You may not be surprised to know that what is good for the heart is good for the brain, and vice versa. This is because, like many other body systems, there is a bidirectional relationship between the cardiovascular and nervous systems, referred to as the “heart-brain axis” or HBA.

This is still a fairly new and emerging area, but so far research has suggested that the HBA  involves a complex network of neurological, biochemical, biophysical and energetic crossover between the nervous and cardiovascular systems.

The heart possesses its own intrinsic cardiac nervous system, populated by 40,000 neurons, sometimes referred to as the “heart brain”. This heart brain has the capacity to send signals to regions of the brain, such as the medulla, hypothalamus, thalamus, and amygdala and the cerebral cortex.

Furthermore, the vagus nerve acts as a go between, carrying information from the heart to the brain, and vagal stimulation by the heart has been indicated to be involved in neurological processes such as pain perception (nociception). 

This intrinsic link between the heart and brain is further evidenced by how cardiac dysfunction has been identified as a predictor for cerebrovascular events. Cardiovascular disease has also  been demonstrated to increase the risk of Alzheimer’s disease, due to shared vascular pathologies.  

3 Key Nutrients for Supporting the Heart-Brain Axis

Prebiotics and Probiotics

The health of the gut is essential for both the health of the brain and the heart. Imbalances in the composition of gut bacteria have been associated with increased risk of cardiovascular disease and Alzheimer’s disease.

Beneficial bacteria can be increased in the gut through consuming probiotic foods, such as fermented rye sourdough, kimchi, kefir, sauerkraut and kombucha. Prebiotics are a type of dietary fibre, which help to feed and maintain beneficial bacteria in the gut. Vegetables such as broccoli, onions and leeks are great ways to increase prebiotic fibre in the diet, as are Jerusalem artichokes, chicory and garlic.   


Polyphenols are naturally occurring compounds in plants, which have been shown to have antioxidant and anti-inflammatory properties. Polyphenols can be enjoyed by increasing consumption of a wide array of colourful fruits and vegetables. Government guidelines suggest 5 portions per day. However, recent research has indicated that individuals with the lowest risk of cardiovascular disease development consumed 10 x 80g portions per day.

Try to include plenty of colourful fruit and vegetables such as blueberries, aubergine, raspberries, red grapes, peppers, red onions, spinach and carrots to ensure you are consuming a wide range of polyphenols. Raw cacao, dark chocolate (85% and above) and green tea, and spices such as turmeric and ginger are also excellent ways of increasing polyphenols.

Omega 3 Fatty Acids

Omega 3 fatty acids are important for both heart and brain health due to their anti-inflammatory properties. The Bacteroidetes:Firmicutes ratio, which is a marker for gut health and integrity, is an important consideration too. Bacteria from the Bacteroidetes family are able to synthesise vitamins that are vital for brain and heart health, including: B1, B2, B3, folate, B5, B6, B12 and Biotin, many of which are important for reducing homocysteine – a risk factor for both cardiovascular and neurodegenerative diseases.

When the Firmicutes:Bacteroidetes ratio is higher in favour of bacteria from the Firmicutes family, there is lower synthesis of these vitamins. Further, imbalances in the Bacteroidetes:Firmicutes ratio may also increase deposition of Aβ plaques, which is involved in Alzheimer’s development. Additionally, individuals with imbalances in the Firmicutes:Bacteroidetes ratio have also been demonstrated to have increased risk of heart failure.

However, this ratio can be addressed through increasing omega 3 fatty acid consumption. This can be done through increasing consumption of oily fish, and taking either a fish oil or vegan omega 3 (EPA/DHA) supplement.