Histamine intolerance (HIT) is a trending buzzword within the realm of functional nutrition and integrative health. Although mainstream medicine has not officially accepted it as a clinical diagnosis, more and more holistic nutritionists, wellness experts, and alternative practitioners are spreading the word about this condition. They're highlighting a distinctive and intriguing trend: people getting allergy-like symptoms following the intake of specific foods — without being positive for conventional food allergies.

So, what is histamine intolerance? Is it the cause of your enigmatic bloating, headaches, skin rashes, or maybe even brain fog? And how do you react to such symptoms?

This in-depth guide will break down what is histamine intolerance, the symptoms to look out for, potential causes, and how a low-histamine diet can alleviate your symptoms.

What is Histamine?

Before going into the condition itself, a basic understanding of histamine's role in the body is important. Histamine is a chemical messenger — or signaling molecule — that plays an important role in a number of physiological processes. Notably, it's implicated in the immune response of the body, digestion, and brain-cell communication.

During allergic reactions, the body releases histamine to defend against perceived threats like pollen, dust, or certain foods. This triggers inflammation, causing symptoms like sneezing, congestion, hives, or swelling. But histamine is also found naturally in many foods and is produced daily in the body in small amounts. It’s perfectly normal — until your body can’t break it down efficiently.

What Is Histamine Intolerance?

Histamine intolerance results when the body fails to metabolize or degrade histamine efficiently — either through enzyme deficiency, gene defects, or dietary load of histamine. This leads to an accumulation of histamine in the blood that triggers symptoms similar to allergic reactions.

Contrary to food allergies, where the immune system is involved, histamine intolerance is considered to be more of a metabolic dysregulation. The body has an enzyme called diamine oxidase (DAO), which is released in the small intestine and is used to degrade dietary histamine. When DAO is low or not working optimally, food histamine can build up and initiate a chain of symptoms.

Notably, histamine intolerance is not yet officially a recognized medical condition by organizations like the American Academy of Allergy, Asthma, and Immunology. Anecdotal evidence, increasing social media discussions, and early research have propelled it into public health discourse.

What Does Histamine Intolerance Feel Like?

Histamine intolerance is commonly referred to as the "great mimicker" due to its symptoms, which mimic various other conditions — ranging from allergies to irritable bowel syndrome (IBS) to hormonal disturbances.

Typical symptoms are:

Gastrointestinal discomfort: bloating, diarrhea, nausea, or cramping in the abdomen

Skin symptoms: hives, flushing, itching, and edema

Respiratory symptoms: nasal congestion, wheezing, sneezing, or shortness of breath

Cardiovascular signs: low blood pressure, dizziness, rapid heart rate or palpitations

Neurological symptoms: headaches, migraines, anxiety, or brain fog

Since these symptoms can be so widespread, involving more than one system within the body, they're so frequently misdiagnosed and missed. Someone may see specialist after specialist without getting an explanation, particularly if standard allergy tests yield a negative result.

Why Does Histamine Intolerance Occur?

There are a couple of main reasons why an individual might develop histamine intolerance:

1. DAO Enzyme Deficiency

The most common cause that has been extensively talked about is a deficiency or malfunction of DAO. If your digestive system is not secreting enough of this enzyme — or if it's inhibited by some foods, drugs, or medical conditions — histamine clearance decelerates, causing accumulation.

2. Genetic Factors

Others can inherit mutations that lead to reduced DAO production or reduced efficiency of the enzyme. Until now, there is limited research, but familial patterns indicate that genetics may be a contributing factor.

3. Drugs That Inhibit DAO

Some medications, including blood pressure drugs, antidepressants, and antibiotics, can inhibit DAO action or cause histamine accumulation in the body. Opioids and narcotics also might contribute to a histamine accumulation.

4. Gastrointestinal Disorders

Individuals with inflammatory bowel conditions such as Crohn's disease or ulcerative colitis tend to exhibit decreased DAO activity as a result of intestinal inflammation. Gut dysbiosis — an imbalance in gut flora — can further inhibit histamine degradation.

High-Histamine Foods: What to Avoid

All foods have some amount of histamine, but some are much higher in histamine content — particularly fermented, aged, and processed foods. The longer the food is stored or aged, the greater the histamine content.

