Every year, when summer comes around, my allergies tend to get worse.
I’m sure sweating and exposure to sunlight play a role, but I also wonder if other factors are involved—for example, food may oxidize more easily in hot, humid weather, while bacteria and mold can multiply more easily.
There may also be physiological mechanisms within the body that are related to the changes I experience.
After more than 15 years of paying close attention to my body and the foods I eat, I’ve gradually learned which foods seem to make me feel better when I avoid them.
So today, I’d like to share my 20 Foods That Tend to Worsen My Allergies in Summer!
These are simply things I’ve noticed through my own experience, but I hope some of them might be useful to you.
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20 Foods That Tend to Worsen My Allergies in Summer
1. Oils
(except organic extra-virgin coconut oil)
This is something I avoid year-round.
For me, it’s like adding fuel to a fire—the inflammation associated with my allergies seems to flare up very quickly.
I’ve tried many different types of oils, production methods, and brands, but so far, the only one that seems to work well for me is organic extra-virgin coconut oil.
I sometimes drizzle it over rice without heating it.
I usually have about 1–2 teaspoons a day.
I also get fats from foods such as ground sesame seeds.
2. Meat
I sometimes eat small amounts of chicken during the winter.
However, from spring through autumn, when temperatures are higher, I tend to develop eczema and find that I can’t eat meat.
Meat from four-legged animals, such as beef and pork, makes me especially itchy, so I almost never eat it year-round.
Even antibiotic-free and grass-fed meat didn’t work for me.
During summer, my main sources of protein are small fish such as shirasu (whitebait) and dried sardines, as well as natto.
As I’ll explain below, I also tend to react to fish larger than dried sardines.
I find that I feel much better during summer when I minimize animal-based foods as much as possible.
3. Fish and Seafood That Isn’t Very Fresh, or Seafood Treated with Chlorine
People often say that oily fish is good for allergies, but in my experience, this only seems to apply when the fish is exceptionally fresh.
Mackerel, horse mackerel, and sardines, for example, can develop higher levels of histamine as their freshness declines, so I’m especially careful with them.
I also feel that other types of seafood can lose freshness more easily during the distribution and sales process in summer.
In addition, seafood that is sold as fillets or served at restaurants may be treated with chlorine as a food-safety measure.
I seem to react to the chlorine as well, so I generally avoid seafood during the summer.
4. Foods Containing Certain Metals
I’m allergic to several types of metal.
One metal that I can unknowingly take in through food is aluminum.
When I eat foods prepared with aluminum cookware, foods containing alum—such as sea urchin or pickled eggplant—or foods containing certain aluminum-based red colorings, I can end up suffering from eczema for about a week.
In my experience, reactions to metals tend to cause eczema on the front of my body and seem to linger for quite a while.
Perhaps it simply takes time for the body to eliminate them.
5. Eggs
Eggs cause more than just eczema for me.
I can suffer from severe fatigue and difficulty breathing for three or four days afterward.
It’s especially frustrating because I love eggs, but I try not to eat them year-round.
6. Dairy Products
I feel that, for me, it may be less of a burden on my body not to consume dairy products regularly.
Fresh milk doesn’t seem to cause much eczema, but I feel that it may upset my gut. If I drink it repeatedly, my fingertips start becoming dry and rough.
Once that happens, I feel more prone to allergic reactions to other foods as well.
Yogurt and cheese tend to make me itchy.
7. Wheat
When I eat wheat, I tend to feel sluggish, and my skin becomes more irritated.
I’ve had the same reaction to homemade bread, noodles, and savory pancakes made with organic wheat grown in Japan.
When I feel like eating noodles, I usually have organic brown rice vermicelli instead.
I’ve wondered whether ancient varieties of wheat might work better for me, but they’re difficult to find, so I haven’t tried them yet.
8. Certain Starchy Vegetables
(except taro, Chinese yam, and Japanese yam)
I wonder if sweet potatoes have become sweeter in recent years, because eating them seems to make me feel irritable.
At one point, I kept a food diary and discovered that I had eaten sweet potatoes every single time before getting into an argument with a family member.
Potatoes and even chestnuts seemed to have a similar pattern.
I’ve wondered whether foods high in sugar might contribute not only to allergic symptoms, but also to irritability and arguments.
9. Soybeans, Adzuki Beans, and Peas
I discovered my delayed reaction to soybeans two years ago.
I hadn’t been feeling well for some time and had a sense that “something wasn’t right.” A blood test eventually showed that I had a soy allergy.
This was quite a shock because I had relied on tofu and other soy products as convenient sources of protein.
I also showed allergic reactions to other legumes, including adzuki beans and peas.
After stopping these foods, I felt that my overall condition improved.
