Saturated Fatty Acids, Hydrogenated Trans-Fats, Health Effects on LDL/HDL Cholesterol Atherosclerosis
What is Saturated Fat?
Saturated fats are simply fats that contain mostly saturated fatty acids. Saturated fatty acids are found mainly animal fats (including dairy products). Only two vegetable fats are saturated: palm and coconut oil.
Typically, we get the greatest proportion of our saturated fat intake from ‘invisible’ fats in prepared or processed foods, like: sausages, bacon, salami, cakes, cookies, pastries, chocolate and cheese.
Saturated fat is usually solid at room temperature.
Why is Saturated Fat Harmful?
In simple terms, saturated fat is a major risk factor for heart attacks and strokes. It’s worth remembering that the body can manufacture its own saturated fat so we don’t actually need to include ANY saturated fat in our diet.
The full story about saturated fat and heart disease is very complex and much of it remains a mystery.
Saturated Fat & Cholesterol – Only Part of the Story
We know that diets high in saturated fat (or high-glycemic index carbs) lead to an increased production of acetate fragments in the body, which usually raise the production of cholesterol.
But increased cholesterol is only part of the story. Although we know that cholesterol is the main component of arterial plaque – the stuff causes a narrowing of arteries [atherosclerosis] – we don’t know exactly what causes arterial blockages, or why some people who eat large amounts of saturated fat have comparitively healthy arteries.
- Part of the explanation for the development of atherosclerosis is to be found in the body’s levels of low-density lipoproteins (known as LDL cholesterol) and high-density lipoproteins (HDL cholesterol).
- In fact, neither LDL Cholesterol nor HDL cholesterol is actually cholesterol per se. They are cholesterol-transporters.
- In simple terms, low-density lipoproteins ferry cholesterol from the liver to the tissues. If there is too much cholesterol for the tissues to receive, the LDL transporters start dumping it in the arteries.
- High-density lipoproteins are the good guys. Their main function is to ‘sweep up’ the excess cholesterol and return it to the liver for disposal.
- Which explains (in part) why the more LDL cholesterol and the less HDL cholesterol we have, the more likely we are to suffer from narrowing of the arteries.
- In other words, it’s not total cholesterol – it’s the relative levels of LDL vs. HDL cholesterol we have, that causes increased risk of heart attacks.
For example, oily fish is relatively high in saturated fat, but it also contains high levels of omega-3 fatty acids which help to raise HDL levels and thus reduce the risk of atherosclerosis.
Many Unanswered Questions About Heart Disease
To what extent is diet responsible for heart disease? Is narrowing of the arteries [atherosclerosis] partly the result of bacterial infection? Can the consumption of other fats reduce the risks of heart attacks and strokes? What role does vitamin C play in reducing the risk of atherosclerosis? How dangerous are refined cards for a healthy heart? These questions, and many more like them, remain unanswered.
Saturated Fat – Bottom Line
For the moment, current dietary opinion on a healthy fat-intake for healthy adults suggests:
- Maintain a modest intake of total fat (25-30 percent of calories).
- Include regular amounts of omega-3 fat in your diet.
- Reduce your intake of saturated fat (maximum 1/3 of total fat intake).
- Eat less margarine and other processed fats.
- Reduce your intake of refined carbs.