Why Seasonal Allergies & Digestion Problems Often Go Together

Transcript:

Leah: Hello and welcome to “Ask a Nutritionist”, our weekly mini episode of Dishing Up Nutrition. I'm Leah Kleinschrodt, Registered and Licensed Dietitian with Nutritional Weight & Wellness. And today we're talking about something that a lot of people might have questions about. Why do seasonal allergies and digestive problems so often show up together?

Maybe every spring your nose gets stuffy, your eyes get itchy and watery, but you also notice more bloating, diarrhea or loose stool, nausea, reflux, upset stomach, or maybe during allergy season, your digestion just feels off. You're not imagining it. Your gut and your immune system, and by extension, your allergies, are deeply connected. And today we'll break down what causes this connection, how to manage symptoms, and how to support your gut to improve your allergy resilience overall.

What’s the connection between seasonal allergies & digestive symptoms?

So let's dive in. So first let's answer the question, “Can seasonal allergies be a contributor to your digestive problems?” The short answer is yes, absolutely. Seasonal allergies can contribute to digestive symptoms in several different ways. Some of those common GI symptoms, I mentioned them earlier, would be diarrhea, maybe actually constipation, bloating, gas, nausea, acid reflux.

And you might even notice that you seem a little bit more sensitive to some of the foods that you're eating. For some people, allergy season can even flare up other conditions like IBS or eczema, migraines, or even just kind of an overall fatigue. So what's happening? Why are allergies and digestion connected?

To understand this, where my brain goes, is we have to think about where our immune system lives. About 70 to 80% of your immune system lives in and around your gut. Your gut lining acts like a security barrier or border patrol. It helps decide what gets absorbed into the body, what stays out, and how strongly that immune system reacts to potential or actual threats around it.

So when seasonal allergies kick in, your immune system becomes more highly activated because now all these allergens are floating around in the air around us. Your body releases inflammatory chemicals like histamines, cytokines and mast cell mediators. And these chemicals don't just affect the nose and the eyes, they affect your entire body, so this can include your digestive tract.

And histamine is a big piece of this puzzle. Most people have kind of heard that term histamines before. It is one of the major chemicals that is involved in allergies. And so when pollen exposures rise, histamine levels rise also. And histamine can affect digestion in several ways. It can increase intestinal inflammation, speed up bowel movements.

So kind of thinking again more along the lines of diarrhea or loose stool, but it can also increase stomach acid, cause cramping, nausea, and just make the gut a little bit more sensitive overall. So that's why some people notice looser stools or an upset stomach on higher pollen days.

Another important factor is something called intestinal permeability, or more people might know it as leaky gut. So inflammation coming from stress, a poor diet overall, a host of different medications, infections, alcohol, or chronic allergies, over time these can kind of weaken that gut lining. Then when the gut barrier just becomes irritated, especially during that higher seasonal allergy time, the immune system reacts more easily.

Food sensitivities can increase, the histamine reactions can worsen, and inflammation becomes more widespread. So allergies can aggravate the gut, and an unhealthy gut can worsen allergies. It becomes kind of this vicious two-way cycle. You might find digestive changes also from post-nasal drip. This can apply to anybody, even if you don't have allergies.

When you have allergies, or say if you get a cold or something that irritates the sinuses anytime during the year, you can swallow that excess mucus from postnasal drip throughout both the day and the night. And this mucus contains inflammatory compounds and allergens.

So for some people, this also irritates the stomach, again, can cause nausea. You just might not have as much of an appetite. It can trigger loose stools, it can contribute to bloating. And especially in kids, this allergy-related mucus drainage can cause stomach aches or they might complain of more stomach aches when this is happening.

How to prepare for allergy season

So, how should you prepare your gut for allergy season? If you know allergy season is coming and those uncomfortable symptoms often follow, there are things you can do proactively. I like to think of allergy season preparation similar to cold and flu season preparation. The goal is to try to clear the slate, if you will, and just strengthen the immune system before that assault of all those pollens come in and the symptoms peak.

So here are some of the most effective strategies. First and foremost, I think about let's put as many resources as possible into our troops or into that border patrol that's at the front lines. Let's prioritize anti-inflammatory foods and focus on foods that own that immune system and support the gut lining.

So this is where we think about lots of vegetables for fibers and antioxidants, a good amount of protein from meats and seafood, eggs and dairy. We think about including some fruit and some whole food starches for good blood sugar balance, but also for more fiber and antioxidants. And then we round out the mix by including some real food fats. Think about butter, avocados, nuts and seeds, olive oil, things like that.

These foods provide nutrients that help regulate inflammation and they support immune balance. Then I think about: let's reduce the things that make our troops weak or deplete them of their resources. So this means reducing excess sugar and ultra-processed foods. Highly processed foods can worsen that gut inflammation and can worsen histamine reactions.

