Mercury In Fish -- How Much Is Too Much?

Mercury In Fish -- How Much Is Too Much?

When you order fish in a restaurant these days, you might feel you need a marine biologist to help you make your selection rather than a waiter. Figuring out which fish is safe to eat -- and how often you should eat fish -- has become fraught with worry, mainly due to concerns about mercury content. You might be tempted to swear off seafood completely to keep things simple. But if you do, you'll miss out on the health benefits of eating fish, including the heart-healthy omega-3 fatty acids in many fish. A wiser approach is to understand why mercury is a concern and when to avoid certain seafood.

Where the mercury comes from How does mercury get into fish and shellfish in the first place? Mercury is a metal that occurs naturally in several forms. The kind inside your thermometer is called elemental or metal mercury. It's used to make dental fillings and some batteries. It's also used in chemical manufacturing plants, coal burning plants and other industries, and that's how it ends up in your swordfish steak. Industrial pollution releases elemental mercury into the air. Rain then washes the mercury out of the air and into streams and oceans where it gets turned into methylmercury. Fish and shellfish absorb methylmercury as they feed and it builds up in the animals' tissues over time. That's why larger and older fish tend to have the most mercury.

Risks to the developing nervous system Most of our exposure to mercury comes from the methylmercury in contaminated fish. Ingesting excessive amounts of mercury is not good for anyone. In adults, it can cause damage to the nervous system, as well as the immune system and heart. But the greatest health risk from the mercury in seafood is to fetuses, infants and very young children. Even small amounts of mercury in a pregnant or nursing woman's blood can damage the developing nervous system of a fetus or infant. Nerve cells multiply and grow at a rapid rate during gestation and infancy and are especially sensitive to mercury. Scientists aren't sure exactly how the metal does its damage, but they think that it may stop the growth of dendrites and axons, the fibers on the cells that deliver and receive signals. Studies of populations that consume large amounts of seafood have found that children who were exposed to methylmercury in the womb or shortly after birth had altered memory, attention and language development.

So how much mercury is too much? Scientists don't know precisely what level of mercury in the blood leads to harmful effects. Studies show that children suffer developmental delays when their mother's blood level is as low as 30 to 40 ng/mL (nanograms per milliliter), while adults usually don't show symptoms of mercury poisoning until their levels are higher. Fortunately, most people have some built-in protection against mercury: A genetically determined mechanism causes the body to expel the metal in 30 to 40 days. A Swedish biologist recently discovered that a small portion of the population carries a genetic mutation that makes their cells retain mercury much longer -- in rare cases up to 190 days -- and those people may be at higher risk.

While mercury poisoning from eating seafood is relatively rare, the early signs include tingling and numbness in fingers and toes and poor muscle coordination. The treatment for mercury poisoning caused by eating contaminated fish is simple: You stop eating the fish and wait for levels to come down naturally.

Guidelines for eating seafood Of course a better solution is to avoid ingesting too much mercury in the first place. That's easy to do. For most adults, eating fish and shellfish is not a health risk -- and it's important to get the health benefits of fish. Seafood is an excellent source of high-quality protein and iron, and it's low in saturated fat. And fish that are high in omega-3 fatty acids, such as trout, salmon and tuna, can lower your risk of heart attack and other cardiovascular problems. That's why the American Heart Association recommends eating at least two servings of fish a week.

However, women who may become pregnant or are already pregnant, nursing mothers and young children need to be more careful. The FDA advises pregnant or nursing women to avoid four fish that contain high levels of mercury: shark, swordfish, king mackerel and tilefish. Instead, they should eat up to 12 ounces a week of fish and shellfish that are lower in mercury. These include shrimp, canned light tuna, salmon, Pollock and catfish. If you eat canned albacore ("white") tuna, limit your intake to 6 ounces per week because it has higher mercury content. Young children should eat smaller portions of these fish.

While pregnant and nursing women should avoid high-mercury fish, they should not stop eating seafood, according to the FDA and others. That's because fish and shellfish contains nutrients that are important for a baby's growth. Plus, the omega-3 fatty acids in many fish can actually promote the baby's brain development (they help adult brains function better, too). So next time you're ordering fish, don't panic. Just make sure you eat a variety of seafood (not a steady diet of the four high-mercury fish) and follow the guidelines if you are pregnant or nursing.

