What Is Cholesterol? Getting to Grips with Heart Health
Chances are, you’ve read about cholesterol wreaking havoc with your body, especially where your heart is concerned. There’s a reason it gets such bad press; over half of all adults in England have raised cholesterol, increasing the risk of cardiac diseases and strokesi. But the story isn’t always as simple as that. When it comes to cholesterol, it’s about striking a healthy balance. Here’s everything you need to know about this fascinating biological matter: the good, the bad, and the ugly.
What is cholesterol?
Cholesterol is a fat-like, waxy substance produced by your liver. Since it doesn’t dissolve in water, cholesterol can’t move through your blood independently; it needs the help of lipoproteins, which are also produced by the liver. Comprised of protein and fat, lipoproteins transport cholesterol and another lipid, triglycerides, through your bloodstream. Lipoproteins come in two forms: high-density lipoproteins (HDL: the ‘good’ kind) and low-density lipoproteins (LDL: the ‘bad’ kind). Every single person has cholesterol; you need it to keep your body functioning optimally. Trouble is, having too much of the ‘bad’ kind can clog arteries and pave the way for future health complications, like heart attack and stroke.
Why do we need cholesterol?
Cholesterol plays a vitally important role in countless areas of health. Firstly, it forms the outer layer (membrane) of every single cell in your body. It’s also used to create steroid hormones and vitamin D, needed to nourish teeth, muscles, and bones. And finally, it supports the production of bile, which enables you to digest fats from the food you eat.
‘Bad cholesterol’ – LDL cholesterol
Low-density lipoprotein delivers cholesterol from your liver to the cells around your body. In excess, this ‘bad’ cholesterol can stick to your artery walls, causing a build up of plaque. Plaque narrows your arteries, restricts blood flow, and leaves you susceptible to blood clots. A clogged artery in your brain or heart can lead to an increased risk of a heart attack or stroke.
‘Good cholesterol’ – HDL cholesterol
HDL cholesterol earns its stripes as ‘good’ cholesterol thanks to it eliminating the ‘bad’ cholesterol from your bloodstream. It redirects surplus cholesterol back to the liver where it’s broken down and removed by your body, reducing the possibility of circulatory or heart diseases. Since women naturally have higher HDL cholesterol than men, they should aim for an HDL level of 1.2mmol/L and over. Men, on the other hand, should aim for a level above 1mmol/L.
Alongside LDL and HDL cholesterol, your bloodstream contains another fat-like substance – triglycerides. Besides being stored in the body’s fat cells, this compound is also found in cooking oils, meat and dairy products. Like LDL cholesterol, triglycerides can contribute to the restricting of your arteries, making a heart attack or stroke much more likely.
Risk factors for high cholesterol
Many things cause high cholesterol – some you can control, others you simply can’t. Unlike age, gender, ethnic background (especially South Asian and African Caribbean), and inherited diseases, you can manage the lifestyle habits that are directly associated with high cholesterol. Smoking, a lack of exercise, excessive body fat (particularly around your abdomen), and eating a diet rich in saturated fat all conspire to throw your delicate cholesterol balance out of whack. As long as you manage these areas of health, you can help to keep a handle on your cholesterol.
High cholesterol symptoms
Unfortunately, high cholesterol is symptomless. In fact, the first you might learn of it is with a heart attack. Thankfully, a simple blood test can reveal your different cholesterol levels, and whether you need to adjust your lifestyle to bring it under control. If you’re over 40 years old, have a family history of heart disease, are overweight or obese, have high blood pressure or diabetes, or have any other medical condition, like an underactive thyroid or kidney disease, you should have your blood cholesterol levels assessed by your GP.
What can I do to lower my cholesterol?
Avoid trans fats
When it comes to keeping your cholesterol healthy, foods laden with trans fats are just about the worst. Trans fats – that is, fats formed by combining liquid unsaturated fats with hydrogen to prevent them from spoiling – run the risk of sending your ‘bad’ cholesterol soaring. One study even claimed trans fats are responsible for approximately 8% of deaths from heart disease globallyii. Fried foods, fast food, doughnuts, and margarine are notorious for their trans fat credentials. Beyond avoiding these treats, become an ingredient sleuth and always read food labels. Some products try to sneakily hide their trans fat content by listing it as ‘partly hydrogenated oil’, but this is code read and you should quickly put it back on the supermarket shelf!
Embrace monounsaturated fats
Not all fats are created equally. And while you should steer clear of trans fats, your heart needs healthy fats to keep it ticking over. Enter: monounsaturated fats. These fellas launch a two-pronged attack against cholesterol; they reduce destructive LDL cholesterol while protecting beneficial HDL cholesterol. In a study of 24 adults with high cholesterol, researchers found those eating a diet rich in monounsaturated fats improved their beneficial HDL cholesterol by 12%iii. Monounsaturated fats are also thought to decrease the harmful oxidation of lipoproteins, which can contribute to blocked arteries. Olives, olive oil, tree nuts (walnuts, pecans, almonds, hazelnuts, and cashews), canola oil, and avocados are chock-full of nourishing monounsaturated fats. For a heart-healthy dip, smash avocado into homemade guacamole. Finish with lashing of extra virgin olive oil for a double-whammy of cholesterol-busting goodness.
