Cholesterol and fat are essential for good health; fat is used for insulation and as an energy source, and cholesterol is in all cells of your body as it is required to build and maintain membrane structure. Both belong to a family of molecules called lipids; these are insoluble in water, meaning lipids circulate your bloodstream in packages called lipoproteins.
The synthesis of cholesterol is influenced by your fat intake; however, there are different types of fat which lead to different types of cholesterol being produced due to different types of lipoproteins being packaged, each having vastly different effects on your overall health.
The good and the bad
There are four types of fat: saturated, trans, monounsaturated, and polyunsaturated. Cholesterol is primarily synthesised in the liver, however, dietary cholesterol is also present in certain foods. Cholesterol packaged in low-density lipoproteins (LDLs) is bad for your health, as opposed to cholesterol packaged in high-density lipoproteins (HDLs).
Saturated and trans-fats are the bad fats. Both stimulate the liver to produce higher levels of cholesterol packaged in LDLs. As the LDLs travel through circulation, the cholesterol detaches from the package and sticks to the walls of your arteries, and over time this causes them to narrow, putting undue pressure on the heart to pump blood to other organs. This is known as cardiovascular disease. In the worst-case scenarios, LDL deposits of cholesterol can contribute to the blockage of entire arteries and increase the risk of a major heart attack.
Monounsaturated and polyunsaturated fats, the good type, stimulate the production of cholesterol to be packaged in HDLs, which has a counteractive effect: HDLs circulate throughout the bloodstream and LDL cholesterol is transferred to it by a regulatory protein, thus removing the cholesterol from your artery walls and keeping them smooth and free of plaque. The HDL transports the cholesterol to the liver for removal and reuse; in simple terms, think of the cholesterol from the LDL as the rubbish, the HDL as the waste-disposal truck, and the liver as the disposal centre!
When consumed in moderation, healthy fats go a long way in boosting your health by helping determine what type of cholesterol and lipoproteins are produced. We recommend having a small intake of healthy fats with each meal.
How to incorporate good fats and good cholesterol into your diet:
- Adding half an avocado to several meals throughout the week is a great way to improve your cholesterol balance. The avocado contains polyunsaturated fat which not only stimulates HDL production, but also reduces inflammation. Bonus.
- Cooking with rapeseed oil is a great alternative to olive oil as it improves your intake of monounsaturated fat, leading to the production of HDLs.
- Try swapping margarine for nut butter, which contains polyunsaturated fat instead of saturated fat.
- If you need a snack or energy hit, reach for some mixed seeds or unsalted nuts instead of a chocolate bar, crisps or sweets. Nuts are rich in polyunsaturated fats.
Fats to keep to a minimum in your diet:
- Cakes/buns and biscuits (trans-fat)
- Margarine/butter (saturated fat)
- Cheese and cheese sauces (saturated fat)
- Processed meats and hard fat on meats (saturated fat)
- Mayonnaise (saturated fat)
- American Heart Association. https://healthyforgood.heart.org/Eat-smart/Articles/Saturated-Fats
- National Institute of General Medical Sciences.https://publications.nigms.nih.gov/insidelifescience/fats_do.html
- NHS. http://www.nhs.uk/Livewell/Goodfood/Pages/Fat.aspx
- The University of Harvard. https://www.cpandr.co.uk/2017/08/18/not-all-carbohydrates-were-created-equal-complex-and-simple-carbs/