Foods high in histamine are:

• Alcohol, especially wine and beer
• Aged cheeses (Parmesan, Gouda)
• Smoked or cured meats (bacon, salami, ham)
• Sauerkraut and pickled vegetables
• Canned fish (tuna, mackerel)
• Tomatoes, spinach, eggplant
• Vinegar and soy sauce

There are some other foods that do not have high histamine content themselves but can cause the release of histamine or inhibit DAO activity. They are:

• Citrus fruits
• Chocolate and cocoa
• Egg whites
• Peanuts
• Black and green tea
• Energy drinks

Can a Low-Histamine Diet Provide Relief?

It's impossible and not necessary to eradicate histamine entirely from your diet. The intention of a low-histamine diet is to lower the total histamine load on your body — taking a break for your digestive system and enzymes.

A low-histamine diet typically starts with an elimination period, in which high-histamine foods are eliminated for a period of several weeks. Foods are then gradually reintroduced to determine the culprits. Consulting with a dietitian or nutritionist is highly recommended, particularly to avoid malnourishment.

Some examples of low-histamine foods are:

• Unprocessed, fresh meats and fish (especially those frozen upon catch)
• Gluten-free grains including rice, quinoa, and millet
• Most fruits that are not citrus (apples, blueberries, pomegranates, mangoes)
• Fresh veggies (apart from tomatoes, spinach, eggplant)
• Coconut and olive oil
• Non-dairy milk (hemp, almond, coconut)
• Non-aged cheese such as mozzarella, cream cheese, or ricotta (if dairy is well-tolerated)

Important principle: The newer, the better. Freshly prepared foods with no preservatives and minimal storage time are best for the control of histamine levels.

Histamine intolerance occupies a gray area in modern medicine. While it lacks formal recognition from most medical authorities, many individuals have found symptom relief through low-histamine diets and targeted lifestyle changes.

Research continues to develop, and additional studies must be conducted in order to determine the mechanisms, diagnostic measures, and optimal treatment regimens for HIT. Until then, if you suspect intolerance to histamine, monitor your symptoms, see a healthcare professional, and consider collaborating with a dietician who is knowledgeable about histamine metabolism.

It started with a simple TikTok video, four large carrots shaved into ribbons, mixed with garlic, sesame oil, lime juice, coconut aminos, rice vinegar, and green onions. The resulting “crunchy and addictive” salad quickly racked up millions of views under the viral trend #EatYourRetinol. But is it just social media hype, or can what’s on your plate really show up on your face?

The trend encourages eating vitamin A-rich foods, like carrots, to support skin health from the inside out. “Skincare always starts within,” says Johanna Salazar, registered dietitian nutritionist and founder of Healing Nutrition, as noted by Martha Stewart. But experts urge a balanced view: while diet can support your skin, it’s not a magic replacement for topical care.

What’s in the Carrot Salad That’s Good for Your Skin?

The base of the salad, carrots, are packed with beta-carotene, a precursor to vitamin A, known for boosting skin cell turnover and promoting a radiant complexion. Pairing it with a fat, like sesame oil, helps your body absorb the fat-soluble vitamin. Lime juice adds vitamin C, key for collagen production, while garlic and green onion offer prebiotics that support gut health, which in turn impacts skin health.

Sesame seeds sprinkled on top bring in vitamin E and fiber, which contribute to skin hydration and a healthy glow.

“It’s a nice mix of ingredients that all play small but beneficial roles in skin support,” says Salazar.

Dermatologists Weigh In: Not a Cure-All

Lauren Kole, M.D., associate professor of dermatology at the University of Alabama at Birmingham, appreciates the effort to eat for skin health—but with a word of caution.

“Deficiencies in certain vitamins and minerals can negatively affect the hair, skin, and nails,” she says. “But eating an excess doesn’t necessarily make your skin better.”

Kole points out that while beta-carotene from carrots is helpful, it's not strong enough to replace prescription retinol or other topical treatments for conditions like acne or hyperpigmentation. “Diet is not a substitute for proper skin care,” she emphasizes.

Beyond Carrots: Other Skin-Loving Foods

Experts agree that eating for your skin isn’t just about one salad. A variety of fruits, vegetables, and healthy fats are essential. Salazar and Kole both recommend incorporating:

Dark-colored fruits like berries and red grapes, which are high in antioxidants that fight oxidative skin damage.

Leafy greens such as spinach, kale, and chard, which are rich in vitamin C and help with collagen production.

