CORONARY HEART DISEASE
Coronary heart disease (CHD) is one of the biggest killers in the Western world, accounting for at least a third, if not half, of all male deaths.
CHD results from the hardening and furring up of the coronary artery walls. This reduces blood flow and leads to less oxygen reaching the heart tissues. In the case of heart muscle, which beats over 100,000 times per day, lack of oxygen rapidly leads to muscle cramping. This causes a characteristic tight, crushing pain known as angina. If the lack of oxygen is extreme, muscle cells will die and a heart attack occurs.
Sudden Chest Pain
Sudden chest pain should always be taken seriously and medical assistance sought without delay. If it is due to a heart attack, the first two hours are critical. If treatment can restore the blood supply to the damaged muscle by opening up a blocked coronary artery, the tissue can be saved. The classic characteristics of a heart attack include:
• sudden, severe, central chest pain which feels crushing, like being caught in a vice
• pain that often begins at rest (e.g. while you are sitting down) and gets worse on exertion but it can occur at any time
• pain that may spread up into the jaw or down the arms, usually on the left-hand side
• Breathlessness, pallor and sweating, and a sensation of impending doom. You may also feel an overwhelming need to open your bowels.
When classic symptoms are present the diagnosis is straightforward. But sometimes, especially in the elderly, a heart attack may just cause sudden tiredness, an irregular pulse or heart pump failure with breathlessness and swollen ankles.
RISK FACTORS FOR CHD
Coronary heart disease is linked with several risk factors. The most significant are:
• being male
• having a family history of heart disease
• smoking cigarettes
• having uncontrolled high blood pressure
• eating a diet high in saturated fat
• being obese
• having a high blood LDL-cholesterol
• following a sedentary lifestyle with little exercise
• having poorly controlled diabetes.
A recent survey in the UK found that seven out of every eight adult men show CHD risk factors. Half the adult male population is overweight, with 12 per cent classified as obese. One in six has high blood pressure, one in five has taken no exercise during the preceding four weeks and seven out of 10 have a harmfully raised blood cholesterol level. The survey also showed that men aged 5574 were more than twice as likely to have suffered a heart attack or stroke than a woman of the same age.
Only 12 per cent of men in the survey were free of the four major risk factors smoking, high blood pressure, raised cholesterol and lack of exercise.
Other studies show that one in every 10,000 apparently healthy adult males dies suddenly each year in the UK. In 95 per cent of cases this is due to an unexpected heart attack or abnormal heart rhythm triggered by CHD.
CHOLESTEROL AND CHD
Cholesterol is a type of fat unique to the animal kingdom. It is essential for healthy cell membranes, nerve conduction, water-resistant skin and the rapid healing of wounds. Cholesterol is also a vital building block in the manufacture of bile acids and steroid hormones such as testosterone.
Most of our blood cholesterol is synthesized by our liver from saturated fats in our diet. Preformed dietary cholesterol makes only a small contribution to total blood cholesterol levels.
Cholesterol travels around the body in the bloodstream where it is made soluble by joining onto a protein carrier (lipoprotein). It exists in two main forms, high density HDL-cholesterol and low density LDL-cholesterol.
Excessive amounts of LDL-cholesterol are harmful. These molecules are small enough to seep into artery walls and fur them up in a process known as atherosclerosis. Swellings called plaques occur which encourage the formation of blood clots. As these grow larger they block small arteries or break off and travel round the bloodstream. Both events are serious and can result in angina, heart attacks, strokes and even death.
HDL-cholesterol, on the other hand, is beneficial. It is too large to pass into artery walls and stays in the bloodstream to transport fats around the body and to neutralize the harmful effects of LDL-cholesterol.
If you are told you have a high blood cholesterol, you need to know how much is in the form of HDL and how much is LDL. If, for example, most of your raised cholesterol is in the form of HDL-cholesterol, you would actually be protected against heart disease.
If your level of LDL-cholesterol is raised, however, you are at increased risk of CHD and must cut back on the amount of saturated fats in your diet. Research suggests that lowering the average blood LDL-cholesterol level by only 10 per cent would prevent a quarter of the CHD deaths occurring in the Western world each year.
Ideally, all males should have their blood cholesterol level checked before the age of 30 and regularly every couple of years thereafter. This is especially important for men who smoke, are overweight, or who have high blood pressure, diabetes or a personal or family history of chest pains, heart attack or hyperlipidaemia (high fat levels in the blood).
Classification of Total
Blood Cholesterol Levels |
| Desirable |
< 5.2 mmol/l |
| Borderline |
5.26.4 mmol/l |
| Abnormal |
6.57.8 mmol/l |
| High |
> 7.8 mmol/l |
If total blood cholesterol is abnormal or high, the level will be further analysed to find out how much is in the form of beneficial HDL-cholesterol and how much is harmful LDL-cholesterol.
| Normal Range for Various Blood Lipids |
| Total cholesterol |
< 5.2 mmol/l |
| LDL-cholesterol |
< 3.5 mmol/l |
| HDL-cholesterol |
> 1 mmol/l |
| Triglycerides |
< 2.3 mmol/l |
Slightly stricter criteria apply to men under the age of 30 and for all patients with CHD.
