Blood sugar highs and lows

I’m sure you’re at least a little familiar with the cycle of blood sugar rushes and crashes that might keep you reaching for the biscuit bowl or chocolate drawer. We’ve been brought up to believe we need to eat sugar for energy, so that’s what we do. What has become increasingly clear however, is that too much sugar, and the impact on how your body regulates blood sugar, can make energy worse in the long term.

What is more, there are now strong links between problems with balancing blood sugar and chronic disease, including heart disease, diabetes and Alzheimer’s disease.

So, what is blood sugar?

We hear doctors, nutritionists and magazines talking about blood sugar all of the time, but what actually is it? And why do you need to keep it in balance?

When you eat foods containing carbohydrates – such as pasta, bread and rice, as well as root vegetables, beans, lentils, fruit and more – your digestive syste breaks them down, mostly into glucose.

This glucose then passes through your intestinal wall into your bloodstream. It has now become blood glucose, or blood sugar.

Your blood keeps glucose flowing around your body so that it is ready and available, together with the oxygen you inhale, when any part of you needs it to make energy. This might be certain muscles when you want to walk, smile or breathe; or nerves that want to send a message between your brain and your gut, lungs or heart.

You can make energy from fat and protein, too, but the most common source is carbohydrates.

How your body keeps blood sugar in balance

Your body is an infinitely clever and fascinating thing. It knows that keeping blood sugar just right is important, so it has several ways it does this:

  • your body continually measures blood sugar, and assesses it against your current needs
  • you then produce hormones, such as insulin and glucagon, that help direct where glucose goes

If your blood sugar is too high:

  • insulin will attach to insulin receptors on the cells that need it, and open the gates to allow glucose in
  • if you still have more glucose than you currently need in your blood, your liver will remove the excess as the blood passes through
  • your liver then converts some glucose to glycagen, which is like popping it in a storage jar in the cupboard so it’s ready to release if blood glucose gets too low
  • if there’s still any excess sugar, it gets converted to fat and sent to live in your fat cells, which are like warehouses for long term storage
  • your fat cells will also release a hormone called leptin that makes you want to eat less

If blood sugar is too low:

  • a hormone called ghrelin is produced in your stomach, and this makes you want to eat more
  • the glucagon from your pancreas tells your liver to convert glycagen back into glucose and release it into your blood
  • if there’s still not enough, then your fat cells will release some of their stores to be burnt as fuel
  • if necessary, glucagon can also instruct your body to make glucose from other nutrients, such as protein (e.g. from your muscles)

What happens if you keep eating too much sugar?

The short answer: inflammation and damage to your blood vessels, nerves and kidneys. Plus potential life threatening illnesses, such as obesity, hypertension, diabetes, heart disease and cancer[1] [2], as well as Alzheimer’s disease.[3]

Insulin receptors are like very selective doormen on the surface of your cells: they’ll shake hands with insulin, listen to their message  (to allow more sugar in and pass it on to your cell), but completely ignore everyone else. They can get overwhelmed, however, if there is too much insulin queuing up and trying to be heard too much of the time – perhaps due to a high sugar diet – and start ignoring the insulin as well. We call this insulin resistance, and it’s bad news on a number of levels. In simple terms, we end up with high levels of circulating insulin (not being listened to), and long term high blood sugar levels, which can eventually cause the damage described above.

At the same time, your leptin receptors in your brain can also become resistant, which means that even as fat cells build up, your appetite stays high.

Does it matter what kind of sugar/carbohydrates you eat?

Yes, it does.

For a start, eating carbohydrates in a more complex form – such as wholegrains – will stress out your insulin pathways less than eating lots of sugar in sweets and refined carbohydrate. In fact, a 2015 study of children on a high sugar diet showed that replacing almost 2/3 of their sugar with starch – so a more complex carbohydrate – had a beneficial effect on insulin sensitivity.[7]

Complex carbohydrates are  generally broken down to glucose, but sugary foods often also contain a different kind of sugar called fructose. Such as the regular cane sugar you might put in your tea or use in baking, the natural sugar in fruit, the many different types of syrups (maple syrup, rice syrup, agave syrup etc.) and the sugars used sweets, fizzy drinks, processed foods, convenience foods, breakfast cereals, sauces, pickles and so on. And some of these contain particularly high levels of fructose, including sweeteners used in the food industry, and the agave syrup sold as a supposedly healthy alternative.

The problem with fructose

The thing about fructose is that you process it in your body differently to how you process other sugars. To begin with, it’s absorbed differently in the small intestine. Then much of it is carried to the liver where most of it seems to join a factory production line for triglycerides, i.e. fat.

These triglycerides are then put into a little carrier and are transported in the blood as VLDL (very low density lipoproteins), which has been associated with increased levels of inflammation in the blood vessels, which means a greater risk of cardiovascular disease.[10]

While all this is going on, fewer leptins are triggered, and more ghrelin, a major appetite stimulator, so you’re more likely to want to keep on eating beyond what you actually need, or is healthy.[11]

A large number of studies have connected high fructose levels with higher levels of obesity, insulin resistance, high blood pressure and other markers for cardiovascular disease.

But isn’t fructose a healthy fruit sugar?

Fructose is indeed the sugar you find in fruit, alongside glucose and sucrose. When you eat an apple or some berries, you are consuming fructose, together with a spectrum of vitamins, minerals and phytonutrients that support your digestion, metabolism and overall health – plus fibre, which seems to reduce the impact too.

We’ve known for years that fruit juice usually spikes insulin more than the whole fruit, and blood sugar drops less after absorption. Appetite is satisfied for longer with whole fruit too.[17]

So how can you help your body keep blood sugar in balance?

