Don't wait for the leptin

Your Enteric Nervous System is affectionately referred to as the second brain; it is primarily responsible for regulating important aspects of digestion. It uses electrical circuitry running along the entire length of your intestines to coordinate the timing of rhythmical, muscular contractions to keep everything moving along.

Electrical messages are also sent to and from your brain via a large bundle of neurons called the Vagus Nerve. Your gut even has its own set of hormones that it uses to communicate via chemicals travelling in the bloodstream up to your brain. These hormones switch the hunger centres of your brain on and off according to whether your digestive system is empty or full.

Ghrelin is a hormone released mainly from your stomach when it is empty. It travels up to your brain's Hypothalamus to produce feelings of hunger, making you want to eat. Having eaten, when food starts moving from your stomach into your small intestine, another hormone is released – cholecystokinin (CCK) along with leptin which is produced by fat cells. Leptin and CCK have the exact opposite influence to Ghrelin. They make you feel full up and switch off your desire to eat more.

The only problem with this system of chemical communication is that there is a small design fault that is the cause of an all-important time lag. It can take a full 15–20 minutes after consumed food first expands your stomach before the hormonal signals reach your brain and even longer before that feeling of being full up kicks in. This delay is the reason why so many people carry on eating long after their stomachs are full. The inevitable outcome being that they end up feeling completely stuffed. This bloated feeling can have a big effect on our moods. As well as feeling sluggish and lethargic, it can make us feel a little disappointed with ourselves because despite having overindulged on so many other previous occasions, we've gone and done it again!

Eat like an Okinawan

There is one place in the world where a greater proportion of people live to be a hundred years old than anywhere else – the Japanese island of Okinawa. As you can imagine, many researchers have tried to unlock the secret as to why Okinawans enjoy such long life expectancy.

Their diet is healthy, consisting of small amounts of meat, fish and lots of low calorie, but nutrient-packed fruits, seaweeds and staple vegetables like sweet potato and tofu. Oily fish is packed with omega oils – extremely good for brain health as they play a vital role in keeping neurons flexible.

In one experiment, when people switched to an Okinawan diet the men lost 18% of their body weight and the women 10%. Blood pressure came down by an average of 20 mmHg, blood glucose/insulin by 30% and cholesterol counts dropped from 195 to 125.

Similar diets, however, are eaten elsewhere in places where they don't age so well. Healthy diet is extremely important, but it is not the only factor.

A big clue to Okinawan longevity could lie in their dinner time mantra: “Hara Hachi Bu” which roughly translates as: “Eat until you are 80% full.”

It's a no-brainer. If you don't overburden your digestive system, fewer substances that pose a long-term health risk will accumulate in your body.

Tip 1: In one sitting never eat more food than you would be able to hold in your two hands cupped together, the exception being a leafy salad. In which case, best make it two lots of cupped hands!

Tip 2: Large plates and large bowls promote the dishing up of large portions. This, combined with a tradition of encouraging people to eat every last scrap of food on their plate, ensures that an awful lot of people do an awful lot of overindulging. If you regularly eat too much then here is a simple remedy – get rid of all your old crockery and replace them with smaller plates and bowls. It may sound somewhat extreme but there is plenty of evidence to suggest that smaller crockery drastically reduces overeating.

The influence of bacteria

Who'd have thought that the bacteria in your stomach could powerfully affect your mood? These single-celled organisms residing in your belly outnumber the cells that make up your entire body ten to one. It's been known for some time that these residents of your gut are essential for proper digestion. However, evidence that these self-same bacteria can determine your frame of mind is a very recent revelation.

The question is: how in the world could microscopic creatures in your gut possibly influence your brain? Well, for one thing, your gut's 100-million-neuron Enteric Nervous System is forever busy marshalling 10 trillion gut microbes to try to maximize your physical and psychological wellbeing.

In rats, where most of the research into the impact that gut bacteria has on behaviour has been focused, the balance between health-promoting good bacteria versus the disease-causing bad bacteria can be tipped by even the slightest amount of stress. Changes in gut bacteria have been found to affect not only physical health, but also pain perception and emotion, along with the variation in stress responses.

