WHO defines brain health as a fast emerging idea that encompasses neural development, plasticity, functioning, and recovery across a lifetime. All life ages as time goes by, and a natural outcome of the ageing process is the shrinking of the brain. Cognitive decline is the ageing of neurons and a decrease in the speed at which the brain functions. There is evidence that high-quality nutrition (a diet that’s high-fiber, rich in fruits, vegetables and unsaturated fats) and regular exercise are critical in keeping cognitive decline to a minimum. It’s important to understand how food affects our brain.
Neurological Health
Improving brain plasticity, which involves stimulating brain cells to create new connections, is an important part of maintaining brain health. There is also evidence that keeping our minds active can help in generating new brain cells that can protect us from future loss of cells. Playing video games, learning a new language, making music, travelling, exercising and making art are some ways one can improve brain plasticity.
Metabolic Health & The Brain
Metabolic health is described as having ideal levels of blood sugar, triglycerides, high-density lipoprotein (HDL) cholesterol, blood pressure, and waist circumference, without using medications.
Glucose is the primary source of fuel for the brain.
The human brain needs a constant flow of glucose for our cells to function. Although our brain is less than 2% of our body weight, it needs up to 20% of its glucose to produce energy.
Glucose is critical for cellular maintenance and also helps in creating adenosine triphosphate (ATP), an energy transferring molecule that stores energy and releases it as fuel for cellular activity.
Insulin is a hormone released by the pancreas. It regulates glucose in the body. Insulin is responsible for managing protein, carbohydrate metabolism, and helping cellular growth and division.
When we eat, insulin levels in our body increase to absorb the sugar spike in our blood and store it for energy. This makes the glucose levels in our bloodstream decline.
The pancreas then produces glucagon, a hormone that prompts the liver to release stored sugar. The interaction between glucagon and blood sugar is vital for stable blood glucose levels in the brain and body. However, with age, the risk of insulin resistance increases.
The cells of individuals who have insulin resistance don’t respond well to insulin, barring glucose from entering them with ease. The glucose level in their blood rises over time, even as their body produces more insulin, and the cells resolutely resist it.
The risk of insulin resistance is associated with senile skeletal muscle dysfunction. Skeletal muscles are tissues that play a crucial role in the body’s glucose metabolism.
After a mixed meal, skeletal muscles are involved in glucose disposal and have an influence on insulin sensitivity. As we age, the skeletal muscles go through many changes and dysfunctions.
(Read our blog on metabolic health and the brain here.)
How Does Metabolism Affect Brain Function?
In more recent studies, the hypothalamus is emerging as the primary player in homeostatic regulation of glucose in our bodies.
Our brains can translate many metabolic signals through the food we eat, insulin secretion, energy expenditure, hepatic (liver) glucose production and glucose/fatty acid metabolism in adipose tissue (body fat) and skeletal muscle.
Efficient communication between the brain and peripheral metabolic organs is critical for the maintenance of energy and glucose homeostasis (the balance of insulin and glucagon to maintain blood glucose).
Inhibition in the brain is commonly targeted in clinical practice. notes Derek Bowie, Canada Research Chair in Receptor Pharmacology at McGill and corresponding author of the study that focuses on how metabolism controls the processes that inhibit brain activity, such as that involved in convulsions.
For example, drugs that alleviate anxiety, induce anesthesia, or even control epilepsy, do so by strengthening brain inhibition. The experiments showed an unexpected link between how the mitochondria of brain cells make energy and how the same cells signal information.
Brain cells couple these two independent functions by using small chemical messengers called reactive oxygen species (or ROS), that are normally associated with signaling cell death. While ROS are known to have roles in diseases of ageing, such as Alzheimer’s and Parkinson’s, the new study shows they also play important roles in the healthy brain.
The brain modulates various aspects of metabolism, such as food intake, energy expenditure, insulin secretion, hepatic glucose production and glucose/fatty acid metabolism in adipose tissue and skeletal muscle.
Highly coordinated interactions between the brain and peripheral metabolic organs are critical for the maintenance of energy and glucose homeostasis. Defective crosstalk between the brain and peripheral organs contributes to the development of obesity and type 2 diabetes.
What Is Neuronutrition Food?
Our brains function best when we eat a nutritious and balanced diet. High-quality foods that contain fatty acids, antioxidants, vitamins and minerals nourish the brain and protect it from oxidative stress—the waste produced when the body uses oxygen, which can damage brain cells.
Low-quality foods, often processed and refined, are not the best choice for our brains and bodies. Because they are low in fiber and digested quickly, processed and refined foods can cause swings in blood sugar levels.
These fluctuations in blood sugar can be harmful to overall brain health and affect mood.
In addition to inhibiting our bodies’ regulation of insulin, refined sugars also promote inflammation and oxidative stress.
The inner workings of our digestive systems don’t just help us digest food, they also guide our emotions. Our bodies produce serotonin, a neurotransmitter that helps regulate sleep and appetite, mediate moods and inhibit pain.
