The Pancreas

While the pancreas may not be one of the A-listers or showstoppers of the organ world (if there is such a thing), it is as important as any other cog in the system. For a long time, perhaps owing to its position behind the stomach, its true function was completely unknown. It is curious in appearance, shaped a bit like a leaf and rubbery in texture (apparently). This gave rise to a certain vagueness in its naming – it means ‘all flesh’ in Greek. Until the late nineteenth century, many thought its only function was as a shock absorber in the upper abdomen just below the ribs and the sternum.

 

 

The discovery of a sneaky duct that connects it with the first part of the small intestine was the first clue that it might have a deeper role. It was then discovered that the pancreas secretes a rich cocktail of juice and enzymes through this duct and into the intestine in order to help with our digestion. Specifically it helps in breaking down fats (with an enzyme called lipase), starches (with amylase) and proteins (with various different proteases). Basically, anything with ‘ase’ at the end generally means it is an enzyme of some form or other.

This is important because, without the ability to break these dietary components into smaller building blocks, we would not be able to absorb them from the intestines into our bloodstream. In addition, the pancreas produces lots of bicarbonate (an alkali) to neutralise all of the acids secreted in the stomach so that once your food gets into your intestine, it is at optimal pH for absorption.

That role alone is extremely useful you might say, but the pancreas is not finished there. While its function in digestion relates to what is known as the exocrine system (essentially ‘exo’ means outside and the digestive system is classed as ‘outside’ because it begins and ends outside!) the pancreas has a vital endocrine role. Endocrine relates to the travels of hormones throughout the closed circulatory system, i.e. the blood.

In those years where scientists considered the pancreas to be nothing more than a glorified cushion, hormones controlling the body’s sugar levels were thought to be pumped into the circulation from the brain. This idea persisted until a chap called Langerhans identified in 1869 an area of tissues in the pancreas different from the rest. When these areas were (rather cruelly) removed under anaesthetic from dogs, the animals went on to develop features of diabetes.

Through various means subsequent to this, it was proved that these ‘islets of Langerhans’ (useful to know for pub quizzes) secreted hormones, the first of which discovered was named insulin after the Latin term for ‘islands’. We now know that the pancreas also produces a second hormone called glucagon as well. As part of the endocrine system, these hormones are secreted from the pancreas into the bloodstream and it is here that they perform their vital work.

Insulin helps the cells around the body to take up sugar from the blood stream to use as fuel and also helps to store it in the liver. Glucagon performs the opposite role, mobilising energy stores in the liver and fatty tissue for those days when we’ve not had time for lunch or have decided to run a marathon.

In this way, to use a rather crude comparison, the pancreas is a bit like the national grid. When it receives certain signals that more energy than usual might be required, like going for a long run (just as TV coverage of a royal wedding, for example, might cause a surge in electricity uptake, to keep the national grid analogy alive), it prepares by secreting more glucagon to draw from the reserve of energy we keep stored in our livers and fatty tissue. If, on the other hand, we are providing more energy than we need by eating lots of sugar, the body switches to insulin to use up the sugar being eaten and store any spare energy left over. 

So evidently the pancreas when it is working well is extremely important. When it is not, diabetes can result. But what else might go wrong?

Sometimes, the pancreas can become inflamed and this is known as pancreatitis. Every medical student will most likely know (or at least have heard of) the pneumonic GET SMASHED. Each letter represents a potential cause for pancreatitis, the two most common being Gallstones and ETOH or Excessive Alcohol. ‘S’ stands for Scorpion venom and, as there are not many scorpions running around Henley, I’ll not dwell on that too much.

Pancreatitis can range from the mild to the severe and can even be life threatening. Symptoms include severe upper abdominal pain going through to the back, nausea and vomiting. You may also sometimes get a fever and also diarrhoea. It often results in a stay in hospital where you can receive pain relief, fluids and oxygen if needed.