In humans, investigation into this exciting new area of research is in its infancy. One study found that when healthy human volunteers were given a 30-day course of “good bacteria,” consisting of a mix of two different probiotics (Lactobacillus helveticus and Bifidobacteria longum), a decrease in symptoms of depression and anxiety became apparent. Another more recent study used the brain imaging technique fMRI to investigate the impact on meddling with gut bacteria on brain function. They found that in people regularly fed a yoghurt drink packed with probiotics, as opposed to those fed with yoghurt not containing probiotics, significant changes in the brain areas involved in creating emotional states were observed. It's early days, but all the evidence so far points to gut bacteria having a significant influence on the brain and, as a consequence, your mood.

Despite this evidence, the question still remains: how exactly do these bacteria do it given the physical separation between gut and brain? Gut bacteria are responsible for manufacturing 95% of serotonin – a neurotransmitter as vital for stabilization of mood as it is for healthy gut function. Gut bacteria also produce and respond to several other chemicals involved in nervous communication including acetyl choline, dopamine, melatonin, GABA and noradrenaline. You'd be forgiven for thinking that gut bacteria are able to influence your brain simply because of the chemicals they produce finding their way into your bloodstream and travelling up to your brain.

However, what gets into the brain from the blood is tightly regulated by a protective wrapping around the brain's blood vessels called the blood brain barrier. It seems that the main route of communication from gut to brain in terms of mood manoeuvres is actually via the Vagus Nerve. This cluster of wire-like neurons connect the brain to many different organs, including the lungs, heart, liver and gut. It enables them to be switched into “action stations” or “rest and digest” mode, depending on what is most appropriate at any given time.

In experiments with rats, when the Vagus Nerve is cut, the influence of gut bacteria on the brain disappears. Emotional behaviours, pain perception, stress response, all return to normal. Vagus Nerve stimulation is actually a last resort option for treating chronic depression in humans. What's more, it often seems to work.

Irrespective of the precise mechanisms by which they achieve this, your gut bacteria are something you should give serious consideration to. If you're feeling irritable, stressed or on a bit of a downer, you may wish to tip the balance in favour of your gut's “good” bacteria by providing reinforcements – in the form of pro-biotic yoghurt drinks!

Fat filled and all sugared up

Let's take a look at the fuel that we should be putting into our brains to help them work better; the last thing we want to be doing is putting diesel into a petrol engine.

Although your brain weighs only 2% of your overall body weight, it consumes up to 20% of all the oxygen and sugar available in your bloodstream, and that's when it's just ticking over.

When it's working flat out, such as when you're really concentrating hard on something, its demand for energy resources from your blood shoots up to 50%. Part of the reason you feel the urge to snack whilst deeply focused is because your brain is using up so much energy. What you choose to put in your mouth to try and meet its demands plays a critical role in how well it functions, not to mention the impact on your waistline.

More often than not people have a tendency to snack on foods made almost completely from sugar and/or fat. These irresistible, beautifully packaged sources of nourishment may feel like they are providing you the consumer with a satisfying instant fix. The truth is, as far as brains are concerned, these quick fixes are nothing short of a nightmare.

The reason why people love these sugar-loaded, fatty foods so much is because we humans have evolved over many years to find such foods delicious – as they were once extremely important to our continued survival. Man's craving for these types of food goes back to times when food wasn't anywhere near as readily available as it is today.

For the majority of people on this planet, death through starvation was once a very real possibility. When starvation is an imminent threat, it pays, for your own survival, to eat calorie-rich foods that are high in sugar and fat, which can be put into storage throughout your body for when food is scarce.

Life was once very much centred around simply staying alive and using anything we could lay our hands on to get by from day to day, a passion back then for consuming sweet, fatty foods made perfectly good sense. Our inbuilt sense of self-preservation hasn't dwindled one bit since then. Nor, unfortunately, has our deeply rooted, subconscious need to source foods that deep down we feel will help us to stick around a bit longer. It's only in recent years that we have begun to understand just how damaging these “comfort foods” actually are.

In today's developed world, the situation is very different. For most, the primary threat to health is not starvation but overindulgence in food and drinks that are always at hand and invariably high in fat and sugar.

