The risks associated with having high cholesterol levels are well documented. Particularly low-density lipoprotein [LDL] which is referred to as ‘bad cholesterol’. Eliminating high oxidized cholesterol from our diet is so important to good health. But what is oxidized cholesterol? How does it differ to normal cholesterol, whether it is high-density lipoprotein [HDL] or LDL ?
In this article I will be explaining what oxidized cholesterol actually is, how it is formed and the associated foods that need to be avoided.
What is cholesterol ?
Cholesterol is a fat that is carried in your blood and produced by the liver from saturated fat in your diet. This is absorbed directly from cholesterol-rich foods like egg yolk and dairy products. Cholesterol consists of LDL and HDL. Low-density lipoprotein is considered to be the real culprit behind heart disease [https://jules4heart.com/the-foods-to-lower-cholesterol/] While HDL actually protects against heart disease, by drawing cholesterol away from the arterial walls and back to the liver.
So what about oxidized cholesterol ?
It is important to the health of arteries that cholesterol is able to move freely into and out of cells. HDL typically transports about 20-25 percent of the cholesterol in your blood, carrying it away from tissues to your liver, which disposes of it. In general, the more HDLs in your bloodstream, the more artery-clogging cholesterol is removed. If cholesterol levels start to build up within the artery instead of returning to the liver, then they are likely to become oxidized.
Research has shown that for every 1 percent increase in HDL level, your risk of heart attack drops by 3-4 percent. In comparison, a 1 percent drop in LDL levels reduces your risk of heart attack by just 2 percent. Having low levels of HDL means that LDL cholesterol can start to build up within the artery walls. This is due to there being fewer ‘dust carts’ or HDL to dispose of the bad cholesterol. This may then go through the process of oxidation.
To understand oxidation, you have to think of it as a metal chair being left outdoors. After a while, the metal chair begins to rust. This is more or less the process of oxidation that occurs to the cells in the body. Oxidized cholesterol develops when ‘normal’ LDL cholesterol is damaged by chemical interactions with free radicals [[https://www.medicalnewstoday.com/articles/318652.php].
Free radicals are produced naturally in the body from normal cellular processes. There are also lifestyle choices that we make, that accelerate their production. These include:-
- Exposure to toxic chemicals, such as pesticides and air pollution
- Fried foods
There are protective compounds in our body called antioxidants, that can stop the cholesterol in our bloodstream from becoming oxidized. Antioxidants basically prevents or lessens the effect of free radicals. This is achieved by donating an electron to free radicals, thereby reducing their reactivity. What makes antioxidants so unique, is their ability to donate an electron without becoming reactive free radicals themselves. As you can see, antioxidants play a critical part in our bodies defense system.
In response to the presence of oxidized cholesterol, the body releases white blood cells called Monocytes to engulf and dispose of them. However, these monocytes are unable to achieve that, if there are a large amount of oxidized cholesterol. This results in monocytes themselves becoming stuffed and turning foamy. These foam cells collect in the blood vessel wall, where they turn dangerous and begin producing more free radicals. These free radicals further oxidize the cholesterol and eventually form a fatty streak, referred to as Plaque. This is the first stage phase of atherosclerosis or hardening of the arteries [https://www.bhf.org.uk/informationsupport/conditions/atherosclerosis].
Over time, plaque hardens and narrows your arteries. This limits the flow of oxygen -rich blood to your organs and other parts of the body. Atherosclerosis can lead to serious problems, which includes heart attack, stroke and even death.
Preventing cholesterol from being oxidized
You can control some risk factors for oxidized cholesterol, such as a lack of physical activity, smoking and an unhealthy diet. Other factors such as age, family history of heart disease are unfortunately out of your control. I want to focus on the main enemy associated with oxidized cholesterol. That enemy is trans-fatty acid.
Trans-fatty acids are called ‘hidden fats’ because they masquerade as healthy vegetable oils. But a process called hydrogenation changes the original chemical composition of oil, resulting in a higher melting point and longer shelf life. Hydrogenation is a process, dating back to 1912, that enables the food industry to use polyunsaturated fats as a food spread, instead of butter and lard. During hydrogenation, oils are heated to a high temperature and hydrogen is sent through them. In the process, synthetic trans-fatty acid [TFAs] are produced, but with a different molecular structure from the essential fatty acid normally found in humans and other mammals.
Trans-fatty acid are very damaging to your arteries. They increase LDL cholesterol and heighten your risk of heart disease. The government food standards agency stated that trans fats found food containing hydrogenated vegetable oil are harmful and have no nutritional benefits. An eight-year study of 85,000 women by Harvard Medical School found that those eating margarine had an increased risk of coronary heart disease. Hydrogenated vegetable oils have not only failed to provide the expected benefits as a substitute for highly saturated fats, but they have actually contributed to the occurrence of coronary heart disease [https://www.ncbi.nlm.nih.gov/pubmed/8094827].
The Harvard study reckoned that TFAs could account for 6 percent of all deaths from heart disease, or 30,000 deaths a year in the USA alone. And of course, heart disease rates are higher in northern European countries, where consumption of TFAs is high, but low in the Mediterranean countries, where TFA intake is low because the main dietary fat is olive oil.
Major sources of trans-fats include:-
- Anything made with partially hydrogenated oils, such as crackers, doughnuts, breads and many frozen potato products.
- Most bagged snack foods, including crisps, cheesy puffs and popcorn.
- Chips or chicken fried in hydrogenated fats.
- Some types of margarine and reduced fat spreads.
Choose healthy options
If you want to lower your LDL cholesterol and raise good cholesterol [HDL], then research is clear that you should exchange saturated fats with unsaturated, particularly polyunsaturated fats. According to research undertaken, this can reduce cardiovascular disease by about 30 percent. This is a similar reduction achieved using statin medication [https://www.ahajournals.org/doi/full/10.1161/CIR.0000000000000510].
I would suggest the following foods to be introduced into your diet, which will go a long way to eliminating oxidized cholesterol:-
- Oily fish – such as mackerel and salmon
- Nuts – such as almonds and cashews
- Seeds – such as sunflower and pumpkin seeds
- I would recommend peanut, soybean, sesame, canola and olive oil.
In this article I have been able to shine the light on oxidized cholesterol and the risks to your health, if you consume those associated foods that contain trans-fatty acid.
Better life-style choices and the introduction of healthier oils into your diet, can have a huge impact on your health and reduce your risk of cardiovascular disease.
I hope you have found this article to be informative. Which foods have you been able to introduce into your diet, that has helped to lower your cholesterol levels ?