Salt controversy: New study links high sodium to earlier mortality

Salt controversy: New study links high sodium to earlier mortality

By Anne Harding

People who eat more sodium and less potassium may die sooner of heart or other problems than people who consume the opposite, a large, 15-year-study has found.

The study of more than 12,000 Americans provides more ammunition to health advocates who say that slashing salt intake will save lives. But not everyone is convinced, as some research is contradictory.

In the new study, men consumed an average of 4,323 milligrams of sodium a day, while women took in 2,918 milligrams.

The American Heart Association recommends people limit their sodium intake to 1,500 milligrams a day or less.

The group with the highest sodium-to-potassium ratio had a mortality risk about 50% higher during the study than the group with the lowest, according to the report by Elena V. Kuklina, M.D., and colleagues at the Centers for Disease Control and Prevention (CDC), Emory University, and the Harvard School of Public Health. The research was published Monday in the Archives of Internal Medicine.

A diet rich in fruits and vegetables is naturally low in sodium and high in potassium. Good potassium sources include bananas, baked potatoes, and raisins. In contrast, a diet of processed foods tends to be the opposite -- it contains more sodium and less potassium, says Kuklina, a nutritional epidemiologist at the CDC.

"We probably should take into account the whole diet and take a more comprehensive look," she says. "Looking at a single micronutrient, we might just miss the whole picture."

Because most of the sodium people in the developed world consume comes from processed food, there has been a movement to get the food industry to reduce the amount of salt it adds to products.

In 2010, the Institute of Medicine recommended that the Food and Drug Administration regulate sodium in food. And the National Salt Reduction Initiative is a partnership of organizations -- including major food companies -- that aims to cut sodium in processed foods by 25% by 2014.

"We now have 28 companies who have committed to reducing the salt levels in at least one of their categories of products," says Thomas A. Farley, M.D., of the New York City Department of Health and Mental Hygiene and coauthor of an editorial accompanying Kuklina's study.

It's the easiest way to reduce sodium intake, says Graham MacGregor, chairman of World Action on Salt and Health (WASH) and a professor of cardiovascular medicine at the Wolfson Institute of Preventive Medicine, in London.

The UK started doing just that in 2006, requiring companies to cut salt content by 25 to 30%. By 2008, according to MacGregor, sodium intake had fallen by 10%.

"It's a very large study...and it clearly shows what we'd expect it to show, that eating too much sodium is harmful and eating too little potassium is harmful," he says.

WASH is a global group established in 2005 with the aim of improving people's health by reducing salt intake.

Health.com: 10 heart-healthy rules to live by

But the case isn't quite closed, some say. For example, a report this May in the Journal of the American Medical Association found that while healthy men and women who ate more sodium than average weren't at higher risk of dying of heart disease or stroke, cardiovascular mortality was 56% higher for people who ate the least sodium. The eight-year study included 3,681 European men and women age 60 or younger who did not have hypertension.

"It's confusing," says Michael Alderman, M.D., a professor of medicine and population health at the Albert Einstein College of Medicine, in the Bronx, and editor of the American Journal of Hypertension.

Health.com: 25 surprisingly salty processed foods

While some people with hypertension do need to reduce their sodium intake, Alderman says, reducing the sodium intake of the entire population could be harmful.

And an analysis of the evidence published in the Cochrane Review in July suggested that there isn't strong evidence that people who cut back on salt will reap heart-health benefits. But it did say that a population-wide reduction might help.

"These findings should not be misinterpreted as showing that salt reduction will not save lives. There was insufficient evidence to make this judgment," the author wrote. "Giving advice to reduce salt is a weak method of reducing salt intake in the population. Reducing hidden salt in processed foods, including bread, would likely have a bigger impact on blood pressure levels and on cardiovascular disease."

Farley says concerns about the risks of salt reduction are unfounded.

"There are populations around the world who take in much, much less sodium than we do and they maintain lower blood pressure throughout their lives, so I'm not concerned about that," he says. "The easiest way for people to think about it is they should be taking in less sodium and more potassium."

