The mother of all hormones

When the subject of hormones comes up, most of us think in terms of themale and female hormones, testosterone and oestrogen. Some of us even take tablets to replace what our doctors feel we lack in these hormones. But we tend to ignore, or remain completely ignorant of, what scientists term the Mother of all hormones - DHEA.

What is DHEA?

DHEA is an acronym for the hormone produced by our adrenal glands known as

dehydroepiandrosterone (dee-hydro-epi-an-dros-ter-own). It is often called the

'Mother of all hormones' since it is the building block used by the body to produce many other vital hormones. These include the sex hormones (oestrogen and testosterone) as well as important steroid hormones. They play a vital role in mineral metabolism, building muscles, controlling stress, maintaining male and female characteristics and keeping the body strong and full of vitality.

Research has shown that the level of DHEA in the body is directly linked to the aging process, since the body produces less of the hormone with age.

Dozens of scientific studies have proved a direct relationship between a low DHEA level and cancer, head disease, diabetes, high cholesterol, Parkinson's disease, obesity, osteoporosis, Alzheimer's and multiple sclerosis. One of the long-term studies involving 5 000 women found that DHEA levels fell drastically up to nine years before the development of breast cancer.

Low levels of DHEA can lead to depression, chronic fatigue, headaches, weakness and an elevated susceptibility to infections caused by viruses or bacteria. Its effect on the immune system has led researchers to believe that DHEA may play an important role in fighting AIDS.

Studies have shown that the body's production of DHEA starts to drop sharply from the age of 30 to very low levels at age 80. This is the largest decline of an important biochemical yet documented.

Directly after birth the brain uses so much DHEA for growth that the levels decline dramatically. As the brain approaches its final development stage, the levels once again increase. In a 12-year study of 240 men aged between 50 and 79 years, researchers found that DHEA levels were inversely correlated with mortality, from heart disease as well as from other causes.

DHEA production varies widely from person to person. Some people seem to maintain youthful levels into later life while others seem to become deficient in DHEA at a young age. Chronic illness and major stress at a younger age, deplete the hormone more rapidly.

Research indicates that DHEA:

• plays a major role in protecting brain neurons from senility-associated disorders such as Alzheimer's and dementia and improves memory function;
  

• increases natural hormone levels, and therefore the libido, necessary for a healthy sex life;
• strengthens the immune system;
• plays an important role in preventing heart disease by helping to lower cholesterol;
• allows insulin to function more efficiently, thereby normalising blood sugar levels and reducing the risk of insulin resistance and/or diabetes;
• is an anti-ageing hormone in that it acts as a buffer against stress-related hormones, in particular cortisol, which damages the body and causes destruction of tissue -the main cause of rapid ageing;
• actively helps the body burn kilojoules for energy rather than storing them as fat.

How can DHEA did weight loss?

Simply by controlling your stress levels as explained in the chapter Stress can make you fat! Stress is a major contributing factor to obesity as well as most of the other auto-immune diseases. Because of the drastic decline in DHEA as we grow older, the body loses its buffer against stress-related hormones, particularly cortisol. To summarise the stress cycle:

• while experiencing emotional stress, adrenaline and eventually cortisol flood the blood stream with excessive levels of glycogen,
• which requires insulin to make it available as energy for the muscle cells;
• however, as a result of long periods of undue stress, coupled with a diet rich inrefined carbohydrates such as white flour and sugar, the body tends tobecome insulin resistant,
• which means the insulin cannot make the glycogen in the blood available as energy, so the blood sugar levels remain unduly high,
• and because high glycogen levels are extremely dangerous, the blood sugar is then stored as fat on the body, in unusual places such as around the stomach area, on the upper arms, back, neck and face.

The process is simple to understand: undue emotional stress for long periods of time + high levels of adrenaline and cortisol + high levels of blood sugar + insufficient or inefficient insulin = body fat + a plethora of auto-immune diseases.

The answer to your spiralling, chronic obesity might therefore be to control your stress levels, which will then cause your weight to be controlled so much more readily. Clinical studies have concluded that DHEA levels are inversely related to cortisol, which means that as cortisol increases, DHEA levels decrease.

Supplementation with DHEA will help your body by acting as a buffer against cortisol and the obesity-promoting chain reaction it evokes.

The GI of food: How low should you go?

Just as all kilojoules are not equal, so all carbohydrates are not equal. Extensive and in-depth clinical trials and studies over the past decade or so have brought about what has become known as The Glucose Revolution, which also happens to be the title of a world best-selling book by Australians Professor Jennie Brand-Miller, Kay Foster-Powel and Dr Anthony Leeds.

Carbohydrates always used to be regarded as the main reason for obesity. Regrettably that theory has remained stuck in the minds of many people in the medical profession and slimming industry and to this day many dieters are following low-carbohydrate diets - much to their detriment, as you know.

Well, here is what every dieter should know about starch: forget all that tripe you were taught and start eating your starches, but eat them wisely. Eat mainly starches with a low GI (Glycaernic Index).

