Cholesterol has been one of the long standing enemies of the western world for the last forty years…until very recently.
As the United States sets to officially revoke it’s ‘most-dangerous’ status on cholesterol – as several other countries already have – there’s still quite a bit of confusing, contradictory information about the organic molecule that could do with clarifying.
A lot of people didn’t quite understand the connections between cholesterol, saturated fat, trans-fat and heart disease before this dramatic turnaround. And, now that the situation has changed again, it’s enough to make for a really confusing time when doing the weekly grocery shopping.
What Is Cholesterol?
It is an organic molecule, a lipid, more accurately, called a sterol, which is vital for the healthy function of humans and animals down to a cellular level.
We synthesize cholesterol in our organs; principally the liver, adrenal glands, intestines and reproductive organs. This is key to understanding the importance of cholesterol, and also that dietary sources ideally should be harmonious with endogenous production.
Cholesterol is essential for cell membrane structural integrity and fluidity and also allows cells to survive without a cell wall, which in-turn gives them the freedom to move around and change shape.
Cholesterol is necessary for the production of steroid hormones, bile acid and Vitamin D.
Dietary Sources of Cholesterol
Sources of cholesterol include eggs (the yolk), cheese, pork, beef, chicken, fish and seafood (e.g. shrimp).
Some plant products (e.g. peanuts and other seeds) contain phytosterols which are cholesterol-like in nature.
They can compete with cholesterol for intestinal absorption and are sometimes supplemented by people to lower their levels of LDL (see section “Good and “Bad” Cholesterol).
“Good” and “Bad” Cholesterol
Most people have heard of “good” and “bad” cholesterol. Actually what these designation refer to are the lipoproteins which carry cholesterol, amongst other molecules – around the body.
The two most important lipoproteins where cholesterol is concerned are low-density-lipoprotein and high-densityilipoprotein; shortened to LDL and HDL respectively.
Therefore, the “bad cholesterol” label has been given to LDL, which is in fact a lipoprotein. And there in lies the rub: LDL is the major transport molecule for cholesterol in our blood.
What Makes LDL “Bad”?
So why have we vilified LDL for so long?
Here’s the simple version: When cells fill up with cholesterol, they stop synthesizing LDL receptor sites so they cannot take up any new cholesterol from them. The problems begin when this process becomes unregulated and LDL molecules with no receptors start showing up in the blood.
It is these LDL molecules which are oxidized and absorbed by macrophages or which deposit their fat contents in blood vessels. Macrophages swell as they fill up and form foam cells that end up as part of the plaque, leading to arterial blockage and ultimately heart disease – artherosclerosis.
HDL – the good guy – on the other hand, can transport cholesterol back to the liver to be wasted or recycled for other uses. This lipoprotein is considered “good cholesterol” because of this, and not because it is in some way a different type of cholesterol.
Balance of LDL and HDL
It has been determined that high levels of HDL and low levels of LDL appear to be concomitant with good heart health.
The organs in the body strive to keep the balance of cholesterol the same in the body. In fact, about a quarter of our cholesterol is produced in the liver, most of the remainder coming from the intestines, adrenal glands, reproductive organs and diet.
When a cholesterol-rich diet is consumed, the body will dial back its endogenous production, and vice-versa when too little cholesterol is consumed.
The simplest and most common medical test of cholesterol levels in the context of health yields a ratio of Total Cholesterol to HDL levels. It is widely recommended that a ratio a lot less than 5:1 (Total:HDL) is healthier.
Fat and Cholesterol
Recent research indicates that polyunsaturated and monounsaturated fats in the diet seems to lower LDL and raise HDL when replacing carbohydrates calorie for calorie (isocalorically).
Conversely, replacing carbs with trans-fats have the opposite – and therefore most negative – effect.
Saturated fats, however, raise LDL, HDL and Total Cholesterol. Saturated fats are therefore making somewhat of a comeback as well, considering its previous demonic reputation amongst health authorities.
Though there are experts firmly residing on both sides of the fence, some are confident that saturated fats will soon receive the same level of vindication as cholesterol is about to.
Conclusion: Reduce LDL Levels
Most authorities are now in agreement that consuming cholesterol in our diets is no longer a health concern. It is, after all, essential for our health. It would appear that even if we cut cholesterol from the diet, the body will make up the difference and synthesize the stuff anyway. So, what can we do?
Rather, it is the balance of LDL and HDL which has more potential impact on a person’s health. That can be largely due to genetics and not an effect of diet at all.
As for dietary cholesterol, it would seem a consensus has not been fully reached. Some studies reveal that it’s beneficial to eat unsaturated fats. Apparently this may both reduce “bad” LDL and increase “good” HDL. Some experts are saying you should eat saturated fats.
Even a meta-study involving 500,000 people has not fully determined the best course to take with our diets.
From our own research, we have come to the conclusion that there are four takeaway points that seem to be solid enough to form as a basis going forward:
1. Do not avoid cholesterol in diet
2. Exercise regularly
3. Avoid trans-fats as much as possible
4. Lower LDL levels where possible
By keeping fit and avoiding trans-fats, much of the good work is already done. Exercise reduces body fat which can store agents that increase circulating LDL levels.
The final and possibly most important message is that everyone should strive for a balanced, healthy lifestyle. A good diet will in the very least rule it out as being a possible culprit for causing disease in the future.
In addition – exercising, taking a supplement and keeping an eye on your general health with regular checkups from the doctor will ensure you are doing everything you possibly can do.
Good health to all.