Vegetables like broccoli, mushrooms, and cauliflower, which support healthy pigmentation and skin repair.

Healthy fats including avocados, walnuts, flaxseeds, and omega-3-rich foods to reduce inflammation and maintain skin moisture.

According to Kole, diets like the Mediterranean diet—rich in plant-based foods and good fats, have shown potential skin benefits in clinical settings.

Don’t Ditch Your Skincare Just Yet

While the “Eat Your Retinol” movement has its heart in the right place, Salazar and Kole stress that no food trend should replace professional skincare or personalized advice.

Lizzy Davis, Ph.D., a dietitian and assistant professor at UAB, advises people to approach such trends with balance.

“Cooking carrots, for example, doesn’t reduce their skin-friendly fiber,” she notes. “It can actually make them easier to digest and still beneficial.”

Davis also warns against over-relying on TikTok or Instagram for skincare advice. “Talk to your doctor or a registered dietitian,” she says. “Social media is convenient, but it can’t give you a plan tailored to your needs.”

We already know that ultraprocessed foods are linked to obesity, heart disease, and diabetes. But now, a new study published in the medical journal Thorax suggests a concerning addition to that list, lung cancer.

According to researchers, people who consume the highest amounts of ultraprocessed foods may face a 41% higher risk of being diagnosed with lung cancer, compared to those who eat the least, even when accounting for smoking and other known risk factors.

What Are Ultraprocessed Foods?

Ultraprocessed foods are industrial formulations made largely or entirely from substances not typically used in home cooking.

According to the Food and Agriculture Organization of the United Nations, these include artificial colorings, preservatives, emulsifiers, and chemically altered fats, sugars, or salts.

Common examples? Think sodas, chips, packaged soups, processed meats like chicken nuggets and cold cuts, instant noodles, diet soft drinks, and even some ice creams.

These additives enhance taste, shelf-life, and appearance, but at what cost?

What Does The Study Reveal About Food Choices and Lung Cancer Risk

Researchers behind the Thorax study analyzed data from over 100,000 adults who participated in the U.S. National Health and Nutrition Examination Survey. Each person filled out a detailed dietary questionnaire, which researchers then compared with medical records to track lung cancer diagnoses over time.

On average, people reported eating nearly three servings of ultraprocessed food a day, most commonly lunch meats and soft drinks.

Despite adjusting for smoking habits, age, sex, and other lifestyle factors, the study found a clear association between higher ultraprocessed food intake and increased lung cancer risk, particularly among people who had never smoked.

“This strongly suggests that these foods may contribute to lung cancer risk in ways beyond just smoking,” said Dr. David Katz, a specialist in preventive and lifestyle medicine and founder of the nonprofit True Health Initiative, as reported by CNN. Though not involved in the study, Katz called the findings “concerning and credible.”

Why Would Food Be Linked to Lung Cancer?

Experts believe multiple mechanisms could be behind the link.

“Industrial processing alters the food matrix,” the study authors explained, “which affects how nutrients are absorbed and may produce harmful contaminants.”

One such contaminant is acrolein. It is a toxic compound found not only in cigarette smoke, but also produced when cooking oils or fats are heated to high temperatures.

The U.S. Centers for Disease Control and Prevention (CDC) lists acrolein as a substance that can inflame and damage lung tissue.

Packaging may also be a problem. Plastics and synthetic materials used in food storage can leach chemicals, some of which are known or suspected carcinogens.

Add to that the fact that ultraprocessed foods are often low in omega-3 fatty acids, said Dr. Tom Brenna, professor of nutrition and chemistry at the University of Texas at Austin, as reported by CNN.

“Omega-3s spoil easily, so manufacturers tend to remove them to increase shelf life,” he explained. That’s unfortunate, because omega-3s help reduce inflammation, a key process in cancer development.

Smoking Isn’t the Only Risk Factor

Lung cancer remains one of the most commonly diagnosed cancers globally, with 2.4 million new cases in 2022, according to the World Health Organization. While smoking remains the leading risk factor, experts now believe diet and environmental exposures also play a role.

Dr. Fang Fang Zhang, a professor at Tufts University’s Friedman School of Nutrition Science and Policy, as reported by CNN, noted that while the study adjusted for smoking, the adjustment may not have been thorough enough. “Smoking needs to be measured more precisely, by cigarettes per day or years of exposure,” she said. Still, she found the link stronger in non-smokers, which makes the data all the more compelling.

