Archive for the ‘chemistry’ Category

Toxins for tots and the rest of us too: part one

Saturday, March 24th, 2012

This speaks for itself

All of us are exposed to potentially dangerous substances in many of our household products, but there's been increasing concern that pregnant women need to pay special attention to  the ever-growing list of chemicals around the home. I just read an article published in The New York Times nine days ago with the gripping title "Is It Safe to Play Yet?" The subtitle described what's going on in many families: "Going to Extreme Lengths to Purge Household Toxins."

I found a reference to an extraordinary study which examined umbilical cord blood samples drawn from ten infants of minority heritage: African-American, Asian or Hispanic. Five independent laboratories were involved and up to 232 toxic chemicals were found. I was familiar with the Environmental Working Group, one of the two non-profits who commissioned the research, but not with Rachel's Network which I found online. It's a women's organization named in honor of Rachel Carson whose book, Silent Spring, in many aspects launched the modern environmental movement.

EWG had been unable to find any published studies focused on minority group infants, yet some of their homes are more likely to be situated near busy highways and roads, to be closer to industrial shops and factories and to have been built before current safety standards were established.

Other studies have found up to 358 chemicals in cord blood of US infants; some are acknowledged as possible cancer-causing agents, nervous-system toxins or endocrine hormone disrupters. The National Institute of Environmental Health Sciences (NIEHS), part of NIH, says those latter toxins can be found in metal food cans, plastic bottles, food, toys, cosmetics, detergents, pesticides and flame retardants. Their adverse effects have increased potential to harm fetuses and young babies as their bodies develop.

asbestos can cause mesothelioma, a rare cancer usually of the lining of the lungs and chest cavity

Our Toxic Substances Control Act, is a 1976 law that, unfortunately, grandfathered most existing chemicals. The Environmental Protection Agency (EPA) was mandated to protect the public by regulating the manufacture and sale of chemicals But 60,000 chemicals were excluded because they were already in use and over the following years the EPA succeeded in restricting only five of those: one was asbestos, but two years after the chemical was banned the rule was overturned by the Fifth Circuit Court as being too broad.

In contrast, the European Union, in 2007, passed REACH, the Registration, Evaluation, Authorisation and Restriction of Chemicals act that applies to all chemical substances; not only those used in industrial processes but also in day-to-day lives, for example in cleaning products, paints as well as in articles such as clothes, furniture and electrical appliances.

REACH places the burden of proof on companies. To comply with the regulation, companies must identify and manage the risks linked to the substances they manufacture and market in the EU. They have to demonstrate to a governmental agency how the substance can be safely used, and they must communicate those risk management measures to the users.

One estimate, published in Health Affairs in 2011, estimated the US spends $76.6 billion a year on kids' medical issues that may be related to their environment.

We have a long ways to go, both in determining which chemicals are actually risky and banning or controlling their use.

And, on the other hand, knowing which chemicals, old and new, are safe for us and our offspring.

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Posted in asbestos, baby food, chemistry, childhood diseases, environmental issues, Environmental Protection Agency, Environmental Working Group, Governmental Efforts, medically-oriented background info, toxins | 1 Comment »

Arsenic Toxicity: Part One, history & worldwide impact

Tuesday, February 21st, 2012

It looks harmless here

I started to write a post on arsenic in baby food since there's been a spate of recent articles on this issue appearing both in newspapers and online (the AMA Morning Rounds email I receive started me thinking of the subject). But, as usual, when I began to pursue a topic, I found there was both a long history I needed to cover and, in this case, a worldwide problem that should be discussed.

Human industrial use of arsenic dates back 5,000 years. I found the Harvard Arsenic Project has a thorough coverage of varying aspects of our utilization of this element, both beneficial and detrimental. It has been used as a poison for many centuries since it has little if any odor or taste, especially when mixed with food or wine. A Roman leader named Sulla outlawed arsenic poisoning in 82 B.C., to no avail. In Italy in the 15th and 16th centuries, the Borgias, especially Pope Alexander VI and his son, Cesare were said to have killed scores of bishops and cardinals by liberally lacing their wine with arsenic; then, by Church laws, they owned the property of their victims.

