Hi Tomi,
the power of digestion does diminish with age, but can remain quite robust if you exercise moderately, as this has a large bearing on its efficiency, coupled with proper food combining.
There is no such thing as good/bad cholesterol: cholesterol is cholesterol, produced by the liver for many vital functions such as brain health.
People with the highest levels actually live the longest.
A book by Shane Ellison MSc (The Peoples Chemist) entitled "The Cholesterol Myth" is well worth a read.