The GI of food indicates the way it scores according to its effect on your blood sugar levels. Carbohydrate foods that are rapidly converted to glucose during the digestive process and therefore rapidly increase your blood sugar (glycogen) levels, have high GI values. Carbohydrates that break down slowly, naturally release their glucose into the bloodstream at a slower rate, therefore raising blood sugar levels at a slower rate. At the school we call this the 'carbo speedometer'. Of all foods, refined sugar (sucrose) and glucose have the highest GI, namely 100. All other foods are rated on a scale from 0 to 100 according to their effect on the blood sugar levels, or to put it plainly, the rate at which they drip into your bloodstream.

Much has been said about the incredible weight-loss benefits of the so-called Mediterranean diet. The popular belief is that it works so well because of the good fats found mainly in the olives and the oily fish prescribed in this diet. Yes, that is true. However, the other main reason for its success seems to have been overlooked. In fact, it is probably the most important reason why it is such an effective, healthy and delicious diet - it also offers loads of (and mainly) low GI starches. That includes beans, pulses and pasta to name but a few, Paradoxically, the one flaw in this diet is the fat: too much of the 'good' fat can make you as fat as bad fat does. And on this diet you are allowed to consume far too much of that lovely good fat! Just think of those tables groaning with tappas and antipasti.

That diet aside, following a low GI eating plan will, in my opinion, be the very best you can do for your weight loss efforts, mainly because of the way in which you are able to manipulate and control your blood sugar levels and consequent insulin production.

The main benefits of low CI foods

• They cause a gradual rise and fall in blood sugar levels, thereby causing lower insulin levels, which makes it easier for fat to be burnt and less likely to be stored.
• They assist in lowering blood fats.
• They are more bulky and are therefore more satisfying.
• They reduce the risk of diabetes and heart disease.

How do you determine the GI of FOOD?

There are no exact GI values available. In order to arrive at the average GI value of specific foods, various repetitive tests are done. Volunteers involved in the tests are exposed to six stages of testing. One might therefore find the values to differ somewhat from one reference source to another. I have used various sources, which makes the list below as representative of those averages as possible. But in general, the steps listed here are the most commonly used way in which the GI of food is determined.

During a test, a sample of blood is taken from a person who does not have diabetes and then he/she is asked to eat an amount of food containing 50 g of carbohydrate. (As a mailer of interest, that amount of carbohydrate is equivalent to 45 ml of pure glucose powder.) A 200 g portion of cooked spaghetti, for instance, will provide 50 g of carbohydrate, equal to 45 g of pure glucose.

During the first hour after the consumption of the carbohydrates, a sample of blood is taken every 15 minutes and for the following hour, every 30 minutes. The blood is analysed and blood sugar levels are measured and recorded in a laboratory. These levels are plotted on a graph, which will indicate the rate at which they rise.

The volunteer's blood sugar response to each particular kind of food is measured against the response to 50 g of pure glucose -the reference food.

The reference food is tested similarly on two or three separate occasions on the same person and from those readings an individual average value is calculated. This is done to minimise the effect of any daily variation in blood sugar responses.

The same tests are carried out on 8 to 10 different people, using the same kind of food as reference. Thereafter the overall average GI of that particular food is calculated.

Following is a list of the average GI values of our most popular and commonly eaten carbohydrates, to be used as a guide. Although all foods have GI values, those of carbohydrates are what affect us most; more so than protein, fat or dairy products and for that matter, most low-carbohydrate vegetables. Those foods in general have very low GI values and I see no point in including them on the list.

Experts advise that it is best to eat those carbohydrates with a GI below 55 at least 80% of the time. The list is therefore in ascending order to make your choices easier.

What is worth knowing at this point is that although a combination of certain foods can lower the overall GI of a meal or a snack, fat remains the danger zone for your weight and your health. Eating a croissant, for instance, will result in a slower rise of your blood sugar than any other kind of wheat-based bread, because the croissant contains loads of butter, which slows down the GI of the wheat flour, whereas ordinary bread does not contain much fat. Similarly, eating a fat-free baked potato will produce a faster rise in blood sugar levels than fat-rich potato crisps or chips would. But in these instances the harm done by the fat literally outweighs the lower GI and unfortunately the fat that goes with the croissant and the chips will soon attach itself to your hips, rendering your careful plans to eat low GI foods utterly fruitless.

The ideal way is to eat mostly low GI foods with a low fat content. That will slim you down faster than any diet you've ever been on Guaranteed.

Unlike the popular myth that fruit makes you fat because of its sweetness, fruit in general actually has a low GI value. It therefore combines well with high GI cereals. Although fruit is sweet, it contains fructose - pure fruit sugar. Compared to sucrose (refined sugar), it is the preferred sugar when you want to slim and be healthy. I urge you to use fructose in all your beverages and foods that need sweetening. It has a low GI value and is all round much better for your health than sucrose. You can buy it from most chemists, health stores and supermarkets (where you will find it on the sugar or health product shelves). If your local suppliers don't stock it, ask them to order it for you. Demerara (raw) sugar is your natural second choice. The latter resists heat better than fructose does, so its ideal for baking. However, demerara also has a GI of 100, so use it as the exception rather than the rule.