So think about highly processed foods as refined carbohydrates. This is like our cereals, pastas, breads, chips, pizza, pastries. This also means things like fast food, foods that are fried in refined oils like soybean and canola oils. And then also look for added sugars in all your ingredients lists, not just the foods that taste sweet. So you do have to think about your salad dressings, take a look at your condiments, check the yogurts, look at the pasta sauces, and more. Leave no stone unturned.

If you experience diarrhea tied with seasonal allergies, it can be from a histamine overload. Some people are very sensitive to high histamine foods during allergy season, so it may help to follow a lower histamine diet for at least a few weeks when those allergens are really high.

So high histamine foods, think about aged foods and drinks and condiments. So this would be things like alcohol, aged cheeses, processed meats like you would see on a charcuterie board, vinegar and mayo, bone broth, fermented foods, and unfortunately, even leftovers. The longer foods sit, the higher the histamine load tends to be with those foods.

So if you have leftovers that you want to save, but you're trying to avoid higher histamine foods, freeze them instead of refrigerating them and get them into the freezer as quickly as you can after that meal has been cooked. So temporarily reducing those foods during that peak allergy symptoms may help just calm those symptoms down.

It can also be helpful to focus on more gentle, easy to digest meals, especially when the gut is irritated. Simple meals are often best. So I like to think, especially as we move into spring allergy season, keep the soups and stews on the menu. It's not just for wintertime or for those cold days, but keep them well into the springtime.

Opt for meals that use more ground meats versus other cuts of meats. And think about using cooked vegetables versus raw vegetables where you can. And I'll also point out like make use of the variety of smoothie recipes that are on our website. Delicious, easy to digest, lots of different options for lots of different palate experiences.

Immune boosting supplements to help with gut health & immune regulation

So there are also some immune boosting supplements that I recommend to help with gut health and some of that allergy regulation. None of these will probably come as a surprise, but we do have to cover the basics. We have to think about vitamin D. We have to think about zinc, omega-3s, magnesium, vitamin C. Vitamin D in particular plays a huge role in immune balance. Low vitamin D levels are associated with increased allergy and immune dysfunction.

I like to recommend a supplement called D-Hist. It is a supplement made by Ortho Molecular. It's more of a natural antihistamine supplement rather than some of the over-the-counter medication options. And D-Hist contains quercetin, stinging nettles, bromelain, and N-Acetyl-Cysteine, which naturally help to lower histamine levels.

Another supplement that works really well, especially if your symptoms are more sinus related is called Sinatrol. This one is also by Ortho Molecular. It's a combination of botanicals formulated to help thin that mucus and just make sure that it still flows well and helps to kind of reduce that inflammation in those clogged sinuses.

It works pretty quickly and people tend to have good results with it. So if you know that you're prone to that springtime sinus infection, jump on this supplement early and continue during the worst part of the season.

How to heal the gut for immune resilience

So let's talk about the gut. How do you heal your gut for seasonal allergies? This really actually is more of a long-term goal. We don't just want to quiet symptoms temporarily. We want to improve immune resilience. And healing the gut is not just about one supplement or one quick fix. It's more about curating and creating this environment where the gut lining, the immune system, and the microbiome can function well again.

So, this includes some of those things I mentioned earlier. Focus on consistent nourishment. Your gut cells regenerate constantly, and they need a ton of nutrients in order to repair and replenish. This means eating enough protein so that we have those amino acids available to repair the gut. This means consuming nourishing, healthy fats, and getting essential vitamins and minerals from a variety of plant foods, mostly vegetables.

But can include some of those starchier carbohydrates and some of those fruits. Chronic gut irritation comes from excess alcohol, highly processed diets, chronic stress, food sensitivities, repeated antibiotic exposure, and so on. So wherever you can reduce those burdens, this is also over time going to significantly improve gut function.

Additional gut healing supplements that you may want to look at could be three to five grams of L-glutamine, a scoop of collagen powder, or three thousand to four thousand milligrams daily of omega-3 fatty acids. It is always helpful to get individualized guidance from a dietitian to find out what protocol works best for you.

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Wrapping it up

So, in wrapping up today's conversation, if you struggle with both seasonal allergies and digestive symptoms, there's likely a real connection happening inside the immune system and gut. The encouraging news is that supporting gut health and inflammation balance through lifestyle and nutrition can improve both digestion and allergy resilience over time.

These small, consistent habits matter more than overhauling or doing something extreme. And if symptoms are persistent or severe, working with a dietitian can help uncover maybe some underlying triggers that we haven't thought about.

And also just creating a personalized plan tailored for your situation. So I want to thank you so much for joining me today. If you found this information helpful, please pass it on to someone who could benefit from listening. And if you haven't joined our Facebook group yet to connect with other listeners and other dietitians, you can do so by searching Dishing Up Nutrition on Facebook. We hope to see you there. Have a great day.

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