Cholesterol has in recent years become something of a villain in the public consciousness. Numerous foods and dietary products are advertised as ‘low fat’, giving the impression that low fat options are a healthier choice. However, manufacturers often replace the fat with sugar to preserve the flavour, putting the consumer at risk of a whole new set of health concerns.
As with so many things, the truth about fat and cholesterol is much more nuanced. Did you know, for example, that about 80% of cholesterol is made in the liver, in response to the body's demand for it? Did you know that cholesterol is needed to make hormones such as the stress hormone cortisol? So it's easy to see how being stressed for long periods of time can lead to higher levels of blood cholesterol. This article will take a deeper look at the cholesterol conundrum and other important lipid markers to give a clearer understanding of cholesterol and heart health.
Understanding Cholesterol
Cholesterol is a fat-like substance that is essential for aiding various bodily functions, including the production of steroid hormones, increasing cell membrane viscosity, vitamin D production (we need cholesterol in our skin cells to make vitamin D from the sun), and so much more.
So why the taxi image above? Cholesterol is a fat-soluble molecule and therefore insoluble in water. To get from the liver to where it is needed in the body, it must be transported by proteins called lipoproteins (i.e. fat carrying proteins). The analogy therefore is that lipoproteins are similar to taxis, shuttling lipids (such as cholesterol) from one part of the body to another.
You may be familiar with the two primary types of lipoproteins - low-density lipoproteins (LDL) and high-density lipoproteins (HDL). The important thing to understand here is that HDL and LDL do not only carry cholesterol around the body, but many other lipids as well, such as triglycerides. If a person has high levels of LDLs, why therefore always blame cholesterol when the 'passengers' in the 'taxis' may well be other lipids such as triglycerides, likely due to eating a high carb diet? It is very important to realise that all cholesterol molecules are identical in structure so there is no such thing as good or bad cholesterol. It is rather the cholesterol-carrying molecules, LDL and HDL, that are referred to as 'bad' and 'good' cholesterol.
However, although LDL is often labelled 'bad', and HDL is referred to as 'good,' this is also a huge over-simplification. Both play an important role. The size and number of the particles, together with other factors such as inflammation and oxidative stress, contribute to overall cardiovascular risk. The issue occurs when levels of the smaller LDL particles (as LDL particles do vary in size and density) become elevated. These smaller particles are thought to more easily penetrate the arterial wall, where they can contribute to the formation of plaques, which can cause blockages and increase the risk of various illnesses such as cardiovascular disease. If you would like to learn more about the specific roles of the different cholesterol 'taxis', these articles on my website, here and here, go into much more depth. For now, we are going to focus on strategies for maintaining healthy cholesterol levels in your body. Please remember that these strategies are intended to complement the advice of your doctor and should not be considered as a replacement for professional medical advice.
If you have elevated levels of LDL, it is important to have a test that checks the size of the LDL particles as the smaller the LDL particle, the higher your risk of cardiovascular disease. Likewise, if there is a family history of cardiovascular disease, it is important to check your levels of another lipoprotein called Lp(a). The particular characteristic of this lipoprotein is that it is 'sticky.' The "sticky" nature of Lp(a) is thought to contribute to the development of atherosclerosis as it more easily sticks to arterial walls, leading to the build-up of plaque. High levels of Lp(a) are influenced by genetic factors, and individuals with a family history of elevated Lp(a) may be at a higher risk of cardiovascular disease.
Dietary Approaches to Managing Cholesterol
It would be perfectly logical to assume that the most effective way to use your diet to lower cholesterol is to eat less cholesterol. However, our current understanding of cholesterol suggests that dietary cholesterol (the cholesterol that is present in the food we eat) has very little impact on our actual blood cholesterol levels (1, 2). Luckily, there are plenty of other dietary tweaks you can make that can help your body to manage cholesterol.
INCREASE DIETARY FIBRE: Dietary fibre, also known as 'roughage', is the part of plant-based foods your body can't digest or absorb. Fibre acts like a sponge in the digestive tract, absorbing LDL and preventing it from becoming clogged. Foods rich in soluble dietary fibre include oats, barley, beans, lentils, fruits, and vegetables.
