Avandia and the "New-Media Man"

In all honesty, I don't give a @$#@ (that's French for rat's ass) about the diabetes drug Avandia. While this article in the New York Times is ostensibly about the recent news that Avandia has been associated with an elevated risk of heart disease, the author spends much of his time discussing his research for the article. He refers* to himself as a "new-media man", meaning that rather than trust the headlines, he utilizes the "entire niche of blogs and digital news sources on relevant subjects — drug risks, Big Pharma, diabetes". I was pretty impressed. This guy was going to do a little digging and come up with a nice take-home message, empowering his reader to use the internet to look past the headlines and scrutinize what they are reading. So what was his take-home message?

"And here is what I found: everything, except insight."

What a disappointment! Maybe I should have guessed as much, after all the title of the article is "Call the Doctor". But this was a gimme! The take-home message is so simple, yet the author got caught up trying to weigh opinions of others when he would have been far better off just reading the study and forming his own. To me, the value of so-called "new-media" is unprecedented access to primary sources, allowing the people (as in "we the") to form their own opinions rather than simply selecting between those of politicians and journalists. (The Durham-In-Wonderland blog is a fantastic example, to which I've linked to multiple times before.)

A quick skim of the actual study in the New England Journal of Medicine given a pretty simple take-home message:

There is a 95% that the increase in risk of heart attack due to the use of Avandia for 24 months is between 3% and 98%, the best estimate being 43%. In other words, Avandia does seem to increase the risk of heart disease, but the studies have been small so the precise magnitude is unknown until larger studies are conducted. This result should be taken very seriously because Diabetics are at higher risk for heart disease to begin with, so even a relatively small percent increase in risk is significant, in the same way that doubling your chances of getting in a car accident is more significant than doubling your chances of being hit by lightning.

* in reference to Jaideep's comment, formerly "refferse"

Bicycle Helmets

As I've often been told to wear my helmet more, I decided to do a little research, and thought I'd write a post on what I found. I browsed some websites and read some original research. Turns out though, I could have just read this amazing wikipedia article on the subject. It is chock full of information, referenced with many of the papers I read, and is completely reasonable in its conclusions.

The gist of it is that it's very difficult to tell if helmets do much or any good. From first principles, they should help if there is a low speed collision involving direct head injury. At high speeds a normal bike helmet will absorb very little of the total energy, and they offer no protection against rotational trauma.

Statistical studies, as is the norm with these things, are difficult and ambiguous. People who wear helmets seem to get head injuries less often, but they're different in many ways. Mandatory helmet laws have not been shown to have a statistically significant effect on the rate of head injuries.

Cycling is safer when more people do it - which is why cycling in the Netherlands, with little helmet use, is much safer than the US, with high use. Helmet laws that discourage cycling are therefore counterproductive.

Of course this doesn't necessarily answer whether I should wear a helmet (any more than the bozo who gets counted in condom failure statistics should impact my decision). My general rule - if I'm wearing sneakers, I'm wearing a hat. I'm traveling slowly, unlikely to fall over, and if I do I can react to prevent myself hitting my head. If I'm wearing bike shoes, I wear my helmet. I'm out for a real ride, up and down hills, and traveling at a higher speed. And given that I'm already going to go click-clack if I try to walk anywhere, it doesn't really matter that I'll have to carry a helmet too.

My final point is that regardless of whether you wear a helmet or not, cycling is not dangerous (by most people's definition). Conservatively, cycling is twice as safe as walking, per mile. Meanwhile, the benefits of cycling are obvious. I mean, obvious.

Sodium Benzoate or Flash - Which is the Silent Killer?

New research indicates a possibility that sodium benzoate - a common preservative - has adverse effects on yeast mitochondria, with possible implications for humans. I'm normally not remotely alarmist about these sorts of things (I could be described as risk-tolerant, to say the least, as may be indicated in a future post). Of course it's worth looking into, and I'm curious to find out whether this is a real concern. It is a preservative, so it's purpose is to kill things, just hopefully not people.

