What is anion?

A negatively charged ion. Anions are the opposite of CATIONS, which carry positive charges. Important anions are formed when weak acids ionize. Anions, together with their cation counterparts, occur in blood and are called electrolytes. They are required to maintain the appropriate effective concentration of ions and PROTEINS in the
blood. Key anions in blood are chloride (Cl–), phosphate (H2PO4–), and bicarbonate (HCO3
–).
Chloride (Cl–) is the predominant anion in body fluids. Neither chloride nor phosphate can be made by the body; they are essential nutrients to be supplied by the diet. Phosphate and bicarbonate ions help buffer blood at nearly a constant pH. These anions are examples of “conjugate bases,” formed when weak acids ionize.

What is anaerobic

Cellular processes that do not require oxygen. Energy can be produced in cells without oxygen. Anaerobic GLYCOLYSIS refers to an energy yielding process by which ATP, the energy currency of the cell, is produced from GLUCOSE without the participation of oxygen. As an example, skeletal muscle produces LACTIC ACID and ATP from glucose when oxygen supplied to muscle is inadequate to meet energy needs during strenuous physical exertion.
Accumulated lactic acid is then converted back to glucose during the recovery period following EXERCISE when the oxygen supply is again adequate.
Anaerobic processes are important for certain bacteria as well. Anaerobic bacteria in the intestine grow without oxygen and block the growth of potential disease-producing microorganisms. Anaerobic fermentation of SUGAR by yeast yields alcohol-containing products such as WINE and BEER.

Ammonia (NH3) and Human Health

The nitrogen waste produced primarily from AMINO ACID metabolism. Ammonia is highly toxic to the nervous system and the brain. It may interfere with metabolic processes required for energy production in the brain. Normally the brain transforms ammonia into GLUTAMINE, a safe, neutral amino acid released into the bloodstream. Next, glutamine is absorbed by the intestine, which releases the ammonia for disposal by the LIVER. Normally the liver very efficiently metabolizes ammonia to UREA, the ultimate nontoxic waste product, via the UREA CYCLE to keep the level of ammonia in the blood at very low levels. Urea is excreted safely in urine. Ammonia is also produced in the intestinal tract by bacteria. Ammonia is absorbed by the intestine and transported directly via the portal vein to the liver for disposal. Liver disease, such as CIRRHOSIS, reduces urea production and leads to elevated blood levels of ammonia (ammonemia), which causes neurological abnormalities. Genetic defects in the ammoniadisposal mechanism of the urea cycle generally lead to brain damage.

What is alkaline tide

The slight rise in blood pH following a meal, when the BLOOD temporarily becomes more ALKALINE. When the STOMACH produces hydrochloric acid (STOMACH ACID) for use in DIGESTION, it removes a fraction of negatively charged CHLORIDE ions from circulation. Chloride is then replaced by BICARBONATE in the blood, which tends to raise blood pH. As the meal is digested, chloride ions are reabsorbed by the INTESTINE and again enter the bloodstream. In turn, bicarbonate is reabsorbed and the pH returns to normal. The URINE may become more alkaline during digestion as the body compensates for the change in blood pH.

Understanding Alitame

A non-caloric ARTIFICIAL SWEETENER that is 2,000 times sweeter than sugar that has not yet been approved by the U.S. Food and Drug Administration. This sweetener was developed to be safer than ASPARTAME. Unlike aspartame, alitame does not contain phenylalanine and consequently would likely be safe for individuals with PHENYLKETONURIA (PKU), a genetic intolerance to this amino acid.

Understanding Alginate

(ammonium, calcium, potassium, and sodium salts of alginic acid) A food additive obtained from the giant kelp, a brown algae commercially harvested off the coast of California. Alginate is a major constituent of the cell wall and consists of polymers of acidic sugars Alginate is used by the food industry as a thickening and stabilizing agent because calcium alginate forms very stable gels in water. It prevents jelly in pastries from melting during baking and provides smooth textures to ICE CREAM, YOGURT and CHEESE, CANDY, whipped cream in pressurized cans, and canned frosting. Alginate also helps keep cocoa butter dispersed in chocolate milk. The red PIMENTO stuffed in green OLIVES contains the most alginate (6 percent) of any food source. Alginate is not used in acidic foods and beverage such as salad dressings and SOFT DRINKS, because it forms sediment under these conditions.
Alginate is on the GENERALLY RECOGNIZED AS SAFE (GRAS) list of the U.S. FDA. Short-term animal testing indicates the alginate is not absorbed by the body and is not toxic. Because alginate forms highly charged gels in water, it remains to be determined whether it can limit the absorption of minerals and other nutrients by the body.

