What is cholesterol?
Before we discuss exactly how exercise affects cholesterol levels, we must first explain exactly what cholesterol is and what it does.
Cholesterol is a type of fat that is found in the bloodstream and in the cell membranes of all body tissue. Most of the time cholesterol is made by the liver from the saturated fats in food, though it can also be found in eggs, liver and kidneys.
Cholesterol is used to make hormones and to build cell walls. It is important for brain and nerve function, as well as the synthesis of vitamin D. The liver also converts cholesterol into bile acid which helps to digest food.
Cholesterol is carried to and from the liver by proteins. The combination of cholesterol and protein is called lipoprotein, of which there are 2 types:
- LDL – carries cholesterol from the liver to the cells
- HDL – carries un-needed cholesterol back to the liver where it can be broken down.
If you have more LDL than HDL then the cholesterol levels in your tissues and blood stream will rise.
Effects of high cholesterol
High cholesterol levels in the blood will lead to atheroma (fatty deposits on the artery wall). This starts to block the arteries, building up layers of a fatty substance on the artery walls. As oxygen-bearing blood flows through the arteries, the narrowing of these channels reduces the efficiency of the circulatory system and reduces the quantities of oxygen available to the organs.
With a high cholesterol level, the pressure in the arteries will increase as the space for blood to pass through becomes narrower. This may cause blood pressure to rise as well. If the arteries leading to the heart are affected, the likelihood of a heart attack increases.
How does exercise affect cholesterol levels?
Dietary fat intake of cholesterol shows up in the blood as triglycerides. Regular physical activity can reduce levels of triglycerides as it is used and removed by muscle cells. This means the triglycerides aren’t deposited into adipose tissue (fat) and they aren’t processed by the liver to create more cholesterol.
In addition, training increases LDL activity, thus it shifts cholesterol from the dangerous LDL to the favourable HDL. This indicates that the muscle fibres are capable of taking up and oxidising fatty acids. As fat is used before it can be deposited in the adipose tissue, this also shows just how exercise can influence weight control.
What other factors influence cholesterol levels?
Making a realistic exercise plan is essential to managing cholesterol levels but we mustn’t forget the range of other things that can influence it too.
High cholesterol levels can be inherited from parents or grandparents, for example, so if you can it is worth finding out if there is a family history of this. Inherited factors may mean that we take up cholesterol from the blood into the tissues at a slow rate, increasing the amount of cholesterol measurable in the bloodstream.
The liver is capable of synthesizing the cholesterol we need so additional sources in our diet may cause a surplus. If high cholesterol becomes a problem, it is likely we are eating large amounts of saturated fats which are turned into cholesterol.
Dietary intake of trans fats will also encourage the production of cholesterol, particularly of the LDL type that increases cholesterol levels in the tissues and bloodstream. Trans fats are found in dairy products, some meat and other animal-based foods, as well as in processed foods where they are used to ensure a long shelf life.
High calorie diets
A high calorie diet will also influence cholesterol levels because the extra calories are made into triglycerides. Calories that aren’t used immediately after being eaten are also converted into triglycerides and stored in the fat cells. Hormones then regulate the release of triglycerides from fat tissue so that they meet the body’s need for energy between meals.
High sugar foods, and refined carbohydrates that break down quickly and easily into sugar, fuel the production of triglycerides.
How can I lower my cholesterol naturally?
Other than exercise…
- Cut down your intake of high sugar foods and refined carbohydrates to stop them being converted into cholesterol
- Reduce saturated fat and trans fats in your diet to reduce the production of cholesterol and triglycerides
- Avoid coffee and alcohol to improve liver function
- Foods such as beans, oats, green leafy vegetables and apples can help the liver process fats
- Stop smoking
- Tackle stress as it can contribute to the production of cholesterol
- Drink plenty of water
- Try Artichoke Cynara Drops! This is a tincture of globe artichoke which has been found to inhibit the production of cholesterol, whilst encouraging its breakdown and reducing its absorption in the gut. Cynara also increases bile production and its movement into the intestines, thereby improving the way dietary fats are metabolised.