Caveat: I'm not a medical proffessional, and this article is my experience and opinion. Food allergies can be very serious, life-threatening problems, so if you suspect you may have a garlic allergy or any food allergy, please see a specialist!
I talk about being “garlic intolerant”, but it’s probably more accurate to say that I am allergic to garlic. I’ve discussed this with an allergist, and he agreed that my symptoms did sound more like a food allergy. So how can you tell whether you are “just” garlic intolerant, or actually allergic to it?
Food intolerance generally refers to an inability to digest some of the key components that make up that type of food. Lactose intolerance, probably the most widely known form of this, is an inability to digest a certain type of sugar in milk and dairy. Common symptoms include increased gas in the gut, loose stools or diarhea, cramping, or vomiting. Symptoms usually come on within a few hours of ingesting the food, as it passes through your body. These are all digestive issues, and may make you think you ate some “bad food” if you’ve never encountered it before. For years I thought I was lactose intolerant – mostly because the cheesy Italian dishes I love are so often also loaded with garlic…
Allergy symptoms are much more systemic – they can affect all different parts of your body, not just your digestion. In some cases, you don’t even need to eat the food to have symptoms triggered. Severe peanut allergies can be triggered by touching or inhaling minute particles of peanuts. In addition to all the classic “intolerance” symptoms, food allergy symptoms can range from mild annoyances like a runny nose, nasal congestion, hives, or redness and itching around the point of contact, to much more severe and potentially life-threatening symptoms like tightening of the throat, shortness of breath and wheezing. Food allergies can also be a trigger for acid-reflux, or GERD, which in my case lead to mis-diagnosis for years of the causes, and self-treatment with over-the-counter anti-acid and anti-gas medicines.
In my experience, my symptoms include both the “intolerant” symptoms and allergy symptoms (in mild forms). The digestive symptoms come on fairly quickly, so drawing the conclusion that I was intolerant seemed obvious. Non-digestive allergic symptoms tended to come on slower than the digestive ones, sometimes not showing up for days, or only after repeated exposure over a week or two… This is why it took me so very long to draw the link between what I was eating, and the symptoms I was having. If you eat cheese and an hour later you’re trapped in the bathroom, it’s pretty easy to say cheese was the problem. If you eat garlic and four days later break out in hives on your legs, it’s not so obvious that garlic is the problem.
Another time, I’ll post more details about my specific symptoms, in the hopes it will help you recognize if you have a hidden food allergy yourself!