"My experience is that chronic hypoglycemia is a very common cause of fatigue in CFS sufferers," writes Dr. Sarah Myhill, MD, a UK-based CFS specialist focused on nutrition, preventive medicine, and patient education. This article is excerpted from Dr. Myhill’s book – Diagnosing and Treating Chronic Fatigue Syndrome – available in pdf format at her website (DrMyhill.co.uk).* It reflects her experience treating more than 4,000 patients with CFS over the past 20 years – many of whom also have Fibromyalgia.
It is critically important for the body to maintain blood sugar levels within a narrow range. If the blood sugar level falls too low, energy supply to all tissues, particularly the brain, is impaired. However, if blood sugar levels rise too high this is very damaging to arteries and the long term effect of arterial disease is heart disease and strokes – this is probably caused by a local reaction in periarteriolar fat [fat around the tiny arteries called arterioles], resulting in release of proinflammatory cytokines causing damage to arteries. [Proinflammatory cytokines are signaling chemicals involved in amplifying inflammatory reactions.]
Normally the liver controls blood sugar levels. It makes the sugar from energy stores inside the liver and releases sugar into the blood stream minute by minute in a carefully regulated way to cope with body demands, which may fluctuate from minute to minute. This system of control works perfectly well until we upset it by eating the wrong thing. Eating excessive sugar at one meal, or excessive refined carbohydrate, which is rapidly digested into sugar, can suddenly overwhelm the liver’s normal control of blood sugar levels.
We evolved over millions of years eating a diet that was very low in sugar and had no refined carbohydrate. Control of blood sugar therefore largely occurred as a result of eating this Stone Age diet and the fact that we were exercising vigorously, so any excessive sugar in the blood was quickly burned off. Nowadays the situation is different – we eat large amounts of sugar and refined carbohydrate and do not exercise enough in order to burn off this excessive sugar. The body therefore has to cope with this excessive sugar load by other mechanisms.
When food is digested, the sugars and other digestive products go straight from the gut in the portal veins to the liver, where they should all be mopped up by the liver and processed accordingly. Excessive sugar or refined carbohydrate overwhelms the liver, which simply cannot mop up the amount of sugar which is there and the sugar spills over into the systemic circulation. This results in high blood sugar, which is extremely damaging to arteries.
If one were exercising hard, this would be quickly burned off. However, if one is not, then other mechanisms of control are brought into play.
The key player here is insulin, a hormone excreted by the pancreas. This is very good at bringing blood sugar levels down and it does so by shunting the sugar into fat. There is then a rebound effect and blood sugars may well go too low. Low blood sugar is also dangerous to the body because the energy supplied to all tissues is impaired. It is when the blood sugar is low that this is called hypoglycemia.
Subconsciously, people quickly work out that eating more sugar alleviates these symptoms, but of course they invariably overdo things, the blood sugar level then goes high, and one ends up on a rollercoaster ride of blood sugar going up and down throughout the day.
SYMPTOMS OF HYPOGLYCEMIA
The problem is that when the blood sugar is high people feel “normal,” indeed maybe slightly boosted by this high level of blood sugar. This is because they have good energy supply to their muscles and brain, albeit short-term. The problem arises when blood sugar levels dive as a result of insulin being released and energy supply to the brain and the body is suddenly impaired. This results in a whole host of symptoms.
The brain symptoms include:
n Difficulty thinking clearly,
n Feeling spaced out and dizzy,
n Poor word finding ability,
n Foggy brain and sometimes even blurred vision or tinnitus.
The body symptoms include:
n Suddenly feeling very weak and lethargic,
n Feeling faint and slightly shaky,
n Rumbling tummy and a craving for sweet things.
The sufferer may look as if they are about to faint (and indeed often do) and have to sit down and rest. The symptoms can be quickly alleviated by eating something sweet – if nothing is done then the sufferer gradually recovers. These symptoms of hypoglycemia can be brought on by missing a meal (or one’s usual sweet snack top up such as a sweet drink), by vigorous exercise or by alcohol. Diabetics may become hypoglycemic if they use too much medication.
When blood glucose levels fall for any reason, glycogen stores in the liver may be mobilized to prop them up. The trouble is that these are probably already rather poor in people with increased carbohydrate intake, where insulin is relied on heavily.
Another rapid and very effective way in which the body repletes the low glucose is by hepatic [liver] conversion of short chain fatty acids to glucose. In a healthy person on a good balanced diet the only time this is of importance is during the night because of the long break between food intake. Short chain fatty acids are then used to prop up circulating glucose and prevent a fall below whatever that person’s usual fasting glucose level is.
Short chain fatty acids are made in the gut by bacteria fermenting fiber (and such starch as escapes small intestinal digestion). Production is maximized from about 3 hours after food intake. That is to say, short chain fatty acids are highly protective against the dips we see in blood sugar. [As indicated below, they have no effect on blood sugar and are the preferred fuel of the cells’ energy producing mitochondria.]
Therefore, a key symptom of a hypoglycemic tendency is disturbed sleep. This occurs typically at 2 or 3 a.m., when blood sugar levels fall and there are insufficient short chain fatty acids to maintain a blood sugar. Low blood sugar is potentially serious to the brain, which can only survive on sugar and, therefore, there is an adrenalin reaction to bring the blood sugar back, but this wakes the sleeper up at the same time.
