Posted in Psychology & Medicine

Voodoo Death

We inherently fear death. Much of what we do biologically is struggling against death. We eat and drink to sustain ourselves. We feel pain to avoid things that may eventually kill us. Even moments before our death, our brain will flash our life before our eyes to grasp at any past experiences that may help us survive.

Because of this, we are also inherently neurotic. Some fear flying in a plane because they can imagine the plane crashing and burning, even knowing that flying is safer than a car ride. Childhood traumas where we thought we might die cause long-lasting damage to how we behave and think as an adult.

The most interesting example of how the fear of death can affect us is the phenomenon of voodoo death.

American physiologist Walter Cannon published a paper in 1942 studying cases of “voodoo death” – where healthy people (usually from tribal societies) suddenly passed away after being cursed. Voodoo death starts when a person is cursed or condemned to die by a medical person, such as a witch doctor or shaman. The victim and those around them must believe that the curse will actuall kill them (due to the culture or tradition). The victim’s family may even prepare a funeral. The victim loses all hope that they can survive the curse. They then die, even though their body shows no signs of physical ailment.

For example, the Australian Aborigines are known to have practised “boning”, where a witch doctor would point a vexed bone at an enemy, causing the victim to immediately convulse and die. A Nairobi woman passed away within 24 hours of finding out that the fruit she ate was sacred and she committed a great sin. A Maori man, who was told he should never eat wild game meat, died a day after finding out that he had accidentally eaten wild game meat – even though he had eaten it 2 years ago.

Voodoo death is not only limited to pre-modern societies. In the 1990’s, there was a documented case where a patient was diagnosed with terminal metastatic oesophageal cancer. After saying his goodbyes to his family as were his last wishes, he swiftly passed away. On autopsy, they discovered that the cancer had not actually spread that much and was not the cause of death.

There are many theories as to what may cause voodoo death. The traditional thought was that intense fear and stress stimulates the release of catecholamines such as adrenaline, inducing a massive fight-or-flight response, as seen in broken heart syndrome. The surge of adrenaline causes the heart to beat too fast and too strongly, until it gives out and causes cardiac arrest.

However, more recent studies showed that animals that die from stress exhibit signs of the opposite happening – that is, the parasympathetic nervous system (responsible for the common type of fainting spells called vasovagal syncope) is overactive. Because the parasympathetic nervous system has the opposite effect to the sympathetic (fight-or-flight), it can cause the heart to slow to the point of stopping.

This parasympathetic overactivity may be triggered by a sense of absolute hopelessness, essentially causing the body to “give up” on life. On a related note, the hopeless victim will likely not be eating or drinking much while under extreme emotional duress, so dehydration and catatonia may play a role as well.

Voodoo death is an excellent example of how much power the mind has over the body. Ironically, the fear of death itself can cause death.

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Posted in Psychology & Medicine

Food Coma

Why do we feel sleepy after we eat? There are two components to the so-called “food coma”: neurological and hormonal. When we eat, the food mashed up by your teeth is swallowed down the oesophagus and into the stomach, where it is churned in a vat of very strong hydrochloric acid. The acid dissolves the food into liquid form, which is then sent to the small intestines. Here, the chemical components of the food such as carbohydrates is broken into simpler blocks, such as glucose. This is then absorbed into the bloodstream.

The body can actually sense when you have swallowed food, as your stomach stretches and sends signals to the brain. This triggers the activation of the parasympathetic nervous system (opposite of the sympathetic nervous system, which is the “fight or flight” system). The parasympathetic nervous system is involved in digesting and rest. It stimulates stomach acid production, gut movement and even reduces your energy level so that digestion can happen smoothly. In old people, it can even decrease blood pressure enough to a point that they feel dizzy (much like head rush). This is the neurological component.

The hormonal component is linked with the absorption phase of digestion. To deal with the increasing level of glucose in your blood, the pancreas secretes insulin. Insulin rounds up the glucose in the blood and stores it away in cells to normalise the blood glucose level. In this process, it also stimulates the uptake of certain amino acids (building blocks of protein) into cells. However, it leaves out one type of amino acids called tryptophan. Because there is more tryptophan in the blood compared to the other amino acids, your brain decides to use this to build more proteins. Tryptophan is converted in the brain into a very important neurotransmitter called serotonin, which is then converted into melatonin. Melatonin is a neurotransmitter involved in triggering sleep. Therefore, through this extremely complicated pathway, food causes sleepiness.

At face value, this makes it look like increasing intake of tryptophan may help induce sleep. It is commonly said that turkey meat and bananas help you sleep because of tryptophan. But this is an urban myth as neither of these foods are particularly high in tryptophan and there is no evidence to suggest that tryptophan itself helps you sleep. Then again, melatonin supplements have some evidence supporting it as a sleep aide. This shows just how complicated the human body can be.

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Posted in Psychology & Medicine

Stendhal Syndrome

There have been recorded cases of people gazing upon a beautiful panorama of Florence or an exquisite painting and suddenly collapsing. The condition is known as Stendhal syndrome, alternatively called Florence syndrome or hyperkulturaemia (excess culture in blood). It has been described as causing tachycardia (rapid heartbeat), dizziness, confusion and fainting after being exposed to a particularly beautiful piece of art or scenery. It is named after French author Stendhal (penname of Henri-Marie Beyle), who upon visiting Florence in 1817 experienced the very condition.

Stendhal syndrome is most likely related to a very common phenomenon known as vasovagal syncope, where extreme emotions overwhelm the brain, induce a massive parasympathetic nervous response, causing the person to faint. There are two major nervous systems: the sympathetic and parasympathetic. The sympathetic nervous system is responsible for the fight-or-flight response and essentially prepares the body for physical activity. The parasympathetic nervous system does the complete opposite and is activated when you are resting or digesting food. Thus, a burst of parasympathetic nervous activity causes a sudden fall in heart rate and blood pressure, causing the brain to lose the oxygen supply needed to maintain consciousness. When the person faints, they collapse and blood flow is restored to the brain. Vasovagal syncope can be caused by anything from standing up very quickly, extreme emotions (e.g. stress, seeing blood or needles) and fatigue. It is the most common cause of collapse and is (usually) completely harmless.

When a person looks at a breathtaking view or a stunning work of art, their brain is overwhelmed by intense emotions of excitement and joy. In the case of Stendhal syndrome, this effect is so great the person is literally blown away by the sight.

The people of Florence have noted that this phenomenon is rather common in tourists visiting the beautiful city.

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