Sunday, 29 September 2019


Fasting in various forms has become very talked about recently, thanks in part to Dr Michael Mosley who 6 years ago popularised the idea of intermittent fasting with his 5:2 diet.  In reality fasting has been part of all the world’s major spiritual denominations for thousands of years, with designated periods throughout the year devoted to abstaining from foods.  It is a practice that is also rooted in our evolutionary biology. As humans evolved through periods of feast and famine, we evolved adaptive strategies to keep functioning in a fasting state, and these adaptations are of great interest to researchers today.

Compare the environment our ancestors lived in to the environment we inhabit today, with often highly inappropriate foods available constantly, snacking culture and sedentary occupations.  The cultural notion that we require three meals per day might have been appropriate when we engaged in largely physical work, but is less so now.  It takes a tremendous amount of energy to digest and process food and when you fast the body diverts that energy to repair and rebuilding. The modern epidemics of insulin resistance, type 2 diabetes, cardiovascular disease, and auto immunity  -  the degenerative diseases of society  - can be directly linked to our patterns of constant consumption.  But rather than looking at it as a diet, consider it to be a change in eating patterns for life, rather than short term punishment to achieve short term goals.

Intermittent fasting is simply a description of eating, and not eating, intermittently, and various forms of it are possible. Probably the easiest, healthiest and most accessible form of it is to eat within a window – such as eating within a 12 hour window and fasting overnight.  This means an early evening meal, and late breakfast the flowing day. It can be adapted to your lifestyle and working day, and if you have blood sugar control issues you can build up slowly. The ideal window to aim for as a daily practice is 16:8. Eat for 8 hours of the day and fast for 16 hours overnight. If you only eat within an 8 hour window you are releasing less insulin in to the blood stream.  Never forget that as well as a role in blood sugar control, insulin is the fat storage hormone and excess levels promote inflammation in the body, the root cause of all degenerative disease.

The numerous health benefits of fasting are well documented:

Firstly, when you fast, your body begins to consume damaged cells first, a process known as 
autophagy, or eating our self. Cells recycle waste material and repair themselves.  This has profound implications for our improving all aspects of our health and ageing. Fasting for more than 6 hours begins the cleaning phase, so eliminate snacking!

As insulin levels drop through fasting, blood sugar control improves and the body burns fat.

Fasting has the potential to improve autoimmune conditions.  In previous Gut Matters posts we looked at the importance of gut barrier integrity to prevent undigested food particles, toxins and microbes crossing the mucosal barrier, the potential trigger for autoimmunity.  Fasting can promote the proliferation of the gut bacteria Akkermansia, which is associated with all good health outcomes.  Akkermansia feeds on the mucosal layer of the gut, and the 16 hour window is considered ideal.  Fasting also increases the diversity of gut bacteria, which impacts on all positive health outcomes.
Fasting promotes the secretion of human growth hormone, important for the build up of muscle mass and muscle strength.
Somewhat counter intuitively, fasting can normalise grehlin, the hunger hormone.  You might struggle to adapt at the start due to habits, but fasting sensitises the body to when you are actually hungry, as opposed to eating routinely.  Eat only when you are genuinely hungry.

Fasting can normalise several markers of degenerative disease, such as triglycerides and oxidised LDL cholesterol. Fasting can stimulate stem cells which heal and repair your immune system.

When not to fast:

If you have poor blood sugar control, are taking medication, or have an eating disorder, discuss time restricted eating with your GP first. Do not fast if you are pregnant or breast feeding.

It goes without saying that when we eat we should avoid simple carbohydrates.  It is common to rely on simple carbohydrates as our source of fuel, and yet they are not an ideal energy source and generally nutritionally poor quality foods.  Eat healthy fats, good quality proteins, and complex low glycaemic load vegetables as the bulk of your diet.

