H 329 haddock (Melanogrammus aeglefinus) A lean saltwater FISH related to COD. Haddock is an impor- tant food fish; its white flesh has a pleasant, some- what bland taste that can be prepared in any recipe for cod or FLOUNDER. Smoked haddock is called finnan haddie. Haddock is an excellent source of high-quality PROTEIN; raw, 3.5 oz. (100 g) provides 79 calories; protein, 18.3 g; fat, 0.66 g; calcium, 23 mg; cholesterol, 60 mg; niacin, 3 mg; thiamin, 0.04 mg; riboflavin, 0.06 mg. hair analysis A convenient, reasonably inexpen- sive preliminary screening tool for detecting min- eral imbalances. Because minerals accumulate in hair as it grows, hair analysis can be used to screen for accumulated toxic metals, including MERCURY, ALUMINUM, COPPER , LEAD, and CADMIUM. Hair analy- sis also has been used to assess body levels of trace minerals (iron, copper, manganese, zinc) and to compare minerals in populations living in different regions with differing degrees of pollution and soil depletion of minerals. These hair samples are easily obtainable, and analytical methods (atomic absorp- tion spectrometry, X-ray fluorescence spectrome- try, among others) are sufficiently sensitive to permit accurate analysis of small samples. However, hair analysis is a controversial test. Some laboratories do not provide reproducible results, and hair is easily contaminated with sham- poo, conditioners, dyes, and air pollutants. More- over, findings can be overinterpreted. For example, hair levels of some MINERALS such as SODIUM and POTASSIUM do not correlate with body levels. (See also HEAVY METALS.) halibut (Hippoglossus) A flat saltwater FISH found in all oceans that is one of the most impor- tant food fishes. Resembling a huge FLOUNDER, the lean flesh is firm with a pleasant flavor and texture. Halibut liver oil is an excellent source of VITAMIN A and VITAMIN D and is a primary commercial source of these vitamins. Food value of 3.5 oz. (100 g) raw has: calories, 100; protein, 19.0 g; fat, 1.1 g; cal- cium, 13 mg; cholesterol, 50 mg; niacin, 8.3 mg. ham The rear leg of a hog. Ham is a red MEAT con- taining 34 percent of total CALORIES derived from saturated FAT that provides high-quality PROTEIN together with many VITAMINS and MINERALS. The glistening greenish sheen on the surface of sliced ham is a sign of oxidation, not necessarily spoilage. To minimize SODIUM intake, patients should reduce consumption of all cured pork products, including ham. Roasted ham contains per 3 oz. (85 g): calories, 207; protein, 18.3 g; fat, 14.2 g; choles- terol, 53 mg; iron, 0.74 mg; sodium, 1,009 mg; zinc, 1.97 mg; thiamin, 0.51 mg; niacin 3.8 mg; riboflavin, 0.21 mg. For comparison lean, roasted ham contains per 3 oz.: calories, 133; protein, 21.3 g; fat, 4.7 g; and sodium, 1,128 mg. Canned ham contains per 3 oz.: calories, 140; protein, 17.8 g; fat, 7.2 g; sodium, 908 mg. (See also DIETARY GUIDELINES FOR AMERICANS; FAT, HIDDEN; FATTY ACIDS.) hamburger Ground BEEF to which beef fat (beef tallow) can be added to bring the fat content up to 30 percent by weight. Hamburger is the most com- monly eaten MEAT in the United States, representing a major contributor of total fat and saturated fat to the average diet. The average fat in lean ground beef is 21 percent, while extra-lean hamburger contains 15 percent fat. When fat is drained after cooking, both regular hamburger and extra-lean have about the same cooked weight. Hamburger can be pre- pared from fresh or frozen beef. Fat, water extenders or binders cannot legally be added. Only 12 states presently require that the fat content of ground beef be listed on food labels. Hamburger and ground beef need to be cooked thoroughly to destroy possible disease-producing strains of the bacterium E. coli, a leading cause of food poisoning in the United States. There is no fixed definition of ground beef; however, if ground beef is designated on the label as being derived from a particular cut of meat, then the product must consist of beef derived entirely from the cut so identified. Ground round roast or top round steak are lower fat alternatives to hamburger. These cuts of meat contain only 6 percent fat, representing 29 percent of the total calories. Food value of lean hamburger, per 3 oz. (85 g) broiled is: calories, 230; protein, 21 g; fat, 16 g; cholesterol, 74 mg; calcium, 9 mg; iron, 1.8 mg; zinc, 3.74 mg; riboflavin, 0.18 mg; niacin, 4.41 mg; thiamin, 0.04 mg; B 6 , 0.39 mg. For “regu- lar” hamburger, the value per 3 oz. (85 g) broiled is: calories, 245; protein, 20 g; fat 17.8 g; cholesterol, 76 mg. (See also ANTIBIOTICS; CHOLESTEROL.) hard cider See CIDER. hardening of the arteries See ARTERIOSCLEROSIS. hard water See WATER . hawthorn (Crataegus oxyacantha) A spiny tree or hedge native to Europe whose berries have medicinal properties. Folk traditions describe the use of berries and flowers as beneficial supple- ments for INFLAMMATION ranging from ARTHRITIS to sore throats; for vascular conditions such as angina, high blood pressure, and clogged arteries. Sub- stances in hawthorn extracts inhibit constriction of blood vessels and strengthen arterial walls, poten- tially protecting against plaque deposits. Hawthorn berries and blossoms contain FLA- VONOIDS, particularly anthocyanins and proantho- cyanins, colored pigments of berries including blueberries, cherries, and grapes. These flavonoid compounds stabilize collagen, the primary struc- tural protein of connective tissue, as well as of tendons, cartilage, and ligaments. They act as antioxidants, prevent FREE RADICAL damage, and prevent the release and synthesis of substances that promote inflammation, such as prostaglandins, his- tamines, and leukotrienes. Hawthorn is unsafe for pregnant women; data