Fast food outlets, kiosks and vending machines continue to pop up all over the place, making treats that look and smell more appealing and alluring than ever, easily available. Strategically placed, brightly lit and designed specifically with temptation in mind, peckish passers-by with a soft spot for immediate reward are drawn in like moths to light.

More often than not the companies that stock them are multinationals who know only too well how irresistible and addictive their tantalizing goodies are, especially to those on the move, in a hurry or just bored. These days it's an around-the-clock snack fest out there with on-impulse fixes available almost anywhere and at any time.

Sadly, it's something that has become the norm for many of the younger sugar-holic generation, with many developing their bad snack habits at an early age. That break-time fizzy drink and a packet of crisps that later on in life becomes a well-deserved biscuit with our coffee for “elevenses,” a mid-afternoon chocolate bar, an after-dinner dessert and a ready sweetened, fat-saturated bedtime drink to round off a tiring day.

Sugar-coated vandalism

For most, snack habits develop not necessarily because they are weak-willed or particularly greedy but because it all seems so harmless. In the 1950s and 1960s smoking seemed harmless. Everyone had an old aunt or uncle that they could point to who despite smoking a hundred cigarettes a day, was fitter than ever. It seemed like everyone was at it and they weren't dropping dead, were they?

Well, yes they were – but it wasn't obvious to the general public what actually caused the premature deaths of the vast majority of smokers. Doctors however had noticed that smokers seemed to die early and in more cases than not, from the same set of diseases. By the 1970s and 1980s the evidence that smoking caused a variety of cancers became overwhelming.

Sweets, fry ups and cakes might not give you lung cancer but high sugar-high fat diets are killing people! Here's why …

When you eat or drink foods high in sugar, for example fizzy drinks, sweets and cakes, all that sugar gets dumped straight into your bloodstream, quickly ramping up to potentially damagingly high concentration levels. As any diabetic will tell you, high sugar levels are bad news.

From a brain's point of view too much sugar is a big “no-no.” You see, in too big a quantity it really does mess things up. It's no exaggeration to say it vandalizes your brain's lines of communication with your body. If you want to see how with your own eyes, go and make a meringue.

The special wrapper that helps your nerve fibres to carry messages from your brain to your body and back at lightning speeds is made almost entirely from fats and protein. In meringue making, when you add sugar to egg white a chemical reaction occurs that turns all that soft, gloopy, transparent protein into hard, white, chalky meringue. Delicious when served with a dollop of lemon curd and lashings of whipped cream but not so great when the sugar has made meringue of your brain wires!

In order to avoid the catastrophic consequences of having all your wires turned into useless strands of meringue, your body releases insulin. Insulin is a fiendishly clever hormone that reduces the concentration of sugars in your bloodstream. It does this by transporting the sugars out of your blood and into the surrounding tissues where they get converted into glycogen for storage in your liver and muscles until needed in leaner times.

No vacancies

All well and good so far, but when the “no vacancies” sign goes up (in other words, when there is nowhere else left to store glycogen), that's when things literally do begin to go pear-shaped.

Running out of options and desperate to find a home, glucose starts getting converted into fatty deposits and seeks refuge under your skin. Not as you can imagine the most attractive thing to happen but nowhere near as dangerous in comparison to what also starts happening. Fatty deposits start getting deposited around your vital organs. Now that, without overstating it, is bad news.

So, if you've started to notice a few blobby bits about your person, there are also likely to be more blobby bits around the important bits that you can't see. The good news for people trying to shed a few blobs at the gym is: if you don't see any changes on the outside to begin with, don't lose faith, the main threat to health – the fat around internal organs – is the first to be shed.

What it all boils down to is that if you are a serial snacker, all the excess sugar you snack on is converted into fat because all the spaces in your glycogen stores are more than likely to be fully occupied. On top of all this, eating fast-release sugar snacks stimulates an all-too-sudden release of shed-loads of insulin. This dramatic hormonal release causes tissues to suck too much sugary glucose out of your blood, which is why you feel really hungry again just a short while after you've eaten. It's a simple rule, if you're producing too much insulin as a direct result of eating large quantities of sugary carbohydrates – you'll very soon be running low on sugar.

Sugar rush – no myth

A sugar rush does make you feel good but it's not so much to do with the impact of the excessive sugar but more to do with the emergency response of the large dose of insulin released by your pancreas into your blood. Insulin is released to remove as much sugar as possible and to help prevent you having a whole range of health problems.