Thursday, 9 August 2018

Gut Matters - Female Hormones - the Oestrobolome

Gut Matters  - Female Hormones – the Oestrobolome

In the last two Gut Matters we looked the microbiome generally and also mood and sleep.  Now we are going to look at female hormones and the influence of the microbiome.   From puberty, to PMS, to pregnancy, to menopause and beyond, women’s bodies go though many changes.  Navigating these changes is easier if we understand the Oestrobolome, an emerging concept that is leading researchers to consider the gut to be an endocrine (hormone secreting) organ.  All three types of oestrogen are actually made in the gut.  So correcting dysbiosis, an unhealthy ecosystem of microbes, can be pivotal in reversing hormonal conditions. Dysbiosis can cause a recycling of oestrogens, as well as chronic inflammation.

Essentially, the bacteria in the gut play a role in the body’s oestrogen levels.  Emerging research indicates that the microbiome controls the way the body regulates oestrogen.  The specific microbes in our gut that metabolise oestrogen are called the oestrobolome.  Understanding the impact of these microbes can help us to think differently about conditions like PMS, endometriosis, infertility, PCOS, and menopausal issues. Your gut makes the enzymes that metabolise hormones, and then excretes from the body excess hormones that can wreak havoc if reabsorbed and recirculated.  Lack of butyrate (an anti-inflammatory short chain fatty acid), often caused by reduced microbes and lack of fibre, can cause chronic inflammation which also damages our hormone balance.  

Research on altering the microbiome by targeted probiotic supplementation is still in its infancy, but is likely to be a safe and effective intervention for hormone related conditions.   There are areas which are becoming well understood.  There is a good body of evidence to suggest that lower diversity of species in our gut leads to a disruption of hormones.    Microbes promote metabolism of oestrogen and prevent the reabsorption of free oestrogens.  Microbes influence the activity of an essential enzyme called beta-glucuronidase, which modifies oestrogen.  If this process works effectively, it is part of the wonderful symphony of appropriate hormonal balance in our bodies.

Research tells us that young women with PCOS have a different microbiome.  As well as reduced diversity, there is frequently a lack of a particularly beneficial microbe called Akkermansia, which at good levels is associated with positive health outcomes.  Endometriosis has also been associated with a dysbiotic gut, as have unpleasant menopausal symptoms.  In animal studies osteoporotic bone loss from low oestrogen has been alleviated by a bacteria, Lactobacilus reuteri.  The contraceptive pill can damage beneficial species of microbes in the gut and allow pathogenic bacteria to proliferate.  The microbiome can also metabolise foods which contain oestrogen like compounds into forms that are biologically active in the body.  

So, we can alter our diet to help feed the internal ecosystem which takes care of us.  This is a safe intervention which we can all do to help ourselves.  We can eat more prebiotic foods, fibre, and resistant starch as detailed in the last two articles.  Fermented foods like sauerkraut, kimchi, kefir and yoghurt are helpful.  Cruciferous vegetables like broccoli, cabbage, and cauliflower, contain specific phytochemical properties that can modify the metabolism of oestrogen.  We can test your microbiome, in order to optimise nutrition and then use targeted probiotics to help regain balance in the gut.

Wednesday, 23 May 2018

Gut Matters - Mood and Sleep

Gut Matters – Mood and Sleep

In last month’s magazine, in Gut Matters I looked generally at the gut and the friendly bacteria that reside within us.  This month I want to focus on the issue that concerns so many of us – our moods and sleep.  In the last couple of years there has been a paradigm shift in neuroscience as researchers have begun to understand the influence of our gut microbiome, the colony of bacteria that lives symbiotically within us, on every aspect of our emotional behaviour.   Interest in this connection between the microbiome and the brain has exploded in the scientific world.

We have known for a little longer that psychological and physical stressors can affect both the composition and functional activity of our gut microbiome.  Now more is understood about the bidirectional communication system between the central nervous system and the gut.  In other words, your gut changes your emotional state and other related brain systems, and your brain changes your gut.  Most of us have experienced butterflies in our stomach in response to stress, or even diarrhoea from performance anxiety.  Our feelings, moods, and cognitive sharpness, are dictated as much by our microbiome as by what we think of as our brain.  This gives us a window of opportunity for change.  Keeping a highly diverse colony of species within, and an intact functional gut lining, mirroring our blood brain barrier, is essential for our mental well being.