Fill up on fibre
One of the easiest ways to tackle high cholesterol is by adding more soluble fibre to your diet. Fibre binds with your bile acids to help digest your food. And since your body utilises cholesterol in your bloodstream to produce bile acids, that fibrous banana effectively flushes your body of ‘bad’ cholesterol. It’s not hard to find foods rich in soluble fibre: beans, avocado, sweet potato, oranges, and grapefruits all pack a powerful punch of the stuff. Grains are fantastic fibre sources, too. Topping the list? The humble oat. A warming bowl of porridge is one of the best ways to jumpstart your day. Add a grated apple and you’ll be on your way to achieving the recommended daily allowance of 30 grams.
Feast on fish
Brilliant for skin, eyes, joints and now cholesterol, fish really is your one-stop-shop to wellness. Oily fish, like salmon, mackerel, anchovies, and sardines, are especially rich in omega-3’s, a polyunsaturated fat, that hugs your heart by reducing ‘bad’ LDL cholesterol. In one study, researchers replaced saturated fats with polyunsaturated fats in the diets of 115 adults. At the end of the investigation, the participants’ total LDL cholesterol was reduced by around 10%iv. To reap the heart-healthy benefits, aim for 2-3 portions of oily fish every week.
Regular exercise is a no-brainer for your overall wellbeing – and your heart is no exception. Besides upping your physical fitness and helping you stay trim, working up a sweat combats ‘bad’ cholesterol and increases the ‘good’ kind. That morning cycle stimulates enzymes to redirect LDL cholesterol from the blood to your liver where it’s excreted. The more you workout, the more ‘bad’ cholesterol your body zaps. While all forms of activity are beneficial for the heart, anaerobic exercise – that is, physical activity that elevates your heart rate to around 85% of its maximum – offers the greatest results for your cholesterolv. Next time you’re on the treadmill, why not intersperse your running session with some sprints?
Stub out the smokes
The notion that smoking is an unhealthy vice isn’t anything new. One of its most insidious implications is that it increases the risk of heart disease. Indeed, smokers are unable to redirect cholesterol from the vessel walls to the liver because of the damage caused by the tar, clogging arteries as a result. In a large Asian study, smoking was directly associated with an increased total cholesterolvi. Thankfully, stubbing out this habit can reverse these potentially fatal effects.
Though cholesterol serves an important purpose in the body, too much of the ‘bad’ kind can block your arteries and leave you vulnerable to circulatory and cardiac diseases. If your cholesterol is sky high, fine-tuning your lifestyle and diet should be your first line of defence. Move more, fill up on cholesterol-busting foods, and stop smoking! And if you’re concerned about your cholesterol levels, book an appointment with your GP for a simple blood test.
Heartuk.org.uk. (2019). Media - HEART UK. Available online: https://www.heartuk.org.uk/about-us/media Accessed 17 Jan 2019.
Impact of Nonoptimal Intakes of Saturated, Polyunsaturated, and Trans Fat on Global Burdens of Coronary Heart Disease. (2016). Journal of the American Heart Association, 5(1).
Jenkins, D., Chiavaroli, L., Wong, J., Kendall, C., Lewis, G., Vidgen, E., Connelly, P., Leiter, L.,Josse, R. & Lamarche, B. (2010). Adding monounsaturated fatty acids to a dietary portfolio of cholesterol-lowering foods in hypercholesterolemia. Canadian Medical Association Journal, 182(18), 1961-1967.
Ulven, S., Leder, L., Elind, E., Ottestad, I., Christensen, J., Telle-Hansen, V., Skjetne, A., Raael, E., Sheikh, N., Holck, M., Torvik, K., Lamglait, A., Thyholt, K., Byfuglien, M., Granlund, L., Andersen, L. & Holven, K. (2016). Exchanging a few commercial, regularly consumed food items with improved fat quality reduces total cholesterol and LDL-cholesterol: a double-blind, randomised controlled trial. British Journal of Nutrition, 116(08), 1383-1393.
Mann, S., Beedie, C., Jimenez, A. (2013). Differential effects of aerobic exercise, resistance training and combined exercise modalities on cholesterol and the lipid profile: review, synthesis and recommendations. Sports medicine (Auckland, N.Z.), 44(2), 211-21.
Nakamura, K., Barzi, F., Huxley, R., Lam, T., Suh, I., Woo, J., Kim, H., Feigin, V., Gu, D. & Woodward M. (2009). Does cigarette smoking exacerbate the effect of total cholesterol and high-density lipoprotein cholesterol on the risk of cardiovascular diseases? Heart, 95(11), 909-916.
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Olivia Salter has always been an avid health nut. After graduating from the University of Bristol, she began working for a nutritional consultancy where she discovered her passion for all things wellness-related. There, she executed much of the company’s content marketing strategy and found her niche in health writing, publishing articles in Women’s Health, Mind Body Green, Thrive and Psychologies.