Are You Sensitive to Lectins? (MTHFR)

Lectins are a type of protein found in especially high amounts in legumes and whole grains (especially wheat). You can read Joe’s SelfHacked articles on lectin sensitivity for a detailed explanation of this poorly understood food intolerance [R, R].

In brief, however, lectins can cause troublesome illness if they cross the gut barrier, enter the bloodstream, and trigger inflammation throughout the body [R].

Some people are more genetically susceptible to lectin sensitivity than others. If you have the rare ‘T’ allele at CNR1 rs1049353 and reduced MTHFR enzyme activity, you are at the greatest risk.

Symptoms of Lectin Sensitivity

Lectin sensitivity is a type of food sensitivity, and as such it may present with many of the same symptoms as other types of non-allergic or autoimmune-triggering intolerance. These include:

• Digestive problems: the most common symptoms of food sensitivity, these can present as bloating, nausea, diarrhea, and flatulence [R, R].
• Brain fog, which reduces mental sharpness and clarity, learning, memory, and concentration [R].
• Anxiety and depression: chronic inflammation decreases feelings of reward and motivation and increases sensitivity to perceived threats. In this way, inflammation can also worsen the symptoms of PTSD [R, R, R, R].
• Insomnia: people (and especially teenagers) with insomnia have more inflammation than people who get a healthy amount of sleep [R, R, R].
• Skin conditions: atopic dermatitis (eczema), rashes, and other symptoms of skin inflammation are common in food allergy and intolerance [R, R].

For more on the symptoms of lectin sensitivity, including Joe’s experience with his clients, check out this post.

The most common symptom of lectin sensitivity include gut problems, brain fog, anxiety, depression, insomnia, skin conditions, and fatigue.

How Can You Tell If You’re Sensitive?

Even if you experience all of the above symptoms, you may not be lectin sensitive; each one can result from a whole bunch of different triggers that might not even have to do with what you eat. Nevertheless, they’re a good jumping off point for you to start investigating the possibility of lectin sensitivity.

If you suffer from some or all of these symptoms, the next steps are:

1. Check your genes for markers of sensitivity and
2. Try a lectin avoidance diet.

Why is MTHFR Important?

The MTHFR gene codes for an enzyme known as methylenetetrahydrofolate reductase or MTHFR. This enzyme is central to folate metabolism, DNA production, and methylation pathways that are essential for all bodily functions [R].

Low MTHFR activity can lead to increased homocysteine, an inflammatory amino acid. Elevated homocysteine can wreak havoc on your health; it has been linked to cardiovascular disease, reduced brain function, and autoimmunity [R, R, R, R].

CNR1 may protect the gut barrier, while MTHFR is essential for cellular growth and division. Together, they may create a risky environment for lectin sensitivity to develop.

Important SNPs

MTHFR rs1801133:

• ‘G’ = Decreased risk of lectin sensitivity
• ‘A’ = Increased homocysteine, increased risk of lectin sensitivity

MTHFR rs1801131:

• ‘T’ = Decreased risk of lectin sensitivity
• ‘G’ = Increased homocysteine, increased risk of lectin sensitivity

MTHFR and Folate Metabolism

MTHFR has gotten a lot of attention in the last few years, and largely for good reason: this enzyme is absolutely necessary for cell growth and division, which implicates it in just about every process in the body [R].

Homocysteine is a toxic and inflammatory amino acid which builds up in people with low MTHFR activity (and, thus, low levels of methylfolate). High homocysteine can lead to oxidative stress and increased rates of cell death (apoptosis), which leads to tissue damage and immune dysfunction [R].

MTHFR and Autoimmunity

Of particular interest here is the connection between MTHFR and autoimmunity. A handful of studies have directly linked polymorphisms in this gene to autoimmune disorders like Graves’ disease and multiple sclerosis [R, R].

Risk alleles that reduce MTHFR activity cause an increase in homocysteine in the body. This inflammatory amino acid may be the reason why MTHFR is linked to autoimmunity: people with high homocysteine are  more likely to produce antibodies against their own proteins (autoantibodies), thereby triggering an autoimmune response [R, R].

MTHFR is also linked to autoimmune disease; increased homocysteine may encourage the formation of antibodies against “self” proteins.