Mind your diet - how to keep your brain healthy for life
Good nutrition builds better brains and nutrient depletion threatens those brains later in life. Alzheimer’s is one of the most feared diseases of our time and is becoming ever more prevalent. Every 65 seconds another person develops Alzheimer’s. Although considered a disease of old age, over 42,000 people in the UK alone are now living with young-onset dementia which is dementia before the age of 65.
Until recently there was little light at the end of the tunnel but that might be changing. New research shows that nutritional and preventative approaches may be able to halt the disease process, and even put it into reverse, if the illness is diagnosed and treated early enough.
‘The brain is the most vulnerable organ in the body to a poor diet’
Of all the organs in the body, the brain is the one most vulnerable to a poor diet. This is because it is the most metabolically active organ that we have, and consequently needs the most energy. Whilst our brains may only account for 2% of our body weight, they use 20-30% of all the calories we consume and about 20% of our body’s oxygen.
But what sets it apart even further is that the cells inside our brains are irreplaceable. Unlike those in the rest of the body, where cells continuously renew and replace themselves, the vast majority of our brain’s cells remain with us throughout our lives. This means it is essential to keep our brains well-nourished if we want them to successfully deliver a lifetime of good performance.
‘The right diet can keep our brains stronger for longer’
The research shows there is an important correlation between a healthy diet and a healthy brain. Food has marked and measurable effects on brain health and function. The right diet can ensure that our brains remain stronger for longer, showing more resilience and activity, regardless of age.
Equally important, staying mentally active through work and play, is a key element in retaining mental acuity. As long as we keep making new connections between brain cells, we can maintain our alertness – providing there is no underlying physical deterioration. And that is where nutrition comes in.
As a society we tend to focus more on using diet to control weight and often lose sight of how our diet is impacting our health on the inside. The body and brain alike need all kinds of nutrients for health. So, if a diet suggests excluding a food group such as fats or carbs, think twice. We don’t really need a ‘diet’ as such, and certainly not one that focuses on food or nutrient restriction. What we need is a way of eating healthily that we can comfortably stick to throughout our lives. So how can we maximise our intake of brain healthy nutrients and keep our brains young?
Of course, it is important to avoid or limit consumption of foods that cause inflammation. The worst culprits are commercial white bread and pastries, fried foods, sugar-sweetened drinks, processed meats, margarine and most processed foods.
‘Not all carbohydrates are created equal’
We need to manage our carbs, and to choose wisely, because not all carbs are created equal. When most people think of carbohydrates, they think about bread and potatoes, but vegetables and fruits are also carbohydrate-rich foods.
Although we are all aware that fruit and vegetables are good for us, surveys suggest as little as 1 in 10 people meet the minimum daily recommendations for fruit and veg intake. Vegetables should make up half of your plate at any given meal. One of the most common recommendations I make to clients is ‘to eat the rainbow’, that is to eat a wide range of different coloured fruits and vegetables. These healthy carbohydrates are full of vitamins, minerals and plant chemicals called phytonutrients that help to reduce harmful inflammation and promote the resilience of our brain cells.
Among them dark leafy greens like spinach, rocket and kale and cruciferous vegetables like broccoli and cauliflower contain disease-fighting nutrients needed to keep your nervous system healthy. Large-scale studies show that people who have one or two servings of leafy green vegetables a day experience fewer memory problems and less cognitive decline than those who rarely do.
‘Many fruits are supportive of memory and mental acuity’
Although fruits have a higher sugar content than vegetables, many fruits are particularly supportive of memory and mental acuity, thanks to their high antioxidant content and anti-ageing properties. In a study of over 16,000 women, they showed that eating at least one portion of blueberries and two portions of strawberries a week could slow cognitive decline by as much as two and a half years.
If you are concerned about sugar, you want to favour low-glycaemic fruits like berries, apples, lemons and grapefruit, and have higher-glycaemic fruits like grapes and mango more sparingly. I always have a mixture of berries in my freezer for convenience because they are as nutrient-dense as fresh berries but much less expensive.
Whole grains, including wild rice, rolled oats and quinoa, are great sources of fibre, antioxidants and B vitamins, which are essential for brain health. Whole grains are quality carbohydrates and nutritionally very different from breads, pasta and cakes. Whole grains are what we should be eating as they release sugar into the blood gradually. This helps to reduce excessive blood sugar and insulin levels that can negatively impact brain cells.
‘Stick to a diverse colourful plant-focused diet with plenty of fibre’
Fibre is a type of carbohydrate that we cannot digest. Fibre-rich foods are digested more slowly and are more filling than simple carbs like refined grains, which helps us to avoid overeating. In many Western countries the average fibre consumption is around 10 – 15g per day, which makes us some of the lowest fibre eaters in the world. We need to be eating more fibre – a good amount to aim for is 35g per day.
There are two types of fibre – soluble and insoluble. Both types are good for you. Soluble fibre dissolves during digestion and turns into a gel-like substance which feeds the good bacteria found in the gut. Insoluble fibre is indigestible and remains more or less unchanged as it moves through the digestive system. Insoluble fibre facilitates bowel movements and the elimination of waste.