TEST FOR HYPOGLYCEMIA
Measuring blood sugar levels is not a terribly useful test for hypoglycemia, partly because they fluctuate so much and partly because by the time one gets the symptoms of hypoglycemia, the blood sugar levels have started to correct. A much better test would be to measure short chain fatty acids in blood collected in the morning before breakfast. The test should be done as follows: It is important to continue your usual diet – indeed, there are no special dietary instructions for the test, but the blood sample must be taken between 9 and 12 hours after a meal….
There is a final twist to the hypoglycemic tale which complicates the situation further. When one becomes stressed for whatever reason, one releases stress hormones in order to allow one to cope with that stress. Insulin is such a stress hormone and has the effect of shunting sugar in the blood stream into cells. This produces a drop in blood sugar levels and also causes hypoglycemia.
Therefore, hypoglycemia can be both a cause of stress and the result of stress, indeed, another one of those vicious cycles that are so often seen in disease states.
TREATMENT OF HYPOGLYCEMIA
Treatment is to avoid all foods containing sugar and refined carbohydrate. The problem for the established hypoglycemic is that it may take many weeks or indeed months for the liver to regain full control of blood sugar, and therefore the symptoms of hypoglycemia may persist for some time whilst the sufferer continues to avoid sugar and refined carbohydrate.
This means that when you change your diet you will get withdrawal symptoms and it may take many weeks of a correct diet before these symptoms resolve. This type of addiction is very much like that which the smoker or the heavy drinker suffers from.
n One needs to switch to a diet which concentrates on eating proteins, fats, and complex (and therefore slowly digested) carbohydrates.
n Initially I suggest doing a high protein high fat diet, but include all vegetables (care with potato), nuts, seeds, etc.
n Fruit is permitted but rationed, since excessive amount of fruit juices or dried fruits contain too much fruit sugar for the liver to be able to deal with. I suggest one piece of fruit at mealtimes.
n I now consider taking high dose probiotics an essential part of controlling low blood sugar. [Probiotics are dietary supplements containing potentially beneficial bacterial cultures intended to assist the body’s naturally occurring gut flora to reestablish themselves.] This is because probiotics ferment carbohydrates to short chain fatty acids – these have no effect on blood sugar and are the preferred fuel of mitochondria. The best and cheapest way to do this is to brew your own – see section on probiotics. Probiotics also displace yeast, which worsens the hypoglycemia problem.
n With time the regime can be relaxed, but a return to excessive sugar and refined carbohydrate means the problem starts again.
n Finally, many sufferers of hypoglycemia may need something sweet to eat immediately before and during vigorous exercise, until the body learns to fully adapt.
n Hypoglycemia is usually accompanied by micronutrient deficiencies. You should also take nutritional supplements.
My experience is that chronic hypoglycemia is a very common cause of fatigue in CFS sufferers.
To tackle hypoglycemia one needs to do a diet based on foods of low glycemic index (GI). The GI is a measure of the ability of foods to raise one’s blood sugar levels. Sugar (that is, disaccharides) have arbitrarily been given a GI of 100. High GI foods are the grains (wheat, rye, oats rice etc), root vegetables (potato, sweet potato, yam, parsnip), alcohol, sugars, and fruits, dried fruits and fruit juices. But expect to see withdrawal symptoms which can persist for weeks. [For more detailed lists of foods with no carbohydrate content and with low, medium, and high GI measures (which also depend on quantity consumed), see "Low Glycemic Index Diet – What to Eat On It" at http://www.drmyhill.co.uk/article.cfm?id=353. ]
WHY SUGAR AND FAST CARBS ARE SO BAD FOR
ENERGY LEVELS – A POSSIBLE EXPLANATION
Yudkin, et al. explains all in the Lancet, May 2005: Too much sugar in muscles is very damaging to muscles. The arterial control of the blood supply to muscles is by tiny collar of fat which wraps itself round tiny arteries (arterioles). If the blood sugar rises, this collar of fat releases a cytokine which makes the arteriole contract.
This has the metabolically desirable effect of preventing too much sugar getting to muscle and damaging it. However, the blood supply to the muscle will be impaired as well, so the muscle cannot work properly. Also the cytokine released by the fat causes inflammation and damages the arteriole wall. This is also probably the basis of high blood pressure and arterial disease.
And don’t forget – in CFS we see high levels of cytokines. The general presumption is that these come from immune activity as a result of viral or toxic stress. BUT they could be produced by fat cells as a result of too much carbohydrate in the diet!
Source: ”Vasocrine” signalling from perivascular fat: A mechanism linking insulin resistance to vascular disease,” JS Yudkin, et al., Lancet 2005: 365:1817-20 http://www.immunesupport.com/library/showarticle.cfm?id=8169
* This material is reproduced with permission from Dr. Myhill’s patient-information website (http://www.DrMyhill.co.uk). It is featured on pp. 46-48 in her free 179-page online book – “Diagnosing and Treating Chronic Fatigue Syndrome”. R Sarah Myhill Limited, Registered in England and Wales: Reg. No. 4545198.
Note: This information has not been evaluated by the FDA and is not meant to prevent, diagnose, treat, or cure any illness, condition, or disease. It is essential that you make no decision about additions to or changes in your health support plan or regimen without first researching and discussing it in collaboration with your professional healthcare team.