Brain health has been a hot topic in the world of nutrition for a long time now, with people becoming increasingly aware of the impact diet and disease have on cognition and the development of conditions such as dementia.
The brain contains more than one hundred billion brain cells or neurons, which receive and interpret sensory information, co-ordinate muscle contraction and perform all the processes required for speaking, thinking and creating.
It is inevitable that brain function will decline with age, and memory lapses are common the older we get. However, eating a balanced diet and maintaining a healthy lifestyle can help slow down the ageing process and protect the health of your brain.
Two common ways of eating can be defined as the Western diet and the Mediterranean diet, but what are they, and which is better for your brain health?
What is the Western diet?
This type of diet is typically characterised by highly processed, refined and convenience foods containing high amounts of saturated fat, salt, sugar and protein from red meat. This way of eating has been shown to be a risk factor for diet-related diseases including obesity, type 2 diabetes, high blood pressure and cardiovascular disease.1
How might the Western diet impact brain health?
There are few positives associated with this style of eating, particularly when it comes to brain health; the Western diet can increase your risk of high blood pressure and stroke, both of which are which are linked to the risk of dementia.2
Recent findings from a study carried out by scientists at Macquarie University in Sydney have shown that eating a Western diet for as little as one week may impair brain function, while also encouraging people to overeat. After seven days the young adults involved in the study scored worse on memory tests and were more likely to desire junk food immediately after finishing a meal.3
The impact that the Western diet may have on body weight is particularly relevant to brain health, as becoming obese, particularly in middle age, doubles your risk of developing dementia.
The Western diet is also high in sugar, which can encourage inflammation in the body. Inflammation is now considered a major risk factor in the development of many diseases, including those of the brain. Bad fats found in many highly processed foods typical of the Western diet can also hasten the formation of harmful amino acids associated with Alzheimer’s disease.4
What is a Mediterranean diet?
This style of eating is considered to be the gold standard for health: research has linked it to the prevention of many diet-related diseases and even the onset of dementia.5
The Mediterranean diet is made up of mostly plant foods, and also includes oily fish, nuts, seeds and olive oil, which are rich in healthy fats. This diet is typically low in sugar and doesn’t contain too much meat - especially red meat.
How might the Mediterranean diet impact brain health?
This style of eating contains many brain-boosting foods. Fruit and vegetables are abundant in this diet and these contain vitamins, minerals and antioxidant phytonutrients, which help to combat inflammation in the body. Folate and vitamin B12 are particularly relevant to brain health, as they help to control levels of homocysteine: an amino acid that can encourage the narrowing of arteries, encouraging memory loss.6
The Mediterranean diet also encourages the intake of oily fish, which is rich in omega 3 fatty acids. These fats are classed as essential, meaning they cannot be produced by the body and have to come from the diet. Having a large enough intake of these fats is vital, as they play a key role in the structural and functional role of the brain, and are also important for eye and heart health. Oily fish is also a natural source of vitamin D, which is vital for healthy bones, teeth, and muscles, and helps support your immune system.7
There is no disputing the fact that eating a Western diet is likely to do little for your health overall, and especially that of your brain. Following a Mediterranean style of eating will ensure a better supply of key nutrients required to support brain health, as well as reduce the risk of many other diet-related diseases.
1Casas, R., Castro-Barquero, S., Estruch, R. and Sacanella, E. (2018). Nutrition and cardiovascular health, International journal of molecular sciences 19(12), p.3988
2Kennelly, S.P., Lawlor, B.A. and Kenny, R.A. (2009). Blood pressure and dementia—a comprehensive review, Therapeutic advances in neurological disorders 2(4), pp.241-260
3Stevenson, R.J., Francis, H.M., Attuquayefio, T., Gupta, D., Yeomans, M.R., Oaten, M.J. and Davidson, T. (2020). Hippocampal-dependent appetitive control is impaired by experimental exposure to a Western-style diet, Royal Society Open Science 7(2), p.191338
4Morris, M.C. (2004). Diet and Alzheimer's disease: what the evidence shows, Medscape General Medicine 6(1), p.48
5Aridi, Y.S., Walker, J.L. and Wright, O.R. (2017). The association between the Mediterranean dietary pattern and cognitive health: a systematic review, Nutrients 9(7), p.674
6Smith, A.D. and Refsum, H. (2016). Homocysteine, B vitamins, and cognitive impairment, Annual review of nutrition 36, pp.211-239
7Sommer, I., Griebler, U., Kien, C., Auer, S., Klerings, I., Hammer, R., Holzer, P. and Gartlehner, G. (2017). Vitamin D deficiency as a risk factor for dementia: a systematic review and meta-analysis, BMC geriatrics 17(1), p.16