Roger Smith, a Dartmouth Medical School Emeritus Professor of Pharmacology and Toxicology has published an online discussion of the uses of the element with the gripping title, "Arsenic: A Murderous History."

Scientifically it is classed as a "heavy metal." Nowadays we think of that term as referring to a form of music. But from the chemistry pound of view it actually is one of a group of elements that, volume for volume, are at least five times as heavy as water. Iron, lead and mercury are in that group, but so is arsenic.

If you were to ingest arsenic, diluted in wine or water, at an incredibly small level, 60 parts per million, you would develop belly pain, nausea, diarrhea and then die. Until a few years ago the US drinking water limit was 50 parts per billion. Then in 2000 the EPA proposed all 54,000 community water systems in this country should cut their arsenic levels to no more than 10 parts per billion.

but it's a a plague here

Our local water lab just told me our Fort Collins levels are less than 1 part per billion. That's clearly not true elsewhere in the world. Over 137 million people in 70 countries are exposed to toxic levels in their drinking water. Bangladesh has the most well-known problem. When more than eight million deeper wells were dug in the 1970s and beyond, as an attempt to lower the infant death rate from ineffective water purification, arsenic  replaced infectious diseases as a major threat. The drinking water for more than 30 million people had levels over 50 parts per billion.

So they potentially could develop chronic arsenic effects include skin, lung, kidney, liver or bladder cancers and perhaps a variety of cardiovascular and respiratory diseases.

We've a long, long ways to go before we solve the issues raised by arsenic.

 

 

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Posted in arsenic, chemistry, environmental issues, food contaminants, Food safety, poisons | No Comments »

What sweetener do you use: Part 6; the fake sugars

Wednesday, February 1st, 2012

Nearly a month ago I started to write a post on the "Fake sugars," I had read an article on them in the Personal Journal section of The Wall Street Journal, but got distracted when I realized I needed to think about (and write about) table sugar and high fructose corn syrup.

they're all sweeter than sugar

So now I'm finally going to start on the artificial sweeteners. There are four major ones that WSJ reviewed (they even had a panel of tasters): Sweet'N Low, Equal, Splenda and Truvia. They came on the market, respectively, in the 1970s, 1980s, 2000 and 2008. All have zero calories per packet, whereas table sugar has 15 or 16, depending on who you read, per teaspoon. They cost much more than sugar and are considerably sweeter. A Mayo Clinic article online reviews the general subject and terms these chemicals as intense sweeteners.

The National Cancer Institute mentions that they are regulated by the FDA and, in an August 2009 online paper, states there is "no clear evidence that the artificial sweeteners available commercially in the United States are associated with cancer risk in humans."

The most recent addition to this mix, called Truvia when it's made by Coca-Cola and Cargill, or PureVia when it's parents are PepsiCo and Merisant, comes from a plant called Stevia, found in South America. Stevia has a curious history in the United States; it was added to teas by Hain Celestial until the FDA got an anonymous letter questioning its safety in late 2007. At  that point the FDA banned its use in foods, but in 2009, faced with major industry interest, Stevia by-products were approved as food additives (but not Stevia itself).

Stevia, saccharin and the real sugar

Now Truvia and PureVia are being used in a wide range of processed food and beverages. A cousin to the chemical they contain has been extensively used in Japan for over twenty years without major side effects being noted and Stevia, the parent plant, has not only been used for centuries in South America, but also touted for its supposed health benefits.

So why do I have some lingering doubts, in fact some major concerns about all of these chemical food additives, not excluding Truvia and PureVia?

As best I can tell the vast majority of the research on them has been sponsored by the same companies that profit from them. I fail to see independent, carefully performed, double-blind controlled studies especially on the "new two." Some research has been done on their chemical components, including one four-month study on type 2 diabetics that did not show either high blood pressure or high blood sugar as a result of consuming the active agent in Truvia.

