The internet is awash with mis-information on what we should and shouldn’t eat, and often it is in relation to heart health. This can be very difficult to navigate and unfortunately can often lead to unhealthy eating patterns. So, let's clarify the situation for each myth, based on the best scientific evidence available, with practical, straight forward advice.

A low-fat diet is needed to lower cholesterol

We actually need fat in our diet for several important roles including a healthy immune system and good brain function. In fact, what is important is the type of fat we eat rather than the total fat. Dietary fats are not all metabolised in the body in the same way.

Saturated fats, found in red and processed meats, full fat dairy products, coconut milk and palm oil, as well as foods made from these such as cakes, biscuits and pastries, raise the amount of bad cholesterol (LDL) in the blood. This in turn raises the risk of cardiovascular diseases including chronic heart disease, stroke and vascular dementia.

On the other hand, unsaturated fats, found in nuts, seeds, cooking oils made from plants such as olive oil and rapeseed oil, avocado and oily fish have been found to lower the blood levels of LDL cholesterol and decrease the risk of cardiovascular disease.

The UK and international guidelines reflect this by recommending we limit saturated fat to 10% of total energy intake which is approximately 20g for women and 30g for men, while keeping total fat intake to around a third of our total energy intake. Therefore, rather than reducing fat intake we should swap foods that are high in saturated fat for the healthier unsaturated fat. For example, instead of fatty meats like sausages or bacon, opt for lean options such as chicken (with the skin removed) and fish.

Nuts are high in fat so should be avoided

Nuts certainly should not be avoided in your diet. In fact, the opposite is true, with the UK guidelines stating that you should eat nuts as part of a healthy diet. This is based on many observational studies that show an association between eating nuts with a lower risk of cardiovascular disease, and also some intervention studies that show eating nuts actually lowers LDL cholesterol.

It is true that nuts have a high fat content, however most of this is the heart-healthy unsaturated fat and some research shows that not all energy from nuts is absorbed by the body. Nuts are also a good source of micronutrients (manganese, potassium, iron, zinc, selenium, vitamin E and B vitamins) and are high in both protein and fibre, so overall, a very healthy option. Walnuts are worthy of a special mention because in addition to heart-health benefits, this type of nut is also one of the few good plant sources of the omega-3 fats, essential in our diet for good heart and brain health.

A palm-sized portion of plain or roasted nuts make a healthy snack but try to avoid flavoured and seasoned nuts which include added oil, salt and sugar. Nuts also make a great addition to stir fries, salads and breakfast cereals.

Chocolate is a healthy option

There is certainly a lot of noise on the internet about this one, possibly because we all want chocolate to be a healthy ‘superfood’, but sadly this is not the case. It is true that cocoa beans used to manufacture chocolate are high in antioxidants and there is some evidence that consuming high levels of these antioxidants are linked to heart health. However, most of the antioxidant content is removed during processing and very little remains in the chocolate we eat (you would get far more antioxidants from eating an apple).

Chocolate is high in sugar and fat, making it very calorific and far from being a healthy option. This does not mean chocolate should be excluded from a healthy diet but it is sensible to eat it in moderation. One interesting study showed that chocolate is more likely to improve your mood if you eat it mindfully, so the best advice for chocoholics is to have a couple of squares of your favourite chocolate and REALLY enjoy it.

When choosing between the different types of chocolate it is worth knowing that dark chocolate made from 70% or more cocoa solids have more antioxidants and less sugar. Milk chocolate contains very few antioxidants and double the sugar while white chocolate contains no cocoa solids so you will not get any antioxidant benefit from it.

Eggs should be avoided

There is a lot of confusion around whether eggs can be part of a healthy diet, which stems from the fact that egg yolks contain cholesterol. Dietary cholesterol is found in animal sources such as whole milk dairy products, egg yolk, meats, poultry and some shellfish. While it does raise blood cholesterol levels, its effect is usually modest.

Foods high in saturated fat have a more significant effect on blood cholesterol so it is much more important to limit the amount of saturated fat in the diet. Eggs are low in saturated fat and have many other nutritional benefits so, for the general healthy population, they can be included as part of a heart-healthy diet.

For certain groups of people however, the recommendation for eggs is slightly different. For those with Familial Hypercholesterolaemia (FH), high blood cholesterol levels and those who are at high risk or have cardiovascular disease, we recommend limiting intake to three to four eggs a week.

Butter is better for you than margarine

Butter is manufactured by churning cream and removing the butter milk. As a result, it is very high in total fat and saturated fat (approximately 82% and 52% respectively). This means that one teaspoon of butter contains 4.7g saturated fat which is a large proportion of the maximum daily quantity recommended by Public Health England of 20g for women and 30g for men. It is also very calorific with one tablespoon containing 110 calories.

Margarine, also known as fat spread, is recommended as a heart-healthy alternative to butter because it is made from vegetable oils such as rapeseed, olive and sunflower oil containing the healthier unsaturated fats. They have been vilified on the internet partially because of the way they are manufactured but also because of the incorrect thinking that saturated fat is healthy. Some spreads provide further heart health benefits because their ingredients include plant stanols and sterols which can lower LDL cholesterol if eaten in the right amounts.

So, while butter can be enjoyed in moderation as part of a healthy balanced diet it is not true that it is better for you than margarine because of its high saturated fat content.

Coconut oil is healthy

Coconut oil has been hyped on the internet as a healthy option and there are even suggestions that it can help with weight loss because it contains what are known as ‘medium chain triglycerides’ (MCT). Although studies have shown that fats made up entirely of MCT raise your 'good' cholesterol (HDL cholesterol), coconut oil contains just 15% MCT which means it is unlikely to provide the same benefits.

More importantly, coconut oil is made up almost entirely of the unhealthy saturated fat. To be precise, it contains a whopping 92% saturated fat which is more than any other edible fat, including butter which contains 52% saturated fat. This means it is likely to cause similar heart health issues to any other high saturated fat food.

Coconut oil does have a lovely flavour and is excellent in Thai style curries but it is best to use it sparingly.

More myth busting

Unfortunately, there are plenty more nutrition myths around so when scrolling through social media sites or reading the news, make sure you check out where the information came from and don’t take it seriously unless it is clearly backed by strong scientific evidence. All national guidelines are based on reviews by leading academics in the field of all the relevant research, so if you are in any doubt, check out Public Health England or the NHS site.

Content sourced from HEART UK (heartuk.org.uk).