The Treatment of High Blood Cholesterol Levels
Coronary artery disease can be reversed without recourse to drugs or surgery. Diet and lifestyle changes alone can lower cholesterol levels, declog the arteries and help to shrink the atherosclerotic plaques that trigger blood clotting. This was recently shown in 41 patients in California. One group of patients met twice per week for exercise, stress counselling, yoga and meditation. They were advised to follow a vegetarian diet and to get less than 10 per cent of their calories in the form of dietary fat.
The fats they did eat were polyunsaturated and their diet was virtually cholesterol free.
After four years, coronary artery disease was reversed in 72 per cent of patients, with coronary artery narrowing falling from 43.6 to 39.7 per cent.
In contrast, the group that continued with conventional medical advice (to lower fat intake to 30 per cent of calories, obtain less than 200 mg cholesterol in the diet per day, take regular exercise, stop smoking) experienced a worsening of CHD in 87 per cent of patients, with coronary artery narrowing rising from 41.6 to 51.4 per cent.
The improvements were not attributable just to the fall in blood cholesterol levels observed, as these dropped in both groups.
These results are similar to the success achieved by men following a Mediterranean-style diet, who have a 75 per cent lower risk of heart attack.
Beneficial Components of the Mediterranean Diet
The Mediterranean diet is thought to reduce the risk of CHD because it contains olive oil, antioxidant vitamins, garlic, oily fish and red wine, and is high in fibre.
Olive Oil
Olive oil (and rapeseed oil) contain vitamin E and are rich in the monounsaturated fat known as oleic acid. This is processed in the body to lower harmful low-density LDL-cholesterol without modifying the desirable high-density HDL-cholesterol. As a result, those who use olive or rapeseed oil regularly (e.g. those of Mediterranean birth or descent) have a lower incidence of CHD.
Antioxidants
LDL-cholesterol that has been oxidized by free radical attack is more likely to be absorbed into artery walls and fur them up. By protecting cholesterol against oxidation, antioxidants can protect against CHD.
Research involving 6,000 middle-aged men showed that the risk of developing angina heart pain was three times lower in men with high blood levels of vitamins E, C and betacarotene. Those taking vitamin E supplements had a 12 per cent reduction in CHD. In those who had taken vitamin E for more than two years, their risk of CHD was further reduced by a total of 25 per cent.
A 10-year study in California has shown that a high intake of vitamin C (including the use of supplements) lowers the risk of heart disease in men by 40 per cent, and reduces the risk of dying from CHD by 35 per cent.
See also Chapter 21.
Garlic
In Germany, garlic tablets containing the equivalent of 4 g of fresh cloves are available on prescription to treat high blood cholesterol levels and high blood pressure.
In patients taking 800 mg dried garlic powder (e.g. Kwai tablets) per day, serum cholesterol levels fell by an average of 12 per cent after four months' therapy. Triglycerides (another form of fatty acid found in the blood) fell by up to 16 per cent.
Research suggests the active ingredient in garlic, allicin, prevents cells from taking up cholesterol and reduces cholesterol production in the liver.
Sulphur compounds formed by the degradation of allicin also contribute to garlic's beneficial effects. These sulphur compounds are incorporated into long-chain fatty acids, to act as antioxidants. This mechanism is particularly important in preventing CHD.
Garlic therapy also reduces average blood pressures by 8 per cent (systolic) and 12 per cent (diastolic) over a three-month period (see Chapter 12 on High Blood Pressure). This is thought to be due to dilation of blood vessels, and to garlic's beneficial effect on the way sodium and potassium ions cross cell membranes.
Oily Fish
Oily fish such as salmon, trout, mackerel, herring, salmon and sardines contain a fatty acid known as eicosapentanoic acid (EPA). This is processed in the body to make the blood less sticky, mainly by stopping blood platelet cells from clumping together. Eating oily fish regularly will lower the risk of CHD. If a heart attack does occur, EPA lowers the risk of dying from it. In men who have already had a heart attack, eating oily fish significantly reduces the chance of a second heart attack. If one does occur, the chances of dying from the second thrombosis are also decreased.
Dutch doctors have shown that men who eat fish once or twice a week can halve their risk of dying from a stroke. The average Western male should increase his weekly consumption of oily fish by a factor of 10 to 300 g per week.
Red Wine
Red wine contains antioxidants that discourage atherosclerosis and decrease the stickiness of blood. It is especially beneficial if drunk while eating, when it neutralizes the effects of saturated fats in the diet.
