A City Guide To Huaicheng for These LDLs carry cholesterol molecules around the bloodstream and can lead to the formation of plaques in the arteries. Cholesterol carried by LDLs is often called bad cholesterol’ whereas cholesterol carried by high density lipoproteins is called good cholesterol’, as it appears to increase the processing and removal of LDLs by the liver. Cholesterol is a lipid fat which is present in our own bodily cells but these normal levels can be increased by a fatty diet and by other factors such as age. Normal circulating cholesterol has a purpose in that it is synthesised to produce steroid H – R I S K hormones and is involved in the production of bile necessary for digestion, but high levels in our bloodstream can reflect high saturated-fat intake which is damaging to our health. Some foods, such as polyunsaturated fats which can be more easily metabolised in the body, or foods such as oily fish which contain Omega- fatty acids and which have been found to raise HDL levels, are beneficial to one’s health. The health argument is that if fat molecules, a good store of energy in our bodies, are not metabolised during exercise or activity, then their circulating levels become high, and plaques fatty layers are laid down on the artery walls atherosclerosis, causing them to thicken and restrict blood flow to the heart. An often related condition, arteriosclerosis, exists when increased blood pressure causes artery walls to lose elasticity and harden, with resulting effects on the ability of the cardiovascular system to adapt to increased blood flow such as during exercise. A City Guide To Huaicheng 2016.