As far as the JAMA study is concerned, Farley says, "I would consider that an outlier."

Tri Challenge: Fitness becomes a family affair

Tri Challenge: Fitness becomes a family affair

When this whole process started, I said I wanted to do the Tri Challenge for me, for my patients and for my family. A perfect example of how the decision has led to changes in my life and changes for my family happened on the Fourth of July.

The Fox Firecracker 5K is run in Kaukana, WI every year on July 4th. None of us have ever participated in it even though it has been going on for years. My wife and I decided that the whole family should do it. Amazingly, everyone agreed.

It was an early start as we had about a 30 minute drive to get to the race. The kids were already tired from swimming and tubing for 8 hours the previous day. Once we arrived the excitement built. Skydivers, the University of Wisconsin Marching Band and the kids-only run got everyone energized for the race. My nine-year old, Owen, looked the most tired but he was ready to go and wanted to run all by himself. Ava, age 4, was sitting comfortably in the stroller waiting to be pushed the 3.1 miles by my wife, Missy, who is finally starting to feel better while running after knee surgery in February. Greta, 12, is not a big fan of running, but was excited to walk with her best friends. This was her first run/walk.

The gun went off and we all started. We went at our own pace and everyone finished with a smile on their face. After the race we talked about how hilly the course was, how it was cool to see the band along the run, how many sprinklers we ran through and the goofy outfits we saw people wearing. Owen has now run as many races as his 46-year-old father! We celebrated with apple pie, pizza and chocolate chips cookies. As they say, a good time was had by all.

I’m so proud of my family for supporting me and being part of this journey. They have inspired me to stay fit and healthy and I look forward to having many more events like this in the future.

Donna already weighs 700 pounds, but wants to weight More

700-Pound Woman Makes a Career Out of Eating -- A Lot

By Lisa Johnson Mandell

Donna Simpson, a single mom in New Jersey, weighs 700 pounds and is trying to gain an additional 300 pounds so that she can claim and hold the Guinness World Records' title of World's Most Obese Woman. She says that she couldn't do it without the help of her 4-year-old daughter, who shops with her, helps her prepare food, and feeds her so that she can pile on additional pounds.

How does someone who relies on a 4-year-old and a reinforced scooter to get around make a living? Online, of course. Simpson pays for her $580-to-$750 per week eating habit plus other expenses by, basically, being overweight. She has a website,OfficialDonnaSimpson.com, geared toward "fat admirers," where people pay to see her eat and flaunt her flab.


She claims that she has 7,000 paying fans, and makes nearly $100,000 annually from the site, according to the Daily Mail. A three-day membership to her site goes for $7.95, and a one-month membership costs $19.95. For that you get to see videos like "Squashing," "Blue Dress" and "Eating a Pie" plus access to more than 270 photos. She believes the record she holds as Heaviest Woman to Give Birth sets her apart from other big women with similar sites.


Apparently, there are a lot of people out there who enjoy watching Simpson eat. She says that they even send her fattening food like protein shake powder to help her beef up quickly. "It makes people happy, and I'm not harming anyone," she says.


Except herself: She suffers from diabetes, high blood pressure and heart disease, plus it's very difficult for her to go anywhere. And then there's the example she might be setting for her daughter, Jacqueline, who Simpson claims prefers healthy foods, like salad, and is active in sports.


You might wonder about the birth of her daughter. It took a team of 30 medical professionals to deliver her during a high-risk Caesarean. She is the daughter of Simpson's former long-term partner, Phillipe Gouamba, from whom she recently split. Simpson told the Daily Mail that she's looking for a new partner to help feed her the 15,000 calories per day she requires, so he can relieve her daughter of those weighty responsibilities.


Simpson has been married before and also has a 15-year-old son. She says that both her partners loved her largeness, and did their best to contribute to it. Her first husband was a chef who brought her leftovers when he came home late at night, according to Wikipedia. Her next partner, she hopes will be "handsome, slim and at least 10 years younger than me," she told the Daily Mail.


Don't be surprised to see media-hungry takers who fit those requirements lining up for the position. They might well appreciate the television face-time they could get from a reality show that could be in the works any minute now.