Fibre
Eating 3 g or more of soluble oat fibre (roughly equal to two large bowls of porridge) per day can lower total blood cholesterol levels by up to 0.16 mm/l. This is a small but significant change.
Dietary Fats
Ideally, adult males should lower the amount of fat in their diet so that it constitutes less than 30 per cent of their daily calories. Saturated fat should contribute less than 10 per cent of calories.
If you suffer from symptoms of CHD it would be better to cut fat intake right back to 20 per cent of calories, with hardly any being taken in the form of saturated (animal) fat. This can reverse your CHD and significantly improve your health. A low-fat diet can be unpalatable, however, although an increasing number of cookery books are available which give delicious low-fat recipes flavoured with herbs and spices.
At present, the average adult Western male obtains 42 per cent of his daily energy from fats, with 16 per cent of calories as saturated fat. This is far too high and is seriously damaging men's health.
Saturated Fat
The fat in our diet comes in several forms including saturated, monounsaturated, and polyunsaturated (see page 316). Saturated fat is mainly derived from meat and dairy products. It is converted in the liver to LDL-cholesterol, which is why we need to limit our intake of it.
Saturated fats are also metabolized to increase the stickiness of blood and encourage constriction of blood vessels. This makes a sluggish circulation and blood clotting (thrombosis) more likely.
Easy ways to lower the amount of saturated fat in your diet include:
• Replace butter and cream with monounsaturated products derived from olive or rapeseed oil.
• Switch to low-fat brands of mayonnaise, salad dressing, cheese, milk, yoghurt, etc.
• Eat less red meat. Once or twice per week is better than the more usual once or twice per day.
• Trim all visible fat from meat and try to buy lean cuts.
• Have regular vegetarian days but don't over-indulge in hard cheese or eggs.
• Eat more fish, especially oily fish.
• Avoid foods high in saturated fat such as coconut, creamy soups, chocolate, patés, oysters, prawns.
• Cut down on cakes, chips, biscuits and crisps.
• Grill rather than fry.
• Eat baked potatoes rather than roasted or fried ones.
Exercise
Regular exercise will lower blood LDL cholesterol levels and raise HDL cholesterol levels see page 268.
Smoking
Smoking cigarettes hastens CHD. It releases harmful free radicals which damage arterial linings and trigger atheroscler-osis. Smoking also increases the stickiness of blood and causes arterial spasm, which significantly reduces the flow of oxygenated blood.
If your blood cholesterol level remains raised despite dietary and lifestyle changes, you may be prescribed lipid-lowering drugs.
Healthy Diet
If you want to reduce your risk of CHD, the following dietary guidelines will help:
10 Point Plan For Healthy Eating
1. Eliminate as much processed and prepacked foods (full of additives and salt) as possible. Eat wholefoods high in minerals, vitamins and fibre instead.
2. Increase your intake of unrefined complex carbohydrates (wholegrain cereals, brown rice, wholewheat pasta, wholegrain bread) to 5070 per cent of daily calories. Most men get less than 40 per cent of daily energy from these starchy foods.
3. Increase your intake of fresh fruit, salads and vegetables to at least a pound in weight per day (not counting potatoes). This works out at around five or six portions (e.g. a glass of unsweetened orange juice with breakfast, a large salad at lunch, two pieces of fruit during the day plus two vegetables with the evening meal). Fruits and vegetables are high in the antioxidant vitamins C, E and betacarotene, which help to protect against CHD and cancer.
4. Decrease the amount of fat, especially saturated fat, that you eat. Fats should make up no more than 30 per cent of daily calories. That's around 75 g per day for men. Most men currently eat over 100 g of fat per day. Switch to low-fat products and use more olive oil for cooking, salad dressings, etc.
5. Decrease the amount of red meat you eat to only one or two portions per week. Have more vegetarian meals instead, including pulses and beans for protein.
6. Increase the amount of fish you eat. Fish, especially oily fish, has beneficial effects on blood cholesterol, is a rich source of trace minerals such as iodine, and is an excellent protein source.
7. Increase the amount of pulses, nuts and seeds you eat. The World Health Organization recommends that we eat 30 g (1 oz) of nuts or seeds per day. These are a rich source of essential fatty acids (EFAs), which have beneficial effects on blood cholesterol levels. Walnuts are especially rich in EFAs.
8. Reduce the amount of simple sugars and sweets you eat. These are rapidly absorbed and cause sugar swings in the blood. This is linked with an increased risk of diabetes and atherosclerosis.
9. Cut right back on the amount of salt you eat. Avoid salty foods and do not add salt to food while cooking or at the table. This will reduce your risk of high blood pressure (see Chapter 12), CHD and stroke. Season foods with herbs, spices and black pepper instead. You will soon get used to the taste of low-salt food.
10. Think about taking vitamin and mineral supplements, such as:
Vitamins C, E and betacarotene (see Chapter 19)
Zinc (see Chapter 20)