for breast-feeding women are inadequate. Hazard Analysis and Critical Control Points (HACCP) A food safety program initially adopted by the U.S. FDA in 2001 for seafood and juice; even- tually, the agency plans to expand it to the entire U.S. food supply. Based on a similar program devel- oped for astronauts in the 1970s, HACCP focuses on preventing hazards that could cause food-borne illnesses by applying science-based controls, from raw material to finished product. The FDA describes the seven principles of HACCP as follows: • Analyze hazards. Potential hazards associ- ated with a food and measures to control those hazards are identified. The hazard could be bio- logical, such as a microbe; chemical, such as a toxin; or physical, such as ground glass or metal fragments. • Identify critical control points. These are points in a food’s production, from its raw state through processing and shipping to consumption by the consumer, at which the potential hazard can be controlled or eliminated. Examples are cooking, cooling, packaging, and metal detection. • Establish preventive measures with critical limits for each control point. For a cooked food, for example, this might include setting the minimum cooking temperature and time required to ensure the elimination of any harm- ful microbes. • Establish procedures to monitor the critical control points. Such procedures might include determining how and by whom cooking time and temperature should be monitored. • Establish corrective actions to be taken when monitoring shows that a critical limit has not been met. This might entail, for example, reprocessing or disposing of food if the minimum cooking temperature were not met. • Establish procedures to verify that the sys- tem is working properly. This might involve, for example, testing time-and-tempera- 330 hard cider ture recording devices to verify that a cooking unit is working properly. • Establish effective record-keeping to docu- ment the HACCP system. This would include records of hazards and their control methods, the monitoring of safety requirements, and action taken to correct potential problems. Each of these principles must be backed by sound scientific knowledge: for example, pub- lished microbiological studies on time and tem- perature factors for controlling food-borne pathogens. This new food safety program was adopted by the FDA as a way to meet the challenges of increas- ing numbers of food pathogens, including ESCHERICHIA COLI 0157:H7 and SALMONELLA. hazelnut (filbert, cobnut) A sweet, grape-sized nut of a deciduous shrub or small tree that is related to the birch. The hazelnut is one of the world’s largest nut crops; it is commercially grown in the United States, Spain, Turkey, and Italy. A native of Europe and Asia Minor, it grows well in regions with mild, moist winters and cool summers. “Divining rods” made from the wood of the tree were believed to have the power to seek out treasure or pockets of valuable minerals. Chopped or ground hazelnuts are often used as flavorings in desserts and sweet snacks. The brown whole nuts are often included in holiday mixes at Christmas. A quarter cup serv- ing provides: calories, 180; fat 16 g; fiber, 4 g; pro- tein, 5 g. HCl See STOMACH ACID. HDL See HIGH-DENSITY LIPOPROTEIN. head cheese A cold cut prepared from the MEAT of a calf and pig heads, (including cheeks, snouts, lips) together with brains, hearts, tongues, and feet. The cooked meat, stripped from bones, is ground, seasoned, and then pressed to create a single jellied mass. (See also BEEF; FOOD PROCESSING; HAM.) heart attack A condition (also known as myocar- dial infarction) resulting from a blocked coronary artery, an artery feeding the heart. When oxygen supplied to the heart muscle is compromised, the tissue may be irreparably damaged. Symptoms include prolonged pressure or painful tightness at the center of the chest, possibly spreading to the left arm and shoulder and to the neck and jaw. There may also be nausea and vom- iting, shortness of breath, and sweating. The odds of heart attack increase with well- established risk factors: a family history of heart disease; high blood pressure; obesity; diabetes; increasing age; cigarette smoking; low folic acid; a high intake of saturated fat; a sedentary lifestyle; and repressed anger/anxiety. A healthful diet, reg- ular exercise, stress management, social and emo- tional support, maintaining a desirable body weight, avoiding smoking, and a semi-vegetarian diet with reduced fat are recommended. Blood clots are one of the dangers of clogged arteries. When clots lodge in arteries feeding the heart, they block blood flow. The heart requires a constant supply of nutrients and oxygen from the blood, and being deprived of oxygen even briefly will damage the heart muscle. It is critically important to secure immediate medical care for a heart attack by dialing 911. Many heart attack patients die before they get to the hos- pital, and delays in summoning help can be fatal. (See also ATHEROSCLEROSIS ; BLOOD CLOTTING; CHOLES- TEROL; CORONARY ARTERY DISEASE; HOMOCYSTEINE; STROKE .) Morrison H. I. et al. “Serum Folate and Risk of Fatal Coronary Heart Disease,” Journal of the American Med- ical Association 275, no. 24 (June 26, 1996): 1,893–1,896. U.S. Department of Health, Education and Welfare, How Doctors Diagnose Heart Disease. Washington, D.C.: DHEW Publication No. (NIH) 78–753. heartburn See ACID INDIGESTION. heart disease See ATHEROSCLEROSIS; CARDIOVAS- CULAR DISEASE; CORONARY ARTERY DISEASE; HEART ATTACK ; STROKE. heart-healthy diet See CHOLESTEROL; DIETARY GUIDELINES FOR AMERICANS . heart-healthy diet 331 332 heat inactivation heat inactivation The loss of biological activity of a substance, such