Sugar is the primary source of fuel to power our bodies.  Failure of sugar delivery to our body cells results in hyperglycaemia (high blood sugar) that accelerates ageing and damages body tissues, causing vision loss, kidney failure, increased risk of heart attack and stroke, loss of sensation and blood supply to the limbs, often leading to leg amputation. 

In this blog, we will review the negative effects of high blood sugar and how it damages various body tissues, accelerates ageing, and changes body shape and function.  How to detect and fix the problem early.  And briefly touch on sugar addiction and cravings and how to avoid or abort them.

After a meal, sugar is absorbed into the bloodstream and distributed to every cell in your body.  The pancreas produces insulin to open the gate for sugar to enter.  Failure of delivery occurs when your body cells become less sensitive to the action of insulin.  The hungry cells prompt the pancreas to produce more insulin to overcome the blockage.  This works for a while, delivering enough sugar to the cells and keeping blood sugar within the normal range.  The pancreas burnout and then loses its ability to produce more insulin, and the blood sugar rises and stays permanently high.

High blood sugar damages the body by a process known as glycation (rusting).  Glycation means glucose bonds with body proteins or fat, forming a compound known as Advanced Glycation End-products (AGEs).  This causes permanent damage to blood vessel lining and blood cells and often triggers inflammation in vital organs, such as the lungs and kidneys.

The extent of damage can be estimated by the routine test haemoglobin A1C, which measures the amount of red blood cells damaged by glycation.  Since the red blood cells’ lifespan is 3 months, the test reflects your blood sugar control over that time.

Sugar is not the lone cause of glycation; food preparation also plays a role.  Browning or darkening food to enhance shape or flavour also causes glycation damage.  Fried, grilled, or roasted food contains high levels of AGEs.

Glycation begins in early adult life and continues at a varying rate to damage the skin and hair, giving skin wrinkles and grey hair and accelerating the ageing process.

How Sugar Damage Your Body

High blood sugar causes glycation damage of essential proteins and cells in blood necessary for the immune system function, which obviously put us at risk of infection and frequent illness.

High blood sugar causes vision loss.  It damages the lens protein causing opacification and cataract formation.  It also damages the blood vessels in the eye resulting in retinopathy.  This usually appears as white patches of infarction (damage due to loss of blood supply) or red patches of bleeding at the back of the eye (retina) and is a common cause of blindness in the UK.

The kidneys preserve blood sugar up to a certain limit. When the blood sugar exceeds the renal threshold, too much sugar pass through the kidney.  Damaging the kidney blood vessels and the filtering units results in loss of kidney function. This eventually leads to chronic end-stage kidney failure and the need for regular dialysis.

High blood sugar is known to cause nerve and blood vessel damage in limbs. Peripheral neuropathy (loss of sensation) and reduced blood supply may result in simple foot ulcers, gangrene and acute ischaemia, a common cause of limb amputation.

Chronic back and neck pain is common in people with a sugar problem.  Fluctuations in blood sugar initially result in back and neck muscle tension and spasm.  High blood sugar later causes oxidative damage (rusting) and spine osteoarthritis.

Depression is a common manifestation of poor blood sugar control.  Fluctuating in blood sugar, with energy spikes and crashes, lowers serotonin, the happy hormone, and brain drive neurotrophic factor (BDNF), the anti-depressant factor.

Every time your blood sugar plummets, cortisol kicks in to boost the blood sugar level for brain use.  Sugar dips and spikes can break down into a series of stress responses, which often cause or exacerbate anxiety.

Hyperglycaemia can also result in headaches, migraine, and premenopausal symptoms (PMS).

You may be surprised that cortisol is not only the stress hormone (its actual name is a glucocorticoid, which means the hormone that regulates blood sugar).  Sugar problems can tax the adrenal gland, resulting in adrenal fatigue.  Signs of adrenal fatigue include fatigue, difficulty getting up in the morning, fluctuating energy during the day, which typically improves in the evening, sugar and salt cravings, and caffeine dependency.  The fatigue often progresses to adrenal exhaustion, characterised by a lack of interest in the surroundings, depression, restlessness, dizziness, and low blood pressure.