The other main condition affecting the pancreas is cancer. Pancreatic cancer is the UK’s 11th most common cancer and tends to affect those in older age groups more. Around 9,600 people in the UK develop pancreatic cancer each year.

The big issue with pancreatic cancer that gives it a high mortality rate is the difficulty in its detection. This means that it is often picked up only at later stages. Researchers are always looking for effective tests that might be used as a good screening tool, but as yet none has been found. The symptoms are often very vague but include…

-Weight loss

-Dull, boring pain or fullness in the upper abdomen which can go through to the back as well

-Jaundice, often without pain or any other symptoms (this occurs because of the pancreas’s proximity to the bile duct which, if pressed on, causes a back-up of the pigment bilirubin in the blood.)

One in ten cases may have a genetic element so, if a family member has had pancreatic cancer younger members may sometimes be screened.

If you are at all concerned about this, it is of course always worth coming to see your GP for a check.

As always, there is always more to learn. Even now, research is being done into other hormones produced by the pancreas which may perform roles as yet unknown, thereby, in the future, potentially opening up different possibilities for the treatment and understanding of various diseases, including diabetes. For that reason alone, I think the pancreas deserves a little more time in the limelight.

 

 

 

 

 

Exercise

“Fit and fat is better than being unfit and thin.”

Forget pills, staying active is the best medication.
After-all, when it comes to being healthy, there is almost nothing else that comes near it in terms of its effectiveness.

There is a quote from a health promotion consultant called Dr Nick Cavill that seems to pop up more and more regularly these days – ‘If exercise were a pill, it would be one of the most cost effective drugs ever invented.’ When you look at the statistics, it is difficult to disagree.

There is strong evidence to suggest that exercise reduces the risk of the following conditions by the following percentages…

Coronary artery disease and stroke – 35%
Type 2 Diabetes – 50%
Colon cancer – 50%
Breast cancer – 20%
Osteoarthritis – 83%
Depression – 30%
Dementia – 30%
Hip fractures – 68%
Falls in older adults – 30%

These are not insignificant numbers as I’m sure you will appreciate. Exercise really is good stuff and also helps with self esteem, sleep quality and energy levels.
The government’s aim is for everyone to be doing around 150 minutes of moderate aerobic exercise each week. Moderate exercise is something that essentially causes you to breath faster, increase your heart rate and feel warmer – a good way to gauge it is if you are breathing too heavily to sing the words to a song. Examples might be going for a brisk walk or hike or playing a game of volley ball. Only half of us in the UK are reaching that target. It doesn’t take too much of an imagination to consider the effect it would have of all of us matching this target on the mortality rates for all of the conditions above.

It goes deeper than this though. We are a species that evolved as hunter gatherers, constantly on the move, but in world with televisions and remote controls, motorised vehicles, and robots that do your hoovering for you, it comes as no surprise that we are suffering from the effects of a sedentary lifestyle. As such, even if we are reaching our exercise targets, if we spend the rest of the time sitting or lying down (and the average person in the UK sits for 7 hours a day, 10 hours if you’re over 65 years old) then those benefits are lost or at least have less impact on the risk of adverse health conditions.

It is therefore key for us to move about every now and again even if we’re not exercising. The recommendation is that every half an hour, we should get up and move about for 2-3 minutes. Practically I know sometimes it may seem difficult but actually when you think about it, is it really? Sometimes only the smallest things need adjusting to achieve this, whether it be an agreement with your boss to get up and walk around the office once in a while or maybe even (as horrifying as this sounds) keeping the remote in the shed at the bottom of the garden. Essentially we’ve all got a bit lazy and our bodies are experiencing the consequences.

For those thinking, ‘well my knee hurts too much for me to do any exercise’, or ‘the local volley ball court is too far away,’ I’m afraid that’s no excuse. Remember, moderate aerobic exercise is anything that gets you breathing and increases your heart rate, so if your knee hurts, do some swimming or even some armchair aerobics, likewise if you can’t get to your local sports centre easily, go for a brisk walk down the road or around the garden for 30 minutes every day. There is a mode of exercise for almost everyone.

