Did You Say Getting Old Was A Good Thing?

No, maybe not for humans, but for wine sure! When a wine ages, there is a reduction in Astringency. Astringency is responsible for a bitter taste and making the mouth feel dry. Tannins contain this astringent which are naturally occurring compounds that exist inside grape skins, seeds and stems.

Young wines contain a good amount of polymerized tannins, which usually taste harsh as opposed to aged wines that are more smooth tasting. This is due to the fact that when tannin molecules polymerize this causes astringency, so as the wine ages the tannins are no longer polymerized.

The reaction below represents the wine making process from a polymerized tannin to a sulfonated tannin by the addition of bisulfite (HSO₃^-). These bisulfite ions attack the polymerized tannins, thus breaking them apart leaving sulfonated tannin as the byproduct.

A study published in the Journal of Agricultural and Food Chemistry, analyzed the tannin profile of three wines using different amounts of bisulfite. The wine with the greatest amount of bilsfulte had the least polymerized tannin leading to the least bitter wine of the three. Results are shown below.

Additionally, tannins are also indirectly responsible for a wine’s smell through reactions with the wine’s alcohols and esters to gradually subdue the flowery, fruity aromas of youth. The winemaker controls how long the mashed grapes stay in contact with the tannin-loaded stems, skins, and seeds which thus determines the amount of tannins that go into the wine. Starting off with a more bitter, dry wine will mature successfully over time.

For those interested in collecting wines over time, it is best to do so in a refrigerator set to 55°F as too much heat will cause the wine to oxidize which causes the wine’s pigmentation, aroma, and flavor to decrease.

Sources:

https://www.acsh.org/news/2018/09/08/chemistry-why-aged-red-wines-taste-better-13394

https://www.winemag.com/2018/09/11/tannins-wine-guide/

Filling You in on the Realities of Dental Amalgam

Going to the dentist is scary enough, right? Well how about being told that you will have to have a filling done on a cavity, and that dental filling was composed of something called dental amalgam. After searching up what dental amalgam is actually composed of, you find out it is 50% elemental mercury by mass. Further research leads you to find out that this mercury is released at low levels in the form of a vapor that can be inhaled and absorbed by the lungs. You probably didn’t want to get that filling in the first place, but now you really don’t want to get that filling, do you?

These are the thoughts going through a person’s mind when they hear that their filling will be made of dental amalgam. After doing further research, they question the filling composite material and wonder if this is even safe for them as high levels of exposure to mercury vapor can be associated with adverse effects in the kidneys and the brain. Negative stereotypes and stigmas of chemistry have made people fear even the word “chemicals,” let alone knowing that you would be constantly inhaling one given that you had used dental amalgam as a solution for your most recent result of a sweet tooth.

https://www.alliancedental.ca/visiting-the-dentist/what-are-silver-fillingsdental-amalgam-made-of/

However, the bottom line is: dental amalgam is completely safe and even FDA approved, despite the contradiction of the filling’s possible adverse effects. Chemistry plays a very large role in the profession of dentistry, and generally of any healthcare field. There’s a reason why mercury is used in the dental amalgam; and that is to bind the alloy particles together strongly, creating a durable and solid filling. As the FDA states, the amount of mercury vapor let off by the dental amalgam is too low to produce any significant effects. As stated in the FDA article, “The weight of credible scientific evidence reviewed by FDA does not establish an association between dental amalgam use and adverse health effects in the general population.  Clinical studies in adults and children ages 6 and above have found no link between dental amalgam fillings and health problems.”

https://cen.acs.org/content/cen/articles/94/i24/Periodic-Graphics-chemistry-dentistry.html

But because of these “environmental concerns” with dental amalgam, some dentists have moved on to composite resins. The most common composite resin used for dental fillings is Bis-GMA, formed by BPA and GMA which polymerize in UV light, according to an article posted on Chemistry & Engineering News.

If you have a cavity filling in which dental amalgam was used, fear not! Nor is it advised to get it removed/changed. By doing this, you are putting the healthy tooth that you have remaining at risk. Unlike your skin or many other parts of your body, once you grow to a certain age, you cannot re-grow tooth structure. So healthy, strong tooth structure is very important and preserving it as much as you can is necessary! Dental amalgam is actually very strong, durable, long-lasting, are less likely to break than most other fillings and are even cheaper! Despite this, most people choose to go with the Bis-GMA composite resin because of the “environmental concerns” and for its natural looking color.

Sources:
https://www.fda.gov/medicaldevices/productsandmedicalprocedures/dentalproducts/dentalamalgam/ucm171094.htm
https://cen.acs.org/content/cen/articles/94/i24/Periodic-Graphics-chemistry-dentistry.html
https://www.alliancedental.ca/visiting-the-dentist/what-are-silver-fillingsdental-amalgam-made-of/

Cutting-Edge Cancer Treatment Turns Deadly

Yesterday, Monday October 1, 2018, the New York times released an article reporting a cancer treatment had go awry. The treatment used immunotherapy, a type of treatment that boosts the body’s natural defenses. In this case, scientists genetically alter a person’s white blood cells so that they are able to recognize cancer cells. This type of immunotherapy was called CAR-T. CAR-T stands for the anti-CD19 chimeric antigen receptor (CAR) T cell product, and it is the first FDA-approved gene-modification cell therapy of any kind. It has had much success in sending aggressive cancers into remission. However, in this instance, when scientists genetically altered the T-cells of patient 116 they accidentally altered one cancer cell’s (leukemia cell) genome as well. The change made the leukemia cell invisible to the newly altered white blood cells. Although the patient briefly entered remission, the leukemia cell began to rapidly divide without detection causing a relapse and, eventually, the death of patient 116. After his relapse, blood tests showed that every new leukemia cell contained the genetic mutation.