State With Top Obesity Rate Named

Obesity Rates Still Rising

WASHINGTON -- In 1995, no state had an obesity rate above 20 percent. Now, all but one does.

An annual obesity report by two public health groups looked for the first time at state-by-state statistics over the last two decades. The state that has the lowest obesity rate now – Colorado, with 19.8 percent of adults considered obese – would have had the highest rate in 1995.

"When you look at it year by year, the changes are incremental," says Jeffrey Levi, executive director of the Trust for America's Health, which writes the annual report with the Robert Wood Johnson Foundation. "When you look at it by a generation you see how we got into this problem."

The study, based on 2010 data, says a dozen states top 30 percent obesity, most of them in the South. Mississippi topped the list for the seventh year in a row, with Alabama, West Virginia, Tennessee and Louisiana close behind. Just five years ago, in 2006, Mississippi was the only state above 30 percent.

No state decreased its level of obesity, which is defined as a body mass index of 30 or more. The body mass index is a measurement based on weight and height.

There was a bit of good news in the report: Sixteen states reported increases in their obesity rates, down from 28 states that reported increases last year. Levi says those increases have been gradually slowing, most likely due to greater public awareness of health issues and government attempts to give schools and shoppers better access to healthier foods.

"We're leveling off to some degree at an unacceptably high level," Levi said.

First lady Michelle Obama has tackled the issue with her "Let's Move" campaign, pushing for healthier school lunches, more access to fruits and vegetables and more physical activity. Republicans in Congress have pushed back somewhat against some of those programs, however, saying a rewrite of school lunch rules is too costly and questioning an Obama administration effort to curb junk food marketing aimed at children.

As in previous years, the study showed that racial and ethnic minorities, along with those who have less education and make less money, have the highest obesity rates. Adult obesity rates for African-Americans topped 40 percent in 15 states, while whites topped 30 percent in only four states. About a third of adults who did not graduate from high school are obese; about a fifth of those who graduated from college are considered obese.

Dr. Mary Currier, Mississippi's state health officer, says her state has struggled to drop its No. 1 status and it has been challenging because much of the state is poor and rural.

"We live in an area of the country where eating is one of the things we do, and we eat a lot of fried foods," she said. "Trying to change that culture is pretty difficult."

She says the state has had some success by making school lunches healthier, taking high-calorie foods and drinks out of school vending machines and trying to find more low-cost exercise facilities for residents of rural areas.

"It is frustrating, but we've had some progress," Currier said. "We just have to continue to work at this. It's not something that's going to change overnight."

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You've Lost Weight. Now How Do You Keep It Off?

You've Lost Weight. Now How Do You Keep It Off? By MEREDITH MELNICK

Losing weight is hard enough. Keeping it off is even harder. Now a new study by researchers at Penn State suggests that the techniques that work for losing weight aren't necessarily the same as those that help keep you slim.

First, the researchers surveyed more than 1,100 people who had achieved significant weight loss and maintained it. The researchers identified 36 weight-loss and weight-maintenance practices that at least 10% of the group used.

Then the researchers conducted a national telephone survey of overweight people (with a BMI of 25 or higher) who had tried to lose weight and keep it off with varying success: about 11% reported successfully losing weight, defined as losing at least 10% of body weight, and 21% were able to maintain that loss for at least a year. The researchers asked them how frequently they employed the 36 previously identified techniques: "often or very often" or "seldom or never."

The survey found that people who lost weight successfully did so by participating in weight loss programs, cutting back on sugar and carbs, eating healthy snacks, not skipping meals and participating in different types exercise.

Not all techniques that led to initial weight loss were associated with weight maintenance, however. Continually switching up an exercise regimen helped people lose weight, for instance, but those who kept weight off tended to stick with a consistent exercise program. That may be because experimenting with a variety of workout routines may help people as they're trying to lose weight, but once they've found what works for them, they tend to stick with it for maintenance.

The study noted four strategies that were associated with weight maintenance but not loss:
-Eating a diet rich in low-fat proteins
-Following a consistent exercise program
-Rewarding yourself for dieting and exercising
-Reminding yourself of why you need to keep weight off

"It seems somewhat similar to love and marriage," study author Dr. Christopher Sciamanna, a professor of medicine and public health sciences at Penn State College of Medicine, told WebMD. "What gets you to the altar is likely to be quite different than what keeps you married in the long-term. [And] not recognizing this transition and adapting with different practices will also get you in trouble."

