Why you get tired after Thanksgiving dinner. Hint: it’s not Tryptophan.

Really the only thing that doesn't make you sleepy

You know the story. Have thanksgiving dinner in the middle of the afternoon, eat right up until you start to feel sick (and maybe a little more), and then find a couch or chair and fall half-asleep. If it happens, it's likely that someone will blame it on the Turkey. The old myth is that Turkey contains the amino acid tryptophan, which causes drowsiness. None of that is actually false. Turkey does contain tryptophan. And tryptophan is related to sleep – it is the only amino acid that can be converted to serotonin, which regulates our sleep patterns. But take a look at this list. Pork, chicken, and peanuts all have as much or more tryptophan as turkey. And beef and eggs are comparable too. But you don't hear people complaining that they are falling asleep because of the chicken sandwich they had for lunch. So what does make you sleepy at 6pm on Thanksgiving? The answer is: carbs. Think about the rest of the stuff on your plate: mashed potatoes, stuffing, cranberry sauce, breads, sweet potatoes, pie… maybe some vegetables (but who really eats those?). Most of what you eat at thanksgiving is carbohydrates. And the research shows that high carbohydrate meals cause sleepiness by releasing insulin, which releases much more serotonin than you get from the tryptophan in turkey. So now, thanks to my help, when someone at your thanksgiving dinner tomorrow claims they are falling asleep due to the turkey, you can be the annoying nerdy guy who tells them they are wrong. Or just have another piece of pie.

Anti-Aging Science

Most things with the words Anti-Aging attached would take quite a leap to be considered science.  But there is some real research in the area.  Here is something that looks like a mini-breakthrough.  A study has found a compound that was given to people as a dietary supplement, and may slow down the process of aging (but not stop or reverse it).  It works by activating enzymes in our body that rebuild parts of DNA (telomeres) which shorten over time and may play a part in making us old and wrinkly.  Telomeres also have something to do with AIDS, so this could be used as a treatment for AIDS patients also.  Read a more in-depth summary of the research here.

Update: Micro-pumps for micro-needle patches!

Patch Pump for Vaccine Delivery (Purdue University)

Remember a few weeks ago, I linked to an article about micro-needle patches? They were an ingenious new way to deliver vaccines easily (and painlessly). However, this new article mentions a problem not stated in the previous one; Large molecules of many drugs do not readily dissolve out of the needles and into the skin. For that, they needed a pump of some sort to drive the medicine into the skin. Scientists at Purdue University have done just that! The mechanism seems complicated (and slightly worrisome if something were to break in the pump), but it's still in the testing phase, so lets just get excited about it!

New pump created for microneedle drug-delivery patch.

Issues: Follow-up, HFCS and Mercury

Well, here I am back at my favorite topic. Over at my first post on the health effects of high fructose corn syrup (HFCS) a commenter brought up the topic of mercury in HFCS. I did a little research and thought the results were interesting enough to warrant a follow-up post. I am presenting an opposing conclusion from the comment left, I am really grateful for the response, and hope I will get more.

On mercury in HFCS, there were two studies done in Jan of 2009, one peer reviewed, by Dufault et. al. in Environmental Health. The other was by Wallinga et al. at the Institute for Agriculture Trade Policy. Wallinga was actually an author on both papers.

The Dufault paper measured the mercury levels in HFCS samples from three manufacturers, and found levels as high as 570 part-per-billion (ppb), with a third of the samples above 100 ppb. A study by Health Canada shows that many common foods have 1-5 ppb levels of mercury, and fish typically are the largest contributor to mercury in our diet with 25-100 ppb levels common. The acceptable level of mercury in drinking water is 2 ppb. At average American consumption of HFCS of 50 g/day, HFCS contaminated to 500 ppm mercury could supply as much mercury as dental fillings or certain mercury containing vaccines, both of which are not recommended for pregnant women or small children, but at the same time are not areas of concern for health toxicity.

