bag of organic hemp seeds

Can You Have a Hemp Seed Allergy? Watch For These Symptoms

[toc]Note: This article is about hemp seeds (the food) which are legal in the US and Canada, since they do not contain THC. This article is not about marijuana or recreational drugs.

When it comes to bona fide peanut allergy, all reputable studies peg the prevalence at only 0.6-1% of the population. The superfood known as jungle peanuts (which is the same species) falls within that category, too.

Admittedly that rate could be underestimated, but even if you tripled or quadrupled it, you’re still talking about only 1 out of 25 people who have a problem with this legume (yes, peanuts are actually a legume and not a nut). Whatever the case, it’s definitely a low number.

Yet it seems like half the people you meet claim to be allergic to peanuts.

But when it comes to hemp hearts, you never hear anyone claim that. Literally, never.

raw peanuts with red skinIs there hypocrisy going on here? Can you be allergic to hemp seeds, milk, or oil?

While peanuts may be exaggerated, the opposite problem seems to be happening with the hemp protein allergy.

Yes, it’s possible

First of all, what is a food allergy anyway?

It’s an autoimmune response to a protein/pollen in something you eat. Your body misidentifies a harmless substance as a threat and goes berserk trying to stop it.

How berserk (or not) the reaction is can vary greatly.

For some, it may be side effects which are more of a nuisance. For others, it could lead to life threatening anaphylactic shock.

Epipen boxIn theory at least, you could be allergic to any food. However because it is the proteins and pollen which we are allergic to, those foods with the highest amounts have become the focus versus something like an apple.

It’s possible to be allergic to an apple, but it has no pollen and so little protein content, any reaction may be too muted to even be detectable.

Now hemp is a rich source of protein, so on that basis alone, it deserves the same scrutiny as other seeds, nuts, grains, milk and eggs. Because if you are allergic to hemp, you’re consuming a lot of that plant’s protein whenever you eat it.

There are 10 grams of protein per 170 calorie serving. That’s 1 ounce of hemp hearts, which is about 3 tablespoons worth.

That’s an even higher amount of protein than what’s found in peanuts – 8 grams for the same weight – so it definitely warrants investigation.

Plus, hemp comes from an extra-allergen part of the Cannabis sativa plant; the flowering buds atop the plant. That means they come in contact with pollen. However since food sources are gathered from crops containing 0.3% or less of THC, they are 100% legal and do not produce any mind altering side effects.

What prompted this topic?

This topic didn’t come up randomly. Rather, it was because one person at Superfoodly has experienced hemp allergy symptoms as “as long as I can remember” whenever he ate the seeds.

The reaction is by no means severe, but it’s the exact same symptom – in a much milder version – as what happens if he eats a cashew. That’s a tree nut he’s highly allergic to.

A specific area in his throat under his Adam’s apple would become itchy and also trigger asthmatic symptoms. He does have asthma regardless, but only cashews would cause that specific area in his throat to react. Not his asthma or any other foods could cause that type of reaction… until hemp came along.

He says the adverse reaction from hemp is a far cry from the magnitude experienced with cashews. Those are a definite allergen for him; medically diagnosed with testing and obviously apparent.

With hemp, the itchy and asthmatic side effects are not enough for him to forego it completely. However he does minimize consumption and stays away from concentrated sources, like hemp protein and heaping raw hulled hearts on oatmeal or salads.

photo of Kind Strong bar showing hemp and pea crisps

For most processed products – like the Kind protein bar pictured above – they love to hype up the hemp it contains, but in reality it’s very little.

Those balls which many people assume are seeds actually are “pea crisp” (pea protein isolate, rice flour, rice starch).

It seems that the Kind Strong bars sprinkle the seeds in there more for marketing purposes, rather than as a primary ingredient. He still eats products like that on occasion, usually with no noticeable reaction.