as an ENZYME, when heated to suf- ficiently high temperatures. In the case of enzymes, heat alters structures critical for catalysts. COOKING at high temperatures destroys vitamins such as VIT- AMIN C , FOLIC ACID, and THIAMIN. Through oxidation or other chemical changes, polyunsaturated FATTY ACIDS and even CHOLESTEROL become oxidized when heated at sufficiently high temperature in the presence of air. The essential AMINO ACID, LYSINE,is partially destroyed when grain protein and carbo- hydrate are heated together. Several processed BREAKFAST CEREALS contain less lysine than that pre- sent in flour because they have been baked. heavy metals Industrial chemicals of LEAD, MER- CURY , CADMIUM, CHROMIUM, NICKEL, antimony, and ARSENIC. These chemicals are general enzyme poi- sons, and the toxic effects of these industrial wastes is well established. As an example, lead exposure causes ANEMIA by blocking a key step in the syn- thesis of HEMOGLOBIN, required for the formation of RED BLOOD CELLS. As a general rule, the greater the exposure to a toxic metal, the greater the risk of poisoning. Wide- spread pollution has created chronic low-level exposure in many regions of the United States, thus increasing the risk of heavy metal poisoning. Therefore, minimizing heavy metal exposure in air, food, and WATER can lead to dramatic, long-term health benefits. Nutrients like sulfur-containing amino acids, selenium, and VITAMIN C seem to have the ability to counteract heavy metals in the body, while diets low in CALCIUM, IRON, or ZINC increase lead uptake. The body has several defense mechanisms against toxic exposure. One of these is metallothionens, proteins rich in the sulfur amino acid CYSTEINE that bind heavy metals and speed their removal. Metal- lothionen synthesis is triggered by exposure to heavy metal ions. The following are specific exam- ples of common toxic metals: Arsenic, which occurs in PESTICIDES, smog and cigarette smoke, is believed to interfere with neu- rological development, and high doses increase the risk of some types of cancer. Cadmium may cause high blood pressure and heart abnormalities, bron- chitis, lung fibrosis, and emphysema. Small amounts are common in consumer items ranging from cigarettes and pesticides to food. Drinking water may be contaminated with cadmium because soft water dissolves the cadmium in galva- nized pipes. Lead exposure leads to distractibility, DIARRHEA, irritability, and lethargy. More serious conse- quences are smaller fetal brain size, increased BIRTH DEFECTS , decreased IQ, anemia, CHRONIC FATIGUE , aching limbs, kidney disease, and sometimes coma. Though the U.S. EPA banned leaded paints and has required lowered lead levels in gasoline, Americans still are exposed to lead through drinking water, glazed ceramic dinnerware, old paint, and decades of environmental pollution. Selenium is a water and soil contaminant in some regions of the United States. In trace amounts, the appropriate chemical form of sele- nium is an essential nutrient. However, the margin of safety of selenium is small, and ingesting only five times the level deemed safe and adequate can cause toxic side effects. (See also BREAST-FEEDING.) height/weight tables Standards of weight and height by age used to assess an appropriate body weight for normal people. Several different tables have been developed. The Metropolitan Life Insur- ance Company assembled the best-known height/weight table, based upon the heights and weights of policy holders. It was later realized that weight depends on body build; therefore, values for an “ IDEAL BODY WEIGHT” were adjusted by including different values for “small,” “medium,” and “large” body sizes. Since ideal body weight implies making a judgment and is subjective, a more liberal version of these tables was published in 1983, based on data obtained from 1959 to 1983. The 1983 revision came up with a “desirable body weight” that is 10 percent greater than that on the older table. This revision suggests that a woman of average frame and average height (5 feet 4 inches) wearing 3 pounds of clothing and wear- ing one-inch heels would weigh 126 to 138 pounds. For an average man (5 feet 9 inches tall, wearing five pounds of clothing), the range is 148 to 160 pounds. Several limitations of life insurance tables restrict their usefulness. Their weights are based on values that were simply reported, not measured. Insurance policy holders for whom the data were collected do not represent the whole U.S. population. High blood pressure, smoking, and diabetes—factors that can affect general health and body weight—are not considered. There is no firm definition of “frame size.” Thus, tables of this kind represent a subjective evaluation. The tables would suggest that a wide range of weights (30 to 40 pounds) poses no risk, in contradiction to common experience. Newer infor- mation indicates that excess FAT, not weight, is crit- ical. Furthermore, it is important to establish how the fat is distributed in order to assess risks. (See also BODY MASS INDEX; OBESITY .) Helicobacter pylori (Campylobacter pylori) A spiral-shaped bacterium that can infect the stom- ach and cause GASTRIC ULCERS, duodenal ulcers and symptomatic, atrophic GASTRITIS (stomach inflam- mation), and a higher risk for stomach cancer. Almost 90 percent of patients with the most com- mon type of stomach CANCER, intestinal-type gas- tric adenocarcinoma, are infected with H. pylori. While stomach acid kills many bacteria, H. pylori burrows deep into the mucus layer to the underly- ing mucosal cell surface, where it is protected from stomach acid. Half of all Americans over the age of 50, and 75 percent of subjects older than 65 have antibodies against H. pylori, suggesting