Food intolerances occur when your body has a reaction, often delayed, to a food or a food additive. In my naturopathic practice many of my patients have food intolerances and do not realize it because the symptoms can be vague and can often come on hours or days after eating the food. This characteristic also makes food intolerances difficult to diagnose. Food intolerances cause irritation to your gastrointestinal tract and worsen the effects of conditions that may not be directly caused by food intolerances. Common types of food intolerance include dairy or lactose, wheat, eggs and food additives such as MSG and sulphites.

What are the symptoms?

The symptoms of food intolerance can vary. For example, two people may have intolerance to cow’s milk but whereas one person may experience sinus congestion, the other individual may experience diarrhea and abdominal cramping. In general, common symptoms of food intolerances include but are not limited to bloating, diarrhea, constipation, acne, skin rashes, joint pain, headaches, fatigue and irritability.

Food Intolerance vs. Food Allergy

A food allergy occurs when the immune system reacts to specific proteins in a food. Your immune cells, IgE antibodies are activated and histamine is released. An allergic food reaction can be mild (ie. hives) or life-threatening (ie. death). Food intolerances are not usually life-threatening but can certainly interfere with your quality of life. Symptoms of food intolerance usually appear gradually whereas symptoms of food allergy often come on immediately. Both conditions can share the gastrointestinal symptoms such as abdominal pain, vomiting and diarrhea.

Get Tested

Food intolerances can be tested by your naturopathic doctor in office by checking your blood for IgG antibodies. IgG antibodies are a part of your immune system that is activated when you are intolerant or sensitive to specific foods. Another way to gauge your food intolerances is to keep a nutrition diary for a week and to note any symptoms that you experience after eating your meals. The latter method can be tricky because some symptoms of food intolerance only appear days after eating a particular food.

Once you have determined which foods you are intolerant to, you will want to avoid them.

Take a Probiotic

When the bacteria that reside in your gut have been reduced, you can become more susceptible to food intolerance symptoms. In some cases food intolerance may develop or worsen after a stressful event. Chronic stress can play a role in reducing your healthy gut bacteria. The overuse of antibiotics and poor nutrition are other factors that are important for maintaining the health and integrity of your intestinal bacteria. Probiotic supplements contain species of friendly gut bacteria and may be helpful in treating and preventing the development of food intolerances.

Prevention Tips

Once you are aware of your food intolerances it is important to read the nutritional labels in order to avoid your trigger foods. If possible, avoid the consumption of processed foods that contain ingredients that are difficult to pronounce. Another way to improve the health of your gastrointestinal tract is to purchase organic food whenever possible. If you are new to purchasing organics, begin with the dirty dozen, a list of 12 to 15 vegetables and fruits, tested by the Environmental Working Group, that contain the highest amount of pesticide residues. Pesticide residues have been linked in scientific studies to an increased incidence of both food allergies and food intolerances.

About the Author

Dr. Olivia Rose graduated from the University of Guelph with a Bachelor of Science Honours degree in Nutritional and Nutraceutical Sciences and in 2006, she graduated from the Canadian College of Naturopathic Medicine.

In addition to her private practice, Dr. Rose is the director of Fertility Acupuncture Services, a mobile service that brings acupuncture to couples undergoing in vitro fertilization and intrauterine insemination at Toronto fertility clinics. Her special areas of interest include infertility; children and teen health; stress management; weight loss; heart disease; digestive and immune health; skin rejuvenation and pain management. She is a birth doula and has additional training in cosmetic acupuncture and needle-less therapies for skin rejuvenation and joint pain.

Dr. Rose is a sought-after lecturer for community organizations; a freelance writer and mentor to new graduates. She has been interviewed by various media outlets including Global Toronto’s, “The Morning Show”, “News at Noon” and “News Hour”. In her free time, she unplugs at the spa and she enjoys spending quality time with her husband, son and tea-cup Yorkie. For more information on Dr. Rose's practice and special events, please visit -