But it's not just diabetics who are being exposed to the chemicals in these sweeteners. Most of us are, if we consume a diet drink or anything labeled "light." And medical history informs us that untoward effects may show up in relatively small number (or perhaps even large numbers), years later.

So I'm going to avoid "fake sugars" whenever I can. And perhaps, just perhaps, someday I'll find out I was being smart in doing so.

 

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Posted in additives, blood sugar, chemistry, Fake sugars, Food Additives, Food and Drug Administration (FDA), Food Choices, Food safety, medically-oriented background info | No Comments »

What sweetener do you use: Part 5; Fructose effects

Saturday, January 28th, 2012

A good place to start researching

I basically knew what happens when we ingest glucose, (eating it or drinking it depending on whether it's in solid or liquid form, e.g frosting versus sweetened tea) : it goes through the liver and heads off to muscle and other body parts where insulin activity is responsible for energy use. But I wanted to compare its effects to those of fructose. First I found an old article (1986 vintage) in the American Journal of Physiology (AJP), hardly a bedside reading item for me these days, but one I used to proofread for as a research fellow. That, once I translated it into English that I could understand, changed my mind a bit.

Glucose does lead to an increase in insulin levels and an increase in carbohydrate breakdown, while lipid (fat) breakdown slows down. The net result is a considerable bump in energy use. 'So far, so good,' I thought. But a comparable amount of fructose resulted in a much smaller increase of insulin, yet considerably more carb breakdown and even less fat breakdown. So even more energy was used. That I hadn't expected, but this study was a one-time experiment with seventeen healthy folk followed for a few hours.

So my next question, and I thought this one was far more important, was what happen longterm?

Let's look at animal research first. A group from Princeton published an article online in a journal called Pharmacology, Biochemistry and Behavior in February 2010. Tha basic conclusion from these scientists contradicted what I had read elsewhere, but made sense. They concluded all sweetener calories are not equal-- after feeding rats standard foods and adding either table sugar-sweetened water or HFCS-sweetened water. Even if the HFCS water was less sweet overall, the rats gained more weight. Long-term feeding experiments showed rats fed HFCS developed many of the signs of the "metabolic syndrome." weight gain, fat deposition in the belly and abnormal blood levels of trigclycerides.

So fructose was being metabolized to form fat, while glucose was being used as it normally is. That brought their thoughts back to why fructose in HFCS is different from that in table sugar. According to this research group, HFCS contains free, unbound fructose while that found in table sugar is always tied to a glucose molecule. Their concept is that table sugar fructose has to go through an additional chemical process, freeing it from glucose, before it can be used by the body.

So why should we care what makes rats fatter?

But here's our real target

I found a long article in The Journal of Clinical Investigation (JCI), the other research magazine my boss (and I) reviewed potential articles for in 1970 to 1972. Here people who who overweight or obese to begin with were fed either glucose- or fructose-containing liquids for ten weeks.

And the results were similar. Those getting fructose had more belly fat develop. I think translates to more chance of heart disease  and other long term complications.

The evidence is gradually adding up; I think HFCS is something to be avoided. Let's feed our kids and ourselves more fruits and vegetables and less processed foods.

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Posted in blood sugar, chemistry, Food Choices, fructose research, Healthy eating, high-fructose corn syrup, medically-oriented background info, our kids and their weight issues, Publications, scientific controversies, Unhealthy eating | No Comments »

What sweeteners do you use? Part 4: HFCS and mercury

Tuesday, January 24th, 2012

A safer place for mercury

In my last post I mentioned that fructose metabolism appears to be more complex than I learned in medical school. Of course that was in 1962-1966 and a lot has changed in medical knowledge in the forty-five plus years since then. We all know that fructose, in the form of high-fructose corn syrup (HFCS) is added to many processed foods and sweetened drinks; the question being debated is, "Is that bad for us?"