Links: Disappearing Amphibians, Rabid Vampire Bats, and Plans for Cleaner Energy

Amphibians have been declining world-wide over the last several decades due to a mixed cocktail of pollution, habitat loss, climate change, and the uncontrolled spread of a devastating infectious fungus. One such amphibian is the elusive Golden Toad, which has not been seen since 1989. Now, scientists have begun a world-wide search for 100 of these frogs that have disappeared, hoping to find residual populations that can be protected.

Global hunt for "extinct" species of frogs.


Peru is battling a vampiric horror! Mainly vampire bats, bats that bite and drink the blood of sleeping mammals, that are infected with a strain of rabies. Four children have died after being infected by these animals, and over 500 people in total have been vaccinated after being bitten.

Peru battles rabid vampire bats after 500 people bitten.


And this week is big news for alternative energy... or at least plans for the next 20-or-so years. Research in nuclear power puts plants around the world by 2030 and a recycling idea that would negate the need for dealing with radioactive wastes! On the other spectrum, research into biodiesels that are made from plant-grown micro-algae claims to be able to produce sustainable and cleaner energy in 10 to 15 years, eventually eliminating the need for fossil fuels! Whether we can afford it is another aspect all together.

Scientists outline a 20-year master plan for the global renaissance of nuclear energy

Industrial production of biodiesel feasible within 15 years, researchers predict.

Links: Crazy Bus, Regeneration, and the Beauty of Alaska

Engineers in China have come up with a pretty elegant solution to the problem of overcrowded streets and buses stuck in traffic. They put the bus on stilts and it just drives over the other traffic while only taking up a tiny strip of road on either side.

China Hush: Straddling Bus


Possibly the holy grail of medical technology is human regeneration. It's the idea that we might coax the human body into growing back a lost limb or heart tissues that has led to all kinds of research. Healing cuts in your skin and broken bones are minor forms of regeneration that happen naturally, but, unlike simpler animals like amphibians, we can't regenerate larger parts of our body, probably because evolution forced us to trade long life and cancer resistance for wildly growing cells that can rebuild parts from nothing. This week plenty of news came out related to regeneration research. Here are a few stories. We are still a long way from regenerating a lost limb, but scientists are working on it.

NY Times: Two New Paths to the Dream – Regeneration

BBC News: Surgeons Rebuild Windpipe with Stem Cells

Nature: Skin Cells Converted to Heart Cells (more technical)

Jim Harris Photography

Last today, an incredible photo-essay of a backpacking trip through Alaskan mountains and glaciers. If you are one for beautiful nature pictures, you probably won't be able to stop scrolling down the page. The picture on the right is just one of many.

33 Days Across Wrangell-St. Elias NP, Alaska: The Southern Spiral


Also, this.

Issues: High Fructose Corn Syrup: Part 2

What's in Your Diet

Yesterday, I wrote about the current research on high fructose corn syrup (HFCS), how there is an ongoing but unclear debate on whether HFCS is any worse for your health than sugar, and that scientists point to sweeteners and lack of exercise for Americans' trouble with obesity. One thing that comes up is whether HFCS and other sweeteners are becoming more common in our food. So, today I decided to perform an extremely unscientific experiment involving my own diet. After my latest grocery shopping trip, I went through the ingredient list of each item I purchased. I tracked which contained HFCS, sugar, both or neither. Results are below, with notes (S,H,D indicate order of ingredients of Sugar, HFCS, and Dextrose):

High Fructose Corn Syrup	Sugar	Neither	Both
Hot Dog Buns	Bread	Potato Chips	Cookies (D,H,S)
Hot Dogs (less than 2% H, more than 2% D)	Hot Pockets	Milk	Lemonade (H,S)
Pickles	Pasta Sauce	Cheese	Yogurt (S,H)
Stuffing Mix	Flavored Rice Mix	Ground Beef	Ice Cream**
	Tortillas (last ingredient)	Chicken
	Chocolate Bar	Fruits… Assorted
	Brownie Mix	Vegtables…Assorted
	Chicken Helper*

*Within the half dozen varieties of Chicken/Hamburger Helper (they were on sale) some listed sugar as high as the third ingredient, while others had none.

