What I'd say at the start, however, is that the most effective approach is to focus on eating foods that enable the body to tackle high cholesterol levels, rather than to start cutting out foods. In this way, people meet their goals and maintain them for life.
Hypercholesterolaemia - the medical name for abnormally high levels of cholesterol - is a risk factor in heart disease, and every year it kills more than 200,000 people in the UK. Evidence strongly suggests that improving the body's cholesterol profile can help reduce heart-disease risk by up to 60 per cent.
As many as two in three men, and growing numbers of women, do have unhealthy levels of cholesterol. Alarmingly, we're also finding children of eight or nine with raised levels and the first signs of atherosclerosis, or furring of the arteries. A routine blood test can indicate a high cholesterol level, but telltale signs include yellowish nodules of fat in the skin beneath the eyes, or at elbows, knees and tendons; or a whitish ring around the eye that an optician could be the first to notice.
Cholesterol only becomes a problem when you have too much of it and it starts to promote the production of a fatty plaque which can clog the arteries. Interruption of blood flow in a main heart vessel can cause a heart attack; a blocked blood vessel on the way to the brain could cause a stroke. Blocked arteries are also to blame for circulation problems and kidney disease.
Don't try to lower cholesterol levels drastically. Cholesterol is the major carrier of testosterone, so men who dramatically cut their cholesterol levels (through extreme dieting or intake of medication) can also suffer low circulating-testosterone levels, and thus low libido. Sudden changes in cholesterol levels have been linked to mood change and depression; cholesterol is also involved in the synthesis of vitamin D and is needed for the production of the myelin sheath, the protective substance that surrounds the nerves. Changes in cholesterol level, then, should be made gradually and carefully.
Cholesterol is a whitish, fatty, wax-like substance produced in the body - primarily the liver - and present in certain foods. The liver repackages the cholesterol the body makes by breaking it down to low-density lipoprotein (LDL). As LDL flows through the blood, it latches on to receptor sites on cells which need the cholesterol. When the cells have had enough cholesterol, they stop producing receptor sites - but unused LDL stays in the blood and can irritate blood-vessel linings, and that causes a fatty plaque to form, which is why LDL is 'bad' cholesterol. 'Good' cholesterol is high-density lipoprotein (HDL), which carries the excess LDL cholesterol from the blood to the intestine, where it is excreted.
Some say that cholesterol-rich foods such as eggs, shellfish and offal should be banished from the diet, but although they contain cholesterol, these foods don't significantly raise LDL levels. The cholesterol in them is broken down quite efficiently and then excreted, so they're fine to eat in moderation.
The real influence on the level of LDL is the intake of saturated animal fats, because these stimulate the liver to produce more LDL. Keeping down your intake of butter, cream, cheese and foods containing them will minimise the production of 'bad' cholesterol. Choose lean meat rather than fatty cuts, and small amounts of dairy foods. You don't need to banish cheese - it's a good source of calcium and other nutrients; just watch the quantity. And be aware of saturated fat in some margarines, especially hard margarines. When cooking, use small amounts of vegetable oils such as olive or sunflower.
Designer margarines like Benecol contain a pine extract which reduces saturated fat absorption and has been shown to cut LDL levels by 13 to 15 per cent. Tablets containing grapefruit pectin can also, apparently, lower LDL cholesterol levels, though studies on these have so far been carried out only in the US, and no hard scientific evidence suggests that anyone with high LDL cholesterol levels should rush out and buy some.
A minority of people genetically produce too much cholesterol (or have related complicating factors) and may need the help of drugs. For most of us, though, it's possible to reduce LDL levels through healthy eating and a simple increase in HDL intake.
HDL is mainly found in oily fish, garlic and alcohol (about which I'll go into more detail next week). Oily fish such as herrings, mackerel, and tuna are rich in omega 3 and omega 6 fatty acids, great for encouraging production of HDL. Garlic contains allin, which boosts HDL levels and, according to some, reduces the size of a fatty plaque. Garlic and oily fish also lesson the risk of developing a blood clot or thrombosis, which can block a blood vessel in a similar way to a deposit of fatty plaque. Garlic (ideally fresh or powdered, but capsule will do) should be taken almost every day; aim to have two or three fish-based meals a week.
Fibre is key to achieving a good blood profile - it produces substances that help clear the blood of bad cholesterol and acts as a 'buffer', so less fat is brought into contact with blood vessels and less is absorbed. Fibre also keeps bad cholesterol within the gut, from where it can be excreted.
Step up all high-fibre foods - wholegrain breads, cereals and pulses - and aim for at least five portions of fresh fruit or vegetables a day. Oats are especially good, so think porridge or oat cereal, and use oats in main meals such as fruit or vegetable crumbles. Just eating your cheese with oatcakes reduces the saturated fat you absorb, and cutting the rind off soft cheese reduces the fat content by half.
Don't forget though that for fibre to perform these tasks, it needs water, too. Water (straight - not coffee, tea or soft drinks) helps fibre swell and, without it, fibre can only perform a fraction of its role as a buffer. If you can get through two and a half litres a day, you should find you can lower those LDL levels significantly.