a wide prevalence of infection. While many adults exhibit evidence of antibodies to this bacterium, it is not clear why only a small percentage develop duode- nal ulcers. On the other hand, irradiation of H. pylori with bismuth compounds combined with several antibiotics decreases the risk of ulcer relapse and yields a significant improvement in ulcers and stomach inflammation. Researchers have discovered that BROCCOLI and broccoli sprouts contain a chemical, SULFORAFANE, that kills H. pylori in mice. Similar studies on humans are ongoing. (See also GASTROINTESTINAL DISORDERS.) hematocrit A clinical lab test used to assess the health of red blood cells. The hematocrit represents the volume of packed red blood cells, expressed as the percentage of total blood volume. For men, the average hematocrit is 47 percent with a range of 40 percent to 54 percent and for women, the average is 42 percent with a range of 37 percent to 47 per- cent. Children’s hematocrit varies depending on the age. Serious fluid loss without cell loss, as in DEHYDRATION , raises the hematocrit, while blood loss or ANEMIA lowers the hematocrit. (See also HEMOGLOBIN .) heme An IRON-containing red pigment found in red blood cells. HEMOGLOBIN, the oxygen transport protein of blood, requires heme to bind molecular oxygen reversibly. Heme also functions as a helper group of CYTOCHROMES, enzymes responsible for transporting electrons in energy-generating reac- tions of MITOCHONDRIA. Heme is synthesized in the bone marrow by the parents of red blood cells (reticulo-endothelial cells). Iron is bound within a complex ring struc- ture, synthesized from small building blocks: GLYCINE, the simplest AMINO ACID, and SUCCINIC ACID , produced from fat and carbohydrate break- down. Heme synthesis requires VITAMIN B 6 , and LEAD inhibits the process. Therefore vitamin B 6 deficiency and lead poisoning cause ANEMIA. When the spleen removes wornout red blood cells it con- verts heme to the BILE PIGMENT, bilirubin, and recy- cles the released iron. Much of the iron in meat, fish, and poultry occurs as heme, which is readily absorbed by the intestine. Absorption of this heme iron is not diminished by PHYTIC ACID , a metal binder occur- ring in certain plant materials, nor is it increased by VITAMIN C . In contrast, most of the iron in vegeta- bles is not bound to heme and is less readily absorbed. The efficiency of nonheme iron absorp- tion from plant sources is only 10 percent to 20 percent that of heme iron. Vitamin C increases the uptake of iron from nonheme sources. Some forms of FIBER bind minerals and lower intestinal absorp- tion of nonheme iron. hemicellulose A form of dietary FIBER, plant mate- rial resistant to digestive enzymes. Hemicellulose helps form plant cell walls. Annual plants contain 15 percent to 30 percent hemicellulose by dry weight in their cell walls, while wood contains 20 percent to 25 percent hemicellulose. Dietary sources of hemi- cellulose include FRUIT, vegetables, LEGUMES, cereal, BRAN, whole-grain flours, nuts, and seeds. Dietary hemicellulose 333 hemicelluloses absorb water, provide bulk, and soften stools. They are broken down by intestinal bacteria. Excessive amounts of hemicelluloses may interfere with mineral absorption. Hemicellulose is structurally distinct from water- soluble fibers such as gums and pectin and insolu- ble fiber like CELLULOSE. Hemicellulose contains long chains of repeating sugar units. Pentosans are chains of PENTOSES, five-carbon sugars like xylose and arabinose. Pentosans form the largest group and occur in CEREAL GRAINS . Galactosans, chains of the simple sugar GALACTOSE, form a second group. Acidic hemicelluloses also occur in food. hemochromatosis A rare condition caused by excessive IRON deposits in tissues, including the LIVER, PANCREAS, and skin. Symptoms include liver enlargement, weakness, moderate weight loss, bronzed skin, diabetes, and, eventually, heart fail- ure. Hemochromatosis is 10 times more frequent in men than in women. Abnormal iron metabolism can be caused by a genetic defect (primary hemochromatosis) charac- terized by increased accumulation of iron in tissues. The inherited trait for iron storage disease is rela- tively common among whites, affecting perhaps as many as one person in two hundred. This suggests that the tendency to accumulate dietary iron is a more general problem in the U.S. than generally rec- ognized. Alternatively, excessive iron consumption can lead to abnormally high iron storage (secondary hemochromatosis). This can occur with chronic iron supplementation in men, because they do not usu- ally lose iron, and in alcoholics, because several alco- holic beverages contain iron. (See also FERRITIN.) hemoglobin The oxygen transport protein of blood and the predominant protein in red blood cells. Hemoglobin is a complex PROTEIN; it contains a total of four individual amino acid chains called globins. Adult hemoglobin contains two alpha glo- bin chains and two beta globin chains. Hemoglobin also contains the iron-containing pigment HEME, which is required to bind oxygen. Heme imparts a red color to hemoglobin and to red blood cells. Hemoglobin is a dynamic molecule and changes its shape and oxygen-carrying characteristics to help regulate oxygen delivery and blood pH. It binds oxy- gen when the oxygen concentration is high in blood exposed to air in the lungs. Next, arteries carry oxygen-rich red blood cells from the lungs to capil- laries, where hemoglobin responds by releasing more of its bound oxygen (the Bohr effect). The re- leased oxygen then diffuses into cells to enable them to continue the oxidation of fuel molecules. During this process of shedding oxygen molecules hemoglo- bin binds carbon dioxide and