95% of serotonin is produced in our gastrointestinal tract, which is lined with millions of nerve cells, or neurons.
The function of these neurons and the production of serotonin is highly influenced by the billions of “good” bacteria that make up our intestinal microbiome. These bacteria play an essential role in our health.
They protect the lining of our intestines and provide a strong barrier against toxins and “bad” bacteria. They also limit inflammation, improve how well we absorb nutrients from food and activate neural pathways that travel directly between the gut and brain.
Foods rich in protein contain amino acids to help produce key neurotransmitters in preventing and treating depression and anxiety. A diet rich in protein also helps improve energy levels, giving you the strength to get moving and feel better. Amino acids, which are the building blocks of protein, play an important role in the production of neurotransmitters. Neurotransmitters are the chemicals which allow brain cells to communicate with each other.
For example, if you eat a piece of chicken, your body breaks down the protein and synthesizes the amino acid L-Tyrosine to produce dopamine. Low dopamine levels are associated with a whole host of disorders, including depression, addiction, ADHD, Alzheimers and schizophrenia.
The amino acid L-Tryptophan, which can be found in poultry, fish, dairy, spinach, soy products, pumpkin and sunflower seeds and nuts, serves a precursor to serotonin. Eating foods rich in L-Tryptophan can help improve mood and help SSRIs and other antidepressants work more effectively.
A balanced diet with enough carbs is essential for good brain health. Eliminating carbohydrates from your diet may help you lose weight, but it could leave you fuzzy-headed and forgetful, a new study suggests.
One week after starting a weight loss diet that severely restricted carbohydrates, participants in the Tufts University study performed significantly worse on memory tests than participants who followed a low calorie, high-carbohydrate diet.
Carbs are imperative for brain health because the body breaks down carbohydrates into glucose, which it uses to fuel brain activity.
Proteins break down into glycogen, which can also be used for fuel by the brain, but not as efficiently as glucose. Eliminating carbohydrates from the diet might reduce the brain‘s source of energy and affect brain function. Some scientists, however, argue this claim and further studies in this area are underway.
Precursors to mood disorders (e.g., depressive symptoms) are emblematic of the powerful impact that microbiota can exert on brain physiology and the pathogenetic consequences of microbiota dysfunction.
Alterations in the microbial composition generate a state of dysbiosis that is a potential pathogenic environment and a threat to the maintenance of the host’s health.
Dysbiosis of the microbiota is responsible for different pathogenetic events, such as changes in the host’s immunity and intestinal permeability. Dysfunctions of the intestinal barrier increase the risk of endotoxins gaining access to systemic circulation, development of a chronic inflammatory state and higher susceptibility to brain disease.
Eating diets high in fat and sugar can cause obesity and diabetes, which can lead to increased risk of memory loss or dementia as we age.
Eating a high-fat-and-sugar diet can have a negative effect on neurons, reducing dendrites and synapses and leading to neuroinflammation that affects learning and memory.
Healthy fats help the brain function more efficiently. They are characterized as omega-3 fatty acids. Healthy fats are typically found in fatty fish, such as salmon, herring, mackerel, and sardines.
When it comes to saturated fats, one of the clear winners is coconut oil. Research suggests it may help increase HDL cholesterol. Saturated fats found in meat and dairy products were once considered bad fats.
But a 2013 study from the Mayo Clinic suggests that individuals consuming a diet high in saturated fats reduced their risk of dementia by 36%.
The acceptable macronutrient distribution ranges (AMDR) are 45–65% of your daily calories from carbs, 20–35% from fats and 10–35% from protein. Some foods to avoid for better health are sugar drinks like soda, sports drinks, energy drinks and fruit juice, refined carbohydrates including sugars and highly processed grains such as white flour.
These types of carbs generally have a high glycemic index (GI). This means your body digests them quickly, causing a spike in your blood sugar and insulin levels. Healthy, lower-GI carbs include foods such as vegetables, fruits, legumes and whole grains.
Trans fats are a type of unsaturated fat that can have a detrimental effect on brain health. While trans fats occur naturally in animal products like meat and dairy, these are not a major concern. It’s industrially produced trans fats, also known as hydrogenated vegetable oils, that are a problem. These artificial trans fats can be found in shortening, margarine, frosting, snack foods, ready-made cakes and prepackaged cookies.
Studies have found that when people consume higher amounts of trans fats, they tend to have an increased risk of Alzheimer’s disease, poorer memory, lower brain volume and cognitive decline.
Excess alcohol consumption is linked to reduction in brain volume, metabolic changes and disruption of neurotransmitters, which are chemicals the brain uses to communicate.