Why does exercise and activity help you may ask? Recently, research has revealed quite in depth benefits that we were previously unaware of. Much of this has to do with the anti-inflammatory effects of activity. At the cellular level, our bodies are in constant turnover. Each cell in our body has something called a mitochondria which is essentially a mini power plant. It is here that we produce energy to be used in various processes throughout the body. Each mitochondria will build up a charge and if we are not using energy, they stay charged. The longer they do, bits of charge will gradually escape in the form of ‘free radicals’. These free radicals are bad news and contribute to cell and mitochondrial damage, aiding the ageing process and generally making us less healthy. It is thought that this process causes microscopic inflammation throughout the body.

Activity and exercise helps by utilising this energy and preventing release of free radicals but also produces anti-inflammatory substances from muscle that help to mediate the inflammation at a cellular level. That is not to mention its effect in increasing insulin sensitivity of cells, reducing risk of conditions like diabetes, along with strengthening heart muscle to reduce average heart rates and contributing to lower blood pressure and cholesterol.

There is a lot of focus these days on weight loss when it comes to exercise. This is quite a damaging concept and is reinforced by many commercial diet plans and courses. Although it is important to maintain a good weight and avoid obesity, weight loss is not the be all and end all. There are two types of fat. Subcutaneous fat (sub – beneath; cutaneous – skin) is the stuff that pads out our waist lines and is the most visible. However, arguably far more important is the fat that surrounds our organs like the liver and the heart. This is called visceral fat (viscera meant ‘internal’ in latin) and build-up of this visceral fat has significant implications for our general health. Even if our exercise seems to be doing nothing to our subcutaneous fat, it will be having far greater effects on our visceral fat and this is very important. Therefore we mustn’t measure the success of our exercise or indeed any form of activity with weight loss. Fit and fat is better than being unfit and thin.

The Brain

While we know more than we ever have, there is still a lot to learn meaning that, in an ironic sense, the brain is still something we can’t fully get our head around.

Someone once said that if the human brain were so simple that we could understand it then we would be so simple that we couldn’t. I would have to agree. The brain is our vastly complicated seat of consciousness and individuality, controlling most functions of the body, some of which we are aware of and some of which are on a more subconscious level.

If one were to zoom in to see it under a microscope, one would find literally billions of nerve cells, or neurons, forming a continuous interconnected network signalling to each other using electrical pulses and chemical transfers. There are around 86 billion of these neurons in the adult brain, meaning that if you were to pick an area of the brain the size of a small grain of sand you might find as many as 100,000 neurons in just that one area. What’s more, each one connects to around 1,000 others via connections known as synapses.

As we zoom out again, we see that the brain has a wrinkled surface that, if stretched out flat, would cover the area of four A4 sheets of paper. It is cushioned and bathed by a viscous layer of cerebrospinal fluid that, as the name suggests, runs all the way down around the spine as well.  Weighing in at around 2% of our body weight, our brains manage around 98% of human function, which is a pretty good return. It follows therefore that it needs a fairly good power supply and, indeed, it has an important network of blood vessels that supply it with oxygenated blood and nutrients – it uses around 20% of the body’s energy supplies.

With such a complex make-up and such a plethora of responsibilities, it is no wonder that it is regarded with such intense interest and yet is still relatively poorly understood compared with other organs of the body. As with much scientific endeavour, much progress has been made in its understanding over the last century.

Take the frontal lobe for example. As part of the quest to understand the brain in more detail, scientists identify areas in accordance with their perceived function. The frontal lobe is thought to be involved in executive function such as judgement, decision-making, planning and control of behaviour – functions that became clear following an accident involving a railway worker named Phineas Gage in which, rather unfortunately, he received a metal pole through his forehead. Though he survived this ordeal, the once calm and understated worker famously showed a marked change in personality towards aggression and surliness.

Had the pole gone through his occipital lobe, he might have had trouble with his vision and, if it had pierced the temporal lobe, he would potentially have had trouble processing sound, using his memory and producing speech.