hydrogen ions and returns them to the lungs via the veins. In the lungs hemoglobin picks up more oxygen and simultane- ously releases carbon dioxide and hydrogen ions. An adult normally produces 6.25 g of hemoglo- bin daily. The hemoglobin blood content of women is 12 to 16 g per 100 ml of blood, and of men, 14 to 18 g. ANEMIA is a deficiency of normal red blood cells. Deficiencies of IRON, VITAMIN A, VITAMIN B 6 , VITAMIN B 12 , VITAMIN D, VITAMIN E, and FOLIC ACID may cause anemia. Over 400 mutant hemoglobins are known. Most do not alter normal physiological function of hemoglobin. However, certain mutations lead to abnormal hemoglobins that malfunction and pro- duce fragile red blood cells and, consequently, ane- mia, including sickle cell anemia and thalassemias. Alteration of a single amino acid in a chain of 146 amino acids causes sickle cell anemia. Environmental factors can decrease hemoglobin function. Carbon monoxide poisons hemoglobin, and cigarette smokers’ blood contains much more carbon monoxide than that of nonsmokers. Fur- thermore, babies born to smoking women are smaller than average because they receive less oxy- gen during fetal development. (See also ERYTHRO- POIESIS; HEMATOCRIT.) Davie, Sarah J. et al. “Effect of Vitamin C on Glycosyla- tion of Proteins,” Diabetes 41 (1992): 167–173. hemolytic anemia A deficiency of red blood cells caused by their rapid destruction and characterized by chronic fatigue. Typically, hemoglobin break- down products accumulate, leading to JAUNDICE, the accumulation of yellow pigment in the skin and in the whites of the eyes. Rapid turnover of red blood cells may be caused by genetic diseases that lead to the production of abnormal HEMOGLOBIN,as in sickle cell ANEMIA and thalassemias. Defects in red blood cell enzymes can also cause hemolytic anemia. A deficiency of one such enzyme, glucose- 334 hemochromatosis herbal medicine 335 6-phosphate dehydrogenase that helps maintain adequate levels of GLUTATHIONE, a cellular ANTIOXI- DANT, is the most common of these defects. Acquired hemolytic anemia can be caused by expo- sure to potentially damaging chemicals, including certain drugs (antimalarials, pimaquine, and Atra- bine). (See also IRON.) hemolytic-uremic syndrome See ESCHERICHIA COLI. hemosiderosis A condition associated with excessive iron deposition, particularly in the LIVER and spleen. Hemosiderin is the insoluble iron com- plex formed in the liver with iron accumulation. Hemosiderosis can be caused by: 1. excessive red blood breakdown associated with chronic infection, malaria, hemolytic anemias, PERNICIOUS ANEMIA, or multiple blood transfu- sions; 2. excessive uptake of dietary iron; 3. impaired utilization of iron. Under severe conditions, with extreme accumu- lation of iron, the resulting disease is called HEMOCHROMATOSIS . This condition in turn causes liver damage and pancreatic damage, which can lead to DIABETES. heparin A carbohydrate that is a naturally occur- ring anticoagulant (prevents blood from clotting). Heparin is produced by mast cells (cells that also contain inflammatory agents like histamine) in connective tissue, the liver and certain white blood cells. Heparin prevents the formation of FIBRIN clots. (Fibrin is the insoluble protein produced when blood clotting is triggered.) In capillaries, heparin also activates the lipoprotein LIPASE, the enzyme that releases FATTY ACIDS from CHYLOMI- CRONS and VERY LOW-DENSITY LIPOPROTEINS, particles that transport fat in the blood. (See also FAT METAB- OLISM; GLYCOSAMINOGLYCANS.) hepatic Refers to the LIVER. hepatitis Chronic inflammation of the LIVER. Symptoms include JAUNDICE, liver enlargement, fever, and gastrointestinal disturbances. Hepatitis can cause a loss of APPETITE, headache, and a change in taste sensation. It can interfere with DIGESTION, leading to MALNUTRITION. Hepatitis can be caused by drugs, poisons, and viruses. Infectious hepatitis refers to a family of viral dis- eases spread orally. Hepatitis A is caused by the hepatitis A virus usually transmitted orally through fecal contamination of food utensils, due to poor hygiene by food workers who have been infected with the virus. Fecal contamination can also spread through drinking WATER. Eating shellfish contami- nated by raw sewage is a common cause of infec- tious hepatitis. The long incubation period, three to six weeks, makes it difficult to associate hepatitis with a specific food. GAMMA GLOBULIN may prevent the disease, provided the shots are administered soon after exposure. Travelers to countries typified by poor sanitation may be advised to receive gamma globulin shots, which will offer protection for up to three or four months. Hepatitis E is an enteric (small intestinal) form of hepatitis that has been associated with waterborne outbreaks of hepatitis in developing countries. Other forms of hepatitis (such as hepatitis B and hepatitis C) are spread through blood. (See also FOOD POISONING.) Fried, M. W. “Therapy of Chronic Viral Hepatitis,” Medical Clinics of North America 80, no. 5 (September 1996): 957–972. herbal medicine (botanical medicine) The branch of medicine that emphasizes the therapeutic prop- erties of plants. Ancient medical traditions from India (ayurvedic medicine) and China (oriental medicine) and others emphasize the health bene- fits of specific plants and plant products, and med- icinal plants provided the foundation of the modern pharmaceutical industry. Recent environ- mental awareness of the diversity of species in threatened tropical rain forests has rekindled research in the pharmacological effects of indige- nous plants. Although natural products, they offer the advantage of containing multiple active princi- ples that possess a variety of often