The problem is that insulin doesn't just extract sugar from your blood, it also takes out amino acids – the building blocks of proteins. That is all the amino acids apart from one that is extremely important to your brain – tryptophan.

Tryptophan is the basic essential building block of a variety of neurotransmitters including dopamine, a vital component of the reward system that makes you feel happy. Under normal circumstances tryptophan has to compete with all the other 19 different types of amino acids, queuing up at the tightly controlled entrance to your brain – the blood brain barrier. But with the insulin sucking the competing amino acids out of the race the tryptophan can easily stream into your brain with fast pass access. The high availability of tryptophan leads to greater amounts of dopamine and serotonin in the brain, which is why you end up feeling good.

Sugar rushes may be an effective way of making yourself feel good in the short term, but in the long term they have the potential to destroy your health. They will make you fatter in the medium term as sugar continues to be converted into fat, and after a lifetime of asking too much of your insulin-blood-glucose regulation system, the long-term prognosis is diabetes along with a whole range of spin-off health problems.

The best fuel

Avoid fast-release sugars and instead eat slow-release sugars. This is the only way to avoid the “sugar roller coaster” – rocketing and plummeting blood sugar levels which are commensurate with periods of high energy and manic behaviour being quickly followed by low energy, low motivation and irritability.

Slow-release carbohydrates like oats, vegetables, whole grains, gradually release sugar into your bloodstream over a period of several hours, so there is no need for a massive release of insulin. For example, having porridge oats for breakfast for the slow-release sugars to help keep you going until lunchtime, perhaps topped with apple, banana or berries to give you a bump start, instant energy boost.

When the urge to nibble does become irresistible, drink water, eat fruit, vegetables or wholegrain snacks. Being in a hungry state with all that Ghrelin and other appetite-stimulating chemicals swilling around in your brain fundamentally changes the way you make decisions. Deciding what to eat when very hungry compared to a bit peckish has a big impact on how much food you try to eat. Not being so hungry at lunchtime and less likely to overeat will mean you won't end up feeling like you're carrying around a “food baby” all afternoon. Food babies like all babies need looking after. Not only do they make you feel completely stuffed they also make your brain all sluggish as blood is diverted from it to your gut to take care of your demanding baby.

If you want to stay on the ball, it's the only way to go. Slow-release snacking means you are full after a modest rather than a large lunch, which means you can remain energized, more alert and hopefully more effective. Instead of going from one moment positively buzzing and the next dropping down to feeling lethargic, unable to focus and getting all irritable, snacking on slow-release carbohydrates ensures that your energy levels are sustained on a more even keel. Throughout the day you'll probably feel a lot happier within yourself, your mood swings won't be so dramatic and those around you will also probably benefit from your newfound slow-release carbohydrate diet!

Three quick points

1. Sugary snacks do have their place – you just need to use them sparingly and strategically. Prior to a big performance it doesn't hurt to eat something packed with fast-release sugars. If your adrenaline is really pumping then your metabolism will be high and the sugar will get used to give you the energy you need to thrive.

2. Healthy snacks are healthy if eaten in moderation. Just because they are “healthy,” it doesn't mean that you should non-stop gorge yourself on them! A lot of cereal bars have more calories than a chocolate bar so select carefully when picking them up in the supermarket. Fight the temptation to eat more than one in any given hour.

3. Go bananas! Bananas are the perfect on-the-go snack. Amongst other things, they fill you up, they're loaded with natural sugars, they contain tryptophan, they are high in fibre, they even help prevent cramp and they come ready wrapped!

Pump that brain

Forget body beautiful, as far as your brain is concerned the body is just a vehicle to help it get around and maintain a steady supply of essential chemicals. When people think about exercise, the emphasis always seems to be about the benefits to their body, giving little thought to their brain.

Today's media very much focuses people's attention on exercises designed to reshape out-of-shape bodies. But as far as your brain is concerned, losing fat and toning muscles are just superfluous by-products in comparison to the profound benefits it gains from you taking regular exercise.

The good news is that unlike the frustratingly long periods of dedicated training it takes to yield the slightest of visible changes to your body, there are several, noticeable and almost immediate improvements to your brain.

