At the start and end of the study, researchers measured the men ™s weight, LDL, HDL, and total cholesterol, and levels of apolipoprotein A-I (apoA-I), one of the protein components of HDL.  ApoA-I production and breakdown are key elements of HDL metabolism.

Both eating plans reduced the men ™s LDL cholesterol and ratio of total/HDL cholesterol.  HDL cholesterol levels fell 10 percent in the AHA/NCEP plan and 3 percent in the MUFA plan.

To examine how the eating plans influenced the metabolism of HDL cholesterol, 18 of the men underwent detailed studies of the production and breakdown of apoA-I.  Men on the AHA/NCEP plan had decreased production of apoA-I, which was linked to lower levels of LDL.  Men on the high MUFA diet had no changes in apoA-I production or breakdown.

With this information on HDL metabolism, we believe that the reduction in plasma HDL-C should not raise concerns about cardiovascular health, Desroches said.   We believe that lower HDL probably means less HDL is needed to remove cholesterol from peripheral tissues.

At this point, people may be confused because of the wide array of diets that are being proposed.  But there is a wealth of evidence to support a low intake of saturated and trans-fats, a moderate intake of the good fats (mono- and polyunsaturated fats from vegetables, fish, legumes and nuts), and a high intake of fiber from fruits, vegetables and grains.

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