Like the other parts of our body, our brain also suffers from the effects of our diet and lifestyle. Most people are familiar with what foods make our body healthier and younger, but little is known about its repercussion on cognition. Miracle diets do not exist. What is truly miraculous is to keep a healthy way of feeding oneself that is only achieved with a lot of imagination and perseverance. In this blog post, we will learn which foods help our neurons to stay as young as possible.
What changes occur in our brains as we age?
As we age, our brain undergoes a subtle but definite decline in structure and function. The volume of the brain decreases, we lose neurons, and the production of hormones and neurotransmitters is altered. However, contrary to the first studies, normal aging is not associated with widespread neuronal loss. Instead, neurons maintain an adequate function during normal activity. Also, as it has been demonstrated, neuronal loss only affects some neuron populations. During this process, neuronal loss is accompanied by some reduction in the size of remaining neurons and a loss of many of the connections between neurons (1). Age-related changes are associated with an oxidant/antioxidant imbalance that leads to an increased oxidative stress and a concomitant decrease in the brain’s antioxidant defense system (2). Another consequence of brain aging is the accumulation of proteins in the form of aggregates that tend to be deposited both inside and outside the neurons. Such an accumulation can trigger the development of age-related neurodegenerative diseases such as Alzheimer’s disease or Parkinson’s disease.
Although the aging process results in a decline in cognitive functions (less capacity for attention and memory, and a delay in information processing) humans can maintain their activities of daily living. Previous scientific research pointed out that brain aging begins after middle age (45 years and above), but nowadays, experts suspect cognitive decline would begin earlier. A recent study with a complex real-world video-game task has elicited that deterioration of cognitive ability would start at about the age of 24 years (3). Authors discovered that slowing response times begin at 24 years of age and persisted regardless of skill level. Researchers also analysed older participants’ behaviours and detected that they compensated a loss in response speed through the usage of game mechanics that reduced cognitive load (3). However, age-related changes are variable and dependent on several factors, both genetic and environmental. We cannot modify genetic factors, but we can act with the modifiable ones. Reasons that science gives us to have healthier habits are: (a) neurogenesis can persist into adulthood; and (b) oxidative damage to the brain can be influenced by diet and other lifestyle factors (c) protective neurotrophic factor production can be enhanced under certain conditions (exercise, diet) (1). Moreover, according to the World Health Organization (WHO), 40% of dementia cases are due to modifiable lifestyle factors. For instance, the Mediterranean diet has been shown to reduce the risk of cardiovascular diseases, Alzheimer’s, and Parkinson’s disease, whereas it is known the negative impact and risk on brain health caused by excess salt, sugar, or trans fats, which are present in many types of meat and ultra-processed products. In fact, most brain diseases, whether vascular or neurodegenerative, start causing changes in the brain many years before the first symptoms. So, brain-healthy eating habits should be taught from childhood onwards.
Which foods slow down brain aging?
A study carried out in Chicago by the Rush University Medical Centre, reinforces the idea that diet is a key factor in brain aging and Alzheimer’s disease (4). The called MIND diet includes neuroprotective dietary components and, according to authors, these components reduce the risk of cognitive impairment and diseases like Alzheimer’s. The study findings suggest that the MIND diet substantially delays brain aging by 7.5 years and reduces the probability of developing Alzheimer’s disease. The MIND diet, which is a combination of the Mediterranean and the DASH diet (specialized in stopping hypertension), is understood as a powerful neurological shield. In fact, it has proved that those who followed it during old age presented fewer cognitive problems, even having accumulated proteins in the brain associated with Alzheimer’s disease (4). These are the food that should include:
– Vegetables: Leafy greens like kale, cabbage, spinach, and lettuce specifically reduce the risk of dementia and cognitive impairment. Leafy greens are packed with nutrients linked to better brain health, such as folate, vitamin E, carotenoids, and flavonoids.
– Berries: Their benefit is due to the flavonoid high level they contain. It is recommended to eat blueberries or strawberries two or more times per week for optimal brain health.
– Nuts: this aliment is full of fat-soluble vitamin E, known for its brain-protective qualities. Eat a handful at least five times a week instead of eating processed snacks. Choose dry-roasted or raw, unsalted options or those that contain no added sodium, sweeteners, or oils.
– Olive oil: researchers recommend using it as the main cooking oil avoiding butter and margarine. It is better to use extra virgin olive oil.
– Moderate meat consumption: A healthy diet for your brain replaces meat with legumes, which are rich in B vitamins. Beans, lentils, and soybeans, which contain protein and fibre, are a good substitute for red meat since it appears less than four times a week in the MIND diet.
– Fish: Adults over 65 who ate fish once a week did better on memory tests and performed better in difficult number games than those who ate seafood less frequently.
– Wine: Don’t be afraid to drink a glass of wine at mealtimes. Studies suggest that light drinking may reduce the risk of dementia and may delay the onset of Alzheimer’s by two to three years.
Conclusions
Age-related process implies structural and functional brain changes. Although memory, attention, and speed processing are affected, humans can maintain their daily activities.
Experts have found that deterioration of cognitive ability would begin at about the age of 24 years, although humans can compensate for it with the application of acquired knowledge.
Although nothing can possibly turn back the clock, we can try to age healthily and reduce the effect of the passing years.
The MIND diet has proven to be neuroprotective. To maintain your brain healthy, your diet should be based on: vegetables, berries, nuts, olive oil, legumes, and fish.
References
(1) Esiri, M. M. (2007). Ageing and the brain. The Journal of Pathology: A Journal of the Pathological Society of Great Britain and Ireland, 211(2), 181-187.
(2) Dröge W., Schipper H.M. Oxidative stress and aberrant signalling in aging and cognitive decline. Aging Cell. 2007; 6:361–370.
(3) Thompson J.J., Blair M.R., Henrey A.J. Over the hill at 24: Persistent age-related cognitive-motor decline in reaction times in an ecologically valid video game task begins in early adulthood. PLoS One. 2014;9:e94215. doi: 10.1371/journal.pone.0094215. p.
(4) Morris MC, Tangney CC, Wang Y, Sacks FM, Barnes LL, Bennett DA, Aggarwal NT. MIND diet slows cognitive decline with aging. Alzheimers Dement. 2015 Sep;11(9):1015-22.
About the author
Julia Vázquez is a clinical and research neuropsychologist working as pre-doc at Vall d’Hebrón Research Institute (VHIR) in different research projects focused on psychological factors and cognition in metabolic disorders. She has expertise in the neuropsychological assessment and treatment of neurodegenerative disease, brain injury and epilepsy patients at Neurology Services at different Hospitals in the city of Barcelona. She had dedicated part of her clinical and research practice to the diagnosis and treatment of learning and language disorders in childhood neurorehabilitation centres. Also, she had collaborated as a teacher of the Neuropsychology master’s degree of the Universitat Autònoma de Barcelona and she is author of contents about Language pathology of the Master of Neuropsychology of the Universitat Oberta de Catalunya.