Still, say many nutrition and obesity experts, the basic underlying principles of weight loss and maintenance are the same: you have to eat a healthy diet and increase your exercise. People who lose weight and keep it off tend to eat significantly healthier foods and do a lot more exercise than the average American.

But what may shift between weight-loss and maintenance phases is a person's mindset: rather than focusing on actively losing weight in the short term, people have to start focusing on long-term, permanent lifestyle changes and behaviors, if they want to maintain the weight that's been lost. The key to success, experts agree, is motivation, not necessarily the particulars of your weight-loss program.

The study had some limitations, including the fact that respondents' weights and behaviors were all self-reported. The study appears in the American Journal of Preventive Medicine.

Get Some Sleep: Why do we have REM?

Get Some Sleep: Why do we have REM?
Lisa Shives, M.D., is the founder of Northshore Sleep Medicine in Evanston, Illinois. She blogs on Tuesdays on The Chart. Read more from her at Dr. Lisa Shives’ Sleep Better Blog.

It seems that the public is just as fascinated with REM sleep. So are sleep physicians and researchers. But fascination often leads to confusion and controversy, and a lot of both surround the subject of REM sleep.

First, to give a brief history lesson, it is important to understand that REM, or rapid eye movement sleep, was discovered and described only in 1953, so it makes sense that there is still much to learn.

One key aspect of REM sleep is that all physical characteristics studied to date are different in REM when compared with non-REM. In fact, REM sleep more closely resembles the waking state. That is likely why people are more alert when they are awakened out of REM compared with other sleep stages.

REM sleep is when we do most of our dreaming, but not all, as researchers thought in the past. Most scientists agree that it is in REM that we have our most vivid, what I call, our magic-carpet-ride dreams, whereas the mundane kind of dreams can happen in non-REM.

Now, the question of why we dream is a whole other matter that deserves its own discussion. Suffice to say that there are many different theories at this time.

There is some debate as to whether all birds and mammals display REM sleep. Most do, so the important thing to remember is that it is not uniquely human.

Interestingly, the average daily amount of REM sleep for a given species appears strongly correlated with how immature the young are at birth. Animals that born in helpless state, such as the platypus and the armadillo, have high amounts of REM sleep at birth and indeed a high amount in maturity.

But the dolphin, which is born able to swim, feed and defend itself, has such little REM sleep that it has been questioned whether it has any at all. Humans fall somewhere in the middle in terms of amount of REM sleep, even though it strikes me that a human baby is pretty helpless for a long time.

REM sleep is present at birth in humans and it is the non-REM sleep stages that take 2-6 months to distinguish themselves. From 6 months until well into old age, REM sleep remains stable in healthy people and makes up 20-25% of the total sleep time.

REM occurs at the end of the 90-minute sleep cycles that characterize normal human sleep. The amount of REM increases as the night progresses and as one goes through repeated cycles so that although REM might only make up 10 minutes of the first cycle, it can last for 30 minutes during the last cycle.

As I stated earlier, the physiologic changes that occur during REM are closer to wake than to non-REM, with a couple of interesting exceptions. Mammals, including humans, can regulate their body temperature except in REM sleep.

During REM, we all turn into lizards and our body temperature drops or rises with the temperature of the surrounding environment.

The other unusual change is that in REM our large muscle groups are almost paralyzed. We think that this is protective mechanism so that when we are having those wild dreams about running away from the big bad wolf we can’t actually get up and start running in our sleep.

There is a disorder, called REM Behavior Disorder, where people lack this muscle weakness in REM and indeed they often hurt themselves or others.

So why do we have this unusual type of sleep? Briefly, today there are two main theories.

One is that we have sleep that resemble wake so that we can still get the benefits of sleep, but if we need to awaken quickly and be alert and ready to defend ourselves, then we can.

The other, and they are not mutually exclusive, is that because certain neurotransmitters, such as serotonin, histamine and norepinephrine are turned off during REM, then perhaps REM represents the down time that these important substances need in order to replenish themselves or reset their receptors.

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