<P> The average amount of blood cholesterol varies with age, typically rising gradually until one is about 60 years old . There appear to be seasonal variations in cholesterol levels in humans, more, on average, in winter . These seasonal variations seem to be inversely linked to vitamin C intake . </P> <P> In lipid digestion, cholesterol is packed into Chylomicrons in the small intestine, which are delivered to the Portal vein and Lymph . The chylomicrons are ultimately taken up by liver hepatocytes via interaction between apolipoproteinE and the LDL receptor or Lipoprotein receptor - related proteins . </P> <P> Cholesterol is minimally soluble in water; it cannot dissolve and travel in the water - based bloodstream . Instead, it is transported in the bloodstream by lipoproteins that are water - soluble and carry cholesterol and triglycerides internally . The apolipoproteins forming the surface of the given lipoprotein particle determine from what cells cholesterol will be removed and to where it will be supplied . </P> <P> The largest lipoproteins, which primarily transport fats from the intestinal mucosa to the liver, are called chylomicrons . They carry mostly fats in the form of triglycerides . In the liver, chylomicron particles release triglycerides and some cholesterol . The liver converts unburned food metabolites into very low density lipoproteins (VLDL) and secretes them into plasma where they are converted to intermediate density lipoproteins (IDL), which thereafter are converted to low - density lipoprotein (LDL) particles and non-esterified fatty acids, which can affect other body cells . In healthy individuals, the relatively few LDL particles are large . In contrast, large numbers of small dense LDL (sdLDL) particles are strongly associated with the presence of atheromatous disease within the arteries . For this reason, LDL is referred to as "bad cholesterol". </P>

How do different types of fatty acids influence the level of cholesterol in the bloodstream