Читать книгу Future Brain - Jenny Brockis - Страница 9

KEY 1
NUTRITION
Refuelling smart

Think of your brain as a car and your body as a highway. Would you prefer to be driving a brand new Ferrari, or a rust bucket leaking oil and coughing smoke all over the road?

If your brain was a car, and you knew it needed fuel, what sort of fuel would you choose? Premium high octane, economy or diesel? What sort of car would you drive? Would you look after it, washing, waxing and cleaning it on weekends, or would you be one of those people who smoked on the way to work and left lolly wrappers and food crumbs all over the seats?

Substitute your brain for the car. How well do you fuel your brain? Are you eating clean, or is every night a frenzy of fast food and fizzy drinks? Then there's alcohol …

Paleo, Pritikin and Pizza Hut aside, we now know from years of nutritional research that our choice of foods can influence:

▪ our memory

▪ our general cognitive skills

▪ our mood

▪ our mental health

▪ our ability to perform well in the workplace

▪ even our potential risk of brain disease.

We eat because we are hungry, because we are bored or to be social. We eat for pleasure or because we are miserable. We sometimes even eat because we are forced to (remember those dreaded cold brussels sprouts from childhood?).

What we are often blissfully unaware of however, is the influence that the many different physiological, psychological, social and environmental factors have on determining the how, what and when of our eating. These in turn impact our decision making and, importantly for many of us, our business outcomes.

So how do we keep our brains in optimal physical condition? In the Neuron Grand Prix, what needs to happen to claim podium position?

Brainy facts about nutrition and work

▪ Our brain is an energy hog that consumes 20 per cent of all the energy we put into our body. Providing sufficient energy through an array of proteins, fats and carbohydrates is essential for good cognitive performance and health.

▪ We can go without food for a while, but water is essential to healthy thinking. Even 1 per cent dehydration is associated with fuzzy thinking, so keep up your fluid intake with six to eight glasses of water every day.

▪ Caffeine keeps us awake and alert. Some studies have shown it also helps the formation of long-term memory following study.

▪ There is no single best diet or food. Following a brain-healthy eating pattern incorporates certain aspects of the Mediterranean diet and sticking to ‘real food’. It's about including a wide variety of fresh, unprocessed foods, vegetables and fruits, lean protein (including three portions of oily fish each week), seeds, nuts and whole grains.

▪ Our food choices determine our mood and contribute to our mental wellbeing and focus. Avoiding processed foods full of fat and sugar is the best way to maintain healthy cognition.

You're such a fathead

The human brain is around 60 per cent fat, so the next time you call someone a fathead, they are well within their rights to say, ‘Same to you’. Consuming the right fats to sustain our brain's function and maintain our neural architecture is absolutely critical to functional integrity and brain performance.

The brain can produce its own cholesterol, but we rely entirely on our dietary intake of essential fatty acids (omega-3) to create neurotransmitters and keep neuronal membranes flexible for optimal brain function.

Low levels of omega-3 may cause your brain to age faster. Studies by ZS Tan and others using MRI scans and memory tests showed that those in the lowest 25th percentile for omega-3 consumption had smaller brain volumes and scored lower on memory, abstract thinking and problem solving.

An imbalance or overconsumption of bad fats changes the brain and contributes to poorer brain performance. Research has linked trans fats, as found in margarines, fast foods, baked snacks, biscuits, pies and frozen pizza, to poorer memory in young and middle-aged men. As Beatrice Golumb expresses it, ‘Trans fats increase the shelf life of foods and reduce the shelf life of people’. For those in the earlier part of their career, where performance matters, paying attention to food choices can make a difference.

Dr Golumb's study found the following:

▪ Men under the age of 45 who ate more trans fats performed worse on word memory tests, even after taking into account variables of age, education, ethnicity and depression.

▪ Each additional gram of trans fat consumed was associated with an estimated 0.76 fewer words correctly recalled.

▪ Those eating the highest amount of trans fats overall showed a 10 per cent reduction in words remembered compared with those adults who ate the least trans fats.

Gut instinct

Everyone knows the saying ‘trust your gut’. But is this actually good advice, not just in relation to our business instincts, but when it comes to what we like to eat?