**Second to the lemonade, ice cream might be the best way to fill up on sweeteners. After cream and milk, the ingredients are, in order: sucrose, corn syrup, high fructose corn syrup, sugar.

There are a few things to point out here, but several ways to interpret the results. Remember this experiment is not designed to draw any scientific conclusions.

Issue: High Fructose Corn Syrup: Part 1

Today is the first part of a topic that grew in length as I was writing until I decided to split it into two parts. This is my first try investigating some issue facing people in the world, something that you may have an opinion about. Feel free to share your thoughts and observations in the comments. Come back tomorrow for part 2 which includes an experiment you can do on your own.
 
A Growing Problem

US Obesity and Overweight Rates

The United States is overweight. Not the land geographically, though it is quite massive, but the people who live there. The level of obesity has been climbing for the last three decades, though it has shown signs of slowing down. Two in three Americans are overweight, and the obvious place to look for answers is in our diet. One ingredient has stood out as a poster child for the growing problem. High Fructose Corn Syrup, or HFCS. I wanted to check out the claims and research, and see if I could clear up what we know about HFCS.
 
There are two discussions involved here. One is whether HFCS is less healthy than other sweeteners, such as sugar. The other is whether the obesity problem in the United States is tied to increased use of sweeteners in general.
 
The Unhealthier Sugar?

To tackle the first, it helps to compare HFCS to sugar chemically. HFCS, a thick liquid made from corn, is a mixture of fructose and glucose molecules, usually in a 55%-45% ratio with more fructose. Sugar is sucrose, found in your grocery store as crystals of table sugar. Chemically, sucrose is a fructose molecule joined to a glucose molecule. These are broken apart in the stomach and small intestine and absorbed. So sugar breaks down to nearly the same half-half mix of fructose and glucose that you get from HFCS.

Links: Smart Tortoises, Distant Planets, AIDS Research

Once a week, eventually every Saturday, we will find a few news stories so you can learn about the newest in science from the source without having to deal with our writing. Well… much of it.

First up, is one of the blogs from scienceblogs.com, which inspired some of what we are doing. It is a long read, but if you wonder how tortoises learn, it's worth a look.

The Thoughtful Animal at Scienceblogs.com

Next is something extra interesting for me. I have been keeping an eye on the Kepler Mission since it launched a year and a half ago. It is a telescope used to look for planets around other stars. Way back in high school I wrote my senior thesis on finding extraterrestrial life. I think I will use a post to write about that topic pretty soon. The Kepler Mission is the biggest leap in that area in 30 years, so I have been waiting for the results. The first batch of data was collected in January, and was scheduled to be made public next January, but apparently someone couldn't wait and "leaked" some of the results during a talk in the UK. They are very interesting and look like the first step in proving what astronomers have suspected for years. Planets like Earth may be very common in the galaxy.

Discovery News: Kepler Scientist: "Galaxy is rich in Earth-like planets"

Finally, quite a bit of news on AIDS research in the past couple days. The first link looks like an early step to a breakthrough, but is still some time off. The second link is something more immediate, but the article is largely focused on the controversial aspects. Take a look.

Singularity Hub: Antibody Neutralizes 91% of HIV Strains  
New York Times: Advance in AIDS Raises Questions as Well as Joy

No More Needles? Awesome.

Vaccinations have just gotten simpler. A patch is being developed that has hundreds of tiny micro-needles that dissolve into the skin, taking the vaccine with it into the blood stream. Simple, pain-free, and, if studies on mice have any indication, more effective at immunizing. Hopefully, this becomes available before the next swine/bird/insertanimalhere flu epidemic comes around.

Additional Links:

BBC News: Vaccine Patch may Replace Needles

Hate Needles? Flu Patch May Take Sting Out of Your Fears

Macroflux® Microprojection Array Patch Technology: A New and Efficient Approach for Intracutaneous Immunization (Scientific Article)