The blood sugar roller coaster

Roller coaster

I have talked about the problems that psychological stressors can have on immune system functioning before, but physical stressors can add to your stress burden – activating the same stress hormones, and in the long-term adding to increased inflammation and autoimmunity, and reduced ability to fight off infection. Worryingly, you may not even know that these things are stressing you out!

Swinging sugars leads to stress

Both high and low blood sugars are stressors. Our bodies work hard to keep the level of glucose in our blood between 4 and 7 mmol/l. Lower than that and we aren’t getting enough fuel to our brain, too high and we can cause damage to cells.

The damaged cells caused by high blood glucose lead to inflammation, which in turn, activates the stress response. Low blood sugars directly lead to the release of the stress hormones adrenaline and cortisol, which act to bring blood sugars back up into range.

As well as benefiting our immune system, having blood sugars in the ideal range for most of the time can help you have more energy and fewer energy slumps, you are less likely to keel over if you don’t get a snack at your normal time, and you may well sleep better – and that’s not to mention the knock on positive effects on hormone balance (think PMS), liver health, cardiovascular health, brain health, diabetes risk….

Does it sound worth it?

Do any of these symptoms ring true for you?

  • Your energy fluctuates throughout the day, often dropping off in the afternoon
  • You feel you need to snack or reach for caffeine to boost your energy
  • You wake in the middle of the night (often hungry)
  • It’s obvious to everyone when you need something to eat – and they all run for cover (hangry anyone?)
  • You get dizzy, shaky or irritable if you wait too long for lunch
  • You can’t see properly if you’ve not eaten for a while
  • Your ability to think is impaired if you skip meals

These are all signs that your blood sugars aren’t as balanced as they might be.

How is blood sugar regulated

The body keeps its tight control over blood sugar by using hormones as messengers. Blood glucose rises after you have eaten a meal containing carbohydrates. This rise is detected by cells in the pancreas, which respond by secreting insulin. Insulin opens channels on the outside of muscle and fat cells to enable glucose to get into the cells. This glucose is then transformed into either glycogen or fat molecules, which store the energy from glucose to be used at a later time.

Glucose also moves out of the blood into other tissues like the brain, the liver and the pancreas, as sugar levels in the blood rise, but this movement isn’t directly regulated by insulin. Insulin does have an effect on liver cells though. It encourages them to store glucose as glycogen, like the muscles. It also stops them from creating new glucose molecules (from glycogen and proteins). This makes sense, as if your blood sugar is already high you don’t want to keep pumping sugar in from the liver.

If blood sugar drops too low, another hormone called glucagon is secreted from the pancreas, and this increases blood glucose by mobilising the stored reserves of energy in fat tissue and the liver, so that they are converted back into glucose. As already mentioned, the stress hormones cortisol and adrenaline also act to raise blood glucose levels in a number of different ways, including making the fat and muscle cells less responsive to insulin (so less glucose is taken out of the blood by these cells).

What can go wrong?

If you eat too many fast-acting carbohydrate foods in one go (more information on that to follow soon), you may overwhelm the body’s capability to maintain blood glucose in its ideal range, and therefore experience a spike in blood sugar (the glucose gets into the blood faster than the insulin can work). If the sugar level goes too high it can make you irritable, tired and thirsty.

As your body is keen to resolve this situation, it continues to secrete insulin – but  this may then lead to your blood sugar dropping rapidly. As your blood sugar drops, you may feel tired, dizzy and hungry – your body craves carbohydrates as your brain is concerned your blood sugars will drop too low for it to function – and the fast-acting carbohydrate, biscuit snack you reach for could drive your sugars high again.

This is the blood sugar roller coaster. If you start your day with a high carbohydrate meal – like cornflakes – you can ride up, and then down. The 10am snack as you’re feeling hungry might start you going up again, only to crash before lunch. If you have a sandwich and crisps – up you go again – and then down at 3pm, when you reach for a coffee… And so it goes on.

This situation is exacerbated if you become resistant to the normal effects of insulin (which can happen if you are repeatedly exposed to large amounts of insulin or have large amounts of the stress hormone cortisol in your circulation), or if you are resistant to cortisol or don’t produce enough cortisol (1) (as might occur if you have been under chronic stress for a long time).

High blood sugars and insulin resistance

Regular high blood sugars and high insulin can lead to insulin resistance, a precursor to type 2 diabetes. Insulin resistance basically means that your muscle and fat cells ‘stop listening’ to the insulin – only responding when the insulin levels get really high.

When this happens, the range of blood sugar levels in your blood stream increases – you are able to ‘tolerate’ higher levels of sugar, before your fat and muscle cells open their doors to glucose. You can take a glucose tolerance test to see if this is happening to you, where your sugars are monitored after you drink a glucose-containing drink. Although this insulin resistance protects the heart, muscle and fat cells from having too much sugar entering them – it really isn’t great for the rest of the body – damaging the lining of the blood vessels, for example.

As your pancreas and liver absorb glucose without direct control from insulin, the sugar concentration in these cells will likely rise. In the pancreas, this excess sugar could damage those cells that you are relying on to secrete insulin – and so worsen the whole situation.

In the liver, this additional glucose can be converted to glycogen, but as the amount of glucose entering the liver increases, the conversion of glucose to fat also goes up. Eventually, you can end up with excess fat being stored in the liver, which causes a heap of other issues. The liver can also become insulin resistant – and this is a problem as it means that the liver might continue to create and pump out glucose, even when there is already a lot of sugar in the blood. If you have a high fasting blood glucose level, this suggests that your liver is becoming insulin resistant.

If I think this is happening – what now?

The first thing to think about is diet – as the amount and quality of carbohydrates in your diet can affect your blood glucose level. What you eat alongside those carbohydrates also matters – including healthy fats and fibre can help slow down the release of glucose into your blood stream. (More information to follow soon).

When you eat can also help improve insulin sensitivity. Reducing the window of time in which you are eating and drinking during the day, (2) and eating more of your calories earlier in the day, with lighter meals at night can help. (3)

It isn’t just as simple as that though. As the stress hormone cortisol makes you more resistant to insulin, it is important to identify and minimise sources of stress, which can come from psychological sources (more information here) or physical ones – for example: inflammation from infection, injury, immune responses to food or self-tissue, high blood pressure, or high blood sugars!

Gut bacteria can also affect how you respond to certain food, making things more complex still.

You can also improve your sensitivity to insulin through exercise. Taking a walk after meals is a particularly good way of lowering the peak of that rollercoaster ride… (4)

If you would like to find out more about what to do to help you balance your blood sugars, or which factors might be contributing to your symptoms of low energy, inflammation and autoimmunity, why not book in for a discovery call to find out how nutritional therapy could help you find some answers.



  1. Rhyu et al., (2019) Endocrinol Metab 34(2) pp.187-194
  2. Page, M., and Johnson, J. (2018) Trends in Endocrinology & metabolism 6, pp. 389-99
  3.  Sutton et al., (2018)  Cell Metabolism 27(6) pp. 1212-1221.e3 
  4. DiPietro, L. et al. (2013) Diabetes Care 36(10) pp.3652-8

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