Cholesterol: Friend of Foe

(Originally posted on bcotoronto.com on Dec 8th, 2011)

Tis the season for family, friends, and fatty foods again. Everyone is enjoying hot drinks and plenty of desserts. But what comes along with fats is cholesterol, that feared villain of the nutrient world. It is very popular to talk about “Good Cholesterol” and “Bad Cholesterol” but the truth is that is only one type of cholesterol and the “Good” and “Bad” aspects come from our own bodies and how the cholesterol is used.

Within our bodies fats can be packaged in two ways, in transport units called “Low Density Lipoproteins” and “High Density Lipoproteins” (lipo referring to lipids or fats and protein referring to…well, proteins). Cholesterol is packaged into these units alongside the fats and signal proteins and it is the concentration of cholesterol which gives the unit its name. The Low Density Lipoproteins (LDLs) are what is referred to as “Bad Cholesterol” and are the units of fat sent from the liver to the body for storage. Their High Density cousins (HDLs) are the “Good Cholesterol” which is traveling back to the liver for use.

Cholesterol is extremely important in the body’s functions as it is the main building block for many important hormones like Estrogen and Testosterone which we cannot live without. Without cholesterol we would be goo puddled around the feet of a skeleton because cholesterol gives stability to the walls of our cells. This is why eliminating and even sometimes just limiting cholesterol is a risky move for our health.

It is not the properties of the cholesterol that make it bad or good, as I said earlier, it is the way it is packaged. We have discussed Free Radicals before and they again play an important part in this story. LDLs are highly sensitive to oxidation (the damage caused by free radicals). It is this damage that causes the “bad cholesterol” to build up in arteries and form atherosclerosis, or “plaque”. This is a long complicated process which I will not go into here but if you are interested it can be found in any pathology or advanced immunology textbook or just e-mail me.

HDLs are considered good because they can act as a buffer to the oxidation (much like those antioxidants I’m always telling you are good for you) and can sometimes reverse the plaquing in the arteries (if it is not too far along in the process). It is the high concentration of the cholesterol that gives the HDLs the chemical stability to take this oxidative damage and not start the plaquing process and as they are on their way back to the liver anyways the damaged ones don’t live long enough to sustain enough damage to push them beyond their limit and make them harmful.

It is the ratio of LDLs and HDLs that is important. If there are too many LDLs or too few HDLs then a large portion of the LDLs will be lacking that protective screen of HDLs. The best ratio is between 2:1 and 3:1 LDLs/HDLs.

If there is one over arching teaching I’ve been trying to convey in my blog so far it is that there is nothing that we cannot affect with diet and lifestyle. The cholesterol ratio is not an exception to this rule. Basically anything that is “Heart Protective” will help either decrease LDLs or increase HDLs. But I wouldn’t be me if I didn’t delve into the specifics a little more.

There are several ways to increase the HDL levels in your blood. The most effective one is exercise. Good, continuous cardiovascular exercise for more than 20 minutes will mobilize fats and cholesterol from storage and increase the rate of your metabolism to use fats more efficiently and quickly. Vitamin B3, “Niacin”, has been shown to have a positive impact on low HDL counts1,2,3 but approximately 1/3 of people experience a “flushing” reaction where their skin becomes itchy and red when they take a large dose of Niacin. This adverse effect is easily avoided by taking Niacin in a “timed-release” form which spreads the dose over a longer period of time. Fish oils, or more specifically Omega-3s, have been shown to have similar effects4,5,6 without the side-effects.

Omega-3s also have an anti-inflammatory effect which helps to prevent Free Radicals from forming in the first place and helps to get rid of them when they do come around. Other antioxidants can be found in dark berries and fruits and vegetables high in the vitamins A, C, and E. A diet rich in these foods is very protective against any Free Radical damage, not just of the LDLs.

Cholesterol is used by our bodies to create bile. Bile is the substance that our digestive system uses to dissolve and emulsify fats in our intestines so they can be broken down and absorbed. In the absorption of fats we also take back in some of the bile we excreted in the first place. Fibre in the gut will trap fat and bile with it and stop it from being absorbed fully, which will decrease the LDLs formed from the fats eaten as well as decrease the amount of bile reabsorbed. This will lower the LDL levels in the blood and raise the HDLs by increasing the body’s need to create new bile.

Like I said before, there is nothing we can’t affect through diet and lifestyle. All it takes is a little knowledge and willpower to use it. Keep this in mind this holiday season and help protect your heart.

Thanks for reading,

Ben

 

1. The AIM-HIGH Investigators. Niacin in Patients with Low HDL Cholesterol Levels Receiving Intensive Statin Therapy. The New England Journal of Medicine 2011 Epublication ahead of print Nov 15

2. Vosper, H. Extended Release Niacin-Laropiprant in Patients with Hypercholesterolemia or Mixed Dyslipidemias Improves Clinical Parameters. Clinical Medical Insights: Cardiology 2011 5:85–101

3. Villines TC, Kim AS, Gore RS, Taylor AJ. Niacin: The Evidence, Clinical Use, and Future Directions. Current Atherosclerosis Report 2011 Epublication ahead of print Oct 27

4. Adámkova V, Kacer P, Mraz J, Suchanek P, Pickova J, Kralova-Lesna I, Skibova J, Kozak P, Maratka V. The consumption of the carp meat and plasma lipids in secondary prevention in the heart ischemic disease patients. Neuroendocrinology Letters 2011 32(Suppl2):17-20

5. Bogl LH, Maranghi M, Rissanen A, Kaprio J, Taskinen MR, Pietiläinen KH. Dietary omega-3 polyunsaturated fatty acid intake is related to a protective high-density lipoprotein subspecies profile independent of genetic effects: A monozygotic twin pair study. Atherosclerosis 2011 Dec;219(2):880-6

6.Siri-Tarino PW. Effects of diet on high-density lipoprotein cholesterol. Current Atheroscerolsis Reports 2011 Dec;13(6):453-60

Share

Leave a reply