Dairy products in general have low GI values (artificially sweetened, low-fat yoghurt has a GI of 14) and so they combine well with high GI breads and cereals to slow down the overall rate of such a meal or snack. A good example of this kind of combination would be white bread with fat-free cottage cheese, tomato and herbs. The overall GI of that snack will be lower, and so -thank goodness -will be the fat content. If you added butter and/or cheddar cheese to the bread, you would also slow down the overall GI, but at the expense of your fat intake and your weight loss efforts,

Vegetables and protein foods such as meat, fish and chicken also have generally lower GI values. They therefore combine well with high GI carbohydrates in order to reduce the overall GI value of the meal in which they are combined.

But remember, foods that slow down the overall GI of a meal do not justify an overload of fat. Which means that fat, oil, fatty meat, buffer, cream cheese and solid cheeses such as cheddar remain firmly within the 'be cautious' zone!

How fibre affects the body continue...

Appendicitis

Appendicitis is inflammation of the appendix, the small blind-ended tube at the beginning of the large bowel. Although the underlying causes of appendicitis are not clearly understood, there is evidence that regular intake of fibre may prevent the development of the disease.

Hiatus hernia, varicose veins and piles

Many doctors believe that abdominal straining due to constipation encourages the development of conditions such as hiatus hernia (where the top of the stomach is pushed upwards, out of the abdomen and into the thoracic cavity), varicose veins and haemorrhoids (piles). It is often necessary to have surgical treatment for these conditions. Treating constipation with high fibre diets and, as a result, avoiding straining, may prevent these problems and may even reduce the need for more drastic treatment in some cases.

Coronary heart disease (CHD)

Coronary heart disease is the most common cause of death in affluent Western countries (see page 151). A large number of factors influence the development of the disease, of which raised blood cholesterol levels, high blood pressure and hypercoagulability (the tendency of the blood to clot too easily) are probably the most important.

Researchers believe that high-fibre, low fat diets protect against CHD by lowering blood cholesterol and probably also by decreasing blood pressure and the clotting ability of blood. It is especially the water soluble or gel-forming dietary fibres - found in oats, legumes and some fruit and vegetables - which help to lower cholesterol levels. While it should be borne in mind that diet is but one of the many factors which influence the development of CHD, it is also one of the controllable ones.

Diabetes mellitus

There are two forms of diabetes mellitus, a disease characterised by the excretion of glucose (sugar) in the urine (see What is diabetes? on page 175). Both forms are today treated with a high carbohydrate, high fibre, low fat diet. Fibre in the diet normalizes the body's response to dietary carbohydrate (glucose tolerance). A regular high intake of dietary fibre also improves insulin function by increasing the sensitivity of muscle and fat cells to the hormone.

Gallstones

The body manufactures these crystalline substances when the amount of cholesterol in the bile is so high that the bile salts cannot keep it in solution. The stones may block bile ducts between the liver and gall bladder or between the gall bladder and small intestine, resulting in severe pain and even jaundice. As in the case of other diseases of affluence, a number of factors may contribute to the development of gallstones. It has however been shown that high fibre intakes stimulate the production of those bile salts which keep cholesterol in solution, thus decreasing the risk of gallstone formation. Populations who follow high fibre diets have a significantly lower risk of the disease than those on the average refined Western diet.

To what degree is fibre involved?

Although research has proved that dietary fibre has a positive effect on body functions in general, the degree to which it is involved in the risk and development of the above diseases is still unclear. Studies are hampered by the fact that a variety of causes play some role and also because high-fibre diets differ in more than one respect from low-fibre ones. For example, they usually have a lower fat content - especially saturated fatty acids from food of animal origin - and are higher in vitamins and minerals. These factors could add to the beneficial effects seen in people who eat a high-fibre diet.

What is diabetes?

Diabetes is a disorder in which the pancreas cannot produce enough insulin, a hormone which prevents blood sugar levels from rising too high, or in which the insulin that has been produced does not function properly. It does this by helping body cells to take up glucose - either to metabolise to energy or to store as glycogen or fat.

If an individual manufactures too little insulin, there are two possible forms of treatment: The young, more severely affected diabetic can only survive if given daily injections of insulin for the rest of his or her life. However, if diabetes develops at a later age, treatment with pills is usually effective. These pills are not insulin; they are essentially compounds which give the pancreas the necessary stimulus to produce more insulin to cope with the carbohydrate (sugars and starches) which the individual eats. Because sugar causes a dramatic rise in blood sugar levels, diabetics should obviously avoid it in their diets; indeed, they should avoid all unnecessary food in general if they are overweight, as not only is the insulin requirement related to food intake, but excess weight has an aggravating effect on the condition. Obese diabetics who develop the disease in later life can often be treated by diet alone.

A low fat, high fibre intake - which 'dilutes' the contents of the digestive tract - slows down the passage of glucose into the blood stream and hence the elevation of the blood sugar is less dramatic.