Legumes are excellent sources of protein, but I wonder whether some of them may be harder for certain people to digest and may trigger reactions more easily.
One saving grace was that I didn’t seem to react to fermented soy foods such as miso, soy sauce, and natto.
I can eat these regularly without noticing much of an effect.
10. Fruit
This one is particularly disappointing because I love fruit.
But when I eat it repeatedly, I tend to develop eczema.
One possibility I consider is the pesticides commonly used on fruit.
I’m especially careful with fruit that is eaten with the skin on, such as cherries, strawberries, and muscat grapes.
But even pesticide-free fruit didn’t necessarily solve the problem for me.
Fruit has become dramatically sweeter in recent years, and I wonder whether its higher sugar content may be contributing to allergic inflammation in my case.
I’ve also heard that sugar can promote the growth of Candida in the body, and that Candida may be related to allergies.
Summer is a season when microorganisms can multiply easily in nature, and I wonder if something similar may happen inside our bodies, which are also part of nature.
I suspect that these microorganisms may be one factor contributing to my increased allergy symptoms.
11. Sugar and Sweet Foods in General
Here we go.
For someone like me, who used to be addicted to sweets, this has been the hardest one.
With so many restrictions on what I could eat, I desperately wanted to find some kind of sweet treat I could enjoy.
So I’ve experimented with all sorts of things:
Honey, amazake, agave syrup, maple syrup, dried fruit, brown sugar, beet sugar, monk fruit, sugar alcohols…
I tried every trick I could think of to find something that would make me say, “Yes! This one works!”
Unfortunately, though, my body doesn’t seem to feel very good after eating things that taste sweet.
As I mentioned in the section on fruit, I suspect that one reason may be changes in my gut environment.
There may also be other factors, such as inflammation triggered by sugar, changes in the body’s acid-base balance, effects on cells, or hormonal changes associated with blood sugar levels.
I know all of this…
But still, I want to eat sweets! 😂
There is one exception, though.
Pumpkin.
Pumpkin is sweet, but I don’t seem to notice much of a reaction to it.
As long as I don’t eat too much, a moderate amount seems to be fine.
In our household, we treasure pumpkin as a little miracle food. 😂
12. Alcohol
I used to enjoy wine, sake, and other alcoholic drinks.
But even a small amount can give me a headache and make me feel nauseous, so I hardly drink anymore.
It also seems to upset my digestive system and make me more prone to allergic reactions.
13. Spicy and Irritating Foods
Spicy foods and strong seasonings tend to make me itchy.
I often crave curry in summer, but recently I’ve started reacting to the ginger in curry powder.
When that happens, I can feel extremely tired and short of breath for several days.
I’ve had the same reaction to herbal medicines containing ginger. In traditional Japanese herbal medicine, ginger is called shōkyō.
In general, I try to be careful with strongly stimulating foods because they seem to trigger itching and can also upset my digestive system.
I do sometimes use a small amount of black pepper to add flavor to vegetable soup.
14. Cold Foods and Drinks
When it’s hot outside, I naturally crave cold foods and drinks, but I try not to have too much of them.
I feel that cooling my digestive system makes it work less efficiently, while at the same time causing heat to build up in my upper body.
For me, I think the keys to managing my allergies are supporting digestion and helping excess heat escape from the body.
15. Additives and Pesticides
When I consume food additives, I may start coughing, feel sluggish, and experience more active allergy symptoms.
Just as pollen and house dust can act as triggers, I feel that certain substances can act like a switch that activates allergic symptoms throughout my body.
For that reason, I try to avoid processed foods that may contain additives, as well as eating out, as much as possible.
I also used to think that pesticides were probably fine as long as I washed my food well.
But when I started choosing pesticide-free foods as much as possible, my chronic headaches disappeared, which really surprised me.
I felt as though I’d shifted up a gear in terms of my energy, and it made me realize how much I had felt run-down when eating foods treated with pesticides.
I understand that growing crops is hard work, and I don’t think it’s fair to simply label pesticides as “bad.”
Still, I feel that living in harmony with nature can be kinder both to the environment and to our bodies.
16. Imported Foods Such as Coffee, Nuts, and Cacao
Many imported foods are transported by ship, and pesticides or other treatments may be used during transportation to help prevent mold from developing.
Because transportation takes time, the food isn’t necessarily at its freshest when it reaches us, either.
Japan’s Ministry of Health, Labour and Welfare publishes examples of violations found during inspections of imported foods.
Examples include pesticide-related violations involving vegetables, E. coli in processed foods, and mycotoxins in nuts and dried fruit.
Thanks to modern distribution systems, we can enjoy a huge variety of foods from around the world.
