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Newsletter - Sugar, Gut health and Brain Health

Date: 2021

Hello, and welcome to the FAB Research newsletter.  We hope you’re well, and may have been able to enjoy at least some time off over the summer.

In this issue, we highlight new research into the effects of high-sugar diets, including their adverse impact on gut health, as well as studies of the links between gut and brain function, which continue to generate some remarkable findings.  As ever, the evidence points to a key role for nutrition and diet, as well as other ‘lifestyle’ factors, in mental as well as physical health and wellbeing.

Sugar – yet more bad news

First, new findings on the damaging effects of excessive sugar intakes on the brain and body just keep on coming.

A recent review in the Chinese Medical Journal explains how fructose is metabolised – and why this sugar (rather than glucose), can cause so many different health problems, including obesity, Type 2 diabetes, heart disease, fatty liver disease, and gout, among many others:

As they emphasise, these metabolic disorders develop when fructose is consumed in excess – as it is in modern, western-type diets (dominated by ultra-processed foods and drinks containing added sugar or high-fructose corn syrup). The quantities released when digesting whole fruit do not cause similar problems.

Even newer findings since that review– just published in ‘Nature’ - add yet more evidence to the case against fructose.  They show that this particular sugar causes changes to the gut lining that actually increase the absorption of nutrients and dietary fats – helping to explain the well-known links between excessive fructose intake and both obesity and many cancers.  

This evidence is all consistent with what Professor Robert Lustig (author of the recent book ‘Metabolical’) – and other scientists allied with the campaign group Action on Sugar - have been saying for many years. And what the leading UK scientist John Yudkin flagged decades ago in his pioneering book ‘Pure, White and Deadly’...  (as did the distinguished medical doctor T.L. Cleave decades before that).

Today, the topic of ‘Sugar and Addiction’ still remains one for academic debate, but ‘withdrawal effects’ on trying to quit sugar have been reported in at least some human studies, and are very well documented in animals.

Sugary foods and drinks can also be craved (or just used) as a ‘quick fix’ for low energy levels.   However, new research shows high sugar diets can actually reduce energy levels – by changing the fat profile of membranes in the mitochondria that produce cellular energy.  (Excess sugar generates saturated fats that displace the polyunsaturated fats needed for these membranes to work efficiently). See:

Gut health and brain health

Other ways that excess sugar can damage health concern its effects on the gut. Broadly, in addition to their effects on metabolism, sugary foods and drinks can feed ‘bad’ bacteria and yeasts (displacing ‘good’ ones), promote inflammation, and increase intestinal permeability (known as ‘leaky gut’), raising risks for allergies and auto-immune diseases, as this recent blog article explains:

The trillions of gut microbes that we each host play fundamental roles not only in digestion and immune health, but also our brain development and function.

In the last 10-15 years, research into the importance of the so-called ‘gut-microbiota-brain axis’ has exploded, with findings linking gut microbial imbalances to stress, anxiety, depression, autism and schizophrenia spectrum disorders and some neurological disorders, including dementia. Some of the newest findings have led to very striking headlines, such as:

Like most studies showing clear causal effects of gut microbes on brain function and behaviour, however, these findings come from pre-clinical (animal) studies. And this clearly limits what can be concluded from them, as one of the leading experts in this field explains more fully here:

He and his world-leading team have also just reviewed the latest evidence on the role of the gut microbiota in myelination – critical both for developing and maintaining connectivity of cells in the brain and nervous system across the lifespan.

Diet has a major influence on the gut microbiota. So these findings all reinforce the importance of (1) eating a wide range of vegetables, fruits, whole grains and other whole, unprocessed foods, and traditonal fermented foods, and (2) minimising intakes of sugar and ultra-processed foods to promote gut health

Medications and Microbes

Many other ‘lifestyle’ and environmental factors can influence gut microbial health and balance - including some common medications.  By their very nature, antibiotics are obviously high among these, as their use can damage ‘good’ as well as ‘bad’ bacteria – but other medications too can have a significant impact.

Recent research has highlighted more potential downsides from the (over-)use of antibiotics than those already well-known - such as antibiotic resistance, and their potential to promote obesity.

In pregnancy and early life, new evidence suggests that these drugs may influence infant brain development (perhaps not surprising in view of the research just discussed above).