We now know that the majority of neurotransmitters are made in the gut, and even the neurotransmitters made directly in the brain are a response to signalling from the gut.  Gut microbes generate serotonin, dopamine, and GABA which promote our emotional health, calm, focus, drive, and good quality sleep.  Eighty per cent of melatonin, which optimises sleep, is made in the gut.  So if we are not sleeping well but cannot identify any particular stressors, it is worth thinking about what we eat.

In practice, common complaints are of sleep difficulties, anxiety, depression, and physical tension. Serotonin is the most generally well known neurotransmitter, regulating our moods and sleep, and 95% of our serotonin is made in the gut.  Too little and we suffer loss of healthy functioning, and often compensate by eating carbs, or medicating with alcohol.  If we eat the wrong, pro-inflammatory foods we can play havoc with our gut flora.  An inflamed gut creates an increased stress response, increasing cortisol (our stress hormone) levels.  Inflammation will shunt the precursor to serotonin, tryptophan, to other anxiety provoking chemicals like quinolinate rather than serotonin and melotonin, guaranteeing mood issues and sleep disturbance.  Sleep is not simply a case of the brain switching off.   Rather, during sleep, the brain moves though a structured sequence of activities, essential for every aspect of our being.

So what can we do to help ourselves?  We can eat a high vegetable diet to help keep a diverse microbiome.  We can keep stimulants like caffeine and alcohol low.  Artificial sweeteners in low calorie drinks are highly destructive of our microbiome.  We can supplement our healthy diet with probiotics and fermented food and drinks like yoghurt, kefir, sauerkraut, and kimchi.  Probiotics can lower cortisol levels.  We can make sure to move as much as possible, even if we don’t take structured exercise. And we can make sure that we always eat some healthy sources of carbohydrate with our evening meal.  Why?  Because serotonin is made from tryptophan, with other co-factors.

Tryptophan in protein foods is not particularly abundant compared to other amino acids, and not particularly able to cross the blood brain barrier.  However, if we eat carbs with protein our body produces insulin, which will shunt other amino acids (not tryptophan), to the muscles, and allows tryptophan into the brain.  However too much insulin depletes serotonin, so as always, balance is important.   And of course, we focus on good carbs from vegetables, pulses, and non gluten grains.

For fine tuning your diet, we can test your microbiome and also the balance of your neurotransmitters.  By our food choices, we can support our mental health and wellness, and literally help to eat ourselves happy.

Monday, 21 May 2018

BANT video

My professional body, the British Association for Nutrition and Lifestyle Medicine (BANT) has produced a short (2.5 minutes) new video outlining the work of nutritional therapists.  You can access the video here :

Tuesday, 27 March 2018

Gut Matters

Has there ever been a more confusing time to make dietary choices, with new and conflicting advice issued on an almost daily basis.  Should we become paleo or vegan?  Or perhaps we should do the 5:2, intermittent fasting, or time restricted eating.  Does red meat give us cancer or doesn't it?  Should we count calories or practice caloric restriction?  Which is better - butter or margarine?  How can we find out exactly which foods we should be eating and which avoiding, to support our health?

Fortunately we can follow a science based approach and focus on our gut microbiome, the collection of bacteria that live in our gut, and today one of the most heavily studied fields in the life sciences.  Good mental and physical health begins in the gut, and is dependent on our own unique gut bacteria.  What happens in the gut doesn't stay in the gut, and affects us beyond digestive issues.  Our bacteria can influence our:

brain function
moods and mental health
immune system

If we want to improve our digestion, and every aspect of our health and well-being, the place to start is to look inside.  Most people think of our gut as a simple tube that processes our food.  Actually our gut possesses a highly complex nervous system that communicates directly with the central nervous system.  In fact there are 400 times more messages going "up" at any given moment than there are going "down".  The gut truly deserves it's name as the second brain as even the brain microbiome (yes, we do have one) derives from the gut microbiome, as bacteria are carried up by immune system cells.  This process is called the gut brain axis.  Ninety per cent of neurotransmitters, the chemical messengers that govern our mood, are made in the gut.  So our ability to think, feel, sleep, and our ability to cope with stress, is dependent on our own unique bacterial composition.  Emerging science gives us psychobiotics, probiotics that directly influence the production of neurotransmitters, which might be the antidepressants of the future as they can produce serotonin and GABA.  Good mental and physical health begins in the gut.

