Thinning Hair

[Guest guest]

This came in to another list - I thought it might be interesting to

the person who said they had thinning hair.

 

Jo

 

Mercurial Effects of Fish-Rich Diets

Janet Raloff

 

In the spring of 2000, one of Jane M. Hightower's patients had been

concerned about hair loss, so the internist referred the woman to a

specialist in her building. That dermatologist probed the woman's

medical history but could find no explanation. That is, until she

suddenly recalled a radio broadcast about mercury poisoning in people

who had been eating lots of fish from tainted lakes. Their symptoms

included hair loss.

 

 

Although the individual pieces of sushi are small, a meal of

such bite-size seafood morsels could deliver a substantial dose of

mercury, depending on the fish species selected and the waters from

which they were pulled.

 

 

 

So, the dermatologist asked her patient if she ate much fish. Indeed,

the woman said, she loved it. The doctor quickly arranged for the

woman to get a blood test and then faxed the results back to

Hightower. After reviewing the findings, which suggested the

patient's mercury concentrations were in fact somewhat elevated,

Hightower put the document atop the papers in her in-box.

 

Which is where it was still sitting, when a patient came in

complaining, " My house is poisoning me! "

 

Hightower listened as the woman described how she sometimes felt so

enervated that she could barely summon the will to get out of bed.

Other times, especially while traveling abroad for months on end, the

woman felt fine.

 

Oh yes, one other thing: The patient's thinning hair had become such

a problem that the woman turned to Rogaine. She told Hightower she

had been using this antibalding drug for 2 years.

 

Glancing at the in-box and her other patient's mercury data,

Hightower asked whether her new patient ate much fish. " And she

said, 'Yes, as a matter of fact-nine times a week,' " Hightower

recalls.

 

This " serendipitous " pairing of cases launched the doctor on a quest

to understand whether a taste for fish might be poisoning any of her

other patients.

 

For the next year, Hightower formally surveyed the fish-consumption

patterns of every person who came through her practice. Among those

720 people, 123 appeared to be eating fairly high concentrations of

fish.

 

She then convinced 113 of these fish eaters-several of whom also

showed symptoms indicative of possible mercury poisoning-to get

tested for the metal. All but seven had blood drawn for testing. The

remainder, including several children, submitted only their hair for

testing.

 

Most of tested individuals exhibited elevated mercury concentrations

despite having little or no known exposure to mercury besides eating

fish, report Hightower and Dan Moore of the California Pacific

Medical Center, also in San Francisco, in an upcoming issue of

Environmental Health Perspectives. Among the patients who had blood

tests, 89 percent had blood concentrations exceeding 5 micrograms per

liter ( m g/L). Indeed, 16 percent had blood concentrations over 20

mg/L of blood-and 4 individuals surpassed 50 mg/L.

 

Because fetal exposure to mercury can later play out as IQ deficits,

the National Academy of Sciences in 2000 recommended that women of

childbearing age should try to keep mercury concentrations in their

blood to less than 5 mg/L(or hair concentrations to below 1 mg/L).

They didn't address other parts of the population.

 

Hightower advised all her patients with blood or hair values well

above those cutoffs to pare fish from their diets over the next few

months. And though follow-up blood tests showed that their bodies

indeed began shedding mercury, the drop was slow. In some cases, even

21 weeks later, the patients' mercury concentrations remained

elevated well above the NAS guideline figures.

 

Among adults, most symptoms abated as their blood concentrations

dropped. Alas, Hightower says, that didn't spare one child, who

initially was screened with nearly 15 times the NAS recommended

ceiling concentrations for mercury. Hightower notes that this boy had

experienced a documented " mental decline " during the 4 years he had

regularly been eating not only canned tuna but also fresh tuna and

salmon steaks. Though his parents eventually purged fish from his

diet, the boy retains a significant neurological impairment,

Hightower says.

 

Since her initial study ended, she has continued to evaluate fish

consumption in her patients. Another 60 or so of them turned out to

be at risk for subtle mercury poisoning. Perhaps most troubling,

Hightower told Science News Online, was that her patients-much like

herself-had viewed fish as a healthy food. Study after study had

extolled the heart benefits of fish-rich diets. She asked: How could

her patients have been so seriously misled? Why weren't they aware

that this food can also serve as the vehicle for a potent poison?

 

In a Nov. 20 letter to President George Bush, she asked for actions

to help consumers avoid unnecessary exposure. For instance, she

requested that the government continue testing fish for mercury

tainting and that the results-and any necessary fish advisories about

mercury- " be readily available where fish are sold. "

 

But they ate pricey fish. . .