Adrenal overactivity with high cortisol can exert negative feedback on the pituitary (master gland) in the brain, which also stimulates the activity of the thyroid gland and gonads (ovary and testicles). High cortisol slows down messages in the motorway that stimulate these organs—creating a state of underactive thyroid with a slow metabolism, cold intolerance, and weight gain.  It can also stop the menstrual cycle (amenorrhea) in ladies due to the negative effect on the gonads.

Detective work to discover the sugar problem early

People at risk of hyperglycaemia include those who are obese or overweight, lead a sedentary or stressful lifestyle, smoke or drink alcohol in excess, have high cholesterol, suffer sleep apnoea, have a family history of diabetes, and, in the case of ladies, have had gestational (pregnancy) diabetes or delivered a large baby (over 9Ib) or have infertility issues.

People with genetic variants like bitter taste and insulin sensitivity genes prefer sugar and sweet tastes over healthy food options.  Genetic testing will help to make these people aware of taking precautions to avoid the damaging effect of hyperglycaemia.

Diabetes is the highest level of the sugar problem, even though 80% of affected people are unaware of the condition.  Thus, 50% of diabetics present for the first time with serious complications, such as a heart attack or stroke.  This may be too late for many.  Don’t let it be too late for you.  Keep an eye on yourself, as prevention is obviously better than cure.

What symptoms should you look out for?

Sugar problems can start with fluctuating blood sugar levels – you may feel strange, get brain fog, feel sleepy after a meal, or experience a major afternoon slump.  You may frequently feel hungry.  You may wake up at night and not get back to sleep.  You may start shaking, sweaty, and light-headedness through low blood sugar (hypoglycaemia).

Taking sugar and fast carbs in your evening meal can result in hypoglycaemia between 1 and 3 am.  Cortisol kicks in to top up your blood sugar levels.  Cortisol is the day hormone, while melatonin is the night hormone.  A cortisol surge at night, therefore, interferes with your sleep.

High sugar and processed carbs consumption put you on a sugar rollercoaster.  Once the cycle starts, it’s hard to stop.  Big dips usually follow Big sugar spikes.  This is debilitating to the extent of making the affected person think of nothing but where the next dose of sugar is coming from.

Persistent hyperglycaemia is usually accompanied by symptoms of dry mouth, feeling thirsty and drinking water to excess (polydipsia.)  Your body will be working hard to push sugar out in your urine, meaning frequent urination (polyuria) but also symptoms of fatigue (low energy due to hungry cells), blurred vision and headache.

How does a sugar problem alter your body shape?

You can usually spot people with sugar problems because they have unique body features like a pot belly, gynaecomastia (man boobs), buffalo hump (fat at the back of the neck), skin tags and acanthosis nigricans – dark spots on the skin.  I saw these first on my own skin before I learned about them in medical school.  The spots can appear in your armpits, the back of your neck, and in skin creases and scars.

You get gynaecomastia due to apparently low testosterone and high oestrogen.  The rise in sex hormone binding globulins (SHBG) that bind to testosterone leaves only a small amount of it as effective free testosterone.  In addition, aromatase, an enzyme produced in fat tissue, converts testosterone into oestrogen to enhance breast tissue development.  This is also aided by the slow detoxification of oestrogen due to fatty liver.

The adrenal gland works very hard to maintain a steady blood sugar level, often breaking your muscles into sugar to top up the blood level.  Again, cortisol transports energy stored as fat in the midbody section.  So, your sugar problem results in a pot belly and inconsistently slim limbs.

The healthy body stores excess energy around the hips giving the individual a pear shape.  The unhealthy body stores fat around the belly – the apple shape.  Belly fat surrounding vital organs is more dangerous and increases your disease risk.

How would you know if you have a problem?

The body mass index (BMI) is the most common test or tool used to assess risk.  It is easy to do, measuring your weight and height using a BMI calculator.  You will likely have a sugar problem if your BMI falls into the obese or overweight range, you will likely have a sugar problem.

Because muscles are heavier than fat, athletes, particularly bodybuilders, will always have a high BMI without being obese.  In this case, a high BMI would not increase the disease risk.

BMI is the most widely used measure of obesity, but WHR (waist-to-hip ratio) is more accurate in predicting the risk of cardiovascular disease.  Your WHR (waist-hip ratio) should be less than 0.90 in men and less than 0.80 in women.

Your waist circumference is a more realistic assessment of your disease risk than weight and BMI.  A circumference of more than 40 inches in men and 35 inches in women puts them at high risk of developing obesity-related conditions.  This can be used as a screening tool but is not diagnostic of body fatness.