How can we influence this process for our health?  Nutrition is the first step as it is the single most important intervention.  However it is a double edged sword as out diet can also be a greatest source of inflammation.  Our diet directly influences, for good or bad, the types of bacteria that live in our gut.  Poor quality fats and high sugar and starches directly affect our bacteria, so junk foods can make us mentally as well as physically less healthy.

"You are what you you eat"  is a phrase that always rings true.  Sensible dietary advice - eat real food, not processed, and eat a wide variety, especially of vegetables.  Try to eat organic foods as chemically treated foods are not as friendly to our bacteria.  Also try to avoid gluten as it can damage the intestinal wall.  Eat plenty of prebiotics, the foods that feed our bacteria.  Good sources are:

Jerusalem artichokes
onions, garlic, leeks
bananas, best when unripe
flaxseeds, nuts, and seeds

In practice we can test your composition of bacteria.  I can then develop a tailored nutrition plan that is right for you, as well as suggesting specialised probiotics.  In the meantime you can nurture your microbiome by eating traditionally fermented foods - full fat organic yoghurt, kefir, sauerkraut, kombucha, miso, and kimchi boost our bacteria.  Our modern lifestyles have reduced the diversity of species that live in our gut, but there is growing evidence that eating these fermented foods can help.

Finally, lack of sleep and chronic stress can damage our bacteria.  So healthy lifestyle is important. Not enough good bacteria, or too many harmful species, can lead to chronic inflammation as well as digestive disturbances.

Every day we are learning more about our bacterial friends.  I look forward to what will be discovered next.

Monday, 27 October 2014

Green Smoothies

A study at Lund University in Sweden has shown that a drink containing spinach extract suppressed food cravings for sweets and unhealthy foods and also promoted weight loss in participants. Substances in spinach called thylakoids induced satiety hormones enabling better appetite control and the green drink before breakfast allowed the participants to feel more satisfied during the day.

We all know that we should be maximising our consumption of vegetables and fruits, but sometimes it is difficult to actually consume the sheer amount and variety that we need. Green smoothies are a great way to enjoy vegetable and fruits in quantity, flooding your body with the phytonutrients from plants. All plants produce phytonutrients as part of their normal metabolic activities and they make a huge impact on our health, reducing the likelihood of our developing chronic disease. Remember organic fruit and vegetables produce more phytonutrients than non-organic produce. Smoothies are different to juices. Juices can also provide you with intensive nutrition but all the fibre is stripped away. A green smoothie grinds up all the beneficial aspects of the plants with nothing lost. Try combinations of avocado, pears, spinach, apple, berries, kale or any other vegetables and fruit that you choose. Search the internet for recipes by entering green smoothies into a search engine and you will see many interesting combinations. They take only a few minutes to make and unlike juices don't have to be consumed immediately. My favourite at the moment is spinach, pear, kiwi fruit, ginger, tumeric and coconut water, with a squeeze of lemon added, but they can be made with any fruit or vegetables to hand. Try to keep a proportion of sixty per cent vegetables and forty per cent fruit.

Monday, 25 August 2014

Bulletproof Coffee

The idea of bulletproof coffee came into being from a traveller experiencing the rejuvenating effect of yak butter tea in Tibet. In our quest to get more healthy fats into our diets, we could try bulletproof coffee. Devotees have their coffee blended with 1-2 tablespoons of butter and 1-2 tablespoons of coconut oil. I tried it with a toned down version of 1 dessertspoon of butter and 1 dessertspoon of coconut oil blended into hot coffee and had to admit that it was delicious, if unusual. Another variation is one dessertspoon of coconut oil stirred into hot green tea – again unusual but palatable. I imagine it is a taste that grows with familiarity.