Can Seasonal Allergies Spike Blood Sugar?

As we delightfully shed our winter coats for warmer weather, For some allergy sufferers, spring ushers in blooming trees, summer grasses, rye, and weeds. Cue the running nose, burning eyes, sneezing, and clogged sinuses. Managing ongoing allergy symptoms can be more cumbersome when you add glycemic control into the mix.

Much more than food can alter our blood sugar. Getting adequate sleep, consistent exercise, and managing stress all participate in inflammation and the immune system, which can disrupt glycemic control.

In this article, we will cover why this is, how to manage blood sugar levels during allergy season, and how your diet can help.

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The Link Between Allergies and Blood Sugar Levels

One of the key players in the allergy response is a tiny yet powerful molecule called histamine. Researchers discovered histamine in 1932 and have since documented its role in almost all physiologic functions. Histamine receptors are present in all bodily tissues but have the highest concentration in the lungs and immune cells, such as basophils and mast cells.

Histamine contributes to many things, such as:

• Anaphylactic reactions
• Itchy, painful rashes
• Acid reflux
• Runny noses
• Shortness of breath (bronchoconstriction) in asthma
• Headaches
• Memory lapses
• Sleep issues
• Inflammation

How Does Allergy Inflammation Impact Blood Sugar?

When someone comes in contact with a spring allergen, whether in the air or on their skin, the immune system frequently misinterprets this as a threat instead of a natural exposure.¹ Immune cells throughout the respiratory tract release large amounts of histamine into circulation, which triggers a cascade of inflammation. 

We can see the downstream effects of this inflammation when we experience the symptoms mentioned above. But how does this affect blood sugar?

Inflammation is a medical term that refers to a set of classic signs and symptoms that occur in response to tissue damage, environmental agents, trauma, overuse, or infection. In most ways, inflammation protects, repairs, and restores us. 

When triggered on a chronic basis, however, numerous studies have demonstrated how inflammation increases our risk of heart disease, impedes glycemic control, ages us faster, and increases our risk of cancer.

Allergies trigger many proteins within the inflammation cascade, such as:²

• Reactive oxygen radicals.
• Cytokines and chemokines that can cause fever.
• C reactive protein (CRP).
• Prostaglandins that play a role in swelling and pain.
• Transcription factors that alter how and which DNA is expressed.
• Other major immune cells.
• The hypothalamus-pituitary-adrenal axis (HPA) that regulates the production and secretion of cortisol.

<p class="pro-tip"><strong>Also Read: </strong><a href=ways-to-reduce-inflammation>How to Reduce Inflammation</a>.</p>

Inflammation Causes Cortisol Levels to Rise

All of these molecules ultimately activate the body’s stress hormone called cortisol. Cortisol has many healthy functions; without it, we could not survive. It keeps our blood pressure at high enough levels to perfuse the heart and brain, keeps many of our organs in good working order, and facilitates the synthesis of many other important hormones. 

Similar to inflammation, when cortisol levels are chronically high, however, this has harmful effects on people with diabetes.

Cortisol receptors exist in every organ, specifically our liver, muscle cells, adipose (fat) tissue, and pancreas. Glucocorticoids (cortisol) play a pivotal role in metabolizing glucose, proteins, and fat.³

At high levels, cortisol:

• Stimulates the liver to release stored glycogen as sugar into the bloodstream.
• Increases the availability of blood glucose to the brain.
• Increases feelings of fear, arousal, heart rate, and respiratory rate.
• Decreases the amount of blood sugar that muscles absorb and causes muscles to break down protein instead.
• Causes the pancreas to decrease insulin secretion and increase glucagon secretion.
• Causes lipodystrophy, which is the process whereby the body redistributes fat to the face and neck and decreases the amount of fat stored in our arms and legs.

Chronically High Cortisol Can Lead to High Blood Sugar

All of this can ultimately lead to high blood sugar levels—or hyperglycemia. When we live day to day with high amounts of stress and poor sleep, this also activates the HPA axis to release more cortisol.³

<p class="pro-tip"><strong>Learn about </strong> <a href="/blog/weight-immune-system">how your weight can affect your immune system</a>.</p>

So, Seasonal Allergies Can Result in Blood Sugar Spikes?

Yes! Seasonal allergies can spike blood sugar. Allergic reactions cause inflammation. Inflammation causes cortisol to rise. High cortisol levels lead to decreased insulin sensitivity and glucagon stores to be released. This results in blood sugar spikes.

This cycle—outlined in detail above—is easily triggered and can be difficult to manage. When I explain the science to patients, I like to use the following analogy:

Seasonal allergies (by way of inflammation and cortisol) and blood sugar levels resemble a spinning merry-go-round. At the right speed, everyone has fun safely. When the merry-go-round spins out of control, it takes an enormous amount of force, energy, and medication to abruptly stop it.

So, how can we better balance blood sugar levels during allergy season?

Allergy Medications and Type 2 Diabetes

Thankfully, many medications have been developed to combat the release of histamine, which can bump your blood sugar by way of cortisol and inflammation.

All of these medications are available over the counter without a prescription. If you take many medications, it’s always a safe precaution to discuss the polypharmacy with your pharmacist the next time you pick up a medication refill.