Alcohol (ethanol, grain alcohol, ethyl alcohol)

A common term for the simple alcohol ETHANOL, the product of FERMENTATION. As a constituent of alcoholic beverages, ethanol is the most common, and longest used, sedative. To produce alcohol, special strains of yeast are incubated with CARBOHYDRATES of FRUIT juices and GRAINS together with other nutrients.
Under ANAEROBIC conditions (in the absence of oxygen), these microorganisms ferment sugar to ethanol and CARBON DIOXIDE to obtain energy. The immediate product of the fermentation of grapes is WINE. When malted grains and hops are fermented, the product is BEER. Distillation, a process introduced in the Middle Ages, produces alcoholic beverages with a higher alcohol content. These include rum, whiskey, liqueurs, and the like. Beer and wine are perhaps the most popular beverages among moderate drinkers. A mug of beer (11 oz., 4.5 percent), a glass of table wine (4 oz.) and a shot (jigger;
1.5 fl.oz.) of liquor (80 proof) contain about the same amount of alcohol (9 to 13 grams.) Excessive consumption of alcoholic beverages can cause MALNUTRITION because alcoholic beverages contain little else besides CALORIES. A glass of red wine contains 88 calories; a bottle of regular beer, 146; and a shot (1.5 fl. oz.) of whiskey (90 proof), 110 calories. VITAMIN, PROTEIN, and MINERAL content of alcohol is exceedingly low, though wine may contain a significant amount of IRON. For this reason, alcoholic beverages are classified as low-nutrient density or EMPTY CALORIES. To the extent they are consumed, they displace nutrient-dense foods. The blood alcohol level is affected by the amount of alcohol ingested. Water and juice slow the absorption of alcohol, while carbonation increases the rate of uptake into the bloodstream. Alcohol taken with food is less intoxicating. How alcohol is metabolized is another factor. A portion of the ingested alcohol is destroyed by ENZYMES in the stomach that are more active in men than in women; consequently, women generally have a lower tolerance to alcohol. The liver’s capacity to destroy alcohol in the blood is limited, and when the liver’s metabolic system is saturated, a fraction of ethanol in the blood is destroyed each hour. The remaining alcohol readily penetrates the bloodbrain barrier and interacts with the central nervous system. Alcohol can pass from maternal blood into breast milk; therefore, lactating mothers may wish to abstain from drinking.
Some studies suggest that a single alcoholic drink a day may slightly reduce the risk of heart attack and stroke in some individuals. Moderate alcohol consumption increases the level of HDL, the beneficial form of cholesterol that tends to protect against heart disease. Alcohol also inhibits platelet formation, which is required to form blood clots. Moderate alcohol use may also help prevent age-related decline in reasoning and problem solving. The apparent benefits decline after more than one or two drinks, however. The American Heart Association does not recommend drinking alcoholic beverages to prevent heart disease because of the hazards of alcohol abuse.

Acrylamide and Human Health

A chemical used in making plastics, textiles, and dyes and in purifying drinking water. Short-term exposure above safe limits (maximum contaminant levels) set by the Environmental Protection Agency (EPA) causes damage to the central nervous system. Long-term exposure can cause paralysis and possibly cancer. The chemical has been shown to cause cancer in laboratory animals. In 2002 the World Health Organization (WHO) convened an emergency meeting of food safety and health experts after a team of Swedish scientists reported that some starch-based foods, like potato CHIPS, FRENCH FRIES, and some BREAKFAST CEREALS and BREADS, contain high levels of acrylamide. The amount of the chemical found in a large order of fast-food french fries was at least 300 times above EPA safe limits for drinking water. Additional studies in Norway, Great Britain, Switzerland, and the United States reached similar results.
Acrylamide apparently forms in some starchy foods when they are baked or fried at high temperatures. Raw or boiled samples of these foods, such as potatoes, test negative for the chemical. Research on the health effects of acrylamide in food is ongoing. For the time being, most health experts have stopped short of advising consumers to avoid the risky foods or change their cooking methods.