The one key thing your brain gets out of you exercising is more blood. It gets more because your heart pumps harder and faster. This occurs in response to a chemical released from the glands that sit on top of your kidneys – adrenaline – and also because of a set of brain wires that branch off your spinal cord to innervate more or less every organ in your body – your Sympathetic Nervous System.

These automatic hormonal and nervous system responses to exercise increase the speed and depth with which the lungs inflate and deflate – upping the intake of oxygen and removal of carbon dioxide waste. The adrenaline also causes sugars to be released from storage in and around your body. So not only does exercise mean your brain gets more blood passing through it, it also means that blood is richer in oxygen and sugars which are required to create the energy that keeps it firing on all cylinders.

Improving the supply of glucose-packed, oxygenated blood that surges through it is so important because, like all brains, yours has no room for storage. Virtually every cubic millimetre of the space inside your skull is taken up by 86 billion wire-like electrical brain cells and a further 86 billion glial cells that provide the support network upon which your whole communications infrastructure is built and is critically dependent upon.

Every single one of those cells rubs up alongside a tiny blood vessel – it's the lifeline to those essential energy molecules that it needs to stay alive. With nowhere to store the glucose and oxygen that combine to release the energy to keep your brain cogs turning, each cell is 100% reliant on a constant flow of blood via microscopically thin tubes that weave an intricate web throughout the massive ball of brain gloop sloshing around in your skull.

Consistent high performance

Exercise is a tool that can be used to change your mood in an instant. Several powerful hormones (of which adrenaline is but one) are automatically released into your bloodstream when you do even a short burst of exercise exerting a positive effect on your mood. A 20 minute jog around the block followed by a quick shower is all that is required to make you feel much more alert and able to concentrate fully. The time invested in a short bout of exercise will be more than compensated for when your brain is positively zinging with everything it needs to function to the best of its abilities.

There are no pain receptors inside your brain, so brain surgeons can prod around without hurting the patient.

For your brain's sake, try not to think of body builders pumping iron on the beach or Olympians performing superhuman feats – daily, gentle exercise is all your brain needs for boosting its performance. The great thing is, once you've got into the habit of doing regular exercise for just a few weeks, your general mood will improve. The blood vessels to your brain will be clearer than those belonging to someone whose only exercise is running for the bus; and your heart will be stronger, enabling it to pump blood through your brain more efficiently. These factors combined lead to improved mood by increasing the delivery of oxygen, but more importantly increasing the removal of waste materials constantly generated by your brain as a result of the fact that it is always switched ON.

Up to 1 litre of blood passes through your brain every minute.

Exercise is probably best regarded as being a multi-purpose tool that has both an immediate and longer-term impact on increasing the efficiency of all your brain functions. It can give you the opportunity to mull things over away from work and, at the very instant your heart starts pumping faster, it can help snap you out of a gloomy mood.

Endorphins – natural opiates

Key to a more positive mood change taking place is also very much thanks to endorphins being released when your brain detects an increase in bodily movement. The original reason why we evolved to release these natural feel-good chemicals in response to exercise is all down to their ability to shut off pain signals and promote survival in dangerous situations.

If you should ever need to run away from danger, fight off an enemy, or take on any other potentially life-threatening challenge you wouldn't want a twisted ankle or a stubbed toe impeding your escape. Endorphins are the reason why people sometimes walk away from accidents only to drop dead of their injuries a few hours later. Brains use them as a natural form of opium to numb inconvenient pain messages.

The endorphin release that accompanies moderate to intense exercise is literally designed by nature to make you feel high so that you won't feel the pain that would otherwise make you stop. The bonus is that these endorphins are still swimming around in your body when you get back from doing exercise and continue with your work. Available to anyone, completely free, ridiculously powerful and perfectly legal, endorphins are guaranteed to change your mood in a positive manner.

Regular exercise can be as effective as drug therapy for stroke and diabetes management.

You may think that brains being brains are fairly streetwise, but the truth is that in these circumstances they honestly can't tell the difference between you genuinely being scared witless and fighting for life or you being on a treadmill in the safety and comfort of a gym. So the next time you want to feel on a bit of high, a good workout should do the trick.