It is estimated that 1 in 3 Australians have high cholesterol, putting those people at a greater risk of coronary artery disease which can cause heart attacks and stroke. So it’s not surprising that coronary artery disease was the leading underlying cause of death in Australia in 2016 contributing to 12% of all deaths.
While there are many factors that put people at an increased risk of developing coronary artery disease high cholesterol is one of the main modifiable risk factors.
What is cholesterol?
Cholesterol is naturally produced by the liver and when produced at normal levels is beneficial for normal functioning of the body. It is an essential part of cell walls, plays an important role in producing hormones and helps to digest food. Cholesterol is carried around the blood in lipoproteins. The two main types of lipoprotein are Low Density Lipoprotien (LDL-cholesterol) and High Density Lipoprotien (HDL-cholesterol).
The good and the bad
LDL cholesterol is known as the ‘bad’ cholesterol (think LDL is Lousy and it should be Low). Excess LDL cholesterol can damage artery walls. Once damage to the artery wall has occurred LDL-cholesterol can get inside and build up over time. The body recognises this as a bad thing so it sends white blood cells to try and clean it up however, they too get trapped inside the artery walls and the build-up continues to grow leading to plaque formations. As plaques develop they can cause narrowing of the arteries and reduce blood flow around the body, this can result in chest pains or angina. Inflammation also occurs at the site of artery plaques which increases the risk of the plaque rupturing or bursting. If this occurs clots develop and can cause a heart attack or stroke.
HDL cholesterol is known as the good or healthy cholesterol (think of HDL as Healthy so it’s OK to be High). HDL cholesterol is known as healthy cholesterol because it picks up excess cholesterol from around the body and takes it back to the liver for processing where it can be used to make hormones or eliminated from the body.
Key message: High levels of ‘bad’ LDL cholesterol can increase plaque formations and blockages in the arteries. ‘Good’ HDL cholesterol helps to remove LDL from the blood and take it back to the liver for processing.
Increasing the good and decreasing the bad
Diet can play a role in increasing the good cholesterol and decreasing the bad.
Trans fats are the worst. They are the worst because they do exactly the opposite of what we want – they increase the bad LDL cholesterol and decrease the good HDL cholesterol. Small amounts of naturally occurring trans fats are found in animal products such as meats and dairy products. Trans fats are also created during industrial processing that adds hydrogen to liquid vegetable oils to make them more solid. These are also known as partially hydrogenated trans fats. Food manufactures use these fats because they are cheap, have a longer shelf life and give foods a desirable taste and texture. Processed foods such as cakes, biscuits, pastries and deep fried foods may contain trans fats. It is recommended that less than 1% of our total energy intake is from trans fats, Australians consume on average 0.6%. Australia has much lower levels of trans fats in our food supply than other countries such as the United States.
The World Health Organisation recently released a plan to reduce industry produced trans fats from the global food supply. They estimate that trans fats lead to more than 500,000 deaths worldwide each year from cardiovascular disease.
Replacing saturated fat with unsaturated fat
Decades of research has found the excess saturated fat can increased bad cholesterol and more recent research shows that replacing saturated fat with unsaturated fat can result in lower LDL cholesterol and higher HDL cholesterol.
Saturated fat is solid at room temperature, it is found in many animal based foods and some plant based foods.
The fat found in meat, chicken and chicken skin as well as processed meats like sausages, burgers, salami and deli meats is rich in saturated fat. Full cream dairy products like butter, cream, milk and cheese as well as lard and ghee are also high in saturated fat.
Plant derived saturated fats are found in coconut products (oil, cream, milk), palm oil and some margarines.
Saturated fat is also the predomint fat in many processed such as foods pies and pastries, cakes and biscuits, chocolate, deep fried foods and fatty snack foods.
Recent studies have suggested that full cream dairy products do not increase the risk of cardiovascular diseases even though they are high in saturated fat. However, until more research is done dietary guidelines and heart foundations still recommend to consume mainly low fat dairy.
Unsaturated fat comes in two different types – monounsaturated and polyunsaturated.
Regular consumption of monounsaturated fats may help to reduce LDL cholesterol. Good sources of monounsaturated fats include extra virgin olive oil, avocado and nuts and seeds especially almonds, peanuts, cashews and sesame seeds (including peanut butter and tahini).
Polyunsaturated fats include omega 3 fatty acids. Omega 3’s have anti-inflammatory properties and may help to reduce triglycerides and blood pressure, reduce plaque progression, thin the blood, increase HDL and decrease LDL cholesterol. There are 3 main types of omega 3 fatty acids: ALA, EPA & DHA. ALA is the omega 3 found in plants and can be found in flaxseeds, chia seeds, walnuts, pumpkin seeds, tofu and canola oil. EPA and DHA are the omega 3’s found in fish and fish oil supplements. There is a lot of evidence to suggest that consuming EPA and DHA from fish is beneficial for cardiovascular health but the same can’t be applied to fish oil capsules. EPA and DHA is found in abundance in oily fish especially salmon, sardines, trout, mackerel and some canned tuna. It is recommend to have at 2-3 serves (150g cooked) of oily fish per week to obtain the benefits of the EPA and DHA fatty acids.
Key message: Avoid trans fats and replace saturated fats with unsaturated fats. Use avocado as a spread instead of butter and margarine, snack on unsalted nuts instead of chips and biscuits, use extra virgin olive oil instead of coconut oil, replace some meat with oily fish.