Understanding acidifiers

Common additives that increase the acidity (lower the pH) of foods and beverages. Acidifiers provide tartness and enhance flavors of processed foods. The increased acidity inhibits the growth of microorganisms; thus acidifiers act as preservatives. Certain acidifiers can also retard spoilage by acting as antioxidants, preventing chemical changes due to oxygen. This group of additives includes ADIPIC ACID (adipate), TARTARIC ACID (tartrate), benzoic acid (benzoate), and CITRIC ACID (citrate).

Understanding acid-forming foods

Foods that create acidic residues after they have been broken down by the body. Protein-rich food, such as EGGS, MEAT, and poultry, produce acidic residues when oxidized for energy. The combustion of sulfur-containing amino acids tends to acidify the body (acidic residue). In contrast, fruits and vegetables make the body more alkaline or basic. They contain magnesium, calcium, and potassium salts of organic acids, which yield an alkaline residue when oxidized. Fruits are accordingly classified as alkali-forming foods, even though juices and fruit taste acidic (sour). Excretion of organic acids (potential renal acid load) can be calculated for various foods based on their content of sodium, potassium, calcium, magnesium, chloride, phosphorus, and sulfur. Choosing more alkaline foods may ameliorate osteoporosis, autoimmune conditions such as rheumatoid arthritis, and chronic inflammation.

Acid and human health

A large family of compounds that taste sour and can neutralize bases to create salts. Strong acids like hydrochloric acid (STOMACH ACID) and sulfuric acid (battery acid) give up all of their protons in water and lower the pH, the effective hydrogen ion concentration. A pH of 7.0 is neutral, that is, neither acidic nor basic, while pH values less than 7.0 are considered acidic. Exposure to strong acids tends to damage cells and tissues. The stomach is the only organ normally exposed to strong acids, but it is protected from injury by a heavy mucous layer.
In contrast to strong acids, organic acids are classified as weak acids because they donate only a portion of their hydrogen ions, lower the pH to a lesser degree, and are less dangerous to tissues.
Many compounds in foods are weak acids, including CITRIC ACID, ACETIC ACID, and TARTARIC ACID. Several weak acids are used as FOOD ADDITIVES, including benzoic acid, CARBONIC ACID, and alginic acid. As food additives and recipe ingredients, weak acids add tartness to foods. Weak acids are common intermediates, products of cellular processes that sustain life, including LACTIC ACID, KETONE BODIES, PYRUVIC ACID, acetic acid, FATTY ACIDS, SUCCINIC ACID, citric acid, even the nucleic acids DNA and RNA. GLUTAMIC ACID and ASPARTIC ACID (two common AMINO ACIDS) are classified as acidic amino acids, and are more acid than most.
In the body, weak acids characteristically have lost all their hydrogen ions and exist as a family of anions (negatively charged ions) classified as “conjugate bases” because they have been completely neutralized by the buffer systems of blood. In the blood, lactic acid exists as its anion, lactate; acetoacetic acid (a ketone body) as acetoacetate; citric acid as citrate, and so on. Often the names of acids and their anions are interchanged in nutrition literature.

Acesulfame-K (acesulfame potassium; Sunett)

This non-caloric, ARTIFICIAL SWEETENER tastes approximately 200 times sweeter than table sugar (SUCROSE) and lacks the bitter aftertaste of SACCHARIN. The United Nations Food and Agriculture Organization endorsed acesulfame-K as a satisfactory artificial sweetener in 1983. Acesulfame-K was approved in 1988 by the U.S. FDA as a sugar substitute to be used in packets or as tablets and now is approved for use in chewing gum and in powdered drink mixes. Unlike ASPARTAME, acesulfame-K can be used in cooking because it does not break down at oven temperatures. Blending Sunett with other low-calorie sweeteners creates a beverage with a more sugarlike taste than one sweetened with any single low-calorie sweetener.
The Center for Science in the Public Interest has raised questions about Sunett’s safety, saying a few tests on rats indicated a possibility of cancer, although this was not proof that the sweetener could cause cancer. The Calorie Control Council counters that the safety of acesulfame potassium has been confirmed by more than 90 studies, and it is endorsed by a committee of the World Health Organization. Theoretically, it would not be expected to be absorbed by the body. Nonetheless, some studies suggest that large doses raise blood CHOLESTEROL levels in diabetic laboratory animals and increase the number of lung and mammary tumors in other animals.