How food affects brain efficiency and thinking
In recent years, more and more information about how the brain reacts to food consumption has been published in scientific journals. As the old saying goes: tell me what you eat, and I will tell you who you are. Nowadays, it seems more true than ever. Researchers draw our attention to the relationship between the diet and the increasingly common brain dysfunctions. Switching to a high-carb and low-fat diet contributes to brain disorders such as:
anxiety and depression
attention deficit hyperactivity syndrome (ADHD)
deterioration of the cognitive functions.
At every meal, we should bear in mind the Hippocrates’ mantra:
let food be thy medicine and medicine be thy food.
It seems, however, that nowadays food often does more harm than good.
Currently, we have the largest number of obese and overweight people in history. In the US, 55% of the population is overweight. Over the past 10 years, obesity in the US has increased by 70% among people aged 18-29 and by 50% among people aged 30-39. The data from Poland does not seem encouraging either. According to the World Food Security Index update, prepared by the Economist Intelligence Unit (EIU) on behalf of DuPont, over 25% of the Polish population is obese. That’s almost 3% more than the average in Europe, which is just over 22%. Poles are at the forefront of the most weight-gaining nations and in this respect are ahead of their neighbours: Russia, where 24% of the population suffers from obesity, as well as Belarus, 23%, and Germany and Ukraine, each with 20%. Of the neighbouring nations, only Czechs (almost 27%) and Slovaks (almost 26%) are more obese than Poles. It should be noted that obesity is determined when the body mass index (BMI), that is person’s weight to height ratio, is above 30. To better understand this, picture an 80 kg woman with a height of 160 cm.
The most important question from the brain functioning perspective pertains to the correlation between obesity and the brain.
It is strong and quite uncomfortable for many obese people, but it is becoming better and better described in the scientific literature. Well, nine years ago, scientists from UCLA and the University of Pittsburgh carried out a five-year joint research project, which consisted of comparing brain images of 94 people aged 70 to 79 years, none of whom were affected by a cognitive disorder. The obtained results were shocking. It turned out that the brains of obese people (BMI over 30) looked 16 years older compared to the brains of other participants in the study with a normal BMI. In the case of the brains of overweight people (BMI 25-30), the brains looked eight years older compared to those with a normal BMI. Obese participants of the study had 8% less brain tissue, and those who were overweight had 4% less brain tissue than those with normal weight. Importantly, these defects included brain areas located in the frontal and temporal lobes, i.e. those that are associated with, among others, decision making, reasoning and memory processes. So the bigger the belly, the older and smaller the brain!
Another interesting study was published three years later. This study concerned the correlation between BMI and cognitive functions and covered 1949 participants aged 65 and over. The collected data focused on, among others, cognitive performance measured according to the MMSE (Mini-Mental State Examination) scale, verbal fluency, intelligence and memory. The study group included: 592 obese people, 850 overweight people and 507 people with normal body weight. The analysis took into consideration the influence of education, prescribed medication, hypertension and alcohol. The test results were also alarming: both obesity and overweight were associated with the lowest results obtained in the parameters describing:
The results of the study indicate that there is a clear link between obesity and deterioration of the cognitive functions.
Therefore, one can only imagine the tragic effects of the rapidly growing overweight and obesity among children and adolescents on the functioning of our entire society. According to the results of the study carried out in the school year 2013/2014, the percentage of overweight and obese 11-15 yearolds in Poland was 14.8% (12.4% and 2.4%, respectively). The cause of overweight and obesity is energy imbalance caused by consuming in foods and drinks more calories than the body needs. The inactive lifestyle and popularity of food products with high sugar content, especially loved by children and adolescents, contribute to this. Excessive consumption of sugar and glucose-fructose syrup very often leads to diabetes, obesity and, as a consequence, to serious neurodegenerative disorders, i.e. Alzheimer’s disease (AD). In addition, it leads to abdominal obesity, and visceral fat is responsible for inflammation in the body. The correlation between diabetes and AD has been described in literature since 2005. Excessive consumption of carbohydrates (especially refined ones) is also associated with neurogenesis inhibition and higher risk of cognitive disorders. Neurogenesis is a process of formation of new nerve cells, which includes embryonic and adult neurogenesis. Interestingly, until recently, there was a common misconception that the formation of new nerve cells does not occur in adults. The creation of new neurons in the hippocampus as well as the reconstruction of dendritic trees is associated with the processes of remembering and learning.
It turns out that diet, next to e.g. moderate and regular physical activity, is yet another potent factor influencing neurogenesis and proper functioning of the brain.
A special role is assigned to fats and B vitamins. The brain loves fats. Essential fatty acids (EFAs), in particular arachidonic (AA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), are the key building blocks of neuronal membranes. Their high content in the central nervous system, reaching about 15-30% of the dry mass of the brain, is the basis for the efficient functioning of the brain. EPA and DHA acids included in EFAs may be produced by the body with the use of alpha-linolenic acid (ALA), but with low efficiency, which is why some typologies classify DHA and EPA as EFAs. Linoleic (LA) and alpha-linolenic (ALA) acids give rise to omega-6 and omega-3 acids, respectively.