After reading about this, I figured it was worth going to a few websites to determine which of my favorite sodas had sodium (or presumably potassium) benzoate. What amazed me is how little the Coca-cola and Pepsi websites had to do with drinks. Go to www.pepsi.com, and in addition to an annoying flash display, you see links to music, car culture, sports, entertainment, and fashion. Smaller links below include "brands and products", which is more than I can say for www.coca-cola.com, which as far as I can tell contains no information on the Coca-cola product whatsoever. After 12 mouse clicks, through the corporate page and more annoying flash crap than I would wish on anyone but my worst enemies, I managed to find out that Sprite "has an honest, straightforward attitude that sets it apart from other soft drinks." I wish I were making this up, but I don't think I'm capable of it, unlike the moron that designed this website. Eventually I googled "Sprite ingredient list" and the first hit confirmed that it does indeed include sodium benzoate (as do diet drinks and Dr. Pepper it seems, but not regular Coke and Pepsi).

Why are Americans so Fat?

This article in the nyt last month makes a good argument as to one cause. Agricultural subsidies are primarily directed towards a few crops, including corn and soybeans. This makes the goods derived from these crops, such as high fructose corn syrup, cheaper, while making other produce, such as carrots, oranges, etc more expensive. This means that healthier food ends up being a luxury good.

So why are we subsidizing farmers at all? As technology advances, fewer people can grow more crops, which lowers demand for farmers overall. Of course this has been true forever, and job churning, while painful to the individual, is exceedingly good for society as a whole (or else 90% of us would still be farmers). These subsidies probably have an adverse impact on immigration also, as poorer countries like Mexico depend more on agriculture and can have difficulty competing with subsidized US crops, which pushes Mexican workers across the border.

Ah, the government, encouraging illegal immigration and obesity in one fell swoop. But hey, ban trans fats, because that's a lot easier than acknowledging where the real problems come from.

When are we really dead?

This is a really interesting article about what happens when a human's heart stops beating. It seems our cells don't really die when the oxygen is cut off, but rather when oxygen is restored to a previously starved cell. This motivates a much different approach to resuscitation than is typically used involving a slow and controlled restoration of oxygen supply and a lowering of the body temperature.

Wear Your Seat Belt, And Make Your Passengers Wear Theirs

New Jersey Governor Jon Corzine was critically injured on Thursday after his SUV was involved in an accident on the Garden Sate Parkway. He broke 12 ribs, his sternum, a vertebra and his femur, which was protruding out of his thigh when paramedics arrived. The revelation that the Governor was not wearing a seat belt at the time of the crash motivated me to look up some statistics about seat belt use:

Wear Your Seat Belt

• Wearing a safety belt reduces your risk of serious injury by 50 percent (source)
• Wearing a safety belt reduces your risk of death by 60-70 percent. (source)

Make Your Passengers Wear Their Seat Belts

• One out of four serious injuries to passengers is caused by occupants being thrown into each other. (source)
• The driver's risk of death in an accident increases by 20% if a passenger in his car is not wearing a seat belt. (source)

Birth Control: A Condom Isn't Enough

If you have regular intercourse for 3 years using only a condom for protection, you have a 36% chance of getting pregnant.

( . . . pause for reflection . . . )

Using the pill instead of the condom is a bit better with a 14.3% chance of pregnancy over three years. Using them both brings the chances down to 5% over three years, which is why my mom once told me to "always use two forms of birth control". Even a 5% chance isn't something to take lightly considering the consequences.

There are two main things which can lower the risk of pregnancy:

1) Make sure you use the condom or pill as directed. For those using a condom alone, perfect use lowers the 3-year risk from 36% to 9%. Of course, nobody's perfect.

2) Use a method that doesn't require user intervention: the hormone shot or implant. Those have a 3-year risk of less than 1% on their own and even less when used in addition to a condom.

Here are some details:

Chances of getting pregnant during one year of sexual activity

Method	Rate of Pregnancy (Typical Use)	Rate of Pregnancy (Perfect Use)
Implant (Norplant)	0.09%	0.09%
Hormone Shot (Depo-Provera)	0.3%	0.3%
Combined Pill (Estrogen/Progestin)	5%	0.1%
Male Latex Condom	14%	3%
No Method:	85%	85%

Chances of getting pregnant during three years of sexual activity

Method	Rate of Pregnancy (Typical Use)	Rate of Pregnancy (Perfect Use)
Implant (Norplant)	0.27%	0.27%
Hormone Shot (Depo-Provera)	0.9%	0.9%
Combined Pill (Estrogen/Progestin)	14.3%	3%
Male Latex Condom	36.4%	9%
No Method:	99.7%	99.7%

(click here for the full table of all birth control methods)

Biking and your boy bits

Biking boys should be wary of their saddles lest their love life suffer. (I know this story has been circulating for a while, but I thought this LA Times article was a good update with lots of exciting details.)

