Hello, my good human and welcome to this newsletter. Every Wednesday I share news that I find interesting from the world of science and academia. I do my best to write small explanations about them and start a discussion. If you found this newsletter online and want to get them right in your inbox you can subscribe using the cute button below! It’s free!
Do you like food? I love food. I love to make it, I love to learn stuff about it, I love to grow it (whenever I can), and most of all… I love to eat it. I eat a lot of it! At the moment, I am trying to lose some weight and if anyone here has also tried to lose weight methodically, you probably came across the term “calories”. How many calories is in this slice of pizza? Are you eating gyros? How many calories is that? Ohhh… want a slice of cheesecake? Do you have enough calories left in your day?
The above **totally random** and **totally not addressed to me** questions made me think about this term. What is a calorie? How do we measure it? How did science determine that my pizza has 285 calories?
What is a calorie?
Our bodies need the energy to move around and just generally exist. Food gives us that energy and the amount of energy we get is determined by the calories. A calorie is a unit of energy that is commonly used in food science. For us engineers, we tend to use the SI unit of measurement of energy which is the joule. One calorie is equal to 4.18 joules and the food labels are actually counting that energy in the kilo calories (or 1000 calories). As such, a calorie has nothing to do with nutrient density or quality of the food. A calorie is the amount of energy required to heat 1 kilogram of water by 1-degree celsius. Now you will ask me, how exactly does that help us determine the number of calories in a burger? Have patience, the best is yet to come.
Nowadays, there are machines like bomb calorimeters that can be used to determine the change of energy during a reaction in a fixed volume. Food scientists place the food in the volume which is surrounded by water. They heat the food until it is completely burned off and then they measure the rise of water temperature in this way they determine the number of calories. While this way is very specific and accurate, there is a way you can do this at home and I found a nice resource that gives you step-by-step instructions about how to determine the number of calories in a piece of food. You can find the instructions here.
The 4-9-4 system.
Now of course you are not expected to do the above step-by-step instructions every time you need to measure your calories for a meal. There are different resources that you can use online that tell you exactly how many calories you can find in each type of food. However, if you are a bit of a stickler and you want to double-check that the calories stated in the label or in your app are correct, you can do a little bit of math. From the measurements, scientists have done over the years, they determined that 1 gram of protein is 4 calories, 1 gram of fat is 9 calories and 1 gram of carbohydrates is also 4 calories.
These numbers were first determined in the late 1800s by Wilbur Atwater. Atwater used a device that was 2.5 meters high and allowed people to enter inside. The device measured the amount of heat released by the person along with the amount of oxygen consumed and carbon dioxide given off. You can see images of the machine, called a respiration calorimeter in the publication by Atwater himself in this link.
New drugs for cancer incoming?
I started the podcast some years ago, after seeing some news about a potential cancer treatment and afterwards reading the comments below that, with people saying that “big pharma” will bury it for profit. While I am no medical doctor or biologist, I have friends who during their PhD either worked in drug discovery or cancer detection methods, and from their experience, I understand the process they need to go through.
This week I read about a new research group from the University of California San Fransico that developed a drug that can mark cancer cells for destruction by the immune system. One of the properties that cancer cells have is that they can very effectively evade the human immune system.
About one in four tumors have a mutated protein called KRAS which makes it the most common gene mutation in cancer. This protein drives the growth of the tumor cells. Because of the extraordinary ability that cancer has to conceal itself, our immune system can’t detect it. This newly developed drug, puts a marker on that protein which gives the green light to
This is not the first drug that targets this cell mutation for the therapy of cancer. Prior work from the same research group has led to the development of a drug now used in cancer therapy. However, this drug doesn’t help all patients with KRAS mutations. With their new drug, they showed that not only they managed to halt the tumor growth, but they also helped the immune system recognize this cell as a foreign cell and attack it. You can read more about this discovery and details from the group itself in the press release from the University of California San Fransisco here.
Any more news?
People in academia are constantly coming up with new and exciting things so if you need more to quench your curiosity here are some more headlines.
What is the best way to group students? by University of Rochester
The Brain That Defied Alzheimer’s, by Being Patient
That’s all for this week! I hope that the rest of the week will be calm and rewarding. Did you like this newsletter? If you did you can subscribe to it at the top of the page and why not share it around using this sexy little button here
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Until next week… take care and be kind [=