And in adults, a large and rigorous population study shows that antibiotic use significantly increases risks for inflammatory bowel diseases like Crohn’s Disease and Ulcerative Colitis, which involve auto-immune damage to the gut lining.

Obviously, however, use of antibiotics is often unavoidable. And when this is the case, the challenge is then to find the best ways to restore a healthy balance of gut microbes – as this article discusses:

More recent FAB News and Research articles can be found below - and on our website. 

We hope you’ve found something of interest to you in this month’s news round-up.  We’d love to hear from you with ideas for topics you’d like us to cover in future newsletters / webinars / blogs - and with any other feedback. 

Likewise, if you have any suggestions on how we could support you further, or help others you care for or work with, please let us know.


Other latest news

AI reveals how glucose helps the SARS-CoV-2 virus

  • This unique study, using artificial intelligence to summarise the huge recent literature on risk factors for COVID-19, found that elevated blood glucose appears to help virtually every step of the COVID-19 viral infection - from its onset in the lungs, through to severe complications such as Acute Respiratory Distress Syndrome, multi-organ failure and thrombotic events.

Increasing your risk of Inflammatory Bowel Disease (IBD) through processed food

  • In this interview, News-Medical speaks to Dr Neeraj Narula about ultra-processed food and how this can increase your risk of developing inflammatory bowel disease (IBD).

Harmful body fat not only increases your waistline, but also your risk of dementia

  • Increased body fat incrementally leads to increased atrophy (loss) of grey matter in the brain - and consequently higher risk of declining brain health, according to the latest research.

Distinctive gut microbiome unrelated to diet may characterize children with autism

  • This study shows for the first time that the gut microbiota of children with autism is abnormally developed and lags that of age-matched peers.

Fatty liver more common in children of mothers with obesity

  • Children and young people whose mothers had a BMI over 30 during early pregnancy have an increased risk of fatty liver disease.  With obesity rates higher than ever in women of child-bearing age, more and more young people are at risk of developing fatty liver disease, the researchers say.

Review suggests vitamin K2 may help prevent Alzheimer’s

  • Vitamin K2 has the potential to slow the progression of Alzheimer's disease and contribute to its prevention, according to the authors of this review. They present a strong theoretical case, along with some supportive scientific evidence, but also acknowledge that direct evidence of causality is still needed.


Latest Research

Please help us to keep helping you

We’ve several new FAB projects in preparation for launch in the Autumn or New Year – (subject to the availability of our staff, volunteers and other resources, as effects of the ongoing pandemic continue to make accurate predictions difficult). These include:

FAB Podcasts, Talks and Webinars

  • Let us know what topics you’d be most interested in hearing about in this way
  • We can also provide speakers for educational events and/or staff training that your organisation may be organising, for public professional or academic audiences

Our FAB speakers panel includes many of the world’s leading researchers and professionals working in the area of nutrition and diet, and its effects on mood, behaviour and learning.

Please get in touch if you’d like more details.

The ‘FAB in Schools’ Project  

The first findings from our new ‘FAB in Schools’ project show that it IS indeed possible to help young children increase their choices of healthier foods to a level where both parents and teachers noted significant improvements in their children’s behaviour and learning.

This initial 3-month pilot study (though not primarily designed to show cause-and-effect) involved over 900 children aged 7-9 years, and used a simple educational programme delivered by teachers that encouraged the children (and their parents) to make healthier selections by improving their understanding of which foods to choose or avoid.  

We are now looking for volunteers to help with further pilot testing as we develop this into an online programme to benefit more children and schools – and interested parents.

We would also love to hear from any volunteers with skills and experience in any of the following areas - or from organisations who could donate either staff time, or funding:

  • Admin and Project Management
  • Computers and IT / Online Data Management
  • Marketing and/or Fundraising
  • Copywriting and E-publishing

We’ll have more details from this first pilot project to share with you next month.  

Meanwhile, please get in touch with us if you think you could help in any way: we’ll be very grateful for any additional assistance.


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As we all know, emails can be easily missed or lost - so you can also find back copies of recent FAB newsletters on our website here.

Thank you again for your interest and support.

With best wishes,

The FAB Research team