Healthoughts

Water, water, everywhere


Quick: how many eight-ounce glasses of water should you drink each day?
If you said eight glasses—the number usually touted by media health experts—you are right. And wrong.


As with many things in life, the truth is not so simple, says Linda Heller, R.D., clinical nutrition manager at Childrens Hospital Los Angeles.


“It all depends. The answer isn’t 64 ounces, because there isn’t just one number for everybody. If you’re small, you don’t need as much water as a 300-pound person. And it also matters if you’re doing strenuous physical activity, the climate you’re in and what your diet consists of.”


Heller says that by following the eight-glasses rule, many people drink far more water than they need. That is partly because the recommendation ignores the fact that most foods already contain some water that the body is able to use. For example, chicken and beef are about 60 percent water, while lettuce is about 95 percent. That means that even if your body does require 64 ounces of water daily, you do not have to actually drink that much.


There is little harm from drinking slightly more water than necessary, but taken to the extreme, drinking too much water can deplete the body’s electrolytes, causing a potentially fatal failure of the kidneys or heart. On the other hand, chronic dehydration can cause problems including fatigue and constipation, Heller says.


The amount of water the body needs depends mainly on the number of calories needed to maintain weight.


A person needs 1cc of water for each calorie consumed (100cc of water is about 3.3 ounces).


This means, for example, a 140-pound woman who needs about 1,600 calories each day requires nearly six glasses of water daily. Depending on her diet, she may get as much as half of that fluid from food, so she would need to drink only 24 ounces.


If you don’t feel like doing the math, Heller suggests an easy alternative: drink enough water so that your urine is colorless and odorless. That is a sign that your body has all the water it needs.

 

Frosty fingers


There may be millions of people with cold hands out in the world—and it is not because they have warm hearts. Recent surveys show that 5 to 10 percent of the population may experience Raynaud’s phenomenon, a disorder affecting the fingers, toes, ears and nose that causes feelings of extreme cold. Three of every four cases occur in women between ages 15 and 40.


According to Glenn R. Ehresmann, M.D., associate professor of medicine in rheumatology and immunology at the Keck School of Medicine, Raynaud’s phenomenon is common in cold weather, though people in warm climates may experience it, too. Even stress may trigger the problem.


For reasons not well understood, people with Raynaud’s often experience episodes in which the tiny blood vessels in their fingers constrict and squeeze, allowing the body to keep more blood in veins deep within the body to maintain body temperature.


As a result, fingers may change colors, from white or pale yellow to blue, and digits may feel numb. Then, as the tiny blood vessels relax and allow more blood to return, the fingers may appear red and feel prickly.


The majority of cases are not life-threatening, but in some patients, the phenomenon is caused by an underlying connective tissue disease such as scleroderma or systemic lupus erythematosus. Simple blood tests, a medical history and examination of the fingers can rule out those conditions.


Most physicians recommend common-sense ways to cope with the disorder before trying medications: dipping hands in warm water, staying indoors during cold weather, quitting smoking, exercising and controlling stress, for starters. Says Ehresmann, “Don’t forget the warm gloves.”

 

Immunity debate


After last year’s anthrax attacks, the idea that smallpox could be used as a weapon suddenly became a more credible—if still remote—threat, prompting debate over whether mass vaccinations might be a good idea.


But infectious disease experts caution that vaccinations, which use a live virus similar to smallpox to evoke a protective immune response, may do more harm than good.


John Leedom, M.D., professor of medicine and chief of the division of infectious diseases, puts it bluntly: “There is no reason for people to get vaccinated.


“The vaccine uses the live vaccinia virus, which is not benign.” He notes that it can kill people with weakened immune systems. Further, the virus is infectious and can spread to people who do not receive a vaccination.
As a result, those with weakened immune systems—including roughly 330,000 Americans with AIDS—could be jeopardized by the vaccinations of their
fellow citizens.


The potentially dire public health consequences vastly outweigh the minute possibility that the vaccinations will prove to be needed, Leedom says.
If a vaccination program is implemented, he says, it should target only those most likely to encounter the virus, such as emergency room personnel and paramedics. Even then, they should probably be barred from going near patients for 10-14 days afterward to ensure they do not transmit the vaccinia virus.


People who received vaccinations in the 1970s and earlier are believed to have no useful immunity remaining. When smallpox was occurring naturally, studies suggested the vaccine only protected individuals against infection for about five years and against mortality for 15 years, he says.


The good news is that medicine has made significant strides in the years since smallpox was eradicated. New antiviral drugs show promise as potential weapons against the disease, and hospitals are much better at supporting patients who are fighting off infections.


For example, Leedom says that many people considered smallpox fatalities actually died of bacterial infections contracted as a result of body-wide smallpox lesions. Today, modern antimicrobials would probably prevent many of those deaths. nFill me in
President George Washington may have had a lot of things going for him, but
a good dental plan wasn’t among them—back in the 1700s, even a
president had to settle for wooden replacement teeth.


A hundred years later, things got better for dental patients, but the only available choice for dental fillings was silver amalgam. But today, dental patients have a wide variety of materials to choose from, says Terry Donovan, D.D.S., executive associate dean for academic affairs for the USC School of Dentistry.


“There has been a tremendous explosion in the materials we use for front and posterior teeth. Many of the materials are fantastic in appearance and mimic nature almost perfectly,” he says.


Tooth-colored materials, including those made from resins, ceramics, ground quartz, glass and porcelain are now popular options that are quickly overtaking long-time standards such as gold and silver amalgam, he says.


But he also cautions that each type has potential benefits and drawbacks that individuals should consider before deciding which is best for them. Chief among the factors patients should consider are cost, durability and appearance.


Silver amalgam, which has been used since 1850, is strong enough to fill back teeth, relatively inexpensive and lasts up to about 20 years. Unfortunately, installing amalgam fillings requires dentists to remove a portion of the healthy tooth, which can weaken it. Many patients also object to its unnatural appearance.


Gold fillings are extremely durable and can last as long as 30 years, but are comparatively expensive and some patients find them aesthetically objectionable.


Tooth-colored fillings are extremely popular because they are practically indistinguishable from real teeth and cost about as much as amalgam fillings. But Donovan says they are much less durable than other types, with ceramics and resin-based materials lasting 6 to10 years and porcelain lasting 10 to 15 years. As a result, a patient may have to undergo multiple filling replacements in a lifetime, potentially weakening the tooth.


Donovan says that patients should discuss their options with their dentists and choose the material appropriate for them.

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