Fibre is the indigestible part of plants which can provide us with many health benefits. Fibre is usually classified as soluble or insoluble and it is the soluble fibre that has cholesterol lowering properties. Soluble fibre forms a gel in the gut which can then bind to cholesterol and remove it from the body in stools which prevents the cholesterol from being reabsorbed. Studies have shown that about 10g of soluble fibre each day can reduce cholesterol by about 5%. Foods that are high in soluble fibre include beans, lentils legumes, wholegrain, fruits, vegetables, nuts and seeds. Superstars of the soluble fibre world include:
Beans and legumes: Beans and legumes are one of my top picks for adding fibre to the diet. Black beans contain a whopping 4.8g of soluble fibre per cup! Chickpeas, kidney beans, lentils and pretty much all other beans are great too. Easy to add to salads, soups, stews and curries.
Wholegrains: My top pick here would be oats and barley. Both are rich in a certain type of soluble fibre called beta glucan. Oats are a great breakfast choice and barley is a great addition to salads, soups or as a substitution for rice such as barley risotto. Bran and psyllium husk are great to add into breakfast cereals or smoothies too to add a fibre boost.
Vegetables: The champions here include Brussels sprouts, broccoli, cabbage, sweet potato, avocado, asparagus and artichokes, however all veggies brilliant.
Fruit: Apples, pears, oranges, persimmon, figs, prunes are all packing a punch when it comes to soluble fibre but again all fruits are great.
Nuts and seeds: Chia seeds, flaxseeds, sunflower seeds, peanuts, brazil nuts and almonds are on the top of my list but all nuts and seeds get a shout out. Great as a snack or to add to oats, smoothies, salads, stir-fries and curries.
If you’re not a high fibre eater don’t increase the fibre in your diet too soon or things could go pear shaped (pun intended). Increasing fibre too quickly can cause bloating, stomach discomfort and flatulence. Increase your fibre intake slowly over a couple of weeks and while you’re at it make sure you’re upping your water intake too to prevent constipation and aforementioned gut issues.
Key message: About 10g of soluble fibre can reduce cholesterol by around 5%. Beans, lentils, legumes, wholegrains, fruit, vegetables, nuts and seeds are rich in soluble fibre. Increase fibre in your diet slowly over time while also making sure you drink plenty of water.
Plant sterols (phytosterols)
Plant sterols are naturally occurring in all plants and are found in higher abundance in vegetable oils, nuts, seeds, wood pulp, leaves and some grains. Plant sterols are similar in structure to cholesterol and can help to reduce cholesterol absorption that occurs in the gut. The cholesterol lowering effects of plant sterols have been well researched and has shown that 2-3g of plant sterols daily can reduce LDL cholesterol by around 10%. Consuming more than 3g of plant sterols per day isn’t detrimental but doesn’t lead to greater reduction in cholesterol.
It is estimated that most people get around 160-400mg of plant sterols daily through naturally occurring sources in their diet. Some foods have been enriched with plant sterols mainly from soybean oil. In Australia, foods approved for enrichment with plant sterols are: margarine spreads, breakfast cereal, low-fat yoghurt and low-fat milk. The amount of plant sterols added into food products varies, for example:
1 sterol enriched weetbix = 1g of plant sterol, therefore 2 weetbix gives you the 2g you need for the day.
250ml of Heart Active milk provides 0.8g of plant sterols therefore you would need over 500ml to get 2g.
For Flora Proactive Spread you would need 1 rounded tablespoon to get 2g.
Personally I don’t recommend the enriched margarines as I feel that consuming 1 tablespoon of margarine a day isn’t a great addition to the diet, however for people who regularly consume breakfast cereal and milk the sterol enriched products can be a great option.
Key message: Plant sterols are similar in structure to cholesterol and can help prevent cholesterol absorption. most people consume on average 160-400mg of plant sterols in their diet but consuming 2-3g each day with the help of plant sterol enriched foods can decrease cholesterol by around 10%.
While the above tips can work wonders at reducing cholesterol they are most effective in combination with eating a minimally processed, mainly plant based diet.
If you are concerned about your cholesterol the first step is to talk to your doctor and have a blood test to measure your cholesterol levels (specifically ask for the breakdown of your ‘good’ and ‘bad’ cholesterol as it is not always included). Diet can play a huge role at managing cholesterol levels however even when following a cholesterol friendly diet some people may be genetically predisposed to high cholesterol and may need the assistance of cholesterol lowering medication.
Eat to beat cholesterol:
- 5+ serves of vegetables (1 serve = 1/2 cup cooked or 1 cup salad) and 2 fruits each day
- 2-3 serves of oily fish each week (1 serve = 150g cooked or 180g raw)
- Choose minimally processed wholegrains such as oats and barley
- 3+ serves of beans, lentils or legumes each week (1 serve = ½ cup)
- Choose healthy fats from extra virgin olive oil, avocadoes, nuts and seeds (have 30g of unsalted, unroasted nuts each day)
- Plant sterol enriched foods can help (must have at least 2g per day)
- If consuming meat and poultry choose lean cuts and trim off any fat (also replace some meat in the diet with fish and plant based protein like tofu, try and have at least 1 meat free day each week)
- Minimise consumption of highly processed foods and high sugar foods and drinks such as cakes, biscuits, pastries, deep fried foods and sugar sweetened drinks