In general, vegetables don't contain gluten. This is good news for celiacs, people with an intolerance to gluten. Celiacs can eat most fresh, canned or even frozen vegetables without experiencing side-effects. Some vegetables may contain small amounts of gluten due to the packaging environment or because of extra ingredients. If you don't know what a vegetable packet sauce or dressing contains, avoid it altogether because it may contain gluten.
Gluten is a sticky substance that occurs naturally in grains, mainly wheat. While grains are plant-based, they generally don't count as vegetables. When a celiac eats any food with gluten, the body attacks the lining of the small intestine as though it was a dangerous foreign body. This triggers symptoms from vomiting and cramps to diarrhea and foul-smelling stools. Celiacs must monitor their diet to avoid foods containing gluten. This includes foods packaged or coated in anything that contains gluten.
Some store-bought vegetables come mixed with other ingredients or with certain additives. These extra substances may include gluten. The National Digestive Diseases Information Clearinghouse suggests avoiding vegetables prepared in sauces. For example, stir-fry vegetables mixed with chow mein sauce may contain gluten. These sticky sauces often use gluten-based thickeners to give them extra texture. Vegetables in canned soups, breaded vegetables, or vegetables cut and mixed with a dressing run the risk of exposing you to gluten.
While most fresh vegetables don't contain gluten, always check the package details on canned, dried or plastic-wrapped vegetables. Some foods packaged in an environment that contains wheat may contain elements of gluten. The label should inform you of any gluten-based ingredients. As well as gluten itself, also look out for ingredients such as starch, wheat stabilizers, malt, glucose syrup and some types of gum. These often contain gluten in doses strong enough to trigger symptoms in celiacs.
As they contain no gluten and high levels of vitamins and minerals, vegetables should make up a large percentage of a healthy celiac's diet. Remember that vegetable products, such as vegetable burgers, vegetable couscous or vegetarian sausages, may contain gluten. Pickled vegetables too may contain some gluten. In particular, vegetables pickled in malt vinegar contain gluten from the malting process. Home-fermented pickles in white vinegar don't contain gluten.