The point is that certain areas of the brain are involved in particular tasks. This can become apparent when someone has a stroke. Most strokes happen when blood supply to an area of brain tissue is interrupted.  The result can be, for example, loss of motor function in one side of the body. If there is a problem in one half of the brain, then the problem (when talking about motor function – i.e. moving an arm) manifests in the other side of the body. This is because nerve fibres from each side of the brain cross over at a certain point before descending the spine to the rest of the body.

We know that the brain performs so many functions. It allows us to move, to smell, to hear and to sense temperature. It also enables us to think. While this complexity is admirable, when it goes wrong the consequences can often be very distressing. Infection, head injury and cardiovascular disease all affect the brain’s health, as well as conditions such as Parkinson’s disease which affects the production of dopamine, (normally used to regulate our movement) and resulting in involuntary shaking, slow movement and stiff muscles.

Most significant of all, as our population grows older, dementia is becoming the largest cause of mortality in the UK and all over the developed world. Research is ongoing and we still have a long way to go both in understanding the processes involved and in treating the effects. It should be mentioned that dementia is not a single disease, rather a term to describe the symptoms that occur when there is a decline in brain function.

Alzheimer’s is the biggest cause of dementia. Though not fully understood, it is believed to be related firstly to the build-up of amyloid plaques and secondly to neurofibrillary tangles made up of proteins called TAU proteins. As more of these build up, the ability of the neurons in the brain to transmit information gradually diminishes. Research is currently focusing on the processes involved in the development of these two features. Just as importantly, the search is on for biomarkers (markers that we can sample in the blood or spinal fluid) that might give us an idea of whether someone might be developing a dementing condition, giving greater opportunity to take early steps to manage the condition and also to research disease progression over longer periods of time. Although it can be difficult to face, and often slow to present, if you have any concerns about memory, it is important to see your GP as there is often support available and it may also be the result of more benign and treatable conditions (for example low vitamin B12 levels or underlying infection).

When concentrating on the more physical effects of the brain, it is sometimes easy to overlook the deeper thought processes that are involved in our mental health. Much of our individuality comes through the environment in which we grow up. In the same way that we form new connections and synapses in our brains through repetition as we learn an instrument or practise our times-tables for example, it is thought that personality traits develop to some extent in the same way. For untold reasons, however, our minds can be fragile and depression and anxiety can be extremely damaging. Often there are so many different factors, both social and physical, that make such emotional issues difficult not only to treat but also to recognise. Chemical imbalance plays its part, for example in relation to levels of serotonin in the brain, and in such cases there can be a role for medication. More recently, there has been a push for increased awareness of mental health conditions in an attempt to remove any stigma attached to something that can cause a lot of problems if left unaddressed.

How do we look after our brains? Staying happy is a good start and there is plenty of support available for people for whom this is not the case. Keeping your mind busy helps to maintain your ‘neural plasticity’ – it ensures you are creating new synapses by learning new things. Maintaining healthy social networks is equally as important.

Regular exercise is vital for brain health as it increases the blood supply to the neurons, reduces blood pressure, helps blood sugar balance, improves cholesterol and reduces mental stress.

Getting enough sleep each night is important (8 hours being the aim).

Your diet can also give you benefits. Anything rich in omega 3 such as oily fish is useful and a ‘Mediterranean-style’ diet is a good start. Blueberries are rich in anti-oxidants, thought potentially to reduce inflammation involved in plaque formation in the brain, and dark leafy greens, such as kale and spinach, will give you good sources of vitamins C and E and folates – all thought potentially to reduce the risk of Alzheimer’s.

There is some evidence to suggest that certain people may benefit from medications like statins and aspirin but it’s always a good idea to come in to discuss any medication with your GP or pharmacist. And don’t forget not to smoke or drink too much alcohol.

While we know more than we ever have, there is still a lot to learn meaning that, in an ironic sense, the brain is still something we can’t fully get our head around.