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1. First-Generation Antihistamines

First-generation antihistamine medications are small enough to cross the blood-brain barrier. This is why common side effects include drowsiness, brain fog, and poor short-term memory. First-generation antihistamines are contra-indicated in anyone over the age of 65 or with memory/neurologic disorders. Examples of first-generation antihistamines include:

• Diphenhydramine (Benadryl)
• Brompheniramine (Children’s Dimetapp Cold)
• Doxylamine (Vicks Nyquil, Tylenol Cold, and Cough)

2. Second-Generation Antihistamines

Second-generation antihistamines were created out of an abundance of need to avoid feeling drowsy. Examples include:

• Fexofenadine (Allegra)
• Loratadine (Claritin)
• Cetirizine (Zyrtec)

3. Decongestants

While antihistamines address the root cause of the allergy, decongestants are sometimes used to provide quick relief from symptoms and help dry out the nasal passages. The problem with decongestants is that they may also raise blood sugar and have other unwanted side effects like insomnia or anxiety. 

If you choose to use a decongestant, make sure to discuss it with your healthcare provider.

4. Corticosteroids

Corticosteroids are available as nasal sprays and in oral form. Nasal sprays are often used to relieve congestion and irritation from allergic rhinitis, but oral or inhaled corticosteroids aren’t typically a first-line treatment for allergies and are reserved for severe allergic reactions, asthma, or when the body needs extra help bringing down inflammation. 

These medications work by suppressing the immune response, but they also raise blood glucose levels. If you have type 1 diabetes or type 2 diabetes and take insulin (or other medications to lower blood sugar), make sure to talk to your doctor before using corticosteroids.

5. Eye Drops

Eye drops can relieve itchy, red, and watery eyes. Some eye drops contain antihistamines in the solution, and others contain steroids that could raise blood sugar. Be sure to check with a pharmacist if you are unsure which is the best choice.

What Should I Eat When I Have Seasonal Allergies?

Some are more likely to indulge in sugary or carbohydrate-rich foods as a way to comfort. This only serves to worsen glycemic control and should be avoided. I recommend reaching for the following foods:

• Berries such as blueberries that contain vitamin K1, vitamin C, and flavonoids.
• Ginger has proven antioxidative and anti-inflammatory phytochemical properties.
• Grab foods high in protein, moderate in fat, and low in sugar to follow a ketogenic diet.
• Bee pollen.
• Foods high in Vitamin C, such as citrus fruits.

6 Tips for Diabetes Management During Allergy Season

Diabetes care takes a holistic approach, and there are multiple ways you can keep your blood sugar at a healthy range. From lifestyle approaches to specialized interventions, here are six tips to consider:

• Refresh Your Respiratory Allergy Panel: As we age, our sensitivity to various pollens can change. I recommend that patients have a thorough respiratory allergy panel repeated every 5 to 10 years if they have ongoing moderate to severe reactions to seasonal allergies. If possible, try to avoid these exposures.‍
• Consider Sublingual Drop Therapy: Many allergy clinics now offer sublingual drop therapy as a remedy for seasonal allergies. Treatment involves consuming tiny amounts of the allergen in a drop several times a day.

Over the course of 3-5 years, a pharmacist will slowly increase your dose until you no longer have a reaction to the allergens. This is called desensitization therapy. The treatment time may feel long, but for a lifetime free of allergies, this is certainly worth it!

• Keep Tabs on Local Pollen Loads: I recommend using the following website and app to track the pollen load in your area:

• Pollen.com
• My Pollen Forecast

Depending on the time of year and the pollen load in the air, you may not require medication year-round. Medications usually take a few days before they kick in and must be taken every day to see the maximum benefit. Frequently missing doses and taking them inconsistently is like trying to stop the spinning inflammation merry-go-round half-heartedly.

• Use a Continuous Glucose Monitor (Cgm) to Monitor Your Blood Sugar: Signos offers a CGM plus an AI-powered app that tracks your glucose—and provides recommendations—in real-time. Knowing your blood sugar levels throughout the day can help you achieve—and maintain—optimal health, which can include insights into whether or not your allergy treatment plan is effective. ‍
• Consider Following an Anti-inflammatory Diet: An anti-inflammatory diet can help reduce overall inflammation levels in the body. Some research suggests that anti-inflammatory diet patterns like the Mediterranean diet may reduce the prevalence of allergies and asthma.

Anti-inflammatory diets are rich in foods like fruits (especially berries), vegetables, olive oil, spices, nuts, seeds, and whole grains.

• Try Vitamins or Herbs to Regulate Your Blood Sugar Levels: For those who wish to avoid medication, here are excellent vitamin and supplement alternatives that have been clinically proven to help:

• Quercetin
• Vitamin C
• Butterbur

Albeit popular, stinging nettle and bromelain need more robust clinical studies before being routinely recommended.

Conclusion

Almost everyone develops an allergy at some point in life, but it doesn’t have to derail your stress response, inflammation, and blood sugar. By treating your allergies before the merry-go-round develops momentum, you can keep your blood sugar in check and enjoy the wonderful things Spring has to offer. Now, get outside and soak in those flowers.

<p class="pro-tip"><strong>Learn More: </strong><a href=benefits-stable-glucose>Benefits of Stable Blood Sugar: How to Reap and Keep Them</a>.</p>