Cardiovascular disease (CVD) is currently the leading cause of death in adults, accounting for 31% of all deaths. Cholesterol is made in the liver and plays essential roles in the body such as the formation of bile acids, steroid hormones and vitamin D. However, too much of anything can be a bad thing and this is no different when it comes to cholesterol. Too high concentrations, known as hypercholesterolemia, is a primary, modifiable risk factor for CVD. Cholesterol concentrations are affected by many factors such as genetics, gender, age, physical activity, stress levels, medications and diet. When looking at cholesterol, it’s useful to look at two of the main subtypes of cholesterol (there are lots but we’ll only be discussing two of the main types):
1. Low density lipoprotein cholesterol known as LDL-C. This is commonly referred to as “bad cholesterol” due to is role in transporting and deposition cholesterol all around the body, including our arteries.
2. High density lipoprotein cholesterol known as HDL-C.This is commonly called “good cholesterol” as it helps bring fat and cholesterol back to the liver where it can be excreted. Both LDL-C and HDL-C play important role in our body.
We need both of them but we run into problems when there is too much LDL-C and too little HDL-C. Our diet, while only one piece in the jigsaw that makes up our cholesterol concentrations, can be a positive or negative. There is not one single dietary component that results in high cholesterol levels but rather a combination of factors which include high trans and saturated fat intakes coupled with low fibre and mono- and polyunsaturated fat intakes.
So what can you do on a daily basis to increase HDL-C and keep LDL-C within healthy ranges?
Eat Your Oats!
Oats contain a type of soluble fibre called beta-glucan. Oat beta-glucan can bind to cholesterol in the body and promote its excretion from the body, promoting lower LDL-C concentrations. Oats have been used for their cholesterol-lowering effects since the 1960s. Since then, lots of studies including meta analyses (this is one large analysis of lots of studies) have confirmed their usefulness. One meta-analysis reported that 3g of oat beta glucan reduced LDL and total cholesterol by 0.25mmol/L and 0.30mmol/L, respectively. A 4.2% reduction in LDL-C when 3.5g of oat beta glucan was consumed daily was reported in another meta-analysis. Another reason to enjoy porridge every day! You can also include oats by blending them into a smoothie or making our favourite porridge bread recipe.
Fibre, especially soluble fibre, is essential for getting rid of excess cholesterol from the body and lowering LDL-C concentrations. Rich sources of soluble fibre include oats, beans, peas, apples, oranges and carrots. Increasing fibre can also be achieved by choosing wholegrain or brown versions of grains such as bread, rice and pasta. Aiming for 7-10 portions of fruit and veggies daily is also a great way to make sure you’re eating enough fibre alongside getting in lots of vitamins and minerals! If you’re stuck for ideas on how to do this, check out our blog post on 10 ways to your 10 a day!
Choose Your Fat Sources Wisely
As humans we need a mixture of all fats in our diets so this means we should be eating saturated, monounsaturated and polyunsaturated fats. Choosing nutrient dense sources of each type of fat is important for overall health and cholesterol concentrations. Like anything in nutrition, balance is key here. While we want to be eating healthy sources of saturated fats such as meat such as beef, eggs, full-fat dairy, coconut and dark chocolate we also need to be consuming enough mono and polyunsaturated fats. Most people find including healthy saturated fat sources easy enough but struggle to include enough monounsaturated and polyunsaturated fats to achieve the right balance in the diet. Choosing sources such as olive oil, nuts, seeds, avocado and oily fish regularly are all great ways to increase your intake of healthy fats. A 2017 study found that including one serving of almonds a day was successful in increasing HDL cholesterol concentrations.
The only type of fat which seems to be harmful to overall human health, including cholesterol concentrations are commercially produced trans fats. Trans fats are produced by hydrogenation of vegetable oils and were commonly used in processed foods such as pastries, cakes and frozen convenience foods like pizzas, burgers and chips. Their unsafety has been recognised and are currently being phased out of production which is definitely a good thing! Commercially produced trans fats have been shown to lower HDL-C and increase our bodies production of cholesterol. However, small amounts may still be present in foods that are imported or deep fried in restaurants so opting for minimally processed foods as much as possible is always a good idea.
Regular physical activity of 30-60 minutes daily has been shown to increase HDL-C concentrations, which results in a more favourable cholesterol ratio. Another reason to get active and move every day!
Don’t Fear Dairy. Or eggs!
Two big nutrition myths that still seem to be doing the rounds are that you need to avoid eggs and dairy if you have high cholesterol. You don’t need to fear either!
Eggs are nutrient powerhouses - They’re a source of high quality protein alongside essential vitamins and minerals such as choline, vitamin D and iron. While the yolk contains some cholesterol, research has shown that the dietary cholesterol from eggs does notnegatively affect cholesterol concentrations. Why is this? When we consume cholesterol our body responds by producing less cholesterol itself, resulting in normal levels.
Research into full fat dairy and cholesterol is also interesting. Full fat milk, cheese and yoghurt do not appear to raise blood cholesterol concentrations and are actually now thought to have a positive effect on cholesterol. This is thought to be due to their high calcium content which binds to cholesterol in the body. Dairy is also one of the few dietary sources of butyrate, a short chain fatty acid, which acts as an anti-inflammatory compound. Dairy consumption has been associated with lower CVD incidence. Choosing minimally processed dairy sources such as milk, cheese and yoghurt regularly is a good choice.