What You Can Do: Eat More Whole Foods

The takeaway? While more research is needed to understand the exact biological mechanisms at play, the connection between ultraprocessed foods and cancer risk can no longer be ignored.

According to Dr. Katz, the solution lies in going back to basics. “Health and diet quality improve when people eat mostly whole, unprocessed foods,” he said, including vegetables, fruits, beans, whole grains, nuts, seeds, and other plant-based ingredients.

Dr. Zhang agrees. “Avoid foods with long ingredient lists full of unfamiliar chemicals,” she advised. “Focus on meals made from whole or minimally processed ingredients whenever possible.”

Fish oil is a star supplement loaded with omega-3 fatty acids like EPA and DHA. It offers a spectrum of vital benefits for women’s health. These extend beyond general well-being to support heart, brain and joint function, especially in areas of concern specific to women.

Fish oil, rich in omega-3s, addresses unique needs across all stages of a woman’s life. From adolescence through motherhood to menopause, fish oil supports cardiovascular, hormonal, mental and reproductive health.

A Boost for the Heart

Fish oil plays a major role in promoting heart health. According to Dr Mohit Bhatia, it helps lower triglyceride levels, a risk factor for cardiovascular disease, and improves blood flow, making it essential for proper cardiovascular function. He adds that it also slows the progression of cardiovascular disease.

Karan Khurana, a health expert at WishNew Wellness, concurs, saying that omega-3s in fish oil reduce triglycerides, lower blood pressure, and decrease arterial inflammation. This is particularly vital for post-menopausal women, who face a greater risk of heart disease. Regular consumption of fish oil, he says, can even lower the risk of heart attacks and strokes.

Hormones, Menstrual Cycles and PMS

Women facing bloating, mood swings or cramps may find some relief with fish oil. Dr Bhatia says that some evidence-based research suggests fish oil can help alleviate PMS and menstrual pain, thanks to its anti-inflammatory properties.

Khurana elaborates that omega-3s may regulate menstrual cycles and reduce cramps by lowering prostaglandin levels, which contribute to pain and inflammation. He adds that fish oil can ease common PMS symptoms such as bloating and breast tenderness.

Pregnancy, Postpartum and a Baby’s Brain

The benefits of fish oil carry into pregnancy too. Dr Bhatia points out the importance of DHA during this stage, saying it is vital for healthy foetal brain and eye development. It may also reduce the risk of preterm birth and help alleviate postpartum depression.

Khurana backs this up, pointing out that fish oil supplementation not only supports cognitive function in babies but also helps mothers manage postpartum depression. It plays a role in maintaining the mother’s brain health during and after pregnancy.

Bones, Joints and the Menopause Years

Post-menopause, bone health becomes a serious concern for many women. Dr Bhatia says that the anti-inflammatory properties of fish oil can contribute to bone health, potentially reducing the risk of osteoporosis.

Khurana adds that omega-3s enhance calcium absorption and support bone density. Fish oil, he explains, helps reduce inflammation linked to joint pain, promoting stronger bones and better mobility for older women.

Better Moods and Sharper Minds

Women are more likely than men to experience anxiety and depression, and fish oil might just help. Dr Bhatia explains that these fatty acids play a role in elevating mood and supporting brain function, potentially mitigating cognitive decline.

Khurana agrees, saying omega-3s support cognitive health and reduce the risk of dementia later in life. Fish oil, he says, may alleviate symptoms of depression and anxiety, contributing to overall mental well-being.

Your Skin Will Thank You Too

Dr Bhatia does not touch on it, but Khurana dives into skin benefits. He says that fish oil improves hydration, reduces wrinkles, and protects against UV damage. Its anti-inflammatory effects can ease conditions like eczema, making skin look and feel healthier.

Final Thoughts Before You Pop That Capsule

Dr Bhatia emphasises that while fish oil is a powerful supplement, it should complement a balanced diet and healthy lifestyle. He strongly recommends consulting a healthcare professional before starting, especially for those on medication or with existing conditions.

Khurana suggests aiming for 250–500 mg of combined EPA and DHA daily, either through fatty fish like salmon or through supplements. Fish oil, he concludes, is a holistic powerhouse that can help women thrive at every stage of life.