Maintaining the Right Amount of Water in Your Body

As much as three-quarters of the water in your body is in intracellular fluid, the liquid inside body cells. The rest is in extracellular fluid, which is all the other body liquids, such as

• Interstitial fluid (the fluid between cells)
• Blood plasma (the clear liquid in blood)
• Lymph (a clear, slightly yellow fluid collected from body tissues that flows through your lymph nodes and eventually into your blood vessels)
• Bodily secretions such as sweat, seminal fluid, and vaginal fluids
• Urine A healthy body has just the right amount of fluid inside and outside each cell, a situation medical folk call fluid balance. Maintaining your fluid balance is essential to life. If too little water is inside a cell, it shrivels and dies. If there’s too much water, the cell bursts.

Investigating the Many Ways Your Body Uses Water

Water is a solvent. It dissolves other substances and carries nutrients and
other material (such as blood cells) around the body, making it possible for
every organ to do its job. You need water to

• Digest food, dissolving nutrients so that they can pass through the intestinal cell walls into your bloodstream, and move food along throughyour intestinal tract
• Carry waste products out of your body
• Provide a medium in which biochemical reactions such as metabolism (digesting food, producing energy, and building tissue) occur
  
• Send electrical messages between cells so that your muscles can move, your eyes can see, your brain can think, and so on
  
• Regulate body temperature — cooling your body with moisture (perspiration) that evaporates on your skin
• Lubricate your moving parts

Phytochemicals Future

Yes, I know that misspelling forecasting as “phorecasting” and future as “phuture” is gross. Yes, I know I already named this chapter “Phabulous Phytochemicals” and that should have been enough, but I just couldn’t resist the tempting play on words.
Please don’t let my lack of semantic restraint turn you away from the fact that phytochemical research is serious stuff that eventually should enable people to identify biochemical reactions that trigger — or prevent — specific medical conditions.
While you’re waiting for final analyses, the best nutrition advice is to dig into those veggies, fruits, and grains — and turn to Chapter 13 to find out why you need to wash them down with plenty of cold, clear water.

Dietary fiber in foods

Dietary fiber is a special bonus found only in plant foods. You can’t get it from meat or fish or poultry or eggs or dairy foods. Soluble dietary fiber, such as the pectins in apples and the gums in beans, mops up cholesterol and lowers your risk of heart disease. Insoluble dietary fiber, such as the cellulose in fruit skins, bulks up stool and prevents constipation, moving food more quickly through your gut so there’s less time for food to create substances thought to trigger the growth of cancerous cells.

Sulfur compounds in your foods

Slide an apple pie in the oven, and soon the kitchen fills with a yummy aroma that makes your mouth water and your digestive juices flow. But boil some cabbage and — yuck! What is that awful smell? It’s sulfur, the same chemical that identifies rotten eggs.
Cruciferous vegetables (named for the Latin word for “cross,” in reference to
their x-shaped blossoms) — such as broccoli, Brussels sprouts, cauliflower,
kale, kohlrabi, mustard seed, radishes, rutabaga, turnips, and watercress — all
contain stinky sulfur compounds, such as sulforaphane glucosinolate (SGSD),
glucobrassicin, gluconapin, gluconasturtin, neoglucobrassicin, and sinigrin, that
seem to tell your body to rev up its production of enzymes that inactivate and help eliminate carcinogens.
These smelly sulfurs may be one reason why people who eat lots of cruciferous veggies generally have a lower risk of cancer. In animal studies at Johns Hopkins University School of Medicine, rats given chemicals known to cause breast tumors were less likely to develop tumors when they were given broccoli sprouts, a food that’s unusually high in sulforaphane. In 2005, a human trial conducted in China by researchers from Johns Hopkins, Qidong Liver Cancer Institute, Jiao Tong University (Shanghai), and the University of Minnesota Cancer Center showed that the sulforaphane-rich sprouts appear to help the body defang aflatoxins produced by molds that grow on grains such as rice. Aflatoxins, which damage cells and raise the risk of cancer, may be linked to the high incidence of stomach and liver cancer in China. Further studies are in the planning phases. (But of course.)

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

• Isoflavones, in fruits, vegetables, and beans
• Lignans, in grains
• Coumestans, in sprouts and alfalfa

The most-studied phytoestrogens are the isoflavones known as daidzein and genistein (found in soy), two compounds with a chemical structure similar to estradiol, which is the estrogen produced by mammalian ovaries. Like natural or synthetic estrogens, daidzein and genistein hook onto sensitive spots in reproductive tissue (breast, ovary, uterus, prostate) called estrogen receptors. But phytoestrogens have weaker estrogenic effects than natural or synthetic estrogens. It takes about 100,000 molecules of daidzein or genistein to produce the same estrogenic effect as one molecule of estradiol. Every phytoestrogen molecule that hooks onto an estrogen receptor displaces a stronger estrogen molecule. As a result, researchers suggested that consuming isoflavone-rich foods such as soy products may provide post-menopausal women with the benefits of estrogen (stronger bones and relief from hot flashes) without the higher risk of reproductive cancers (of the breast, ovary, or uterus) associated with hormone replacement therapy (HRT). The theory was supported by the fact that the incidence of breast and uterine cancer, heart disease, osteoporosis, and menopausal discomfort is lower in countries where soy — a primary source of phytoestrogens — is a significant part of the diet.
However, recent animal and human studies offer conflicting evidence. On the one hand, these studies

• Raise questions about the safety of phytoestrogen-rich foods for women with hormone-sensitive tumors
• Show that phytoestrogen may stimulate tumor growth in animals whose ovaries have been removed
• Demonstrate that isoflavone-rich foods have only modest effects on preserving bone and relieving “hot flashes” at menopause One the other hand, including isoflavone-rich soy foods such as tofu, miso, tempeh, soy milk, soy flour, and soy protein in a healthful diet
• May reduce total cholesterol, lower LDL (“bad cholesterol”), and maintain or even increase blood levels of HDL (“good cholesterol”). In 2005, researchers at the Johns Hopkins University School of Nursing announced the results of a 216-woman study funded by the National Heart, Lung, and Blood Institute in which women consuming 20 grams of soy proteins per day had significant decreases in LDLs, while women who were given the same amount of milk protein did not.

• Helps people feel full longer so they can stick to a lower-calorie diet for managing weight loss. Bottom Line? According to the International Food Information Council, “Further clinical studies will continue to increase understanding of the role of soy in maintaining and improving health.” Couldn’t have said it better myself.

Understanding Antioxidants

Antioxidants are named for their ability to prevent a chemical reaction called oxidation, which enables molecular fragments called free radicals to join together, forming potentially carcinogenic (cancer-causing) compounds in your body.
Antioxidants also slow the normal wear-and-tear on body cells, so some researchers noted that a diet rich in plant foods (fruits, vegetables, grains, and beans) seems likely to reduce the risk of heart disease and maybe reduce the risk of some kinds of cancer. For example, consuming lots of lycopene (the red carotenoid in tomatoes) has been linked to a lower risk of prostate cancer — as long as the tomatoes are mixed with a dab of oil, which makes the lycopene easy to absorb.
However (you knew this was coming, right?), recent studies show that although a diet rich in fruits and veggies is healthful as all get-out, stuffing yourself with the antioxidant vitamins A and C has ab-so-lute-ly no effect on the risk of heart disease.