Encyclopedia of Diets - A Guide to Health and Nutrition

Origins

Food sensitivity is often misdiagnosed due to the
lack of well-controlled clinical trials proving its exis-
tence. However, it is very difficult to investigate food
sensitivity in the same way as you would a particular
medical intervention because of the number of varia-
ble factors involved, such as the type, amount and
frequency of foods consumed in a typical diet as well
as other environmental factors that could provoke
similar symptoms.

Food sensitivities that involve particular food
additives are more easy to study and have indeed
shown that certain individuals can be sensitive to syn-
thetic colourings, such as azo dyes, as well as the
preservatives,sodiumbenzoate, benzoic acid, sulphur
dioxide and sulphites.

Other studies have excluded gluten (a protein
found in wheat, barley and rye) and casein (a protein
found in milk and dairy products ) in children with
autistic spectrum disorder (ASD) and attention deficit
hyperactivity disorder (ADHD) and have noted
improvements in behaviour and communication. It is
important to note that these trials did not take any
baseline dietary measurements and so the ‘exclusion’
diet, whilst excluding certain food groups are highly
likely to increase intakes of fruits, vegetables, fish,
seafood, nuts, brown rice and soya-based foods ( eg.
tofu and soya milk ), all of which are rich sources of
key nutrients known to be vital for good physical and
mental health. The positive outcomes highlighted
from these studies may have more to do with which

foods were included, rather than excluded, or even a

combination of both.

Description

Food sensitivity can occur for a variety of reasons,

outlined in detail below:

Enzyme -Deficiency: The classic example would be

the loss of the lactase enzyme needed to breakdown

lactose found in milk and dairy foods. The undigested

lactose is fermented by gut bacteria that produce large

amounts of organic acids and gases, resulting in

abdominal pain, distension and diarrhoea.

Pharmacological: Some foods contain pharmacologi-

cally active substances that can cause adverse effects in

some people. Good examples include caffeine, found in

in coffee and cola drinks, and monosodium glutamate,

often used in manufactured foods and some Chinese

meals.

Histamine-Release: Foods, such as shellfish and straw-

berries, contain histamine-releasing agents which can

cause adverse reactions in sensitive individuals.

Irritant: Excessive consumption of foods such as

onions, nuts and prunes can act as an irritant to the

gastrointestinal tract (gut) and result in unpleasant

symptoms.

Toxic: A small number of foods contain naturally

occurring toxic compounds, such as lectins found in

under-cooked kidney beans, which can be lethal.

Depending on the actual cause, food sensitivity

can cause adverse effects throughout the body. If the

gut is involved, symptoms can include vomiting, diar-

rhoea,constipation,irritable bowel syndrome, infan-

tile colic, abdominal pain and bloating. However,

these symptoms may also be a consequence of poor

nutrition and dysbiosis, which is when the beneficial

bacteria that live in the gut are out of balance with

more harmful varieties. This can often occur following

a period of gastroenteritis or after taking broad-

spectrum antibiotics. Including probiotic-enriched

food and drinks in your diet and eating foods that

contain prebiotics, which help feed the probiotic bac-

teria, can help redress the balance in favour of benefi-

cial bacteria and consequently improve gut function.

Prebiotic-rich foods include oats, bananas, onion, gar-

lic, leeks, artichokes and asparagus.

If the gut is not working properly then potentially

any food could exacerbate the situation and cause

symptoms to worsen. In these situations it is difficult

to differentiate between food sensitivity and compro-

mised gut function.

Common food sensitivities

• Eggs


• Milk and dairy


• Peanuts and other nuts


• Shellfish


• Soy


• Strawberries


• Wheat
  Possible symptoms


• Abdominal pain and bloating


• Constipation


• Diarrhea


• Excess coughing


• Hyperactivity


• Infantile colic


• Irritable bowel syndrome


• Itchy skin


• Migraine


• Skin rash


• Sneezing


• Unexplained joint and muscle pain


• Vomiting


• Wheezing

(Illustration by GGS Information Services/Thomson Gale.)

Food sensitivities