In North America, Europe and much of the Soviet Union, these are seen only as deficiencies in brain function, hence causes are very difficult to segregate and identify. The reason that brain disorders are associated with certain subclinical nutritional deficiencies is that the blood supply of oxygen to the brain is critical for brain growth and development. Any nutritional disorder that deprives the brain of oxygen can result in brain disorder. Many other possible disorders may be related to subclinical nutritional deficiencies, but we have not yet discovered the correlations or relationships. Lead competes with iron, calcium and zinc in our bodies, displacing those metals from enzymes and body structures, and interfering with their function.
Some people are allergic to one or more foods.
Components in foods that cause an immune response in the body are referred to as food allergens. Food intolerance's and food aversions are separate and distinct terms. Food Allergy - The prevalence of food allergies is highest in the first several years of life and then declines with age. Allergies always involve antibodies, but don't necessarily involve symptoms. Foods that most often cause allergies include nuts, eggs, milk, soybeans, wheat, and shellfish.