Do Histamine Symptoms Worsen in Summer?

The relationship between symptoms related to histamine release and summer is primarily explained by several reasons such as:

• The increase in exposure to allergens

• Insect bites

• Heat

• Changes in diet

These factors increase the activity of mast cells, the cells responsible for histamine release in the body.

Summer Allergies

In summer, the increase in environmental allergens can lead to greater mast cell activation. This activation is an immune response to allergens and results in the release of histamine and other chemicals that cause allergic symptoms.

Some key points on how heat and other summer-related factors influence allergies:

• Increased pollen: During summer, many plants, especially grasses, release large amounts of pollen into the air. Pollen is a major trigger for seasonal allergies. Warm and dry temperatures can intensify pollen production, thus prolonging the allergy season.
• Mold growth: High temperatures and humidity create an environment conducive to mold growth, another common allergen. Mold can grow indoors and outdoors, especially in damp areas like basements and bathrooms, increasing exposure to its spores.
• Dust mites: These microscopic allergens thrive in warm and humid conditions. During summer, increased humidity in the air can raise the number of dust mites in the home, aggravating allergic reactions.
• Air pollution: Summer often brings higher levels of air pollution due to factors like dust particles. Air pollution can worsen allergy symptoms, especially in urban areas.
• Insect bites: During summer months, insects like mosquitoes, bees, and wasps are more active.

Summer allergies can manifest through a variety of symptoms, including:

• Sneezing

• Nasals congestion or discharge

• Watery and itchy eyes

• Coughing

• Fatigue

• Headaches

• Wheezing

• Rashes

• Difficulty breathing

Strategies to Control Summer Allergies

• Stay indoors during peak pollen hours, usually early in the morning and late in the evening.
• Use allergen-proof mattress and pillow covers, wash bedding regularly with hot water, and vacuum frequently using a HEPA filter vacuum cleaner.
• Use dehumidifiers to keep indoor humidity levels below 50% and ensure good ventilation in damp areas like bathrooms and kitchens to prevent mold growth.

Heat

Heat can increase stress and stress leads to histamine release.

The body works harder to dissipate heat through sweating, which can lead to feelings of exhaustion and increased physical stress.

High temperatures can disrupt restorative sleep, causing insomnia or interrupted sleep. Lack of quality sleep is a known factor contributing to increased stress and irritability.

Heat increases the risk of dehydration. Dehydration can affect mood, cognitive ability, and increase anxiety and stress levels.

Extreme heat can make people feel more irritable, impatient, and prone to negative emotional reactions, which can increase the feeling of stress.

High temperatures can limit daily activities and the ability to perform physical and mental tasks. This can cause an increase in stress levels, especially if it affects work or daily responsibilities.

Strategies to Mitigate Heat Stress

• Drink plenty of water throughout the day to stay hydrated.
• Wear breathable, light-colored clothing to help maintain a lower body temperature.
• Engage in outdoor physical activities during cooler parts of the day, such as early morning or evening.
• Maintain a proper sleep routine and use methods to cool the sleeping environment, such as fans or cooling mattresses.

Changes in Diet

In summer, during vacation periods, some people tend to “skip their diet,” not considering that one should not skip any diet but maintain a healthy lifestyle year-round, with fresh and minimally processed foods.

Some people change their eating habits just because they are on vacation, indulging in buffets or eating out, choosing different dishes “taking advantage of the vacation,” which stresses their digestive system.

It may also happen that people with histamine intolerance “relax” a bit during the vacation period, either due to being in another place or due to increased social encounters. The dosage and frequency of this flexibility in eating can have consequences during or after the vacation. Eating excessive amounts or frequently consuming high-histamine foods for those with intolerance or inflammatory bowel diseases or any health condition requiring DAO enzyme inhibitors may cause symptoms related to histaminosis.

Enjoying vacations is important, but maintaining health is crucial.

Conscious and responsible flexibility regarding possible consequences is key.

For this, it is important to keep in mind that:

• It is essential not to abandon healthy eating habits during vacations.
• Excessive consumption beyond needs (overloading plates at buffets) can stress the digestive system.
• There is not enough scientific evidence to ensure a beneficial dose from alcohol consumption.
• You can enjoy meals while avoiding excesses or foods that might cause discomfort.

Food Poisoning

On the other hand, food poisoning is also common in summer.

Heat promotes the development of pathogenic bacteria on foods.

Most of these can grow at temperatures between 5°C and 45°C approximately, but they develop more easily and quickly if the temperature is high, 25°C-40°C.

Why does histamine form in foods?

Histamine formation in foods depends on four main factors:

Histidine content: precursor to histamine.
Bacterial enzymes: transform histidine into histamine.
Temperature and pH conditions: high temperature and low pH favor its formation.
Hygienic handling: poor hygiene in food handling and delays in refrigeration increase its formation.

Refrigeration at temperatures below 4ºC minimizes histamine formation. However, once formed, histamine cannot be eliminated through cooking, pasteurization, sterilization, refrigeration, or freezing. Additionally, its presence does not significantly alter the appearance, color, or texture of the food.

Foods Associated with Histamine Poisoning

The foods most frequently associated with histamine poisoning are certain fish with high histidine content, such as: tuna, mackerel, bonito, sardine, or anchovy.

It can also form in fermented products like cheese, wine, and beer, though poisoning from these foods is less common.

Frequency of Histamine Poisoning

In the EU, in 2020, 43 outbreaks of histamine poisoning were reported with 183 cases and 17 hospitalizations. In Spain, the same year, four outbreaks were reported. However, as it is not a notifiable disease and is often confused with allergies, the actual number of cases may be higher.

Symptoms of Histamine Poisoning

Symptoms appear within minutes to a few hours after ingesting the food and are similar to an allergic reaction:

• Itching and burning in the tongue and throat

• Redness and swelling of the face and neck

• Hot flashes

• Hives

• Headache and dizziness

• Abdominal pain, nausea, vomiting, and diarrhea

Symptoms are usually mild and resolve within a few hours. Some individuals, due to genetic intolerances, medications, or digestive diseases, may show symptoms even with normal histamine levels in foods; in such cases, a personalized study is needed.

Measures to Control Histamine in Foods

Food companies are responsible for preventing histamine formation in their products. EU legislation imposes strict requirements on temperature conditions and histamine limits in fish. Good hygiene practices and programs to control histamine throughout the food chain are implemented.

Authorities conduct inspections, audits, and sample analyses to ensure food safety.

Recommendations for Consumers

To avoid histamine poisoning, especially when buying fish:

• Keep the cold chain with insulated bags.
• Refrigerate or freeze the fish immediately upon arriving home.
• Keep the fish refrigerated below 4ºC until preparation and cook as soon as possible, not leaving it more than 24 hours in the refrigerator.
• Do not defrost at room temperature. Defrost in the refrigerator.
• Practice good kitchen hygiene as a habit: wash hands, utensils, and surfaces before and after handling food.
• Store cooked fish in the refrigerator or freezer if not consumed immediately.