Any problem which results out of ingestion of certain foods is commonly labeled as food poisoning. The term food allergies is also used unreasonably, many a time. However, there is a clear distinction between food allergies, food poisoning and food intolerance. The three disorders also produce symptoms which are peculiar to the respective disorder only. Amongst all the food related disorders, food intolerance is the most common one. It affects adults as well as children, however, its occurrence is more in adults than children. What is Food Intolerance Food intolerance is the body's inability to digest certain foods, beverages or food additives. It is said to have occurred when the body generates certain undesirable physiological responses, even when a non allergic food is consumed. Food intolerance is a result of absence of low amount of certain enzymes which are required to break down the proteins in the food in order to facilitate digestion. Food allergies on the other hand, are caused due to trigger to the immune system caused by certain foods. These foods are capable of producing allergic response only in certain people and may be entirely safe for others. Food poisoning is another case, in which toxic substances enter the body through the medium of food. These substances then cause certain undesirable symptoms in the individual. Symptoms in Adults Food intolerance is a common phenomenon in adults as well as children of all ages. The most common type is lactose intolerance. It affects about 10% of adult population in America. It occurs due to low amount or absence of an enzyme named lactase. People with lactose intolerance cannot digest dairy products. Babies are usually born with high amount of lactase. Hence, the symptoms of lactose intolerance surface only after the age of 2 years, when the production of lactase in the body begins to diminish. Given below is a list of common foods that cause intolerance reaction in some people:

• Dairy products, such as milk, cheese and yogurt.
• Strawberries, citrus fruits and tomatoes.
• Flavor enhancers such as MSG (monosodium glutamate).
• Chocolate.
• Eggs, particularly egg white.
• Histamine and other amines in some foods.
• Food additives.
• Wine, especially red wine.

Food intolerance is often associated with conditions such as asthma, chronic fatigue syndrome and irritable bowel syndrome (IBS). Another fact about food intolerance in that, you may not experience it until late in your life. Meaning, you might be eating a certain food item for the whole of life without any problem, but suddenly develop a response to it once you reach your sixties or seventies. The truth is that, there was always a problem with digestion of that particular food item in your body, only you never experienced any symptoms. Old age, a bout of illness or stress can compromise your digestive system. Hence, you are more likely to experience food intolerance symptoms in such circumstances. In older age, the body cannot produce enough enzymes and hence, becomes more susceptible to various food related disorders. The occurrence of symptoms is also largely dependent upon the amount of food you consume. You may not have any problem if you only consume small portions of the problematic food everyday. In fact, your body may become used to it and may not react in a dramatic way. However, eating large portions of the food in question is bound to invoke undesirable effects in body. Food intolerance symptoms develop over a period of time, say days or even weeks after ingestion of the food. Whereas, symptoms of food allergies are instantaneous and more dramatic. Typical food intolerance symptoms include:

• Nausea
• Stomach pain
• Gas, cramps or bloating
• Vomiting
• Heartburn
• Diarrhea
• Headaches
• Irritability or nervousness

Food intolerance is mainly attributable to genetic predisposition. Some people are naturally programmed to produce the requisite enzyme in small amount or not produce at all. There is very little that can be done to overcome this problem. The best solution is to identify foods that are troublesome for you and avoid them entirely. However, it is important to incorporate substitute foods so as to avoid nutrient deficiency. People with lactose intolerance can take lactase enzyme tablets while children can be given soy milk. Food intolerance symptoms can be controlled with the help of medications and diet. However, consult your doctor before introducing substitute substances in your diet.