Nutrition and Allergy

Transcription

1 Nutrition and Allergy Who Cares? William Reisacher, MD FACS FAAOA Assistant Professor Weill Cornell Medical College We should and why? Oxidant Load Chronic illnesses such as allergies have tremendous energy requirements and this requires adequate nutrition. Allergies increase the oxidant load Diet is often adversely altered by substitutions and eliminations either from food sensitivity or the Oral Allergy Syndrome We need to be able to guide our patients Oxidants are reactive chemicals Electron acceptors Normal, healthy cells are able to neutralize regular levels of oxidants, but when oxidant load is excessive, cellular defenses may become overwhelmed Genetics, nutrition, load level and chronic illness play a role in the body s ability to handle the load Sources of Oxidants Results of Excessive Oxidant Load Mitochondrial aerobic respiration Hepatic microsomal detoxification By leukocytes during phagocytosis and degranulation Spontaneous auto-oxidation of polyunsaturated lipids in cell membranes and fat stores When iron stores exceed normal limits Preformed oxidants entering the body from consumption of rancid food or inhaling smog, smoke and chemicals Exposure to high oxygen concentrations Released by leukocytes during allergic reactions Destroy lipids, proteins and nucleic acids Metabolic inefficiency DNA mutations Carcinogenesis Cell death Organ failure 1

2 Natural Defenses Against Oxidants (Antioxidants) Enzymes that neutralize oxidants protect cell organelles Require mineral cofactors (iron, zinc, copper) Vitamin cofactors B complex Small reducing molecules Vitamins C and E Plant derived: carotenoids, polyphenols, flavonoids These mechanisms are linked Toxins and pollutants decrease efficiency of system The Elements of Nutrition Water waste removal, universal solvent Fiber intestinal function Carbohydrates energy requirements Protein amino acids and muscle Fatty acids cell membranes Salt / minerals electrophysiology Vitamins catalyst for chemical reactions Functions of Water Solvent essential for life Participates in metabolic processes Aids in digestion, circulation, absorption, excretion Transport medium for nutrients and chemicals Necessary to dilute urine Water statistics to remember Water constitutes 63% of body weight 35% in obese individuals 70% in athletes Necessary free water intake = L/day Urine volume should be cc/day 35 cc/kg/day Fiber Increases stool water content and bulk Decreases intestinal transit time Binds bile salts, metals and bacteria Two types: Soluble fiber: pectins, gums Insoluble fiber: lignin, cellulose, hemicellulose Recommended intake: g/day Adverse Effects of Excessive Fiber Decrease food absorption Sigmoid volvulus Antinutrients such as lectins and tannins can injure the mucosa and interfere with digestion Silica particles in cereal may contribute to esophageal CA 2

3 Carbohydrates Preferred energy source Two types: Simple sugars converted in liver to fat Complex starches converted to glycogen Sources include grains, starchy vegetables, legumes and fruits Importance of Carbohydrates Typically supplies about 50% of calories May be entirely omitted from diet can be synthesized from protein and glycerol Maintains exercise capacity Glucose is preferred energy source for brain Reduces protein degradation Calorie needs depend on age, weight, metabolism and activity level To Low-carb or Not to Low-carb Currently, no evidence to suggest that carbohydrate consumption effects hunger level Low-carbohydrate diets have been successful in weight loss programs High-carbohydrate diets have been shown to be more atherogenic than high-fat diets Protein Source of amino acids - repair body tissue Essential and non-essential amino acids Sources include meats, poultry, fish, milk products, legumes, grains, nuts and seeds Represent about 15% of daily calories Most food allergic reactions are due to reactions with proteins. Functions of Fats Concentrated energy source Forming cell membranes Surfactants Provide essential fatty acids Carrier for fat soluble vitamins Hormones Steroids Eicosanoids Antioxidants More About Fats Sources include meat, fish, poultry, eggs, oils, nuts and olives Three different types: Lipids fatty acids Sterols Vitamin D Fat soluble vitamins Vitamins A, E, K Essential fatty acids (EFA) Highly unsaturated fatty acids Linoleic acid (Omega 6) from plants Linolenic acid (Omega 3) from marine phytoplankton High Omega 3 / Omega 6 ratio has anti-inflammatory effect All other essential fatty acids can be made from these two 3

4 Salt and Minerals Salt and Minerals - Classification Maintain electrolyte balance across cell membranes to achieve homeostasis and facilitate transport Activate enzymes that catalyze metabolic reactions Macrominerals Sodium Potassium Calcium Magnesium Phosphorus Iron Zinc Copper Iodine Trace Minerals Selenium Chromium Manganese Ultratrace Minerals Molybdenum Boron Silicon Nickel Arsenic Fluorine Calcium Magnesium Daily requirement is mg/day Major dietary source is milk products Calcium requirements peak in puberty 75% of women over age 35 are deficient Older people are deficient because of lower sunlight exposure and gut efficiency Limit calcium in sarcoid, renal stone patients High P and low Mg levels lead to low Ca levels Widely distributed in foods Requirement is mg/day Mg deficiency may be seen in intestinal malabsorption and alcoholism Phosphorus Requirement is mg/day Usually ingested along with calcium Absorption is impaired with excessive ingestion of antacids Excessive dietary phosphorus stimulates PTH production, which can lead to osteoporosis Iron The most common nutrient deficiency Requirement is mg/day Iron is poorly absorbed from the diet, but stored in the body to keep hemoglobin levels normal Iron deficiency is problematic for menstruating women, children, adolescents and the elderly Hemochromatosis (iron overload) Check TIBC, transferrin, ferritin prior to supplement 1/250 people have hereditary hemochromatosis 4

5 Zinc 2-3 grams present in the entire body Acts as membrane stabilizer Cofactor in DNA, RNA, protein synthesis Zinc deficiency is common in hospitalized patients Breast milk and zinfandel wine enhance absorption of zinc Useful in treating Wilson s disease Copper Cofactor in cellular energy production and detoxification reactions Like zinc, it is a cofactor in superoxide dismutase leukocyte oxidative killing Non-food related sources of copper include pipes and cooking utensils Deficiencies may result in infants drinking only cow s milk Iodine Vitamins Worldwide, iodine deficiency is as common as iron deficiency The best dietary sources include seaweed, marine fish and shellfish In many areas of the world, iodine has been depleted from the topsoil because of overwatering and excessive cultivation of the land. Requirement is mcg/day Fat soluble Vitamin A Vitamin D Vitamin E Vitamin K Water soluble B1 - Thiamine B2 - Riboflavin B3 - Niacin B6 - Pyridoxine B12- Cyanocobalamin Biotin Vitamin C Folic acid Pantothenic acid Vitamins Fat soluble Vitamins Water soluble Vitamin A High in fruits and vegetables Enhance vision, reproduction, complement production Possibly teratogenic at high doses do not supplement during pregnancy Vitamin D Absorbed from fatty fish and transported to the skin where they are activated by UV light Important for calcium and phosphorus absorption Vitamin E A group of 8 chemically similar plant tocopherols and tocotrienols Function as antioxidant and free radical scavenger to stabilize cell membranes Vitamin K Half the daily requirement is synthesized by intestinal flora Leafy green plants are a good dietary source Regulates synthesis of clotting factors and prothrombin, stimulates platelets Rapid excretion enhances safety profile, but storage capacity is limited Alcoholism may lead to thiamine deficiency Vitamin C 200 mg daily is enough to saturate plasma levels ( mg/day is RDA) Smokers deplete vitamin C at twice the rate Strong antioxidant properties Facilitates normal neutrophil function Shifts AA pathway towards bronchodilating prostaglandins Has antihistamine activity 5