I've been reading a variety of articles from the medical literature and some popular websites on the subject and not all scientists, physicians and dietitians agree on the answer. I previously mentioned a Mayo Clinic online article that stresses the need to cut our added-sugar intake, both table sugar and HFCS, and mentions that research on HFCS isn't yet at the point to implicate it as worse for you than other added sweeteners.

There's also an article by Jennifer Goldstein from Prevention magazine that I found on the msnbc website. I'm not sure of her science background (she's now the Beauty Director for the magazine). Nonetheless, her article is reasonably well-balanced, if you read between the lines. The over-all conclusion is that anti-HFCS evidence is slim. She quotes an NYC-based nutritionist as saying the calories in HFCS and table sugar, gram for gram, are equal, but mentions several reports that have shown HFCS samples may contain mercury... in small amounts.

But you don't want it here, or in your food

Mercury is a neurotoxin, a substance which can damage the brain, especially the developing brain of a fetus or infant. Even "small amounts" are considered dangerous for babies in the womb. We have all heard of its presence in fish, but mercury in HFCS was new to me. I'm about three years behind, it appears. I found a Washington Post article from January, 2009 which mentioned two studies examining this issue.

At that time, in spite of industry denials, nearly half of HFCS samples tested contained mercury as did almost a third of processed food and beverage products. The researchers writing on this  enormously significant problem noted that HFCS had been made using chemicals produced in industrial plants clinging to an outmoded, 19th century method

A now-retired FDA scientist, Renee Dufault, headed a study in 2009 showing low levels of mercury in all the processed foods she and colleagues tested (and none in organic foods) and then had their results verified by two independent labs. She then says the FDA's head of their Food Additives section told her to quit her HFCS studies. She quit the FDA instead and published her results. A physician-headed team at the Institute for Agriculture and Trade Policy, a non-profit watchdog, repeated her studies using commercial beverages and foods. Their twenty-plus-page paper is worth reading.

By the middle of December, 2010, the HFCS industry had gotten the message. But until all HFCS made in the United States is mercury-free I'm going to avoid it.

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Posted in blood sugar, chemistry, Food Additives, Food-related disease, Healthy eating, high-fructose corn syrup, medically-oriented background info, Metabolic Syndrome, Obesity, our kids and their weight issues, scientific controversies, Unhealthy eating, weight gain | 1 Comment »

What sweeteners do you use: Part 3. Fructose & HFCS

Friday, January 20th, 2012

It's time to dissect out the science behind sugars

I knew that sugars are found naturally in milk, fruits, vegetables and honey. MedlinePlus, from the NIH's National Library of Medicine has a brief discussion of those natural sugars. I also knew that glucose was absorbed in the small intestine and leads to the pancreas putting out insulin. It's eventually converted to energy, though some may be stored in another form in the liver and muscles until needed.

But before I get to the artificial sweeteners, I needed to read more about fructose, the other half of table sugar.  My first source, a Mayo Clinic article, didn't make it to be much of a villain, but then I started to put the whole picture together. To start with, table sugar is half glucose and half fructose. The two "simple sugars," called monosaccharides by chemists, have the same chemical formula with six carbon atoms, twelve hydrogens and six oxygens, but the way those are arranged is quite different. They each supply four Kilocalories per gram or fifteen per teaspoonful (That's technically correct, but most of us just use the term "calories.").

If you taste table sugar and call it a "one" in terms of how sweet it is, glucose is about three-fourths as sweet and fructose is nearly one and three-fourths as sweet.  Both are considerably sweeter than lactose, the kind of sugar found in milk. Fructose is also easier to dissolve in water and hangs on to water better; that's apparently how it can lengthen the shelf life of baked goods.

That's not why I think high-fructose corn syrup (HFCS) became ever-present in sodas, other sweetened beverages and processed goods. In a blog post I wrote many  months ago, I mentioned that after WWII our government wanted to find a way to use two kinds of war-time chemicals; they eventually became pesticides and fertilizers. Corn turned out to be an extremely efficient plant in turning sunlight to stored energy, so it was subsidized. Eventually that led to "monoculture, huge farms raising nothing but corn.

