The Weekly Dose - Episode 25

The Weekly Dose...

... the latest from Dr Karan

  Here is your weekly dose...  

Hi all!Here is your weekly dose of the Sunday Six! A few things I found interesting this week. If you enjoy this please feel free to forward this to friends. families and enemies alike!**You'll find more in depth analysis of some of these subjects on my social platforms in the links just below, including Dr Karan Investigates! for deep dives into interesting topics on my YouTube channel.**

A cancer vaccine?

When the COVID vaccine was released, one of the most common questions was: if we can make a vaccine against COVID, why can't we do the same against cancer?Well....now researchers have released early data about the successful completion of a trial of a personalised cancer vaccine that uses the same messenger-RNA technology as Covid vaccines.

It's designed to prime the immune system to seek and destroy cancerous cells and could help find new ways to target skin, bowel and other types of cancer.

Early analysis suggested this "cancer vaccine" meant patients with advanced melanoma were less likely to die, or have the skin cancer reoccur, a 44% relative reduction in the risk of dying of cancer of having the cancer progress. It's worth noting that the trial consisted of just 157 patients and is yet to be thoroughly scrutinised by independent experts or regulators.Yet this remains a significant findings and could help shape a new paradigm in the treatment of cancer patients. Watch this space... 

  The ghosts of the Black Death... 

The black death wiped out between 30 and 60% of the European population in the 14th century across a 4-year span making it the deadliest pandemic in recorded history. The culprit, Yersinia pestis, a highly contagious and deadly bacterium.Infectious diseases have always been one of the strongest drivers of human evolution by selective for genetic mutations that confer resistance or protection from an infection. New information has recently come to light after analysing ancient DNA from London and Denmark from those who died around the time of the Black Death and suggests that there certain genetic mutations in a normal population that made those individuals 40% more likely to survive the plague. However these same variants, passed down along the years, are seemingly associated with a higher risk of autoimmune and inflammatory disorders today. 

Your jaw is shrinking...

People tend to think of evolution as a process is occurring over thousands, if not millions of years...but thats not the case.When a 2015 scientific study announced that humans once had "an almost 'perfect harmony' between their lower jaws and teeth," this echoed what scholars had been saying for years - the human jaw is shrinking..

Humans have had a dramatic shift in diet, from hunting and gathering to pastoral farming and processed food - this caused a decrease in the force required to chew. Over time, the jaw took on a new shape, which is problematic. 

The jaw shrinkage means more people experienced dental crowding, wisdom tooth pain, periodontal disease and thus a rise in orthodontic work. This has also heralded a sharp increase in the cases of sleep apnea and associated sleep disturbances.In fact, more humans are now being born without wisdom teeth as an adaptation to shrinking jaws, a microevolution.

Your entire body can smell and taste...

You might have come across a bizarre trend on TikTok (if you haven't, count your blessings) where young men would dip their balls into pots of soy sauce. This trend arose due to some revelation that testicles have "taste receptors".This is true but not quite what you imagine and they're certainly not gustatory taste receptors or in anyway linked to your tongue or brain...poor soy sauce..Have you ever wondered how your organs and intestines know how to use the good stuff that you put into your body while jettisoning the toxins that you shovel into yourself on a daily basis? It turns out most of your internal organs can "smell" or "taste" toxins. 

The main organs that sniff out danger in your body are the kidneys, which actually have smell receptors that are able to discern whether or not they should make blood pressure changes. This allows them to best carry out their health-related functions. Similarly testicles can "taste" abnormal proteins or toxins which can it can flush out to protect the quality of sperm.The more you know...

Auto-regeneration...

You've likely heard or been told that your liver can "heal" itself and regrow. It's sort of true but also isn't the whole truth.So if you want to donate 70% of your liver it would regrow in about a year and on the flip side if you got even 30% of a liver from a donor those cells would create a full size organ in about a year. This is because when the liver cells receive a signal to start growing and multiplying until there's just a whole organ there again. Unfortunately this isn't an infinite liver glitch where you can donate infinite livers because when the liver regrows, the shape and structure of the tissue isn't quite the same as in a brand new organ.When you first grow a liver, you use stem cells so you get a nice fresh organ. However, when someone regrows their liver, they're using mature liver cells which are just multiplying to fill in gaps and regrow by a process of fibrosis (scarring). It doesn't have the exact same function as a brand new liver. So you can't then donate this regrown liver to transplant into someone else! No loopholes with biology I'm afraid 

You are losing bones...

The anatomist Henry Gray, of Grey's anatomy fame (the anatomy book not the TV show) said we have 206 bones in the 1850s.Well, we know more about how bones change and it turns out your bone count decreases by about 25 bones from your 20s to old age. The bones aren't literally disappearing mind you but they're fusing.As a 6 to 7 week old fetus you started growing bones.. hundreds of bones and at your peak bone collection phase you had about 800 little growing bones, most of which connected to four bigger ones. By the time you were born you only had a few hundred and this fusion continues all throughout childhood..but it doesn't stop. In your mid 20s you have about 215 bones. In your 40s that decreases to about 209-ish and senior citizens are left with about 190. At some point you'll have 206 bones but not for long!

As always, please give me feedback on Twitter. Which of this weeks Sunday six is your favourite? Is there something you want more, or less of? I'm open to any suggestions so please let me know! Just send a  tweet to @drkaranrajan and use the hashtag #theweeklydose at the end so I can find it!

Have a wonderful week, all.

Much love,

Karan