complementary properties. Often, the active ingredients of herbs correct an underlying problem rather than simply treating a symptom. Most herbal preparations are considered foods by the U.S. FDA and they cannot be labeled with health claims. Quality control is an issue with herbal prepara- tions. Their potency is affected by the plant’s age at the time of harvest, the season of harvest, the type of soil used for cultivation, the climate, and the methods of storage and preparation. Producers often measure the amounts of active ingredients in a given herbal preparation or extract and then adjust the strength to a standard level to assure a reproducible activity. The appropriate amount consumed is a second concern; an amount that is safe for an adult may not be safe for a child. Some herbs are appropriate for short-term use, and not for long periods. A third concern is safety. According to the U.S. FDA, extracts of the following plants are potentially dangerous: arnica, belladonna (deadly nightshade), Culcana, blood root, Scotch broom, buckeye nuts, heliotrope, hemlock, henbane, jalop root, jimson- weed, lily of the valley, lobelia, mandrake, mistle- toe, morning glory, periwinkle, St John’s-wort, spindle bean, tonka bean, snakeroot, and worm- wood (once used to flavor absinthe, a liqueur). Often foods themselves provide substances that promote health. Beyond the nutrients they con- tain, ONIONS, GARLIC, CHILI PEPPERS, LICORICE, TUR- MERIC, CRANBERRY , GINGER, DANDELION, BLUEBERRIES, and cherries contain a variety of substances that fight infection, reduce the risk of cancer, stimulate the nervous system or reduce inflammation. (See also ALFALFA; CHAMOMILE; COMFREY; GINSENG; GOLD- ENSEAL ; HAWTHORN; PEPPERMINT; SARSAPARILLA; STRAWBERRY.) Wehrbach, M. R., and M. T. Murray. Botanical Influences on Illness. Tarzana, Calif.: Third Line Press, 1994. herbicides A diverse family of chemicals used to kill weeds during cultivation of crops. Many herbi- cides are suspected of causing CANCER or BIRTH DEFECTS . The health risks of herbicides are greatest for those with chronic exposure, such as farm workers and professional applicators. The following herbicides are examples currently in use: • Alachlor is a widely used herbicide and is among the most dangerous. • Atrazine accounts for about 10 percent of PESTI- CIDE sales in the United States and was restricted by 1991. This herbicide has been found to widely contaminate underground water sup- plies in the United States. • Dinoseb was subject to an emergency ban by the EPA in 1986 because of a possible link to birth defects, skin rashes, cancer, and sterility in experimental animals. Because a substitute was not developed, the EPA permitted the continued use of Dinoseb on LENTILS, PEAS, CHICKPEAS, green beans, and RASPBERRIES. • Linuron is a common herbicide used on SOY- BEANS , carrots, celery, asparagus, corn, potatoes, and wheat. It is associated with tumors in exper- imental animals. Linuron frequently contami- nates water supplies, • Paraquat is used to treat fields before planting or before harvest. It is used extensively in soybean agriculture and in orchards. Paraquat cannot be washed off produce, and direct exposure to this chemical is hazardous. Inhalation of its mist causes lung inflammation and repeated expo- sure can lead to kidney and lung damage. It is also toxic to fish. • 2,4-D is widely used by home owners and home gardeners to kill dandelions. It is the toxic agent in over 1,500 pesticide products. Exposure is greatest for children and animals who play in treated areas. Farmers use 2,4-D on CORN, WHEATS , and hay. A National Cancer Institute study linked this weed killer with cancer of lym- phoid tissue in experimental animals. (See also DIOXIN ; PESTICIDES.) herbs The leaves, shoots, stems, and seeds of many widely distributed plants. In contrast, SPICES are prepared from the FRUIT, bark, or pepper corns from tropical plants. Culinary herbs have appealing aromatic or savory characteristics and make food tasty and flavorful. In addition many herbs affect physiological processes, which is the basis for their medicinal properties. In some cases, research has provided deeper insights into the active ingredients. Culinary herbs that exhibit physiologic effects include: • ANISE and CARAWAY may relieve gas and stomach cramps. Caraway contains carvacrol, a com- pound that eases muscle spasms. • Carrot seed may relax smooth muscles, relieve stomach cramps, and lower blood pressure. 336 herbicides • Celery seed contains phthalides, chemicals that are sedatives. Celery seed has antibiotic activity. Celery juice may lower blood pressure. • CHERVIL contains the mild carcinogen estragole, which is also found in basil and tarragon. • Coriander (cilantro) may lower BLOOD SUGAR and increase GLUCOSE TOLERANCE. Coriander lowers blood fat. According to folklore, it curbs bad breath. • Dill oil reduces cramps, lowers blood pressure, and slows heartbeat in experimental animals. Dill water reduces colic, according to folklore. • FENNEL contains sulfur compounds that relieve cramps. According to folklore, it helps with colic and upset stomach. • LOVAGE seeds, leaf, and root can be steeped in boiling water to prepare a tea, used in folk med- icine to reduce water retention and ease joint pain. Lovage increases urination and water loss in experimental animals. • PARSLEY lowers blood pressure and stimulates uterine contractions in experimental animals. Parsley acts as a mild LAXATIVE and also freshens the breath. Parsley oil contains apiol and myris- ticin, which induce menstruation. Parsley oil can induce miscarriages and should not be administered during pregnancy. Herbs of the mint family that exhibit physiologic effects: • BASIL relieves FLATULENCE and gastrointestinal discomfort. • Lemon balm is an ANTIOXIDANT. Animal studies suggest the oil relieves inflammation. • MARJORAM may relax smooth muscles and re- lieve stomach cramps. According to folklore, marjoram tea eases cramps and upset stomach. • OREGANO can function as an antiseptic. Its oil con- tains carvacrol, which possesses broad anti- microbial properties. It relieves upset stomach and is a smooth muscle relaxant. According to folk- lore, chewing oregano reduces toothache pain. • ROSEMARY and SAGE contain strong antioxidants. Like CLOVES, oregano, and GINGER, they have long been used to preserve food. Sage is used commercially to preserve salad oil and potato chips. According to folklore, rosemary aids memory and induces sleep. • THYME contains thymol, an antiseptic. Thyme is used as a mouth wash. Oil of thyme causes dan- gerous side effects, however. hermetically sealed Refers to food containers that do not permit entry of either microorganisms or air. For example, bottled or canned foods are hermetically sealed. (See also FOOD PROCESSING.) herring (Clupea harengus) A small, saltwater FISH related to the shad and SARDINE. Silvery and streamlined, the herring reaches a length of 10 in. at maturity. A freshwater variety is known as cisco. Herring is an important food fish that is also processed for animal feed. Intensive fishing prac- tices worldwide have placed this fish in jeopardy. Herring is an oily fish, and most of the fat is unsaturated. It is available frozen, pickled, or smoked. Herring roe is used to prepare CAVIAR. Pickled herring, 3 oz. (85 g), provides calories, 190; protein, 17.3 g; fat, 12.8 g; cholesterol, 66 mg; cal- cium, 31 mg; iron, 1.2 mg; sodium, 1.38 mg; zinc, 0.85 mg; vitamin A equivalents, 20; niacin, 2 mg; thiamin, 0.04 mg; riboflavin, 0.18 mg. hesperidin A substance found in rinds of ORANGES and lemons and in the peels of ripe fruit. A mature orange contains about a gram of hesperidin. Citrus FLAVONOIDS are commercially extracted from the pulp remaining after juicing oranges and lemons. Hesperidin is believed to strengthen capillary walls in conjunction with VITAMIN C . Like most flavo- noids, it is also an ANTIOXIDANT and limits oxidative damage. (See also CITRUS FRUIT.) heterocrine Refers to tissues that secrete differ- ent types of materials. The PANCREAS is a notable example; it combines an endocrine function (secre- tion of hormones INSULIN and GLUCAGON directly into the blood) and an exocrine function (secretion of digestive enzymes into the intestine). (See also ENDOCRINE SYSTEM.) heterocyclic amines (HCAs) A family of cancer- causing agents that occur in cooked MEAT. HCAs tend to form inside meat with longer cooking times and higher temperatures of barbecuing. They can- heterocyclic amines 337 338 hexose not be scraped off and once eaten they can become activated to attack DNA of cells, a possible first step in cancer development. HCAs can also inflame the heart. There are several ways to minimize the risk of HCAs. Precooking hamburger for a short time before barbecuing seems to eliminate some of the compounds that can form HCAs. On the other hand, green and black tea contain tannins, bitter substances in brewed tea, that can block the ability of HCAs to damage DNA. Garlic and onions behave similarly. The green plant pigment chlorophyll can also block the damaging effects of HCAs. Supple- menting with the bifidobacteria can protect the COLON against HCAs. (See also CARCINOGEN.) hexose A large class of simple sugars composed of six carbon atoms that can serve as an energy source. FRUCTOSE and GLUCOSE are the two most important hexoses in the diet. As BLOOD SUGAR, glucose is the most important CARBOHYDRATE fuel in the body. Hex- oses also function as building blocks for more com- plex sugars and for important large molecular weight carbohydrates. Thus, fructose is linked to glucose in table sugar, and LACTOSE contains two hexoses, GALACTOSE and glucose. Polymerized MANNOSE is found in glucomannan, a form of fiber. STARCH, GLYCOGEN , and CELLULOSE are polysaccharides made from glucose. (See also NATURAL SWEETENERS .) hiatus hernia (hiatal hernia) The protrusion or bulging of the STOMACH through the esophageal opening (hiatus) of the diaphragm into the chest. Aging or damage of supportive tissue can lead to hiatus hernia and DIVERTICULOSIS, which is the bulging of the large intestine. For Americans, there is a 50 percent chance of having a hiatus hernia after the age of 40. Symptoms resemble DYSPEPSIA, including a burning pain under the breastbone and heartburn in which stomach con- tents regurgitate into the ESOPHAGUS, causing inflammation. Inability to breathe deeply and fre- quent belching are also experienced. Symptoms are most noticeable after a large meal, when straining or when stooping. Hiatus hernia is often a recurrent condition. Several steps can be taken to minimize its effects. Consumers should: • Practice good posture to allow less crowding of organs in abdominal area. • Eat light meals that are less likely to force the stomach through the diaphragm. • Eat in a peaceful environment. • Receive physical manipulation by a skilled ther- apist or bouncing on one’s heels to move the stomach down into place. • Avoid swallowing air; this inflates the stomach. • Take licorice extract. hidden fat See FAT. high blood pressure See HYPERTENSION. high-calorie foods See FAT, HIDDEN. high complex carbohydrate diet See DIET, HIGH COMPLEX CARBOHYDRATE . high-density lipoprotein (HDL) A type of lipid- protein complex or particle in the blood that scav- enges CHOLESTEROL from peripheral tissues and transports it to the LIVER for disposal. HDL’s func- tion is opposite that of LOW-DENSITY LIPOPROTEIN (LDL), which transports cholesterol to tissues. HDL can transfer cholesterol to another lipid carrier, VERY LOW-DENSITY LIPOPROTEIN (VLDL), prior to its conversion to LDL. Because HDL possesses the highest protein con- tent, which is more dense than lipid, HDL is the densest of the various circulating lipoproteins. HDL precursor is synthesized by the liver. HDL 3 is an intermediate form, to which lipids and proteins are added from other lipoproteins in the circulation. The mature, spherical HDL is called HDL 2 . Gener- ally speaking, the higher the HDL level, the lower the risk of ATHEROSCLEROSIS. Women have a lower risk of heart disease than men and their HDL levels are higher. Evidence suggests that HDL 3 is inversely linked to the risk of coronary heart dis- ease more strongly than HDL 2 . HDL contains proteins that determine its role. For example, Apoprotein D catalyzes cholesterol transfer between HDL and LDL, and Apoprotein CII is transferred to VLDL and CHYLOMICRONS, enabling these lipoproteins to interact in capillaries [...]... regulate the pituitary gland, the “master gland” of the endocrine system, smooth muscles such as those around blood vessels, and cardiac muscles The parasympathetic and sympathetic portions of the autonomic NERVOUS SYSTEM counterbalance each other The sympathetic division adapts the body to stress, while the parasympathetic division of this system restores energy to tissues and restores the body after... structure of the body contributes to maintaining a normal internal environment In particular, homeostatic responses are controlled by the nervous system and the ENDOCRINE SYSTEM The regulation and integration of these two systems is accomplished by the PITUITARY GLAND, the HYPOTHALAMUS, and the ADRENAL GLANDS The hypothalamus is the region of the brain that controls the autonomic nervous system, nerves that... placenta produces human chorionic gonadotropin, which provides a stimulus for the continued production of progesterone, which is required to keep the embryo attached to the uterine lining Hormones of the Digestive Tract Several hormones regulate the activity of the digestive tract The pyloric mucosa (the lining of the lower region of the stomach) and duodenum (the first section of the small intestine)... GLANDS, endocrine PANCREAS, THYROID and PARATHYROID glands, glands of the stomach and intestine, pineal gland, THYMUS, ovaries, testes, and placenta Each endocrine gland secretes a characteristic hormone or set of hormones Hormones from each source act on a specific target tissue or tissues The hypothalamus is a region of the brain that activates the pituitary gland, known as the master gland, by means of. .. mg hormone A chemical messenger sent through the bloodstream to target tissues The name hormone is derived from the Greek word hormon, which means “to set in motion.” The brain and nervous system control hormone release from specialized tissues called endocrine glands, and the ENDOCRINE SYSTEM consists of all the hormoneproducing tissues They include the HYPOTHALAMUS, the PITUITARY GLAND, ADRENAL GLANDS,... also helps lower fat consumption Drug therapy may be recommended when the cholesterol is very high, when the cholesterol value doesn’t drop with diet therapy and other lifestyle changes, and when the risk of cardiovascular disease is high for other reasons, such as heredity (See also CHOLESTEROL-LOWERING DRUGS.) in 30 to 60 minutes after eating starchy foods, then returns to a baseline level within three... reabsorption of WATER into blood from the urine in kidney tubules, and OXYTOCIN, which stimulates contractions of the uterus at the termination of pregnancy and stimulates milk release The hypothalamus regulates the PITUITARY GLAND, the master gland of the ENDOCRINE SYSTEM, by means of a battery of hormones Thyrotropin-releasing hormone directs the pituitary gland to release thyroid stimulating hormone... “releasing hormones.” The hypothalamus also makes two hormones that are released through the pituitary gland: ANTIDIURETIC HORMONE (ADH) decreases the amount of WATER in urine by increasing SODIUM retention in the kidney; OXYTOCIN stimulates lactation and uterine contractions for birth 342 hormone-free meat The pituitary gland is connected to the brain through the hypothalamus It regulates many other glands... Corticotropin-releasing factor directs the pituitary to release ACTH, which activates the adrenal glands The hypothalamus also secretes growth hormone releasing hormone, and growth hormone inhibiting hormone (somatostatin), which regulate pituitary secretion of growth hormone; luteinizing hormone releasing hormone, which directs the pituitary to release luteinizing hormone to help regulate the menstrual... a hydrophobic end and a hydrophilic (water-attracting) end They form a ball-shaped shell, in which the attracting portions of the molecules face outward to interact with water, while their hydrophobic regions point inward, embedded in the oily droplet they surround Certain amino acids possess hydrophobic regions (side chains): PHENYLALANINE; METHIONINE, TRYPTOPHAN, ALANINE, LEUCINE, ISOLEUCINE, and . is accomplished by the PITUITARY GLAND, the HYPO- THALAMUS, and the ADRENAL GLANDS. The hypothal- amus is the region of the brain that controls the autonomic nervous system, nerves that regulate the. are added from other lipoproteins in the circulation. The mature, spherical HDL is called HDL 2 . Gener- ally speaking, the higher the HDL level, the lower the risk of ATHEROSCLEROSIS. Women have a lower risk. NATURAL SWEETENERS .) hiatus hernia (hiatal hernia) The protrusion or bulging of the STOMACH through the esophageal opening (hiatus) of the diaphragm into the chest. Aging or damage of supportive tissue