 

That fish can serve as a dietary vehicle for bringing mercury to the

dinner table is hardly new. Mercury is the most commonly cited basis

for state warnings that locally caught fish might be dangerous to

consumers' health.

 

 

American lobster is among the shellfish species that tends to

carry mercury, typically about 0.3 parts per million, according to

FDA data. Though roughly comparable to the mercury tainting of tuna

steaks, it carries only about a third as much as swordfish or shark.

By contrast, its mercury load is generally about twice the

concentration typical of crab or canned tuna.

 

 

 

However, Hightower says, those advisories generally addressed only

freshwater species caught by noncommercial anglers from especially

tainted waters. Her patients were eating primarily marine fish.

Moreover, these bankers, scientists, physicians, business executives,

investment brokers, and Internet entrepreneurs weren't hauling in

their own catch of the day. They either ordered it from the counter

of a local food retailer or from the menus of white-tablecloth

restaurants.

 

A message that federal health officials have failed to effectively

communicate to the public, she says, is that many large, predatory,

and long-lived oceanic species also accumulate plenty of heavy

metals, including mercury. Many of Hightower's patients noted that

they had been selecting precisely these large, predatory marine

species because they tasted least fishy and their bones were easy to

remove.

 

Overall, elevated mercury readings among her patients tended to

correlate most strongly with any consumption of swordfish. However,

many with high mercury scores also ate plenty of tuna-especially

steaks-and salmon.

 

The heart of the matter

 

In her readings on health effects of mercury, Hightower ran across a

1999 Italian study in the Journal of the American College of

Cardiology. It described finding highly elevated concentrations of

mercury in heart-but not other muscle-of patients who had died from

heart failure related to a condition known as idiopathic dilated

cardiomyopathy. Because none of the patients had known elevated

exposures to mercury, the data hinted that heart muscle might

selectively accumulate the metal, leading to its selective poisoning.

 

On November 28, the New England Journal of Medicine published two

epidemiological studies offering further support for a heart

sensitivity to methylmercury-the organic form of the metal found in

fish.

 

In one international study probing cardiovascular risks, Eliseo

Guallar of the Johns Hopkins Medical Institutions and his colleagues

correlated risk of first heart attack with toenail concentrations of

mercury and concentrations of a fish oil (docosahexaenoic acid, or

DHA) in body fat. Their data came from 684 men who had had a heart

attack and another 724 who hadn't.

 

In this study, increasing concentrations of mercury in toenails-which

serve as a relatively long-term record of exposure-were " directly

associated " with increasing risk of heart attack, the study found,

whereas DHA concentrations in body fat appeared protective against

heart attack. Guallar and his colleagues say that their data suggest

that mercury tainting of fish diminishes the cardioprotective effect

normally associated with heavy consumption of DHA and oily fish.

 

The authors noted that they had not collected information on the

sources of mercury or DHA among their participants-nor data on fish

intake. However, they noted, the substantial DHA concentrations

measured in some subpopulations of the participants would suggest

their mercury likely derived from consumption of marine fish.

 

To date, health advisories against eating mercury-tainted fish have

tended to focus on pregnant women and children, with a goal of

protecting the neurological development in youngsters, Guallar's

group observes. " Our results raise the possibility that this advice

should be extended to the general adult population, " the researchers

say. They recommend that people should not eschew fish, just

judiciously choose species that are not likely to be heavily

contaminated.

 

According to a table of data that the U.S. Food and Drug

Administration compiled nearly 2 years ago, tilefish, swordfish,

shark, and king mackerel lead the list with mean mercury

concentrations of between 0.7 and 1.4 parts per million (ppm).

Although the agency had fewer samples from a number of other popular

marine species, among them red snapper, moonfish, orange roughy,

marine bass, and marlin also tended to be fairly heavily tainted,

typically averaging 0.4 to 0.6 ppm.

 

FDA reported somewhat lower-but still far from negligible-mercury

tainting in grouper, tuna, halibut, pollock, cod, whitefish, and

herring. All were down in the 0.2 to 0.15 ppm range. Canned tuna had

less contamination than fresh or frozen. Some shellfish also fall in

that category, with lobster containing more mercury than crab.

 

Seafood with the least mercury contamination includes tilapia,

salmon, shrimp, oysters, clams, sole, and flounder.

 

Bon appetit!

 

http://www.sciencenews.org/20030104/food.asp