What's the motive: health or profit?

Like any other industry, the corn producers needed to make a profit and have their stock prices increase. That resulted in HFCS being produced and added to lots and lots of food and beverage items.

So what? A 2208 article in Science Daily gave me a clue. The way our bodies handle fructose is considerably more complex than that of glucose. The two simple sugars are separated from each other in the small bowel and glucose quickly passes through the liver on its way to all the other spots in the body where it can become energy. Fructose, according to scientists, makes the liver work harder and there's some data pointing toward its triggering the production of fat.

And we don't just get straight fructose in our diets: HFCS, according to the USDA, is about one fourth water and the rest dissolved sugars. HFCS42  (with 42% fructose) is added to many products, especially processed foods. HFCS55 (with 55% fructose) is added to soft drinks. It's roughly comparable in sweetness to table sugar; the issue is why do you need to ingest any more sugar?

There's been more research in this area and I'll cover that in my next post.

 

 

 

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Posted in blood sugar, chemistry, Healthy eating, high-fructose corn syrup, medically-oriented background info, Obesity, Publications, weight gain | No Comments »

What Sweeteners Do You Use? Part 2

Monday, January 16th, 2012

Sugarcane grows in the tropics

In my last post I said I'd dig more fully into the background and safety record of the artificial sweeteners. Then I got diverted; one question was what kind of sugars were there before the artificial sort? I ended up at a website called Lab Cat which, in a brief verbal and visual format, described the sugars we commonly might ingest. Table sugar usually comes from either sugarcane or beets; it's a combination of two other sugars, glucose and fructose, the former found, typically in grapes and corn; the latter in honey, fruits and vegetables.

When a physician measures your blood sugar level; he or she is checking for glucose. The WebMD site has a nice discussion of blood sugar, mainly focused on those who have too much of it, namely diabetics. Another brief discussion, this one by a Harvard Medical School professor, can be found in an abcNEWS piece online. Normal fasting blood sugar levels are in the 70 to 99 milligrams per deciliter (mg/dl) range.  A deciliter is one-tenth of a liter, a little over three and a third ounces or six and two-thirds tablespoons. A liter is 1.05 quarts and a liter of water has 33.81 ounces of water. Even after eating, a non-diabetic person doesn't usually  have a blood sugar level over 135 to 140 mg/dl.

Diabetics may have considerably higher blood sugar levels, enough so their urine contains sugar. Up to levels of 180-200 mg/dl your kidneys can reabsorb sugar; above those levels a urine dipstick test will be positive (briefly immersing a plastic strip into the urine; the chemicals on the strip will cause a color change if glucose is present in the urine).

If your blood sugar is low, below the low 70 mg/dl level, either from missing meals or overdosing with insulin or oral drugs used for diabetes (there are a host of other causes), you usually will feel shaky, hungry and perhaps have other symptoms. Most of us who are otherwise healthy  are unlikely to have our blood sugar level fall to really low levels, but those can be extremely dangerous.

If you get an IV with sugar, it's really glucose under its pseudonym, dextrose. A common IV solution is D5W; that means the composition of the fluid is 5% dextrose (glucose) dissolved in water. another is D5NS, meaning the sugar is dissolved in a salt solution. That is usually given to patients who are dehydrated and need volume; the sugar, in the form of dextrose, is added to make the sterile intravenous fluid "isotonic," An isotonic solution has the same salt concentration as the normal cells of the body and the blood.(using only salt enough to approximately match what your normal blood level of sodium should be and not adding the dextrose would result in a fluid too dilute for safety).

Fructose can be added to foods, drinks, or, eventually, your waistline

When I read what I had written thus far I realized I wasn't sure anymore what exactly happens to the fructose part of table sugar, or for that matter the high-fructose corn syrup added to so many processed foods. That turns out to be more complicated than I remembered so I'll save that discussion for my next post.

 

 

 

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Posted in additives, blood sugar, chemistry, diabetes type 2, Fake sugars, medically-oriented background info, Obesity, weight gain | No Comments »