Inflammation
Inflammation is a process by which your body’s white blood cells and the chemicals they make protect you from infection from outside invaders, such as bacteria and viruses. But in some diseases, like arthritis, your body’s defense system—your immune system—triggers inflammation when there are no invaders to fight off. In these autoimmune diseases, your immune system acts as if regular tissues are infected or somehow unusual, causing damage. Inflammation can affect your organs as part of an autoimmune disorder. The symptoms depend on which organs are affected. For example:
Oxidative stress
A phenomenon caused by an imbalance between production and accumulation of reactive oxygen species (ROS) in cells and tissues and the ability of a biological system to detoxify these reactive products. Multiple studies have found a correlation between a diet high in refined sugars and impaired brain function, and even a worsening of symptoms of mood disorders, such as depression. If your brain is deprived of good-quality nutrition, or if free radicals or damaging inflammatory cells are circulating within the brain’s enclosed space, further contributing to brain tissue injury, consequences are to be expected. (source)
During oxidative stress, excess free radicals can injure structures within brain cells and even lead to cell death, which may increase the risk of conditions like Parkinson’s disease. Oxidative stress also transforms essential proteins, such as amyloid-beta peptides. Inflammation can prompt oxidative stress and reduce cellular antioxidant capacity.
Low-quality foods, often processed and refined, are not the best choice for our brains and bodies. Because they are low in fiber and digested quickly, processed and refined foods can cause swings in blood sugar levels.
This glycemic variability can cause oxidative stress. These fluctuations in blood sugar can be harmful to overall brain health and affect mood. In addition to inhibiting our bodies’ regulation of insulin, refined sugars also promote inflammation and oxidative stress.
Anti-Inflammatory Neuronutrition Diet
An anti-inflammatory diet, include foods like:
- Tomatoes
- Olive oil
- Leafy green vegetables (spinach, collards)
- Nuts (almonds, walnuts)
- Fatty fish (salmon, tuna, sardines)
- Fruits (berries, oranges)
These foods can trigger inflammation:
- Refined carbohydrates (white bread)
- Fried foods (French fries)
- Sugary drinks (soda)
- Red and processed meats (beef, hot dogs)
- Margarine, shortening, and lard
The keto diet is a low carb, high fat diet.
It lowers blood sugar and insulin levels and shifts the body’s metabolism away from carbs and toward fat and ketones (the ketones, a fatty acid, are released from the liver and go into your bloodstream and are used as fuel to drive the body’s metabolism and to support muscle function.
The body typically needs ketones when insulin levels are low). While the keto diet may work for some, it might not be the right fit for everyone.
Metabolic health is not a one-size-fits-all process but a highly individualised one.
Ketones are the primary fuel source for the brain instead of glucose on a ketogenic diet. The liver produces ketones when carb intake is very low. Ketones can serve almost 75% of the brain’s energy requirements.
Ketosis is a process that happens when your body doesn’t have enough carbohydrates to burn for energy. Instead, it burns fat and makes ketones.
Studies offer evidence in favour of a ketogenic diet owing to its ability to increase the number of mitochondria, the energy powerhouses in brain cells.
A recent study shows enhanced expression of genes encoding for mitochondrial enzymes and energy metabolism in the hippocampus, a part of the brain involved in learning and memory. This diet was used in 1920 to treat drug-resistant epilepsy, a neurological disorder, in children.
A traditional Mediterranean diet consisting of large quantities of fresh fruits and vegetables, nuts, fish rich in Omega 3 fatty acids, and olive oil—coupled with physical activity—can improve brain health by: Reducing the risk of Alzheimer’s. Research suggests that a Mediterranean diet may improve cholesterol, blood sugar levels, and overall blood vessel health, which in turn may reduce your risk of Alzheimer’s disease or dementia.
Halving the risk of Parkinson’s disease. The high levels of antioxidants in a Mediterranean diet can prevent cells from undergoing oxidative stress, thereby cutting the risk of Parkinson’s disease in half.
A 2013 study published in Neurology, the medical journal of the American Academy of Neurology, lends credence to the Mediterranean diet and suggests that it may help protect the brain. Researchers found that those who consistently adhered to the Mediterranean diet exhibited a lowered risk (by 19 percent) of thinking and memory problems.
Conclusion
Brain health encompasses neural development, plasticity, functioning, and recovery across a lifetime.
The brain regulates various aspects of metabolism, such as food intake, energy expenditure, insulin secretion, hepatic glucose production and glucose/fatty acid metabolism in adipose tissue and skeletal muscle.
It’s important to understand how dietary intervention affects the brain. Foods rich in protein contain amino acids to aid in production of key neurotransmitters in performing neurological functions.
High-quality foods that contain fatty acids, antioxidants, vitamins and minerals nourish the brain and protect it from oxidative stress which can damage brain cells and can make for effective neuronutrition.
Some studies lend support to the correlation of keto and mediterranean diets with brain health.
Disclaimer: The contents of this article are for general information and educational purposes only. It neither provides any medical advice nor intends to substitute professional medical opinion on the treatment, diagnosis, prevention or alleviation of any disease, disorder or disability. Always consult with your doctor or qualified healthcare professional about your health condition and/or concerns and before undertaking a new health care regimen including making any dietary or lifestyle changes.
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