What are the most recent and interesting discoveries linking the heart with brain health?
We have known for some time about major modifiable risk factors for dementia which include hypertension, diabetes and smoking. Furthermore these factors also cause heart diseases, for example ischaemic heart disease, many of which are associated with increased risk of dementia, partly by co-association and possibly through direct effects.
More recently, the importance of socioeconomic status, education and early life factors have been recognised as critical risk factors for both heart and brain vascular disease. A good diet, sufficient sleep and plenty of exercise are also essential to maintaining a healthy heart and, directly or by co-association, a healthy brain. There are epidemiological and mechanistic explanations for this, even though there is a limited amount of evidence from randomised clinical trials.
What are the main reasons why cardiovascular health has such a significant influence on brain health?
The brain is a highly metabolic organ that takes 20-25% of the cardiac output at rest – more during increased brain activity. It would be very strange if heart and brain disease were not closely linked.
The heart and brain are exposed to the same risk factors, and vessels in both organs share many features of diffuse disease including stiffening and breakdown of the vessel walls. Indirectly, there are downstream effects for the brain from heart disorders such an inadequate supply of blood to the energy ‘hungry’ brain.
How important is an interdisciplinary approach in tackling neurodegenerative diseases?
This is exceptionally important due to the complexity of the brain. We should avoid seeing the blood vessels in isolation from the rest of the brain, and the brain in isolation from the rest of the body.
The brain should not be considered from the perspective of only one ‘ology’; I would never have tracked the importance of early life factors on vascular brain damage had I not known about epidemiology as well as stroke, cardiovascular disease, neurology, neuroscience, neuroimaging and the specifics of small vessel disease and dementia.
Read the full report, The Brain-Heart Connection, from GCBH and find out more about the work of Prof Joanna Wardlaw’s lab.
Article published: 24 February 2020