Exercise Builds Brain Cells

As if the plethora of aliments already known to be prevented or mitigated by exercise weren't good enough (hearth disease, stroke, diabetes, high blood pressure, colon cancer, depression, anxiety and osteoporosis to name a few), now there is another: Exercise actually builds brain cells! MRI scans indicate that cell growth occurs in the region of the hippocampus associated with memory and memory loss. So if you are worry about losing your memory, or just have a bad one to begin with like me, try getting on the treadmill :-)

Safety of Artificial Sweeteners

The safety of artificial sweeteners (wikipedia) is an eteremly politisized topic, and you can find someone arguing everything from "it's 100% safe" to "it's poison" but most scientists seem to agree that they are safe for human consumption, especially in the relatively low doses we ingest them. Hey, even water will kill you if you drink enough of it.

Equal/Nutra Sweet (Aspartame): Aspartame is common in diet sodas and other low-calorie foods as well as a tabletop sweetener. Administration of large amounts of Aspartame has been shown to cause increased rates of cancer in lab rats; however, studies have not found evidence that Aspartame causes cancer in humans. There has also been suspicion that Aspartame can cause headaches and other unwanted effects in humans, but multiple studies have debunked this anecdotal evidence.

Sweet and Low (Saccharin) Saccharin was the first sugar substitute, and caused an uproar when it was found to cause bladder cancer in rats. Further research by Dr. Samuel Cohen showed that the mechanism by which Saccharin causes cancer in rats is not applicable to humans because of a specific difference in urine composition. Saccharin has since been taken off the list of suspected carcinogens by the FDA and is, for the most part, considered safe, particularly in small doses.

note: In Canada, NutraSweet does not contain Aspartame, which is banned in Canada; It contains Cyclamate, which is banned in the US.

Sweet One (Acesulfame Potassium or Ace K) Ace K is relatively new, and thus there is limited information about it's safety. It was approved by the FDA but watchdog groups argue that Ace K has not been properly tested. Ace K is most often used to mitigate the unpleasant aftertaste of Aspartame by using the two together.

Splenda (Sucralose) Introduced in 1999, Splenda recently became the market leader in artificial sweeteners. Now common in some diet sodas and other low-calorie foods as well as a tabletop sweetener. Unlike the other available sweeteners, it can be heated without causing chemical decomposition and can thus be used for baking. Because Splenda is new to the market, research on it is limited; however, animal tests have shown that Splenda can cause an enlarged thymus glad in rats when administered in very large quantities. Although this effect has not been reported in humans, it remains a potential long-term health problem.

Health Benefits of Cocoa

According to Dr Norman Hollenberg, of Harvard Medical School, the Kuna people of Panama have extremely low rates of stroke, heart disease, cancer and diabetes. Of course that doesn't really help me because, as you might have guessed, I'm not an Indigenous Panamanian . What's interesting about Hellenberg's research is that the death rates rise for Kuna populations who have migrated to mainland Panama, indicating an environmental mechanism rather than a genetic one. (BBC News report)

The suspected cause is something called a flavonoid, an anti-oxidant, high levels of which are found in natural cocoa (also in citrus fruits, green tea, red red wine). While the health benefits of anti-oxidants have been widely publicized, recent research has shed some light on how and what specific types of flavanoids effect health. So far, both the biochemical studies and the observational ones seem to support the hypothesis that the specific flavanoids in cocoa can have dramatic health benefits.

So we should all go get some cocoa powder and start drinking cocoa drink 5 times a day, right? Well, not quite. The cocoa which the Kuna people drink is flavanol-rich, while the cocoa available in the US is generally low in flavanoids, a consequence of processing techniques. Mars Inc. has developed a product called Cocoapro which is made using a proprietary processing method which apparently produces flavanol-rich cocoa. Unfortunately, this is not slave-labor free, so for now you'll have to choose between social justice and health benefits.

Fish Consumption Guidelines

We know that eating too much fish can be harmful because of high levels or mercury. We also know that eating fish is healthy because it is low in artery-clogging saturated fat and has lots of omega-3 fatty acids, whatever they are. So how do we strike a balance between too little fish and too much. Contrary to popular believe, the answer is not "avoid eating fish", even for pregnant and nursing women. Recent research has shown that for the pregnant and non-pregnant alike, the benefits of eating fish out weight the risks. In fact, according to recent research, women who eat fish during pregnancy may even have smarter children.

