55 percent contained bisphenol-A, or BPA. One of the protein powders tested contained 25 times the allowed regulatory limit of BPA in one serving.
The study also revealed that plant protein supplements tested worse than animal-derived protein powders, and that 75 percent of the plant-based protein powders tested positive for lead. According to the Clean Label Project, this is the result of a combination of manufacturing processes and the existence of toxins in the soil in which the plants are grown.
- Congressional Research Service: "Defining Hemp: A Fact Sheet"
- FDA: "The Safety and the Generally Recognized as Safe (GRAS) Status of the Proposed Use of Hemp Protein Powder in Human Food"
- USDA: " Full Report (All Nutrients): 45332735, Hemp Protein Powder, UPC: 039978006035"
- MedlinePlus: "Facts About Polyunsaturated Fats"
- Annals of Allergy, Asthma & Immunology: "Cannabis sativa: The Unconventional “Weed” Allergen"
- Mayo Clinic: "Food Allergy"
- Cleveland Clinic: "Improving Your Health With Fiber"
- National Academies of Medicine: "Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids"
- NIH: "Iron"
- Harvard Health Publishing: "The Hidden Dangers of Protein Powders"
- Clean Label Project: "2018 Protein Powder Study"
- Clean Label Project: "Frequently Asked Questions"
- Manitoba Harvest Foods: "Hemp Yeah! Max Protein"