Is there an allergy test for hemp seeds? A standardized extract for doctors to use “off the shelf” doesn’t exist. You definitely won’t find it within a standard skin prick panel, which tests up to 40 of the more common allergens at once, such as peanuts and cat dander.

That being said, an allergist can still check using a custom test. Though outside of medical studies (discussed below) we haven’t heard of anyone doing that. The person here with the suspected allergy says for him “it’s not bad enough to bother.”

What the research says

Some websites promoting the plant claim that allergies to hemp do not exist.

That simply is not true.

In a 2015 edition of the Annals of Allergy, Asthma and Immunology, they published a piece of research titled: Cannabis sativa: the unconventional “weed” allergen (1).

Fast forwarding to the first sentence of the paper’s conclusion, this sums up the situation quite well:

“Although still relatively uncommon, allergic disease associated with C. sativa [hemp plant] exposure and use has been reported with increased frequency.”

While you’re certainly not expected to know what the following compounds are, we’re listing here the actual things cited as the probable allergens in the plant:

  • Delta-9-tetrahydrocannabinol (THC, the psychoactive agent)
  • Ribulose-1,5-biphosphonate carboxylase/oxygenase (RuBisCO)
  • Thaumatin-like protein
  • Oxygen-evolving enhancer protein 2
  • Nonspecific lipid transfer protein (Can s 3)

So there you have it… not only does it exist, but researchers have even been able to hone in on exactly what compounds in the plant are responsible.

Which parts are most allergic?

While you can be allergic to any part of a plant, as mentioned the worst offenders tend to be the parts which have the most protein and/or pollen.

Since the seeds check both of those boxes, they are a prime culprit.

pouring oil out of bottleHemp oil allergies would be unlikely – refined oil is 100% fat, which is not an allergen. It would be the 0.01% or less of other stuff contaminating it that you could have a reaction too… which is an exponentially lower concentration than what you get when you eat the seeds!

That’s why in Canada, for example, enhanced allergen labeling isn’t required when a food oil is highly refined. Tree nut, fish, soybean, and sesame oils are not required to have that type of warning (2). Only peanut oil requires it. They say this…

“The very low levels of protein present within highly refined oil are not considered, based on the available science, to pose a risk to the health of individuals with food allergies.”

If you know someone who eats the hearts without problem, but claims to be allergic to hemp oil… to be frank, they’re probably delusional. At least if you’re talking about the typical food grade oil that’s refined and sold in a bottle.

allergic skin reaction of hives and itchingBeing allergic to hemp lotion and experiencing hives isn’t that unusual of complaint. If unrefined oil (or lightly refined) is used in skin care products, then it would contain more of the problematic compounds. However, a hives reaction is more likely caused by one or more of the other ingredients in the lotion.

What is hemp milk made from? The hearts are ground to a fine powder and diluted with water. Any chunky residue is then strained, leaving you with a plant-based milk.

For that reason, having a hemp milk allergy would be expected if you have reactions from eating the seed.

Side effects of a hemp allergy

hempseed allergy test results
Immunoblotting showing IgE binding to a 6-kd protein in the extract of raw hulled and roasted unhulled hempseed, which was consumed by a patient who experienced anaphylactic shock.

An allergy manifests itself differently depending upon the person’s unique biology. Those allergic to eating hemp may experience one or more of the following side effects:

  • asthma – difficulty breathing (dyspnea), chest tightness, and abnormal spirometric results (from a lung function test)
  • allergic rhinitis – nasal congestion, runny nose, sneezing
  • hives – skin rash, pale red bumps or plaques
  • eye irritation – itchiness, swelling, puffiness
  • conjunctivitis – pink eye, bloodshot eyes
  • anaphylaxis – anaphylaxis from ingested hempseed has been confirmed (3)

How common is it?

It might not be as rare as people make it out to be.

Before even getting into the science, we can tell you that since first reporting on this, we have received an overwhelming number of comments from people who either suffered a reaction themselves or had someone close to them experience it. Sure, some cases may be circumstantial, but many sound like they legitimately have reason to be confident that it was the hemp which caused it.

Considering the “new” found use of it as a food source, within two to three decades it may very well become a major food allergen in the same league as tree nuts and other common culprits.

A study in 2011 looked at 340 patients, 140 of which who were inhalation users with asthmatic symptoms (4). Among them:

  • 53.2% (74 people) had a positive skin prick test to the leaf extract of cannabis
  • 34.3% (48 people) has a positive serum specific IgE test

How about all of us who only eat hemp seed, do we have anything to worry about?

antique postcard showing hemp field in Kentucky

Even in the United States, environmental exposure of pollen does occur, especially in more rural areas where the plant may still be found growing wild. It used to grow freely throughout the country. The antique postcard pictured above shows a field of it growing in Kentucky, but that was back when a stamp costed a penny.

In a 1983 study, an allergy doctor practicing in Arizona and New Mexico tested 129 patients by skin for both hemp pollen and tobacco leaf (5).

The results? 250% higher rate of allergic reactions to hemp pollen versus tobacco (63 and 18 patients, respectively).

A 2009 study done in India found that 8.3% of patients who had a nasobronchial allergy tested positive in a cannabis skin prick test (6). That was more than double the rate for animal dander at 3.1%, but inline with pollens overall at 7.8%.

Worse yet, if one develops an allergy to the cannabis plant, there is evidence to suggest that it might lead to cross-reactivity and the development of other food allergies.

The Journal of Allergy and Clinical Immunology reported how a 28 year old smoker developed progressively worse allergy symptoms from inhalation, which was believed to cause (7):

“Without previous food allergies, the patient went on to develop urticaria [hives] to peach peel, food pollen syndrome to several foods (apple, almonds, eggplant, and chestnut), and anaphylaxis to tomato, pepper, and fig. Immunoblotting identified a 9-kDa lipid transfer protein (LTP), speculated as the reason for cross-reactivity and development of his food allergies.”

Regarding tomato, there appears to be some sort of connection. In the 2011 study mentioned earlier, those who were sensitive to tomato had:

  • 92% positive readings for cannabis skin prick tests
  • 68% positive for serum IGE tests

Giving up this plant as a dietary source would be no problem for most people. But how tragic would it be if it led to cross-reactivity with tomato, triggering an allergy to that too? Some of us here at Superfoodly would rather die than give up pizza for the rest of our lives!

Should you be worried?

The evidence seems to suggest the bigger problem may be for the people who are smoking it, not eating it.

It appears the smokers are the ones who are developing higher rates of being allergic to the plant.

For those who only eat hemp seeds and/or are environmentally exposed to the plant’s pollen in the air, the prevalence of problematic side effects seems to be quite minimal.

Yes, even for those who were not noted for inhalation, some studies have shown a relatively high percentage of positives on skin tests. However as the Asthma and Allergy Foundation of America says (8):

“A positive test result for food allergy is not, in and of itself, diagnostic for food allergy.”

The Food Allergy Center at the University of Michigan describes diagnosis this way (9):

“By itself, the positive result just indicates that your body has made allergic antibodies, called IgE, to a specific food.   This is called “sensitization,” and by itself is not enough for a diagnosis. Your allergist will use your medical history, a physical exam and his own specialized training to interpret your results.”

Since not many people experience any noticeable side effects from eating hemp, it may be thatTHC which is the most problematic allergen in the plant. As it is the THC content which is the major difference between the drug and the legal food source of plant seeds.

Alternatives if you have symptoms

If you think you have reactions from eating the seeds, then compare hemp vs. whey vs. pea vs. rice. vs. pumpkin protein. Maybe one of those others is a better fit for you.

As far as alternatives nuts and seeds to use on your food, it’s hard to beat the health benefits of pistachios which most people don’t know about.