Excess cholesterol on the blood is a sign that one is at risk of cardiovascular diseases. However, according to new research, too-low cholesterol levels could increase the risk of cancer, reports the Shukan Post Watcher. According to the Japan Atherosclerosis Society, the standard figure of high cholesterol is 220 mg per decilitre of blood. Above this level, doctors suggest to lower cholesterol through dietary change or medication. However, Dr Rokuro Hama, representative of the non-profit Japan Institute of Pharmacovigilance for Evidence-based Healthcare Centre, said: "It is a two-edged sword. Certainly, the more cholesterol there is in the blood, the greater risk there is of heart diseases such as a cardiac infraction. On the other hand, if your cholesterol level is too low, the chance of getting cancer increases. In fact, a lot of research shows that people with a high percentage of cholesterol in their blood, ranging from 240 to 260 mg per decilitre, tend to be at less risk of death. Their life expectancy may be even longer." Cholesterol is one of three important ingredients for human health, with carbohydrates and proteins. "Cholesterol makes necessary materials for cells and cell membranes by cooperating with protein," explained Hama. "While killer T-cell are immune cells which eliminate cancer cells, if there is not enough cholesterol within a human body, the immune cells cannot work to break cancer cells at all." "The causes of myocardial infraction are smoking, excessive overweight, high blood pressure, diabetes, or angina. If people have one of these conditions as well as high cholesterol, then they may be at risk of suffering cardiac infraction. The point is, a high cholesterol level alone won't cause heart disease, so going on a crash diet to reduce cholesterol might be worse in the long run." Sachiko Yawata, a specialist of cancer preventive diets, warned, "Some people worry about cholesterol too much and do not take any meats, oils and fats. This is not good. This kind of eating habit makes for an unbalanced health condition. As long as you take in a modest amount of nutrients and exercise properly, you can get rid of excess fats without letting the rate of cholesterol in your blood go down."