Our food choices have been shown to affect how we feel. If we are unhappy at work, we sometimes seek consolation through eating – and what we choose to eat then is often not good food. We go for ‘comfort foods’, high in trans fats and refined sugar, which provide an instant high, followed by a big crash and burn, leading to a further drop in mood and energy.

Food choice matters because it determines mood and performance. One Spanish study of more than 12 000 subjects (average age 37 years), followed over a six-year period, revealed that those consuming a diet highest in trans fats had a risk of depression that was 48 per cent higher than those who consumed the least trans fats. Yes, not everyone in Mediterranean countries necessarily follows a healthy Mediterranean diet!

Medically, this finding is explained by the fact that trans fats stimulate a higher level of inflammation in the body, increasing the risk of fatty plaques being laid down and interference with the brain's neurotransmitters concerned with regulating mood.

Conversely, enjoying a diet higher in omega-3s, the fatty acids essential for good brain health and function as found in oily fish, has been shown to be associated with a lower risk of depression and cognitive decline.

So should we trust our gut when deciding what we feel like putting in our stomachs?

The answer is, not necessarily!

We have what is called a gut microbiome, a diverse bacterial population that lives in our gut. These bacteria can direct our brain's food choices to suit their survival needs, although we can counterbalance this through healthy food choices to change the gut microflora so as to stay healthier both physically and mentally.

Fat is not always ugly

Not all fats are bad fats. Cholesterol, which has typically been portrayed as the Dr Evil of the fat world, is essential to the brain for synaptogenesis (the formation of new synapses) and hence critical for brain plasticity, learning and memory. Saturated fats, as found in meat, dairy, nuts and olive oil, benefit brain function when consumed in moderation.

Our brain has a very special relationship with cholesterol. The brain synthesises its own, retaining it and effectively shielding it from the rest of the body behind the blood–brain barrier. Twenty-five per cent of the body's total cholesterol is found in the brain, mostly as myelin, the fatty coating around nerve cells that speeds up the transmission of electrical impulses.

Cholesterol is needed also for the formation of dopaminergic neurons, involved in our brain's reward response system and motivation. Feeling good and being mentally rewarded for our efforts are critical for maintaining engagement and performance.

Minding your mind includes minding your weight

Obesity shrinks the brain. It reduces brain volume. It is also a risk factor for cognitive decline. With 30 per cent of the world's population either overweight or obese, there are now more than 2.1 billion people at risk of cognitive decline through this factor alone.

Having a smaller brain volume affects brain function (see figure 1.1, overleaf):

▪ in the hippocampus, the area of the brain associated with learning and memory

▪ in the frontal lobes, the area associated with higher-level thinking, including paying attention, planning and organising

▪ in the anterior cingulate gyrus, the area associated with decision making, empathy and emotion

▪ in the thalamus, the area associated with coordinating other areas of brain function.

Figure 1.1 : parts of the brain affected by obesity

Obesity affects our cognition because greater effort is required to complete complex decision-making tasks. Encouraging all staff to watch their weight not only helps them to stay fitter and healthier; it is a way to maintain their cognition.

Food and focus

We reach our cognitive peak for motor performance around the lofty age of 24. But before you slump into a deep depression about being ‘over the hill’, although your speed of processing may have slowed down, your increasing ability to use your experience and growing wisdom enables your brain to take a few mental shortcuts.

It's a bit like discovering the disguised cut-throughs that enable you to escape the Ikea store more quickly without having to follow the illuminated arrows for the 30 kilometres required to reach the checkout, when all you wanted was to buy a nice new office lamp.

A study in 2014 by Thompson and others analysed the influence of age on performance in 3035 players (aged 16 to 44) of the video game StarCraft II and found that while cognitive motor decline starts early, it is compensated for by the continuing adaptability of our massively plastic brain.

Hurrah!

One of the things we want to be able to do at work is focus on what matters, so we stay on task and get our work done. In some instances, the modern workplace seems to conspire against us by presenting us with ever-increasing levels of distraction.

We can help boost our focus by paying attention to which foods we choose to eat. It really is as simple as focusing on eating ‘real food’. The following foods have been shown in nutritional studies to assist in boosting focus, and this list is by no means exhaustive. Just think of fresh, minimally processed foods and you will be on the right track, but consider especially: