inflammation & autoimmunity
CNR1

How to Tell if You’re Lectin Sensitive Using Your Genetic Data (CNR1)

Written by Jasmine Foster, BSc, BEd on August 19th, 2019
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Do you have inflammation, digestive problems, brain fog, migraines, or daytime fatigue that your doctor just can’t explain? If you have the risk allele in this unexpected gene, lectins may be responsible.

Why is CNR1 Important?

CNR1 codes for cannabinoid receptor 1 (CB1), which binds the cannabinoids in the brain, gut, and other tissues. SNPs in this gene can make you more or less susceptible to inflammatory bowel disease (IBD), and people with risk alleles are likely to have worse IBD than those without. This association suggests a role for CNR1 in maintaining the gut barrier and preventing harmful lectins from entering the bloodstream [RR].

CNR1 rs1049353 is also associated with:

  • Protection from stress [R]
  • Response to antidepressants [R]
  • Likelihood of becoming dependent on marijuana or alcohol [RR]
  • Fat deposition in obese people [RR]

Your Genetic Results for Sensitivity Risk

Important SNPs

CNR1 rs1049353:

  • ‘C’ = Decreased risk of lectin sensitivity
  • ‘T’ = Increased risk of lectin sensitivity

SNP Table

variant genotype frequency risk allele
rs1049353

 

How Does CNR1 Cause Problems?

Gut Inflammation

CNR1 rs1049353 has recently been linked to inflammatory bowel disease, or IBD. More specifically, the T allele at rs1049353 can make a person less susceptible to ulcerative colitis; it may also decrease the riks of developing Crohn’s disease before 40 years of age. Although this underactive variant protects from IBD, it may worsen the symptoms in people already suffering from this condition. A study in mice found that those lacking CNR1 had more severe colitis [R, R].

People with IBD tend to have increased intestinal permeability; that is, more compounds are able to cross from the intestine into the bloodstream. People with IBD also have immune systems which are more reactive to lectins; their antibodies may bind to lectin antigens that closely resemble human proteins, thereby triggering autoimmunity [R, R].

Meanwhile, a lectin avoidance diet reduced symptoms in 800 people with autoimmune diseases. No single study has connected all of these dots, but Joe’s observations of his clients strongly suggest that CNR1, inflammatory disease, and lectins are closely linked [R].

Variants of CNR1 may increase the severity of inflammatory bowel disease (IBD) and promote other forms of autoimmunity.

Adiponectin: the Missing Link

Animal and clinical studies suggest that cannabinoids (via CB1) impair fat burning and reduce adiponectin levels [R, R]. In a 305 subjects trial, those with rs1049353-T had higher adiponectin, compared with the "C" allele carriers [R].

Adiponectin has beneficial metabolic effects, but according to a recent paper, it may also be a marker of food sensitivity [R]. One possibility is that elevated adiponectin indicates lower CB1 activity, associated with gut inflammation and autoimmunity [R, R].

Possible Role of the Th1/Th17 response

The Th1 and Th17 responses are associated with food sensitivities, as well as with diggestive issues such as IBD and IBS. Their excessive activation produces too many cytokines, which cause inflammation in the gut. Moreover, an overactive immune system is more likely to attack not only foreign microbes, but also harmless food-based components [R, R, R, R, R].

Interestingly, research in animals and cells shows that the cannabinoids anandamide (which is naturally produced in the body), CBD, and THC suppress the Th1 and Th17 responses by activating both CB1 and CB2 receptors. Cannabinoids may be less effective in carriers of the underactive "T" variant at rs1049353 [R, R, R].

Recommendations

Diet

Lectin Avoidance Diet

A study of 800 autoimmune patients evaluated a diet with no grains, sprouted grains, pseudo-grains, beans and legumes, soy, peanuts, cashews, nightshades, melons and squashes, non-Southern European cow milk products (Casein A1), and grain/bean-fed animals.

Most of these patients got their TNF-alpha (an inflammatory molecule) levels reduced to normal after 6 months on this diet [R].

Joe has written extensively on his Lectin Avoidance Diet protocol, which he uses to manage his genetic sensitivity. Check out this deep dive into the theory behind the diet and this list of the best and worst foods for sensitive people for more information.

Reduce Gut Permeability & Inflammation

One of the best things you can do to reduce gut permeability and prevent lectins from entering your bloodstream is to eat resistant starch and other prebiotic foods. These will promote healthy gut flora that produce butyrate, which in turn nourishes your intestines [R, R, R].

Avoid Caffeinated Drinks

CB1 activity stimulates adenosine receptors and drops cAMP levels. Caffeine can partly reverse this by blocking adenosine receptors [R, R]. Coffee & tea consumption is associated with higher adiponectin levels [R]. In theory, this effect may further suppress your cannabinoid system and worsen food sensitivities. 

Caffeine can irritate the digestive system in higher doses. Coffee is among the most common symptom-triggering item in patients with IBS [R, R].

Consume More Healthy Fats

Omega-6 fatty acids can stimulate the cannabinoid system via the CB1 receptors [R]. Try to consume a variety of healthy, whole-food omega-6 sources such as nuts, seeds, eggs, soybean & avocado [R].

People with lectin and other food sensitivities often struggle to gain weight, so they may benefit from a higher intake of healthy fats. They deliver two times more calories per gram, compared with carbs and protein [R].

Lifestyle

Psychological stress decreases CB1 expression and weakens the gut barrier. As such, avoiding stress and taking up stress-busting hobbies like yoga or meditation can increase CB1 and help heal a leaky gut [R, R, R, R].

Moderate exercise increases the sensitivity of the CB1 cannabinoid receptor and strengthens the gut barrier as well [R, R].

Likewise, cold exposure stimulates the cannabinoid system [R, R].

Finally, vitamin D deficiency weakens the gut barrier in mice; make sure you get enough sunlight [R].

Supplements

DHA (as found in fish oil) and CBD oil increase CB1 expression and strengthen the gut barrier [R, R, R, R].

You can also improve the health of your gut flora (and, thus, your gut barrier) with butyrate, resistant starches, or probiotics (especially Lactobacillus species) [R, R, R].

Author photo
Jasmine Foster
BSc, BEd

Jasmine received her BS from McGill University and her BEd from Vancouver Island University.

Jasmine loves helping people understand their brains and bodies, a passion that grew out of her dual background in biology and education. From the chem lab to the classroom, everyone has the right to learn and make informed decisions about their health.

Disclaimer

The information on this website has not been evaluated by the Food & Drug Administration or any other official medical body. This information is presented for educational purposes only, and may not be used to diagnose or treat any illness or disease.

Also keep in mind that the “Risk Score” presented in this post is based only on a select number of SNPs, and therefore only represents a small portion of your total risk as an individual. Furthermore, these analyses are based primarily on associational studies, which do not necessarily imply causation. Finally, many other (non-genetic) factors can also play a significant role in the development of a disease or health condition — therefore, carrying any of the risk-associated genotypes discussed in this post does not necessarily mean you are at increased risk of developing a major health condition.

Always consult your doctor before acting on any information or recommendations discussed in this post — especially if you are pregnant, nursing, taking medication, or have been officially diagnosed with a medical condition.

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