Posts Tagged: Diabetes

Are you receiving me?

Receptors are message receivers located on the surfaces of cells, which initiate a sequence of changes in our bodies : for example, changes in the use of energy, tissue growth or the perception of pleasure and pain. These receptors receive hormones and neurotransmitters, which lock onto the receptors and trigger the event. When there is an excess of a certain hormone, first receptor resistance occurs and then the number of receptors decreases. There is some evidence that obesity is in part caused by a deficit in dopamine receptors. This leads the obese to overeat to achieve the level of satiety that normal individuals reach with less food. Bingeing raises the level of dopamine even higher, which leads to resistance and a ‘down-regulation’ of dopamine receptors, only worsening the craving problem. Genes may cause the initial problem and poor diet exacerbates it. Low levels of dopamine receptors are also found in alcoholics and drug addicts. Cocaine, or heroine, bind to the receptor, causing dopamine to accumulate since it no longer can get in.
While dopamine receptors are located largely in the brain, serotonin receptors are to be found all over the body – 80% are in other organs. Depression has been linked to low dopamine and serotonin receptor levels. Antidepressants can therefore make things worse in the long run since they temporarily raise the amount of serotonin in the body but this saturation decreases the number of serotonin receptors. In all these cases – depression, obesity and addiction – receptors react to excessive levels of hormone by becoming less sensitive to them.
The good news is we can also increase the number of receptors – for serotonin, dopamine and in the case of diabetes for insulin – since diabetes is caused by low levels of insulin receptors. Intense exercise, particularly on an empty stomach, resensitises receptors, and increases their number. In this way satiety from food and pleasure from life is more easily achieved. Fasting works in the same way. A decline in dopamine receptors is associated with ageing, but once again here is evidence a symptom of ageing can be reversed.
If we have enough dopamine receptors life becomes more than merely bearable. It is not just worth living, it becomes a source of fascination and adventure. Dopamine receptors enable us to max out on pleasure. Biology is not destiny and the decline associated with ageing is not inevitable. There is no quick fix, but a sustained exercise programme and calorie restriction can work wonders.
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Hunger is the natural state of man

Samantha is in a wheelchair. A few years ago she developed an open sore on her foot which would not heal. The infection restricted the blood supply and gangrene developed. To save her life doctors had to amputate her leg from the knee down. She can walk short distances on crutches, but is seriously overweight. She has diabetes, which was the cause of the open sore.

Hunger is a reaction in the body that has served us well since the dawn of time. It was an important survival mechanism for early man, prompting him to hunt and forage for food and ensure survival. Cyclical famines have been a prominent feature of societies since the dawn of agriculture. In fat times, food is consumed and broken down into the simple sugar called glucose, which serves as the life-sustaining fuel for those trillions of cells that constitute the human body. Some of this fuel is stored in the muscles and liver, but only enough to last several days. In lean times, with such limited fuel reserves, the body acts quickly to conserve energy. After just eight hours of fasting, the body begins to slow its metabolism — the rate at which it consumes energy. The heart pumps blood more slowly, and the body produces less heat – which is why we feel the cold more when we are hungry. At this point the gut sends us a signal : eat! eat! – an evolutionary kick in the pants to go out and hunt. Hunger is a natural response, meant to be a common occurrence, and is part of the body’s weight regulation mechanism or “energy homeostasis”, which depends on a balance between energy intake and expenditure. It is the natural state of the hunter. Early man learnt to live with hunger.

Those who have experienced long fasts report grinding hunger at the beginning, but after a few days a sudden surge of energy. This is when the body begins to burn fat rather than stored glucose; it is accompanied by a cessation of hunger pangs and often a feeling of euphoria – no doubt assistance from nature to help us get up and find that meal.

So hunger developed for societies where there was a real danger of starvation; but when limitless food supplies are available eating abundantly every time we feel hungry is not a good thing. It can lead to obesity and diabetes, scourges of modern life, the prevalence of which continues to rise sharply.

Hunger 2Restricting our calorie intake, allowing hunger and travelling through it – ‘feeling the burn’ – is an important part of staying ageless. When the metabolism slows, it produces fewer aging free radicals. Calorie restriction has been scientifically proven to extend life. There are ways to extend periods between meals – coffee, doing stuff, telling ourselves we will wait another hour or two. Eventually this should be extended to restricting the number of meals per day from three to two. There is nothing in human physiology which dictates three meals a day. After a while feeling hungry becomes a normal part of life. One of the wonderful things about us as human beings is we can get used to anything.

Hunger is the natural state of man. Let’s check it out.

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