There are many levels on which you can do this, and you may benefit from some more than others. Here are just a few of the things that might help:

  • Work towards keeping your sugar intake low
    Before the food industry was invented, our natural sugar intake would have fluctuated with the availability of fruit, and would rarely been in a refined form. We would probably have got more carbohydrates from starchy roots and tubers, and maybe small amounts of grains. The only way to get back to this is to cook everything from scratch using seasonal whole foods. It may be an interesting journey to get to this, that needs extra support reducing your sugar cravings – we’ll talk about this more in future blogs and workshops.
  • Include a good portion of protein in your breakfast
    Studies are increasingly showing this to help keep blood sugar levels stable throughout the day
  • Manage stress levels and give your adrenals support
    If your adrenals and their stress hormones are overworked, then this will eventually impact your pancreas and its blood sugar regulating hormones
  • Keep your liver happy
    This isn’t just about reducing alcohol. You may also want to think about levels of pesticides in your foods, pollution in your environment, highly processed and damaged fats in your diet, your work and stress load, and unresolved issues involving anger, resentment and frustration, for example.
  • Keep hydrated
    Everything in your body needs water to work well. If you’re having a blood sugar dip, sometimes a glass of water can make all the difference. While having a sugary snack might keep you a quick boost, but that can then put pressure on your insulin pathways, and keep you on a cycle of sugar rushes and crashes.

You may also benefit from supplements such as magnesium and chromium to help keep blood sugar in balance, and natural anti-inflammatories such as turmeric, cinnamon (which also balances blood sugar) and zinc.

Plus there is a lot more you can address through what you eat, how you eat and how you live your life.

To find out more, come to our Bloom Weekend Retreat on Sugar:

Nutrition & Holistic Cookery
for Balancing Blood Sugar, Calming Sugar Cravings and Easing Inflammation
July 8th-9th @ The Loxdale English Centre, Portslade Village, East Sussex





[1] Gerald M Reaven, Role of Insulin Resistance in Human Disease, Diabetes December 1988vol. 37 no. 12 1595-1607

[2] Muntoni SMuntoni SDraznin B., Effects of chronic hyperinsulinemia in insulin-resistant patients, Curr Diab Rep. 2008 Jun;8(3):233-8.

[3] Talbot, Konrad et al. “Demonstrated Brain Insulin Resistance in Alzheimer’s Disease Patients Is Associated with IGF-1 Resistance, IRS-1 Dysregulation, and Cognitive Decline.” The Journal of Clinical Investigation 122.4 (2012): 1316–1338. PMC. Web. 11 Nov. 2015.

[4] A. Christine Könner, Jens C. Brüning, Selective Insulin and Leptin Resistance in Metabolic Disorders, Vell Metabolism, Volume 16, Issue 2, 8 August 2012, Pages 144–152

[5] Meghana D. Gadgil et al, The Effects of Carbohydrate, Unsaturated Fat, and Protein Intake on Measures of Insulin Sensitivity, Diabetes Care May 2013 vol. 36no. 5 1132-1137

[6] Penny M Kris-Etherton, Monounsaturated Fatty Acids and Risk of Cardiovascular Disease, Circulation.1999; 100: 1253-1258

[7] Lustig, R. H., Mulligan, K., Noworolski, S. M., Tai, V. W., Wen, M. J., Erkin-Cakmak, A., Gugliucci, A. and Schwarz, J.-M. (2015), Isocaloric fructose restriction and metabolic improvement in children with obesity and metabolic syndrome. Obesity. doi: 10.1002/oby.21371

[8] Nishan S. Kalupahana, Naima Moustaid-Moussa, Kate J. Claycombe, Immunity as a link between obesity and insulin resistance, Molecular Aspects of Medicine, Volume 33, Issue 1, February 2012, Pages 26–34

[9] Richard D Feinman and Eugene J Fine, Fructose in perspective, Nutrition & Metabolism 2013 10:45

[10] Welty FK. How do elevated triglycerides and low HDL-cholesterol affect and atherothrombosis? Curr Cardiol Rep. 2013 Sep;15(9):400.

[11] George A Bray, How bad is fructose? Am J Clin Nutr October 2007 vol. 86 no. 4 895-896

[12] George A Bray, How bad is fructose? Am J Clin Nutr October 2007 vol. 86 no. 4 895-896

[13] Michael Alderman; Kala J. V. Aiyer, Uric Acid: Role in Cardiovascular Disease and Effects of Losartan, Curr Med Res Opin. 2004;20(3)

[14] Lustig, R. H., Mulligan, K., Noworolski, S. M., Tai, V. W., Wen, M. J., Erkin-Cakmak, A., Gugliucci, A. and Schwarz, J.-M. (2015), Isocaloric fructose restriction and metabolic improvement in children with obesity and metabolic syndrome. Obesity. doi: 10.1002/oby.21371

[15] Richard D Feinman and Eugene J Fine, Fructose in perspective, Nutrition & Metabolism 2013 10:45

[16] Richard D Feinman and Eugene J Fine, Fructose in perspective, Nutrition & Metabolism 2013 10:45

[17] R P BoltonK W Heaton and L F Burroughs, The role of dietary fiber in satiety, glucose, and insulin: studies with fruit and fruit juice, Am J Clin Nutr February 1981 vol. 34 no. 2 211-217

[18] Jaroslawska, J., Wroblewska, M., Juskiewicz, J., Brzuzan, L. and Zdunczyk, Z. (2015), Protective effects of polyphenol-rich blackcurrant preparation on biochemical and metabolic biomarkers of rats fed a diet high in fructose. Journal of Animal Physiology and Animal Nutrition. doi: 10.1111/jpn.12321