The routine lab work to confirm the sugar problem

If you want to check earlier how efficient your body is at dealing with sugar, a blood sugar test 2 hours after a meal (or 75g of glucose) is more appropriate.  Two hours after a meal, a normal level would be below 7.8 mmol/L (140 mg/dl).

Healthy people in the UK have fasting blood sugar levels between 4.0 mmol/L (72 mg/dl) and 5.4 mmol/L (97 mg/dl).  Studies have confirmed that a level below 4.7 mmol/L (85 mg/dl) is associated with low disease risk.  The disease risk starts to escalate gradually from 4.7 mmol/L.

A fasting blood sugar level between 6.0 mmol/L (108 mg/dl) and 6.9 mmol/L (124 mg/dl) reaches a prediabetic level.  Like diabetes, this increases your risk of diabetic complications such as heart attack and stroke.  A level of 7.0 mmol/L (126 mg/dl) and above is diagnostic of diabetes.

A ‘snap’ blood sugar test like this is helpful, but a cumulative one is more accurate, reflecting your blood sugar control over the last three months.  Haemoglobin A1C (HbA1C) test returns a reading of less than 5.5 in normal people, 5.5 to 6.4 in prediabetes, and 6.5 and above in people with diabetes.

Continuous Blood Glucose (CBG) monitoring at home is an effective non-invasive new technology to monitor your blood sugar, giving you a practical experience of the effect of food and other lifestyle habits on your blood sugar and helping you to make good choices to keep a steady blood sugar within the normal range most of the time.

Sugar addiction & craving

Sugar is addictive, triggering the release of the reward hormone, dopamine, which makes you feel great.  According to research, sugar is more addictive than cocaine!

Cocaine users develop tolerance with overuse, and they must increase their dosage.  The same happens with sugar.

Craving is the intense desire for specific foods.  Besides sugar, people can crave spicy and savoury food, coffee, chocolate, and ice cream.  Men crave savoury foods, whereas women crave fatty and sweet foods more frequently during pregnancy.

Common causes for cravings include dehydration and mineral deficiency.  When your craving kicks in, a glass of water would be a good idea.

How to prevent the craving

  • Enjoy 7 to 8 hours of restful sleep at night.
  • Have a loving relationship, enough sunshine and vitamin D.
  • Manage your stress and practise stress-relieving techniques.
  • Eat protein (plant or animal) with every meal to settle your appetite.
  • Avoid fast carbs such as potatoes, bread, pasta, pizza, and white rice.
  • Avoid eating fast food and drinking commercial juices, high in HFCS.
  • Eat healthy fats, including omega 3 in oily fish, avocado, nuts, and seeds.
  • Take enough B vitamins, chromium, magnesium, and zinc to produce energy.
  • Eat more magnesium-containing foods, such as nuts and seeds.
  • Sweeten your food with spices like cinnamon that do not contain sugar.
  • Apple cider vinegar makes your cells more sensitive to insulin and lowers cravings.

Simple steps to abort sugar cravings

  • Chew a piece of gum to reduce your craving.
  • Drink a cup of herbal tea, a glass of water or fresh, unsweetened lemon juice.
  • Eat a healthy snack like avocado, seeds and nuts, or dip celery or cucumber in hummus.
  • A good portion of kale can abort an irresistible craving episode.

Real whole food makes glucose available for your body cells to make more energy to optimise your vitality, while the energy-dense food in the Western diet diverts more glucose for storage as fat.

You can prevent or reverse sugar problems by adopting a healthy diet of real food, losing 5 to 7% of your body weight, and exercising regularly.

So, my friends, you can see how the sweetness of sugar can have bitter consequences for your health.  But there are straightforward ways to avoid, abort or reverse high blood sugar and sugar cravings.  As always, please ask any questions in the Comment section below – and please subscribe to the newsletter so that you don’t miss further vital information.  Thank you!



What causes food cravings?

Cravings sugar? Your body is probably lacking this nutrient

Blog: blood sugar control the key to metabolic health

Blog: all about metabolic flexibility

Normal body mass index can rule out metabolic syndrome

What is glycation and how can it age your skin?

International Diabetes Federation. The IDF consensus worldwide definition of metabolic syndrome. Brussels. 2006.