According to the American Heart Association (a big fan of those omega-3's) normal people (ie the non-pregnant, non-nursing, non-kids among us) should eat no more than 14 oz (3 to 4 servings, or 2 normal meals) of low-mercury fish and no more than 7 oz (one meal) of high-mercury fish per week. For those of use who are pregnant, nursing or young children, the guideline are to avoid high-mercury fish all together and limit low-mercury fish consumption to 12 oz (2 average meals) per week.

High Mercury Fish (more than 0.6+ ppm) Shark Swordfish Tilefish (golden bass or golden snapper) King mackerel Moderate Mercury Fish (0.2 to 0.6 ppm) Lobster Grouper Halibut Fresh or frozen tuna Canned tuna (albacore) Red snapper Orange roughy

Low Mercury Fish (less than 0.2 ppm) Pollock Salmon (fresh,frozen) Cod Catfish Flounder or sole Crabs Scallops Oysters Clams Shrimp Canned tuna (light) Herring

The Science of Weight Loss

At the most basic level, losing weight simply involves consuming fewer calories than are burned by your body. This is called a calorie deficit. When people diet to achieve this calorie deficit, however, they often become so hungry that the diet is unsustainable and inevitably fails, causing any weight lost to be regained. Fortunately, utilizing some of the science of digestion and nutrition, we can begin to understand how to maintain a calorie-deficient diet while still being satiated (feeling full), and thus maximizing the chances of sustained weight loss.

The number of calories you burn in a day of doing absolutely nothing is called your basal metabolic rate (wikipedia) and can be estimated based on your age, weight, height and gender (here). If you then add in all the calories you burn walking, talking, brushing your teeth, chewing and everything else, you’ll get your calories expended. Here is an online calorie calculator for common activities. Subtract from that the number of calories you intake to get your calorie deficit. For every 3500 Calories (kcal) you are deficient, you’ll lose 1 lbs of fat, which means that if you have a daily calorie deficit of 500 Calories, you’ll lose one pound of fat per week. Interestingly, the act of keeping track of the calories you burn can actually help you be successful at maintaining a reduced calorie all on its own. Here is some information about what types of habits successful dieters have.

Studies on the effect of exercise on weight loss are, surprisingly, somewhat ambiguous. Two major factors are suspected which combine to limit the effectiveness of exercise on weight loss in certain situations. First, people tend to eat back a average of 30% of the calories they burn exercising, so if you aren’t keeping track of the calories you intake, you can unwittingly counteract the benefits of exercise by eating more. Second, some have suggested that people who are forced to exercise compensate by decrease their activity level while not exercising, thus reducing the effect of the exercise on the total calories burned. (I couldn’t find all the articles I read for this, but here’s a good review article on the topic)

So how does one maintain a calorie deficit without feeling hungry? One way is to eat foods that have a large physical volume relative to the number of calories or energy density. This concept is called Volumetrics (book), developed by Dr. Barbara J. Rolls at Penn Sate. The idea can be crudely summarized as: Eat half a burger and a huge salad rather than a small salad and two burgers. You’ll feel just as full, you’ll be content because you got you eat the burger you were craving and you’ll have eaten far few calories than you would have otherwise. Eating smaller portions is also a central tenant of Volumetrics. A good starting point is to learn the energy densities of the different types of food (sugar, carbohydrates, protein, fat) Wikipedia has a list.

Another way to achieve satiety on a reduced calorie diet is to eat a higher than normal proportion of protein. Protein has been shown to cause a greater level of satiety (fullness) than other forms of food, so you can feel more satiated on fewer calories. Also, it takes more energy for the body to digest protein than other forms of food. This is called the Thermic Effect (wikipedia) and some studies have suggested that it can be as high at 25% for protein. In other words, when you eat 100 calories of protein you will burn up to 25 of those calories just to digest the food, leaving only 75 to go toward your total caloric intake. High protein diets can cause some health problems associated with the metabolism of the abnormally large about of protein but is generally considered safe for otherwise healthy people, if done in moderation. This is a good review article on high protein diets, including safety issues. Unfortunately, only those of you with access to university journal subscriptions will be able to access the full article.

So, what does this all mean? In short, to diet effectively, start by keeping track of your caloric intake and expenditure with a goal between 500 and 1000 Calorie deficit per day. Try to eat eat foods that have low energy density (Volumetically) and replace some of your carbs/fat with some additional protein.

Obviously, this is easier said than done :-)