Sticking to a diverse, colourful, plant-focused diet with plenty of fibre will keep our gut microbes going strong. Not having enough variety of good bacteria in the gut has been linked with poorer cognitive performance, as well as increased inflammation. To feed our gut and keep it healthy, we can consume prebiotics. Prebiotic foods are high in soluble fibre and act as fertiliser for the good gut bacteria. Garlic, onions, asparagus, cabbage and leeks are all great sources, as are beans and lentils.
Probiotics can also help to create positive changes in the gut. Probiotics are live bacteria that, upon reaching the gut, replenish the good bacteria. You can find them in fermented and cultured foods, including yogurt and kefir, and in fermented vegetables like sauerkraut and kimchi.
Take care when choosing commercial yogurts as some are full of artificial colours, sugars and additives. Instead of delivering the desired health benefits, these products may end up nourishing the potentially harmful bacteria in your gut instead. In my opinion, plain, full fat yogurt containing live cultures is the only yogurt worth eating.
‘Oxidative stress accelerates brain ageing by damaging brain cells’
Of all the organs in the body, the brain is the one that suffers most from oxidative stress. This is when too many harmful free radicals are produced without antioxidants to counteract them. When antioxidant levels are lower than those of free radicals – due to poor nutrition for example – oxidative stress can accelerate brain ageing, by damaging brain cells and overloading the brain’s immune system.
The Western lifestyle, with its processed foods and high exposure to chemicals and environmental pollutants, lays the foundation for the proliferation of free radicals. And the more free radicals there are in the brain, the more damage can be done. A diet rich in antioxidant foods is important to mop up these excess free radicals and to quench inflammation.
Some of the most powerful antioxidants are vitamins C and E, beta-carotene - which is the precursor to vitamin A, selenium and a variety of plant-made phytonutrients, that give fruits and vegetables their bright colours. Brain imaging research shows that diets rich in antioxidants are associated with steady brain energy and fewer Alzheimer’s plaques.
‘Herbs, spices, cocoa and coffee have the highest antioxidant potency of all foods’
Plant-based foods make up the bulk of the best antioxidant choices available to us. You may have heard that blueberries, blackberries and gooseberries are antioxidant powerhouses, but did you know that artichokes have a higher antioxidant density than any other vegetable?
Herbs, spices, cocoa, and coffee have the highest antioxidant potency of all foods. You can increase the antioxidant value of your diet by adding herbs and spices like cinnamon, cloves, turmeric, oregano, rosemary and sage in cooking.
Consuming dark chocolate with a cocoa content of 70 percent or higher has some impressive health benefits so there’s no need to feel guilty about having dark chocolate as an occasional treat. Clinical trials have shown that consuming cocoa can improve attention and memory, while reducing inflammation and insulin levels, in as little as 8 weeks.
Omega-3 fats, found in oily fish, nuts, seeds and extra-virgin olive oil, promote neuroplasticity and help to maintain the adaptability of the brain. Additionally, nuts, seeds and oily fish provide us with quality protein. Adequate stores of protein are needed for brain cell signalling. These foods are broken down into amino acids, which are the building blocks of protein, and used to produce neurotransmitters, which are the chemical messengers of the brain.
‘The Mediterranean diet is associated with a much reduced risk of cognitive impairment’
The Mediterranean diet has been widely studied for its beneficial effects on heart and brain health. It’s not a diet as such, but a food feast. The Mediterranean diet is high in fibre and complex carbohydrates, moderate in fats and plentiful in vitamins and minerals. Vegetables and legumes, wholegrains, fruits, nuts and olive oil are the stars of the show. Fish and shellfish are a primary focus, and other forms of lean protein, such as poultry are eaten in moderation.
Thanks in part to its beneficial effects on the heart, the Mediterranean diet does a lot of good for the brain too. Greater adherence to the Mediterranean diet is associated with increased longevity and a much reduced risk of cognitive impairment and Alzheimer’s disease.
In brain imaging studies, those who followed a Mediterranean diet had healthier and younger looking brains than people of the same age who had been eating a Western diet. Though none of the participants outwardly showed any signs of cognitive impairment, the Western dieters carried more Alzheimer’s plaques than usual for their age, whereas the Mediterranean dieters showed none.
‘The MIND diet may lower the risk of Alzheimer’s by as much as 53%’
A specific diet, appropriately called the MIND diet, which is rich in fish, fruit and wholegrains, and light on processed foods, has highlighted that certain ingredients are beneficial to the resilience of our brains. Though similar to the Mediterranean diet, the MIND diet deviates slightly, in that it eliminates foods with a potentially unhealthy effect on the brain such as red meat, sweets and pastries, and it also restricts the consumption of dairy products, potatoes and high glycaemic fruits.
By tracking nearly 1,000 people over several years, researchers have found that the MIND diet can lower the risk of Alzheimer’s by as much as 53% for those who follow it strictly. And even those who only stick to the diet part of the time can lower their Alzheimer’s risk by more than a third.
While you probably get the biggest payoff from adopting such a diet early in life, it is never too late to reap the benefits of a healthy shift toward better choices. Although a complex and not fully understood set of factors, involving genetics, environment and lifestyle, likely contribute to the development of Alzheimer’s, the evidence is clear – good nutrition can protect the brain from cognitive decline.
In summary, what should you eat and what should you skip? Include brain-healthy foods like leafy green vegetables, berries, other vegetables, nuts, whole grains, fish, beans, poultry, olive oil and red wine. Try to limit red meats, pastries and sweets, fried or fast food, butter, margarine and cheese.