LIMIT SATURATED AND TRANS FATS: Saturated fats are found in red meat, full-fat dairy products, and some oils such as coconut oil. While saturated fats play a role in your health, too much can lead to raised levels of LDL. Those with a family history of cardiovascular disease should limit saturated fats in their diet. Trans fats, often used in processed foods to extend shelf life, are particularly harmful and have no nutritional benefit. They are found in foods like chips (fries), pizzas, margarine and biscuits (cookies). They should be avoided as much as possible as they can raise LDL levels while lowering HDL.
CONSUME OMEGA-3 FATTY ACIDS: These fats are essential for heart health. They can help lower blood pressure and reduce the risk of blood clots. Foods rich in omega-3s include fatty fish like salmon, mackerel, sardines, and flaxseeds.
EAT MORE NUTS AND SEEDS: Almonds, walnuts, and chia seeds, among others, have been shown to lower LDL cholesterol levels (3). However, ensure they're consumed in their natural form, without added salts or sugars.
MODERATE YOUR ALCOHOL: Some studies suggest that moderate alcohol consumption can actually increase HDL, while lowering LDL, suggesting a potential benefit and a reduction in the risk of heart disease (4). However, the mechanism behind this is still poorly understood and the other potential risks associated with drinking alcohol should not be overlooked. Always stay within the recommended daily intake of alcohol units and try to avoid binge drinking.
EMBRACE PLANT STEROLS AND STANOLS: Stanols are cholesterol-like compounds found in breads and cereals, seeds, nuts, legumes, and fruits and vegetables. Eating around 2g per day can help to reduce LDL by as much as 12% (5). To give you an idea of how much this is, a typical healthy diet might contain around 200mg of stanols and sterols, so you would need to eat a lot to make a difference. Luckily, certain foods such as spreads, milk and yoghurt are often fortified by the manufacturers and can provide the full 2g in one serving, so it is worth looking out for these when you shop.
Lifestyle Factors and Cholesterol Management
While tackling your diet should be the first step towards managing cholesterol, other lifestyle factors play a crucial role. As with the nutrition tips above, many of these can help you to avoid numerous other health conditions so even if your cholesterol is at an ideal level, your body will thank you for making some of these adjustments:
PHYSICAL ACTIVITY: Engaging in moderate exercise can help control your cholesterol. This happens in a number of ways. Exercise is thought to raise levels of HDL, while lowering LDL. It also lowers levels of triglycerides, which can combine with LDL to increase the risk of coronary heart disease. Exercise can help improve insulin sensitivity, which is good because better insulin sensitivity can help to raise your HDL levels. Aim for at least 30 minutes of physical activity most days of the week. Both aerobic and weight-training exercises can help with cholesterol and each works in a different way so ideally you can implement both in your weekly workouts.
AVOID SMOKING: Smoking can lower HDL cholesterol and damage blood vessels, making them more susceptible to accumulation of fatty deposits. It can also cause a buildup of plaque in the arteries, making LDL more likely to become trapped. Much of the damage is reversible and quitting smoking can lead to raised HDL levels within weeks or months, while your risk of coronary heart disease will also drop within a year.
MAINTAIN A HEALTHY WEIGHT: Being overweight or obese can increase LDL, while reducing HDL. Even losing a small amount of weight can help lower LDL and total cholesterol levels, as well as bring numerous other health benefits.
Understanding the Microbiome and Cholesterol
The microbiome consists of trillions of bacteria that exist in the gut. You can learn about the intricate and essential role of the microbiome in this article. The link between your microbiome and cholesterol is only just beginning to emerge, but research is suggesting that cholesterol metabolism may be controlled by the microbiome. Foods that nourish the gut, such as prebiotics and probiotics, might indirectly assist in managing cholesterol. Fermented foods like kefir, yoghurt, sauerkraut, and kimchi can be beneficial for supporting your microbiome.
As this is a relatively new area of research, many of the potential benefits are speculative and need further testing but the established benefits of a healthy gut are so numerous that it is worth taking steps now to develop a strong microbiome.
Stress and Cholesterol
Chronic stress can adversely affect cholesterol levels. Stress causes the body to produce excess energy, breaking down stored fat and cholesterol, which then enter the bloodstream. In addition, as most of the cholesterol in our body is produced by the liver and as cholesterol is required to produce stress hormones, during times of stress the body often produces higher levels of cholesterol in response to the need for it. While we can never remove all the stressors from our lives, finding strategies for limiting them, while learning to manage the unavoidable bits can have a positive impact on your cholesterol. This article takes a close look at the role stress plays in your body and the techniques you can use to limit it.