The secrets of nutrition and improved mental performance

Food – we all know it is the fuel our bodies need to maintain our energy levels. But do you know the role it plays in supporting your brain function too? Whether it is brain fog, the post-lunch slump, or a caffeine crash; what we eat can impact our performance, productivity, sleep, and mood – so it is important to learn how to use it to our advantage.

Good brain health has long been linked to a healthy diet; from reducing the risk of stroke and dementia to accelerating the recovery from depression. However, on a day-to-day basis, what we eat also impacts our performance, productivity, sleep, and mood.

With growing numbers of employers invested in improving the health and wellbeing of their employees, we asked Harley Street Nutritionist and Owner of Rhitrition, Rhiannon Lambert, for her advice on eating and drinking our way to health, happiness, and success.

Listen to your gut

No, we are not talking about your instincts in this instance; we are talking about gut health. Our digestive tracts are full of trillions of microbes — bacteria that play a critical role in our physical health as well as influencing our behaviours, as Rhiannon explains:

‘A lot of people think it is your head that tells you when you are hungry or impacts your mood. But research in this area suggests that much of this is dictated by our gut health, which is directly related to the things that we eat and the nutrition we absorb. Signals constantly run from your gut to your brain, and with 90% of our happy hormone, serotonin, located in the gut, it’s important our gut is sending the right messages.’

Think of your gut as a garden

In the same way a garden needs biodiversity to flourish, our guts also need a diverse range of foods to develop gut bacteria that provide a wide range of defences; it is why what you eat is not just nutrition for you, it is feeding the bacteria in your gut too. Rhiannon suggests eating as many plant-based foods as possible to get as much fibre in our diets to encourage our gut microbes to flourish:

‘Our main source of fibre comes from carbohydrates and vegetables, so to get the widest variety of fibre in your diet, eat more whole grains, beans, pulses, and colourful fruit and vegetables.’

Rhiannon’s simple change:

«Adding fermented food and live cultures, known as probiotics into your diet can also support a healthy gut. You can find these friendly bacteria in products such as kefir, miso and kimchi as well as sourdough bread and some types of yoghurts and cheeses.»

Your brain needs carbohydrates

It is fair to say that carbohydrates have had their fair share of controversy in recent decades; from diets that promote their exclusion to debates over ‘good’ or ‘bad’ carbohydrates. The type of carbohydrates we eat and the quantity we consume depends on individual circumstances, however, Rhiannon advocates the important role carbohydrates play in our brain health:

‘Carbohydrates contain the only fuel our brain loves to use: glucose. Our brains thrive on this natural sugar, while fat and proteins are unable to get through a barrier in your brain. When people go on low carb diets their mood and productivity can severely decline.’

Rhiannon’s simple change:

«Not all carbohydrates are the same, so when it comes to what you consume, try reducing your consumption of refined carbs found in things like fruit juices, white bread and pastries and instead, build more whole, fibre-rich foods into your diet to boost your brainpower.»

Eat your way to better sleep

It is easy to put bad sleeping patterns down to the stresses and strains of daily life, but Rhiannon advises that we should be paying more attention to what we eat when it comes to getting a better night’s sleep:

‘Serotonin, which you get from a varied diet and exercise, converts in your brain to melatonin, a natural hormone which helps to regulate your internal sleep cycle. As humans, we thrive on routine, so these natural rhythms are important for our mental health.’ 

Rhiannon’s simple change:

«To help these natural rhythms and boost your serotonin levels through food, try adding more eggs, nuts, seeds, cheese, salmon and tofu to your diet.»

Hydrate, hydrate, hydrate

Do you frequently get to the afternoon and find it difficult to concentrate, feel tired or cranky? If so, it may be that you are like almost 80% of employees in the U.S. who say they are simply not drinking enough water. Rhiannon explains why drinking water is one of the quickest fixes when it comes to improving your mental performance:

‘Our bodies are around 60% water overall, so as well as helping to maintain every function within our bodies, our hydration levels can also impact our mood. People are more likely to experience a low spell and lack of concentration if they are not hydrated.’

Rhiannon’s simple change:

«Always have a bottle of water on your desk while you work, and you could also add more hydrating foods into your diet, such as cucumber, strawberries, celery and melon to keep you feeling refreshed.»

A Mediterranean diet can improve your mental health

Often considered as one of the most balanced diets in the world, offering a wealth of physical health benefits, the Mediterranean diet has also been linked to greater mental health too. A meta-analysis in 2018 reported the associations between dietary patterns and risk of depression, discovering that people who followed a healthy Mediterranean diet had a decreased risk of depression.

Rhiannon’s simple change: ‘As well as helping you to eat more vegetables, fruits, beans, nuts and whole grains, a Mediterranean diet that includes oily fish and olives will also give you the healthy fats your brain needs. If your job involves you sitting looking at a computer screen all day, this type of diet will also be helping your heart pump oxygen around and therefore help your concentration.’

Time to reassess your relationship with caffeine?

Caffeine and work go hand-in-hand for most people, and while a moderate amount can help improve your physical and mental performance at work, if you are having trouble sleeping or relying on that next cup to get you through the day it might be time to reconsider your relationship with your daily dose of coffee/tea, as Rhiannon explains:

‘Caffeine is a habit for so many people and is the most commonly used psychoactive stimulant in the world. It is so powerful that it stimulates stress in the body by triggering your fight or flight response. While many believe it is responsible for elevated levels of performance, this is likely to be accompanied by a crash shortly after, which in turn may tempt you to reach for another coffee or sugary foods.’ 

Rhiannon’s simple change:

«If you are not ready to swap your daily coffee for a caffeine-free alternative like mint tea just yet, consider having your last cup no less than 12 hours before bed, as caffeine can stay in your body for such a long time after drinking it that it can prevent you from getting into the deep sleep that your body needs.»


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