Essential and nonessential proteins

To make all the proteins that your body needs, you require 22 different amino acids. Ten are considered essential, which means you can't synthesize them in your body and must obtain them from food (two of these, arginine and histidine, are essential only for children). Several more are nonessential If you don't get them in food, you can manufacture them yourself from fats, carbohydrates, and other amino acids. Three glutamine, ornithine, and taurine are somewhere in between essential and...

Fiber and your heart The continuing saga of oat bran

Oat bran is the second chapter in the fiber fad that started with wheat bran around 1980. Wheat bran, the fiber in wheat, is rich in the insoluble fibers cellulose and lignin. Oat bran's gee-whiz factor is the soluble fiber beta-glucans. For more than 30 years, scientists have known that eating foods high in soluble fiber can lower your cholesterol, although nobody knows exactly why. Fruits and vegetables (especially dried beans) are high in soluble fiber, but ounce for ounce, oats have more....

What Are Dietary Guidelines for Americans

The Dietary Guidelines for Americans is a collection of sensible suggestions first published by the Departments of Agriculture and Health and Human Services (USDA HHS) in 1980, with five revised editions since then (1985, 1990, 1995, 2000, 2005). My personal favorite among the many editions of the Dietary Guidelines is the 2000 edition. Its greatest virtue is that it seemed to have been written by real people who actually liked food. You could see this right up front in the very first...

Hand in hand How vitamins help each other

All vitamins have specific jobs in your body. Some have partners. Here are some examples of nutrient cooperation I Vitamin E keeps vitamin A from being destroyed in your intestines. I Vitamin D enables your body to absorb calcium and phosphorus. I Vitamin C helps folate build proteins. I Vitamin B1 works in digestive enzyme systems with niacin, pantothenic acid, and magnesium. Taking vitamins with other vitamins may also improve body levels of nutrients. For example, in 1993, scientists at the...

Adding colors and flavors

Colors, flavoring agents, and flavor enhancers make food look and taste better. Like other food additives, these three may be either natural or synthetic. Coloring agents make food look better. An example of a natural coloring agent is beta carotene, the natural yellow pigment in many fruits and vegetables. Beta carotene is used to make margarine (which is naturally white) look like creamy yellow butter. Other natural coloring agents are annatto, a yellow-to-pink pigment from a tropical tree...

Hormonelike compounds

Many plants contain compounds that behave like estrogens, the female sex hormones. Because only animal bodies can produce true hormones, these plant chemicals are called hormonelike compounds or phytoestrogens (plant estrogen). Seems fair. The three kinds of phytoestrogens are i Isoflavones, in fruits, vegetables, and beans i Lignans, in grains i Coumestans, in sprouts and alfalfa The most-studied phytoestrogens are the isoflavones known as daidzein and genistein (found in soy), two compounds...

Exploring the Nature and Science of Food Additives

What are food additives Here's a really simple definition Food additives are substances added to food. The list of common food additives includes i Flavors and flavor enhancers i Preservatives Food additives may be natural or synthetic. For example, vitamin C is a natural preservative. Butylated hydroxyanisole (BHA) and butylated hydroxy-toluene (BHT) are synthetic preservatives. Many people think natural additives are safer than synthetic ingredients, probably because synthetic seems...

Understanding How Your Body Digests Food

Each organ in the digestive system plays a specific role in the digestive drama. But the first act occurs in two places that are never listed as part of the digestive tract your eyes and nose. When you see appetizing food, you experience a conditioned response. (For the lowdown on how your digestive system can be conditioned to respond to food, see Chapter 14 for information on your food preferences, see Chapter 15). In other words, your thoughts Wow That looks good stimulate your brain to tell...

Complete proteins and incomplete proteins

Another way to describe the quality of proteins is to say that they're either complete or incomplete. A complete protein is one that contains ample amounts of all essential amino acids an incomplete protein does not. A protein low in one specific amino acid is called a limiting protein because it can build only as much tissue as the smallest amount of the necessary amino acid. You can improve the protein quality in a food containing incomplete limiting proteins by eating it along with one that...

The two kinds of dietary fiber

Nutritionists classify dietary fiber as either insoluble fiber or soluble fiber, depending on whether it dissolves in water. (Both kinds of fiber resist human digestive enzymes.) Insoluble fiber This type of fiber includes cellulose, some hemicellu-loses, and lignin found in whole grains and other plants. This kind of dietary fiber is a natural laxative. It absorbs water, helps you feel full after eating, and stimulates your intestinal walls to contract and relax. These natural contractions,...

Using Food to Prevent Disease

Using food as a general preventive is an intriguing subject. True, much anecdotal evidence I did this, and that happened suggests that eating some foods and avoiding others can raise or lower your risk of some serious diseases. But anecdotes aren't science. The more important indicator is the evidence from scientific studies tracking groups of people on different diets to see how things such as eating or avoiding fat, fiber, meat, dairy foods, salt, and other foods affect their risk of specific...

Nuts

Skip the chips. At snack time, reach for the almonds. Although nuts are technically a high-fat food, a series of studies including several at California's Loma Linda University say that adding moderate amounts of nuts to a cholesterol-lowering diet or substituting nuts for other high-fat foods such as meats may cut normal to moderately high levels of total cholesterol and LDLs bad cholesterol as much as 12 percent. These guys should know. A while back, they made headlines...

The original USDA Food Guide Pyramid

Usda Food Pyramid

The first food pyramid was created by the U.S. Department of Agriculture USDA in 1992 in response to criticism that the previous government guide to food choices the Four Food Group Plan vegetables and fruits, breads and cereals, milk and milk products, meat and meat alternatives was too heavily weighted toward high-fat, high-cholesterol foods from animals. Figure 17-1 depicts the original USDA Food Guide Pyramid. As you can see, this pyramid is based on daily food choices, showing you which...

How freezing affects the texture of food

When food freezes, the water inside each cell forms tiny crystals that can tear cell walls. When the food is thawed, the liquid inside the cell leaks out, leaving thawed food dryer than fresh food. Beef that has been frozen, for example, is noticeably dryer than fresh beef. Dry cheeses, such as cheddar, turn crumbly. Bread dries, too. You can reduce the loss of moisture by thawing the food in its freezer wrap so that it has a chance to reabsorb the lost moisture that's still in the package. You...

Help Im turning orange

Because you store retinol in your liver, megadoses of preformed vitamin A can build up to toxic levels. Not so with carotenoids, which serve up another form of that vitamin. They aren't stored in the liver, so these red and yellow pigments in fruits and vegetables are safe even in very large amounts. But that doesn't mean that excess carotenoids don't have side effects. Carotenoids, like retinoids, are stored in body fat. If you wolf down large quantities of carotenoid-rich foods like carrots...

Chemical Warfare

About two dozen chemicals are used as food additives or food preservatives to prevent spoilage. If the mere mention of chemicals or food additives makes the hair on the back of your neck rise, chill out with Chapter 22. Here are the most common chemical preservatives Acidifiers Most microbes don't thrive in highly acidic settings, so a chemical that makes a food more acidic prevents spoilage. Wine and vinegar are acidifying chemicals, and so are citric acid, the natural preservative in citrus...