There are some people who have a heart attack or heart disease, yet they don't have a 'high' cholesterol level or 'high' blood pressure. They are lean, active and have never smoked. How can that be?
We are all different in various ways. Our genetic makeup, which is set in place at conception, to a large extent determines how we behave. Our behaviour leads to internal changes and our body, in turn, responds to those changes. Although some of our body's responses are genetically controlled, we can influence how our body responds by changing our behaviour.
Food intake does not always influence weight
We all know of people who can eat large amounts of food and never become fat. Others are the opposite. Overweight people seem to:
- Absorb the foods better than thin people
- Store calories more efficiently (as fat)
- Burn up less calories (by being less active, less demonstrative, less fidgety, less excitable).
Maybe overweight people will survive best when a famine comes! We are fortunate to live in a place and time where famine is not an issue. This is one reason why we are all becoming bigger and fatter than our ancestors.
Fat and cholesterol
Some people can eat large quantities of saturated fats and still have a low cholesterol level (the metabolic qualities of a wolf). Others seem able to produce a high cholesterol level from even a small fat intake (the metabolism of a rabbit). Most of us can manage a moderate amount of fat in the diet. We can eat almost anything without adverse affects (we have metabolisms similar to pigs).
Salt intake – the effects are different
Some people who use excessive salt end up with high blood pressure. Many others don't react this way; they can handle excessive salt intake because they lose the excess salt in their urine and sweat without a rise in their blood pressure.
Smoking doesn't always cause heart disease
Some people appear to be able to smoke throughout their life without developing diseased arteries before they die of lung cancer or emphysema. Their arteries are 'insensitive'. Some smokers die of a heart attack at an early age without widespread changes to their arteries and long before they’ve developed bronchitis and the lung changes which lead to emphysema and cancer. Their arteries are 'sensitive' to the chemicals or carbon monoxide from the burned tobacco.
Our arteries react differently to cholesterol levels
Our arteries, their linings and the muscles in their walls respond to any stimulus in the same way, for most of us. However, as with smokers, the 'sensitivity' of the response varies.
Cholesterol levels considered 'acceptable' are derived from studies of large groups of people. A normal or acceptable cholesterol level of 5.5 millimol per litre (the average for a 35 year old man or a 45 year old woman) may produce no negative effects in the arteries of most people. However, for some people, it is far too high. For some people, levels of 5.5 will lead to cholesterol deposits in their arteries. This can lead to heart attacks and other vascular diseases. For others even 4.5 millimol per litre is too high.
Maybe it would be better (safer) if we all had cholesterol levels of 3.5 millimol per litre. If cholesterol is kept at this level (and other health risks are removed), it is unlikely you will ever develop cardiovascular disease.
The same applies to blood pressure. An 'acceptable' blood pressure of 140 over 90 millimetres means that we would not treat that person with drugs. We would advise them to:
- Exercise more often
- Eat less salt
- Lower their weight
- Reduce their fat intake.
It now seems that the lower the blood pressure, the better (to a point well short of faintness).
Ideal health for healthy hearts
It seems that the ideal state is to:
- Be lean (but not thin)
- Have low blood pressure (but not faint)
- Maintain low cholesterol (without starving)
- Be physically active throughout life
- Not smoke.
Researchers are trying to find the answers
Research projects around the world are trying to discover why people's bodies respond differently to the same situations. Researchers are trying to understand why:
- Some people are more likely to have their blood platelets clump together.
- Some people are less likely to dissolve small blood clots as they form.
- Blood vessel linings respond differently.
When these questions are answered, it may be possible to find ways to change the way our bodies respond in different situations.
Some foods protect our arteries
There is increasing evidence that certain nutrients that are found in traditional diets, particularly in foods or groups of foods with antioxidant properties, may protect the walls of arteries from damage. Some foods may prevent or stabilise clot formation and therefore prevent heart attack.
What about the effect of stress?
We are all concerned that the stress of our everyday lives may be harmful. Yet while life is supposed to be more and more stressful, life expectancy is increasing.
Maybe stress is harmful for some. If stress leads to more eating, sitting, smoking, brooding and a more depressed mood - then stress may well be harmful. If it leads to more activity, walking, gardening, pacing, loss of appetite, even fidgeting - that may be beneficial for your artery walls but not necessarily beneficial for you!
Where to get help
- Your doctor
- Your local community health centre.
This page has been produced in consultation with and approved by:
Better Health Channel - (need new cp)
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