DHA is a basic building block of cell membranes, cones and rods of the eye, which are responsible for night vision and colour vision. DHA stimulates the growth of nerve cells making them more branched, multipolar, with longer protrusions, which increases the efficiency and the amount of transmission of nerve impulses. EPA plays an important role in the functioning of the nervous system, as it takes part in the transmission of information between nerve fibres. It is used to treat concentration and learning difficulties. It has an anti-inflammatory effect, like other omega-3 fatty acids.
The main sources of EPA and DHA in the diet are: fish – especially oily marine fish such as salmon, tuna, herring, mackerel, sardines, anchovies, halibut, fish oil, seafood, algae and breast milk. The search for alternative sources of omega-3 fatty acids, obtained, among others, from the culture of microalgae Crypthecodinium cohnii, whose oil contains 40% DHA (with a small amount of other unsaturated fatty acids), is in progress. In turn, the source of LA and ALA are vegetable oils, e.g. rapeseed, linseed, corn, hemp, soybean, grape seed, walnut, wheat germ, rice bran, as well as walnuts, pumpkin seeds, chia and linseed. The supply of omega-6 fatty acids contained, for example, in corn, soybean, safflower oil, sunflower oil, and sesame oil should be limited.
One of the indicators of diet quality is the level of omega-3 EFA intake and its proportion to omega-6 fatty acids. The correct ratio of omega-6 to omega-3 is 4-5: 1. However, in the average diet of a European, this proportion significantly deviates from the correct one (15-20: 1). Vegans also consume much more omega-6 than omega-3, which interferes with the absorption of omega-3. Nowadays, the cascade of omega-3 fatty acids transformation is not enough to ensure optimal amount for the health of the body in a person who does not prefer fish foods (rich in omega-3 acids). Therefore, omega-3 EPA and DHA should be properly supplemented.
Deficiency of vitamins B1, B2, B6, B12 and folic acid in the body may result in mental illnesses such as depression and contribute to the degradation of myelin. Myelin is a fatty substance that surrounds the nerve fibres, acts as an insulator and contributes to the faster movement of nerve impulses in the brain. The more myelinated the fibres, the faster the communication between neurons and the more efficient the cognitive functioning. The lower the level of folic acid in the body, the more evident the symptoms of depressive states. The cause of B vitamins deficiency is primarily the consumption of highly processed products that lack these vitamins. These products are mainly white flour and flour preparations, husked rice and products that have lost their folic acid due to heat treatment at high temperatures – everything that is a basic component of today’s Western diet. Where can you find folic acid? Raw vegetables are rich in folates – lettuce, spinach, legumes, raw fruit, whole grains, liver and yeast. It should be emphasized that plant products do not contain vitamin B12, and a deficiency of this vitamin leads to problems with the nervous system, blood health and macrocytic anaemia. In addition, people with B12 deficiency may experience tingling in fingers and toes and increased levels of homocysteine, which adversely affects nerves and vein walls. Vegans should take supplements to keep vitamin B12 and homocysteine at the right level.
Increasing the consumption of foods rich in antioxidants such as vitamin C, E and β-carotene can also stimulate intellectual performance. One of the spices with strong neuroprotective (brain-protective) properties is turmeric, which contains curcumin. Modern research indicates that turmeric may be effective in the prevention and treatment of Alzheimer’s disease. In addition to inhibiting inflammatory reactions in this disease, turmeric reduces the risk of damage caused by oxidative stress thanks to its antioxidant properties. It also reduces cholesterol levels and slows down the progression of Alzheimer’s disease.
If you want your brain to be properly nourished and to function well,
first of all give up excessive consumption of sugar and processed food and include omega-3 fatty acids in your diet and daily, even low, physical activity. Some people struggle with giving up sweet or farinaceous snacks. It may result from emotional eating or, simply, boredom. Such emotional eating leads to an increase in consumption of foods with high sugar and fat content, which directly translates into an increase in body weight and worse mental functioning. Before you eat such a snack, think about whether it is worth it and what emotions lead you to eat such junk food. A healthy, well-nourished body will repay you with better functioning, higher energy levels and mental acuity.
A neuropsychologist with many years of experience, co-author of publications in the field of neuropsychology, neuroscience, psychosurgery and psychopathy. Teacher at full-time and part-time studies. Responsible for substantive supervision over the psychodietetics study program at the post-graduate program “Personal development coach with psychodietetics”. Co-creator of BBClab, together with Tomasz Gordon, author of the Neurodietetics and mental training addressed to dietitians, psychodietetics, psychologists, life-coaches and everyone interested in healthy eating. Author of the FITBrain test, which can be used for both self-development and work with clients. Its aim is to determine the respondent’s resources: eating habits, stress level, mental patterns and ways of coping with difficult situations and their impact on psychodietetic success.
Unlike many trainers who follow the fashion for neurosciences, Dr. Dorota Ackermann-Szulgit has solid, internationally acclaimed practical experience in human brain research. She is currently conducting research on the effects of obesity on cognitive functions using EEG and neuropsychological tests. During the Art of Healing Fair, she will talk about the impact of diet on brain functions.
Together with a team of psychodietetics from Ekipa na Zdrowie, she prepares “breakfasts for the brain” recipes.