4. Cholesterol – the good and the bad
Cholesterol is a type of fat (lipid) found in all body cells which is essential for the production of some hormones and vitamin D, and for the digestive process. It is manufactured in the liver and transported in the blood stream to wherever it is needed. Cholesterol is not water soluble so binds with fatty proteins called lipoproteins to carry it through the bloodstream. Low Density Lipoprotein (LDL) transports cholesterol from the liver to the cell walls and High Density Lipoprotein (HDL) returns any excess cholesterol back to the liver.
An elevated level of LDL in the blood can lead to an increase of fatty deposits on the walls of arteries with a consequent increase in the risk of stroke or heart disease, which is why LDL is simplistically labelled “bad” cholesterol, although it is neither intrinsically bad nor actually cholesterol.
The Mayo Clinic states that the risk of heart disease may be best determined by considering the level of non-HDL cholesterol rather than the commonly used cholesterol ratio (which is calculated as Total Cholesterol/HDL) : https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/expert-answers/cholesterol-ratio/faq-20058006
The Mayo Clinic also states that either of these measures is a more reliable predictor of the risk of heart disease than the level of either Total Cholesterol or LDL. A non-HDL cholesterol of less than 3.37mmol/l is considered optimum by some. The alternative metric of Cholesterol Ratio should be less than 4.0 for low risk of heart disease.
In my case the readings for blood lipids have fallen significantly as a result of my change in diet and lifestyle. My before and after readings are as follows :
|
|
Units |
Before |
After |
Target |
|
Total cholesterol |
mmol/l |
6.6 |
5.7 |
less than 5.0 |
|
Triglycerides |
mmol/l |
|
0.7 |
less than 1.7 |
|
HDL |
mmol/l |
1.46 |
2.15 |
greater than 1.0 |
|
LDL |
mmol/l |
|
3.2 |
less than 3.0 |
|
Non-HDL |
mmol/l |
5.2 |
3.55 |
less than 3.37 |
|
Cholesterol ratio |
|
4.5 |
2.65 |
less than 4.0 |
The effect of diet and exercise has produced some remarkable changes in about six months. My Cholesterol Ratio dropped from 4.5 to 2.65 and is now comfortably under the 4.0 threshold for increased risk. My HDL has increased 50% from 1.46 to 2.15 mmol/l while my non-HDL cholesterol has dropped from 5.2 to 3.55mmol/l. The latter remains slightly above the Mayo Clinic’s optimum 3.37mmol/l threshold while my Cholesterol Ratio is comfortably below the 4.0 threshold, so these measures are obviously not forecasting risk in the same way. Nevertheless my risk indicators for heart disease have been improved spectacularly by the dietary and lifestyle changes made in only six months, and without resorting to any drugs. Hopefully my indicators will continue to improve as I maintain these changes going forward.
If you have your cholesterol readings, and ideally blood pressure too, then you can obtain an estimate of your current “heart age” using this NHS tool :
https://www.nhs.uk/conditions/nhs-health-check/check-your-heart-age-tool/