A food allergy is basically the immune system over reacting by mistake and over producing mediators such as histamine. In normal circumstances the body defends against harmful substances such as bacteria, viruses and toxins which enter the body but in some people their immune system is triggered by specific foods. The IgE antibodies react to an antigen within the food which causes the mast cells to produce the mediators.
Symptoms of a food allergy start to develop within a couple of hours of ingestion. Some of the main symptoms to look out for are wheezing, hives, hoarse voice, swellings, itching, trouble swallowing, light headedness, feeling faint, stomach cramps and vomiting. In severe food allergy reactions such as a peanut allergy the mast cells within the mouth, tongue and lips will be triggered and will cause the blood vessels to leak and produce swelling. This will cause a sudden drop in blood pressure and blocked airways which will cause the victim to go into shock and will collapse. Allergies to foods can become life threatening.
Many people who have food intolerances believe it to be an allergy and this is not the case. In a true food allergy scenario the body’s immune system produces the antibodies and mediators in response to the specific food being ingested in a very short time and doesn’t need a large amount of the food to cause this reaction. Food intolerances however can produce a varied range of symptoms that also vary from person to person and are not life threatening. Food intolerances show up as a slower reaction to the food that the individual is intolerant to, more of the intolerant food is needed to be ingested to show any signs, an unspecific cluster of symptoms can appear, disappear and then reappear depending on the frequency of eating the food.
Generally foods that some people are intolerant of are cow’s milk and dairy products (lactose intolerant), Wheat and gluten (celiac disease) and also some are intolerant of corn products. The only real proven treatment for allergies to foods is to avoid it altogether.
Elimination Diets -
Elimination diets are used if people have an allergy or intolerance to foods, more so for intolerance as it doesn’t involve a clear action in the immune system and so cannot be determined by scientific measurement. This type of diet involves removing specific foods from your daily eating plan that are suspected to be causing the intolerance over a 21 day period. It is a drawn out process and sometimes is not always conclusive. First of all the person should keep a food diary of what they are eating and the symptoms they are having, this is so a comparison to the changes can be seen later. Symptoms such as lethargy and fatigue, heart palpitations, shaking, digestive issues, weight fluctuations and food cravings can be an indicator of food intolerance. These are by no means the only symptoms and some peculiar ones can manifest themselves in one individual on not others.
There are a few different elimination diets that can run for 21 days, 14 days and 4-7 days. Each has its place and should only be done with the help and advice of a qualified consultant as persons with Crohn’s disease or a severe allergy can have a dangerous reaction to them. One example of an elimination diet is a 21 day plan where the person would have to eliminate foods that are regularly eaten such as dairy products, breads/wheat, citrus fruits etc. Foods that should only be eaten on this plan are -
1 – Plain meat (beef, pork, lamb, turkey, duck but not chicken)
2 – Fresh Vegetables
3 – Fresh fruit (but not citrus as stated before)
4 – Plain fish (plaice, mackerel, trout, haddock but not smoked or processed)
5 – Only drink things such as spring and filtered water, herbal teas and fruit juice
6 – Condiments such as salt, pepper and herbs only
Anything that isn’t mentioned is to be avoided over this time period. Symptoms are expected to worsen over the first 1-2 weeks as withdrawal takes place of the foods the body became sensitive to, but these should clear up after this time period and an individual should see improvements in health if food intolerance is to blame.
Re-Introducing foods -
Once the elimination diet has finished it is time to start re-introducing foods to test for food insensitivities. You can’t just add the foods in a lapse nature it has to be a controlled manner with careful planning. Each foodstuff needs to be re-introduced on its own, separately and completely without bringing in any other that may have an association with them. For example intolerance to milk does not mean a person has intolerance to cheese, white wheat flour does not mean intolerance to wholemeal flour and so by re-introducing everything in a planned manner is the way to find out what is causing the specific intolerance. The process of re-introduction after elimination diets that are run 14-21 days is as follows:
1 – Select whole and single foodstuffs with no mixtures
2 – Eat a large portion of the food only on its own
3 – Monitor for up to 8 hours and observe if any reactions occur. If no reactions occur then eat additional portions to double check this
4 – Take Epsom salts if intolerance is noticed and avoid this foodstuff
5 – Observe the resting pulse over the first 12 hours after eating the chosen food and if a pulse rate has increased by 10 or more then this could suggest intolerance. Repeat this process for the foodstuffs introduced daily but remember that one food should only be introduced per day. If intolerance is detected then you need stop the introduction and eliminate foods until the symptoms have subsided. This way over time the individual will be able to record a list of safe foods that have not given a reaction. If the elimination diet was a fast for 4-5 days then the individual should introduce foods that they haven’t normally eaten and the same process is followed at introducing one foodstuff per day. As all foods have to be introduced in this manner the process can be lengthy and can take up to 8 weeks and longer dependant on how many foods trigger a reaction and if re-introduced in the correct manner. Therefore it would be a good idea to introduce foods that are less associated with allergy/intolerance at the start of the re-introduction so the individual gets a more enjoyable range of foods that they can build up on their lists and continue eating.
Foods that are found to be less common triggers of intolerance are:
Some meat and fish (Turkey, Lamb, Goose, Fish but not shellfish).
Carbohydrates such as rice, tapioca, chick peas and buckwheat.
Fruit and vegetables such as bananas, pears, passion fruit, lettuce, pumpkin, swede and bean sprouts.
Oils in the diet should be the likes of olive oil, sunflower oil and rapeseed oil.
Some seed and nuts such as cashews, Brazil nuts and pumpkin seeds.
Drinks along the lines of spring water, fruit juices and herbal teas should be consumed. A selection of these foods should be eaten in different combinations at least once a week and in a reasonable quantity. If any reactions/symptoms flare up again then the food causing it should be noted and avoided.
Testing for intolerance to food is very time consuming and can be difficult but can be very beneficial to health in the long term.