You might know him, Erik Scherder, the most famous Dutch professor of neuropsychology in the Netherlands. He regularly joins talk shows on Dutch television where he advocates more exercise and less sitting. This professor has written many books on the brain, yet much of his work can be summed up in one message, namely "What's good for your heart is also good for your brain". But why is this the case?
The heart and the brain are connected. The heart pumps blood through the body, including to the brain, ensuring that the brain gets enough oxygen and energy to function properly. When you move, your heart starts beating faster to supply the body with oxygen. Your brain then also gets more oxygen. This increased amount of available oxygen in the brain creates a temporary improvement in concentration. Exercise also has a positive effect on the brain in the long term. Because if you move regularly, new microvessels are formed in the body, including the brain. These ensure that your brain is better supplied with blood. As a result, cells are more effectively supplied with oxygen, and waste products can be disposed of faster. Next to that, exercise promotes neuroplasticity, making it easier to make new connections. In short, putting your heart to work makes your brain healthier.
Conversely, the same applies. If the heart and blood vessels are less healthy, for example, due to cardiovascular disease, smoking, or obesity, the brain will suffer. The most extreme example of this is cardiac arrest. When someone has a cardiac arrest, the heart suddenly stops pumping blood around. The organ that suffers first is the brain. This is because our brain can only go without oxygen for a very short time, just 3 - 4 minutes. After that, we enter a comatose state and brain cells will die causing permanent brain damage. This is why it is so important to start CPR as soon as possible when someone suffers cardiac arrest. Every minute counts.
When people survive cardiac arrest, all the focus is initially on the heart. You end up in a cardiology department, the cause of the cardiac arrest is examined and measures to prevent it in the future are taken (think placing an implantable cardioverter-defibrillator (ICD) or pacemaker). You then go home again, often without seeing a brain specialist. Although the heart is back in working order, people regularly encounter non-heart-related problems after a cardiac arrest, such as difficulty concentrating, fatigue, and forgetfulness. The link between these problems and the cardiac arrest is not always made (to someone who does not know about the connection between the heart and the brain, this does not make sense because "after all, I had something happen to my heart, not my head"). And if these patients do not raise the alarm themselves, it can potentially have major consequences in a person's life (think losing a job, developing depression, or divorce). In short, problems with cognition (the brain) are regularly overlooked after cardiac arrest.
To prevent this, it is important that people are aware of the link between the heart and the brain. Studies are currently ongoing where we are trying to predict, based on brain activity (fMRI and EEG), which people will experience cognitive problems (and thus have suffered brain damage) after cardiac arrest and which will not. If we know this, patients can get help earlier, for example in the form of cognitive training or psychological support. I am currently testing different types of interventions that could potentially be used to help these people. These include methods that are already widely used, such as strategy training, which involves practicing ways to give the brain a helping hand (such as coming up with mnemonics for things you keep forgetting or talking out loud to keep track). We are also testing a whole new method, namely using transcranial magnetic stimulation (TMS) to improve (working)memory. These studies are still in progress. Hopefully we will discover something that works well. I will keep you posted!
Author: Pauline van Gils