HSW 45 – Shift Work Cognition with Emily Breese.

Healthy Shift Worker Podcast Episode:

Do you struggle with poor memory?  Perhaps you leave sticky notes everywhere as a reminder so that you don’t forget things?  Well if you work shift work, chances are you answered “yes” to that question and have experienced bouts of ‘forgetfulness’ thanks to your sleep deprived lifestyle.

In this episode I chat with Emily Breese, who is a PhD student from UK’s Open University, and is based in Milton Keynes, a town just outside of London, in the United Kingdom.  Emily is currently conducting a research study on some of the affects of shift work (including the disruption to our circadian rhythm, or sleep/wake cycle), and how this affects our cognitive function.

Emily is looking for shift workers to be a part this study, so if you’re interested in participating or wanting to learn more, contact Emily via the links below:

Email – emily.breese@open.ac.uk

Twitter – @emily_louise548

Leaky Gut and a Damaged Fly Screen:

What is the correlation, and why are shift workers prone to it?

Leaky gut.  It sounds like a weird phenomenon – and in a way it is.

Now the technical, more scientific way to describe leaky gut is intestinal permeability, and is when space between the cells within the intestine or tight junctions of the epithelium become wider, which allows food particles to enter into the blood stream.

This causes the body to raise an inflammatory response because these food particles do not belong there, and over time, can be a contributing factor to conditions like autoimmune disease.

How Does This Relate to Shift Workers?

Animal studies have shown that long term stress and nocturnal sleep deprivation, typically associated with shift work, impacts on our gastrointestinal health by altering the delicate balance of the gut microbiome or microbiota, which can lead to dysbiosis and an overgrowth of pathogenic bacteria.

This dominance of pathogenic bacteria, impacts on tight junction proteins called ‘occludin’, which help to keep the gut “sealed”.  It was also shown to be made worse when combined with a high-fat, high sugar diet, and alcohol.

Hmm.  Me thinks that sounds very similar to a shift worker’s diet …

The best way to describe “leaky gut” or intestinal permeability, is to liken it to a fly screen.

Yes, I know this sounds a bit odd, but just stick with me here.

You see, instead of having lots of tiny holes in your gut, a “leaky gut” has lots of large holes scattered amongst the little ones which allows food particles to enter into the blood stream.

Kind of like in the image above, although this fly screen looks like some almighty mosquito has broken through the net – lol!

In addition to circadian dysregulation, or the disruption to our sleep/wake cycle, nutrient deficiencies such a low levels of vitamin D, zinc and glutamine, can also be a contributing factor to leaky gut; along with ingestion of gluten which is found in wheat, barley, oats and rye; as well as the use of certain medications such as proton pump inhibitors, non-steroidal anti-inflammatory drugs (NSAIDs), and antibiotics.

How to Test for Leaky Gut?

To test for a leaky gut, or intestinal permeability, a Lactulose/Mannitol test is conducted through a pathology lab which involves taking a urine specimen in the morning, followed soon after by consuming a drink containing two non-meatbolized sugars called lactulose and mannitol.

Mannitol are small molecules that are readily absorbed by the intestinal villi, whilst larger molecules such  Lactulose are not.  The lab will measure how much lactulose and mannitol are excreted, and if leaky gut syndrome is NOT present, the large lactulose molecules should remain in the GI tract and thus test low in the urine. If the count is high in the urine, then it is possible that leaky gut may be present.

What Can You Do To Prevent Leaky Gut?

Taking care of your gut, or gastrointestinal tract has to be a priority whilst working 24/7, purely because you are more vulnerable to developing it, as a result of the disruption to your sleep/wake cycle.

When your gut is healthy, it remains “sealed” (as opposed to being “leaky”), thereby preventing toxins and waste from within the digestive tract from getting into the bloodstream, and spreading throughout the body.

Some dietary and lifestyle strategies to help prevent the development of leaky gut include:

  • consuming more whole-food, minimally processed foods which are made up predominantly of plant-based foods.  These foods are rich in fibre which are going to feed the good gut bacteria in your digestive tract.  They include whole grains, vegetables, fruits, legumes, nuts and seeds.
  • include more polyphenol rich foods – which are plant compounds that give many fruits and vegetables their bright colours, and are high in antioxidants and anti-inflammatory properties that are great for gut health.
  • consume more prebiotic rich foods – prebiotics are food for the good gut bacteria and are rich in fructooligosaccharides (FOS) and galactooligosaccharides (GOS).  These include garlic, onions, leeks, asparagus, Jerusalem artichokes, legumes and seeds.
  • avoid refined and processed sugars as the pathogenic bacteria or “bad bugs” love them, which will help them to multiply leading to an overgrowth in your gut!


Konturek, P, Brzozowski, T & Konturek, S 2011, ‘Gut clock:  Implication of circadian rhythms in the gastrointestinal tract’, Journal of Physiology and Pharmacology, vol. 62, no. 2, pp. 139-150.

NutriPATH Integrative Pathology Services 2013, Intestinal Permeability.

Voigt, R, Forsyth, C, Green, S, Mutlu, E, Engen, P, Vitaterna, M, Turek, F & Keshavarzian, A 2014, ‘Circadian Disorganization Alters Intestinal Microbiota’, PLoS ONE, vol. 9, no. 5.

Wang, S & Wu, W 2005, ‘Effects of psychological stress on small intestinal motility and bacteria and mucosa in mice’, World Journal of Gastroenterology, vol. 11, no. 3, pp. 2016-2021.

Shift Work, Insulin Resistance and Type II Diabetes:

Are You At Risk?


Over the last week or so I’ve been immersing myself in online library data bases, scrolling through randomised clinical trials and observational studies, trying to find a link between shift work, insulin resistance and type 2 diabetes mellitus or T2DM.

Why would I do such a thing you may ask?  Well I may be a little crazy, but it begins with the letter ‘L’ , which stands for Literature Review, and in my case, I have a 2000 word Literature Review due this weekend.  Fortunately for me, I was able to choose a topic which I’m quite passionate about – that being shift work health.

However I have to say, what I’ve found in the depths of those data bases wasn’t exactly pretty.

So let’s talk firstly about working the night or evening shift.  Studies have shown an increased risk of diabetes in nurses who worked nights or evening shifts, which can be explained by a variety of different mechanisms.

  1. Exposure to light at night leads to a decrease in the pineal release of melatonin, a strong antioxidant which plays a key role in the synthesis, secretion and action of insulin.  A reduction in melatonin has been associated with an increase in insulin resistance which over time, can lead to Type 2 Diabetes Mellitus or T2DM.
  2. Persistent circadian stress as a result of disruption to the normal sleep/wake cycle, is common in night shift workers which may cause excessive secretion of cortisol (a stress hormone) and interleukins (proteins which are involved in the immune response).  These two things combined, along with an increase in insulin concentrations can lead to the build up of abdominal fat, lipid disorders and insulin resistance.
  3. Working nights are often accompanied by changes in lifestyle, such as changing mealtimes which alters the timing of insulin response.

OK, now let’s talk about rotating shifts(more…)