Basics of immunotherapy

This article, showing what can go wrong with engineered genetic mutations, was coincidentally published the same day the Nobel Prize for Medicine was announced. The 2018 winners, Dr. James Allison and Dr. Tasuku Honjo, were awarded the prize based off of their research on/discovery of immunotherapy in cancer treatments. They used different target antigens than the study mentioned above, however the basis of the treatments is the same. The idea behind immunotherapy is portrayed in the image below. Essentially, scientists are prompting T-cells to recognize and destroy cancer cells that usually have defenses to evade such white blood cells. This can either be done with drugs to block the cancer’s defense, or with a transfection which allows the T-cell to produce the antigens they need themselves. A transfection is when a group of cells is exposed to a virus that contains DNA that is to be incorporated into the host’s genome so that they may produce the desired proteins (antigens).

This article shows the good and the evil of genetic modification. Patient 116 was the first of over 400 patients to have this negative side effect of the treatment. Not all of the other 400 patients were sent into permanent remission, but overall the treatment had been more successful than negative. Patient 116 died as a direct result of the engineered genetic mutation. This plays directly to the fears that the public has on genetic mutation, whether it be immunotherapy or GMOs in foods. People worry that scientists may create super bugs, or that GMOs are dangerous. As scientists, we know that this is largely untrue and that there is generally no danger in eating GMOs. However, when it is people’s own cells, there is increased risk.  

Genetic editing is still an emerging science. Although there are risks, as exemplified above, it is important to think about the long term, positive implications. Genetic editing has the potential to cure diseases that previously would have been a death sentence. Although patient 116 died from this treatment, there were over 400 other patients who experienced benefits. It is important that one failed attempt does not take away from the successes and that we do not allow it to impede research and scientific discovery.

Sources:

https://www.nytimes.com/2018/10/01/health/nobel-prize-medicine.html

https://www.nytimes.com/2018/10/01/health/leukemia-immunotherapy-kymriah.html?smid=fb-nytimes&smtyp=cur

https://www.nature.com/articles/s41591-018-0201-9#ref-CR2

The Age Old Myth: "It ain't easy bein cheesy"

A wise cartoon Cheetah had once said, “It ain’t easy bein cheesy,” but we are now understanding that maybe it is in fact extremely easy to be cheesy.  A recent study conducted by the University of Michigan is saying that they have shown evidence for the fact that cheese is one of the most addictive foods. News networks are running with this idea saying that cheese is as addictive as crack cocaine. Crack cocaine is the most addictive form of cocaine known as a “free base” form.  This comes from the deprotonating of the amine group of cocaine hydrochloride, which makes it more efficient to smoke. 

The study published in the U.S. National Library of Medicine shows evidence that food addiction is a tangible thing, but just keep in mind that food addiction is much different than drug addiction. Researchers were looking to identify the most addictive foods by having 500 participants complete the Yale Food Addiction Scale. This survey is designed to show if someone does or does not have an addiction to food. Unsurprisingly the food that was rated the most addictive was pizza. The main reason was due to the amount of processed cheese on it. 

The National Institute of Health Dairy guidelines (yes that’s a real organization) says that your recommended daily cheese intake should be around 1.5 ounces of cheese. To put that in perspective, a large cheese pizza has around 5 ounces of cheese on it. So if you are a normal human and eat more than a few slices, you’re already over the amount of cheese you should ingest on a daily basis. The more cheese you eat, the more "addicted" you become.

But why is cheese so darn addicting? That answer lies in 2 parts. The first part being that it is incredibly processed. In rat studies looking at addiction-like reward dysfunction, researchers found that rats showed addiction-like behavior to foods that are processed, such as cheesecake, but showed no similar behavior to their regular rat food. The second part of the answer to the question of, “why is cheese so addictive” is due to the way the human body breaks down milk proteins. Your body cannot fully break down the amino acid chain of casein (a protein in all milk products), which leaves a leftover product called casomorphins. Casomorphins do what any other addictive chemical does, which is binding to you dopamine receptors to activate the reward centers of your brain. This can cause similar effects (to a much lesser extent) of heroin and morphine. 

The big thing to take away from this is that claiming something is addictive is very tricky. Is cheese addictive? Kind of. The casomorphins in your body do trigger the reward centers of your brain just like other addictive substances. However, this study helps people be more aware of what they choose to eat and why. In conclusion, go ahead and grab some pizza or mac and cheese, because things can trigger your opioid system but not be classified as addictive. So unless you’re skipping class to eat a wheel of cheese, or spending your hard earned cheddar on pizza every day, it’s okay to let your cheese eating habits brie. 

http://www.latimes.com/food/dailydish/la-dd-cheese-crack-science-20151023-story.html

https://www.sciencenews.org/blog/scicurious/no-cheese-not-just-crack
Image taken from Family Guy