At the same time, I think it’s worth remembering that foods traveling long distances can also come with risks that aren’t always visible to us.
17. Foods Prone to Mold Contamination
As with some imported foods, I feel that certain foods may carry a higher risk of mycotoxin contamination.
These include grains such as wheat and corn, legumes, nuts, dried fruit, and spices.
I’ve also heard that mycotoxins can sometimes be detected in livestock or milk from animals that have consumed contaminated feed.
Apples can also be susceptible to contamination by a mycotoxin called patulin, particularly in processed products.
18. Oxidized Foods
One surprising reaction I’ve had was to rice and nukazuke—vegetables pickled in rice bran.
I suspect it may have been related to the oxidation of the oils in the rice bran.
There was a time when I believed brown rice and nukazuke were especially healthy and ate them regularly.
But during summer, I didn’t feel good after eating them, so I stopped.
I switched to pre-washed rice, started storing it in the refrigerator, and made a point of eating rice within one month of milling.
I’ve been feeling better since then.
In general, I also try to avoid foods that aren’t very fresh.
Whenever possible, I choose the freshest food I can.
19. Vegetables with Strong “Astringency”
(such as eggplant)
I don’t feel very good if I eat too much of these, so I try to keep the amount moderate.
Perhaps they’re simply a little too stimulating for my body.
The substances we commonly refer to as “astringency” can include what are sometimes called antinutrients, which may interfere with nutrient absorption.
I don’t think there’s any need to become overly concerned about them, but I do try not to consume too much.
20. Foods That Test Positive for Delayed Allergic Reactions
This is something you can’t really know without taking a blood test.
I suspect that most people probably have some foods to which they have delayed reactions.
However, foods that we eat frequently can sometimes show up as positive, while we may also experience an allergic reaction to a food despite a negative test result.
So I don’t think test results are absolute.
If you’re not experiencing any particular symptoms, I don’t think there’s necessarily a reason to worry about them.
In my case, I was struggling with ongoing unexplained health problems when a blood test revealed a delayed reaction to soy.
After eliminating soy, my condition improved.
I don’t think I would have been able to figure that out on my own, so I’m glad I took the test.
That said, eliminating foods based solely on test results can potentially lead to nutritional imbalances, so it may be a good idea to consult a specialist first.
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That Was My “20 Foods That Tend to Worsen My Allergies in Summer”
When Subjective Observations Add Up
After 15 years, I’ve become so accustomed to instinctively avoiding foods that don’t agree with me that I was actually surprised to see how long this list became when I wrote it all down.
I feel that identifying the foods that don’t work for me has played a very important role in improving my allergies.
Looking at this list, you might think my diet sounds extremely restrictive or overly cautious.
But this way of eating has naturally developed through years of paying attention to my body, day after day.
At this point, it almost feels like second nature.
Ultimately, I’ve simply been pursuing what feels good to me.
There have been times when I’ve wondered, “What could anyone possibly learn from such a personal example?”
But I’ve also come to think that when subjective observations accumulate over many years, they can become valuable data in their own right.
By combining personal observations like these with scientific, medical, and traditional knowledge, perhaps we can discover practical insights that are genuinely useful for people living in the modern world.
You Don’t Have to Aim for Perfection
Please take the 20 items on this list simply as:
“Oh, interesting. Apparently this is what works for her.” 😂
The reason I say that is because what works for one person’s body may be completely different from what works for another’s.
And some of my own assumptions could be wrong, too.
I wrote this article simply hoping that it might offer a few ideas for anyone who is trying to understand their own body.
I don’t think there is one “right answer” that works for everyone.
Each of us has to keep searching for our own answer.
And I don’t think we need to avoid every single thing that doesn’t agree with our bodies, either.
I certainly don’t manage to avoid everything.
Sometimes I eat something anyway and call it “food for the soul.” 😂
I think that’s important, too.
Once you know that something doesn’t agree with you, you can make adjustments to how much you eat, how often you eat it, and what you do afterward.
No matter how hard we try to be perfect, it will only ever be the version of perfection created by one small human mind.
There are countless things we don’t know about the human body, society, and the natural world.
And when we try too hard to be perfect, our minds gradually become closed off and life starts to feel suffocating.
When that happens, our bodies may suffer, too.
I think it’s useful to have a certain amount of knowledge, but rather than aiming for perfection, it’s important to find a balance between our mind and body.
We make mistakes, listen to the voices of our minds and bodies, and practice learning what works for us.
Along the way, we discover all kinds of new things and learn from them.
These days, I’m hoping to keep walking this path patiently, one step at a time.
Thank you so much for reading all the way to the end. 😊
I hope this article gives you even a small idea that might be helpful!