26 July 2011

Diet and exhaustion

Are you always tired? DietDoc discusses some of the physical causes that may underlie chronic fatigue and the role that dietary changes can bring about.


Are you always tired? DietDoc discusses some of the physical causes that may underlie chronic tiredness and the role that dietary changes can bring about.

I often receive questions from readers who complain that they suffer from extreme exhaustion and want to know if dietary factors can improve their condition. “I have been exhausted for most of my life and struggle to get up in the morning. What supplement can I take to give me some energy?” is a typical cry for help.

A multifactorial problem

Individuals who are chronically fatigued, who have no energy and have to drag themselves out of bed in the morning, need to keep in mind that exhaustion is a multifactorial condition. There are so many different physical and psychological factors that can make you feel exhausted that it is vital to have a full medical examination as a first step in trying to counteract this debilitating condition.

Today, we will consider some of the physical causes that may underlie chronic tiredness and the role that dietary changes can bring about. 

Physical causes of exhaustion

Typical physical conditions that can cause exhaustion, include:

  • Malfunction of the thyroid gland

Both hypothyroidism (lack of thyroid hormone) and hyperthyroidism (overproduction of thyroid hormone) can make you feel exhausted. A blood test and physical examination for goitre will identify if your tiredness is related to over- or underactive thyroid function. Your medical doctor will advise what treatment is required to either increase thyroid hormone levels in the case of hypothyroidism or reduce overproduction of thyroid hormones if you suffer from hyperthyroidism.

From a dietary point of view, it should not be necessary to take iodine-containing supplements such as kelp, because all the table salt sold in South Africa is already fortified with iodine. In fact, taking additional iodine if you have a thyroid problem may make the condition worse. For example, a patient with an enlarged thyroid due to hypothyroidism who takes iodine supplements may stimulate the thyroid to grow so large that some of the tissue may have to be removed by surgery.

  • Malfunction of other glands

Under- or overproduction of any one of the many hormones (including sex hormones) our bodies produce, can cause tiredness. In such cases, the doctor will have to identify if you have an imbalance of a specific hormone and provide the necessary treatment. For example, women who no longer produce oestrogen after the menopause, may find that they are constantly tired and lack the energy they had when their ovaries were still manufacturing sufficient oestrogen. The decision if a woman should take hormone replacement therapy (HRT) or use homoeopathic remedies such as soy-derived oestrogens, yam extract or black cohosh (to name but a few non-pharmacological treatments), has to be carefully discussed with the treating doctor of gynaecologist.

  • Anaemias

The two most common types of anaemia which can cause patients to become so exhausted that they can no longer function, are iron-deficiency and vitamin B12-deficiency anaemia. A blood test to determine blood iron and body ferritin levels will identify if a patient is suffering from iron-deficiency and also indicate the severity of the deficiency.

Some patients may be so severely iron-deficient that they require intravenous iron treatment, while most patients will respond well to an oral iron-folic acid supplement. It is important to remember that it takes time to replenish depleted body iron stores and you may have to take your iron-folic acid supplement for 3 months or longer to start feeling more energetic.

The following foods are rich sources of easily absorbable iron: liver, red meat, fish, egg yolk, poultry, iron-fortified breakfast cereals, iron-fortified maize meal and wheat bread, and certain dried fruits (raisins which still contain their pips). Having a glass of orange juice or half a grapefruit with your breakfast cereal or maize meal porridge will help your body absorb the iron more easily thanks to the vitamin C content of the citrus fruits.

Vitamin B12-deficiency is also determined by blood tests and can be treated by using a vitamin B12 supplement or eating foods derived from animals such as liver, meat, fish, eggs, poultry and dairy products. Some patients also need to take a supplement that contains the so-called intrinsic factor. The latter is a specific binding protein that is found in stomach secretions. Intrinsic factor binds vitamin B12 and helps to transport it into the body. Individuals with an intrinsic factor deficiency or pernicious anaemia, have to take a supplement that contains both vitamin B12 and intrinsic factor. 

  • Blood sugar level problems

Of all the tissues in the human body, the brain has the highest requirement for a constant supply of glucose. Low blood sugar levels due to hypoglycaemia can produce symptoms of extreme tiredness, constant yawning and lack of concentration.

Low blood sugar levels can be due to:

  •  an inadequate diet: (eating too little to sustain blood sugar levels or skipping meals, particularly breakfast, so that blood sugar levels drop to very low levels, or eating too little carbohydrate, or the wrong kinds of carbohydrate such as high-glycaemic index (GI) carbohydrates that overstimulate insulin production which then in turn makes blood sugar levels plummet)
  • reactive hypoglycaemia (a tendency to produce too much insulin)
  • insulin resistance (a condition where the body produces insulin, but the body cells are resistant to the hormone and cannot receive the glucose they require to produce energy)
  • type 1 or insulin-dependent diabetes mellitus (which is characterised by the inability of the pancreas to produce insulin)
  • type 2 or non-insulin-dependent diabetes mellitus (caused by gradual loss of pancreatic insulin productive capacity after many years of insulin resistance, unbalanced dietary intake, obesity or metabolic syndrome).

Patients who suffer from any one of the above mentioned blood sugar level problems may constantly feel tired because their brains and body tissues are starved of glucose.

Your medical doctor will arrange for you to have a glucose tolerance text (GTT) to determine if you do have problems with your insulin levels and to pinpoint which one of these conditions is responsible. Type 1 diabetics are usually treated with insulin, while type 2 diabetics and some patients with insulin resistance will require treatment with antidiabetic medications such as sulphonylureas, acarbose or metformin.

In most cases of blood sugar level irregularities, the correct diet can play a vital role to normalise these conditions. Overweight patients who lose weight with diet and exercise usually achieve excellent improvements in their blood sugar levels and can often reduce  medication doses. Even a loss in weight of as little as 5% can have a dramatic impact on blood sugar problem-related conditions and associated chronic tiredness.

A low-fat, low-GI diet is usually prescribed to help normalise weight, as well as blood sugar and insulin levels. It is essential for all patients who suffer from true hypoglycaemia, insulin resistance, and types 1 and 2 diabetes, to consult a registered dietician because you need an individual diet prescription that is tailored to your unique needs and condition. Being told to “Cut out all sugar and carbs!” is not helpful and will certainly not improve your problem or your tiredness. So if possible, make an effort to consult a dietician if your doctor has diagnosed that you have a blood sugar problem. Visit the Association for Dietetics in SA website and click on "Find a Dietician" to find a dietician in your area, who will advise you how to apply the low-fat, low-GI diet.

Next week we will consider some other causes of chronic exhaustion that can benefit from dietary interventions.

- (Dr IV van Heerden, DietDoc, July 2011)

Any questions? Ask DietDoc

Read more:

Diet and exhaustion - Part 2
Anaemia and diet
Thyroid problems and diet
The glycaemic index

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