Archive 2007 2008 2009 2010

Q: What causes rusty water, and is it safe to drink?

A: Rust is oxidized iron. It can originate anywhere from a water main to your own plumbing. Tap water can turn reddish brown due to iron particles that break free from sediment inside corroded iron or steel pipes. Corroded pipes are common in North American cities, where some water systems are more than 100 years old.

Iron also occurs naturally in some drinking water sources. If the water is exposed to air before coming out of the tap, it, too, may be rusty or turn rusty after standing.

Though rusty water may look and taste unpleasant—and possibly stain sinks and clothing—it is not a health concern (a possible exception is people with hemochromatosis, a rare disorder that causes excess iron accumulation in body organs). On its own, rust in water is not a sign of harmful bacteria or lead, which are hazards. In fact, the limits set by the EPA for iron in drinking water are based on aesthetics (taste, odor, color), not safety concerns.

You’ll know the problem is in the pipes in your house (or apartment building), not the municipal water supply, if rust appears only in hot water, comes only from certain faucets, or clears after running for a short time. You can filter the water if it bothers you, but you may want to consult an experienced plumber or water-quality expert to find out what device will work best (treatment depends on the form and amount of iron in your water).

A sudden appearance of rusty water, however, can occur if a water main breaks, a fire hydrant is activated, or some other disturbance causes an increase or change in water flow. In such cases, you may be notified and told not to use the water until it clears; if the problem persists, call your local water department or Department of Health.

Q: My hand shakes when I write or move it certain ways. Is this an early sign of Parkinson’s?

A: You probably have essential tremor, the most common type of shaking, which affects up to 10 million Americans, including the late Katharine Hepburn. It is called "essential" because no underlying factor causes it; it isn’t associated with any illnesses. But you should see your doctor to make sure your tremor isn’t caused by a treatable problem, such as an overactive thyroid.

Many people worry that their shaking is a sign of Parkinson’s disease, of which tremor is one sign. But with Parkinson’s, the tremor occurs at rest, and there are other signs, too, such as slowed and rigid movement. Essential tremor is generally seen not when you are at rest, but when you move your hands or other affected body parts.

Essential tremor usually shows up in middle age, though it can begin as early as adolescence. It often becomes more noticeable with age or affects more parts of the body (and sometimes the voice). The shaking typically starts in the hands, occasionally just one hand. Most people discover it when they move their hands or try to hold them in particular positions—it can be frustrating to write, put in contact lenses, or drink from a glass. If one of your parents has essential tremor, there’s about a 50% chance you’ll get it—thus it’s also called familial tremor.

Try avoiding stimulants like caffeine. Alcohol may temporarily help—thus, you might try a drink at a social event. More than one drink, however, may make matters worse. Fatigue, anxiety, and stress may worsen the shaking. If your tremor really bothers you, a few prescription medications may help. For more advice, go to www.essentialtremor.org or call 888-367-3667.

Q: I heard that smokers can protect themselves by taking tocotrienol supplements. What are they, and is this true?

A: Vitamin E is not one substance, but eight related compounds—four are called tocopherols (the most abundant in the body, and the best known), and the other four are tocotrienols. All eight act as antioxidants and may—in theory at least—help protect against cancer. The tocopherols have received more research attention than the tocotrienols, but lately researchers have been investigating tocotrienols as well. So far, studies trying to gauge their action in lowering blood cholesterol, protecting from the health effects of tobacco smoke, or lowering the risk of diabetes have been contradictory or inconclusive. There have been few good studies of tocotrienols in humans.

We see no reason to take any vitamin E supplement, whether tocopherols or tocotrienols. Vitamin E is a powerful antioxidant, but studies on supplements have yielded disappointing results. A healthy diet is a better way to get E. Some plant foods (nuts, vegetable oils) are high in vitamin E. And if you smoke, your best course of action is to quit, not rely on supplements to protect you.

Q: When you write about blood cholesterol, why do you give the numbers two different ways?

A: There are two systems of measurement. In the U.S., blood cholesterol is usually measured in milligrams per deciliter (one-tenth of a liter) of blood, or mg/dl. In Canada, England, and many other countries, scientists use millimoles per liter of blood (a millimole, one-thousandth of a mole, is a measure based on the molecular weight of a substance), abbreviated as mmol/L. This is called the International System, which is also increasingly being used in the U.S.

To convert a cholesterol result from the International System to the U.S. system, multiply it by 38.67. To convert a U.S. number to the International System, divide by 38.67. For a rough estimate, simply multiply or divide by 40.

UC Berkeley Wellness Letter, August 2007