Coronary heart disease (CHD) is usually caused by a build-up of fatty deposits on the walls of the arteries around the heart. The build-up of these fatty deposits, which are called ‘atheroma’, makes the arteries narrower, restricting the flow of blood to the heart muscle in a process called atherosclerosis.
A report in 2014 found that fewer than half of women knew the major symptoms of heart disease2. Just under 50% were able to name smoking as a risk factor, and less than one-quarter named hypertension or high cholesterol.
Main causes of atherosclerosis are:
- High blood pressure
- High cholesterol levels
- Lack of regular exercise
- Poor nutrition and obesity
So how can we use nutrition to keep our hearts happy and healthy?
Including fats in your diet is an absolute must for a healthy heart. We know there are ‘good’ fats and ‘bad’ fats, but which are good, which are bad, and which should be avoided entirely?
Let’s look at the different types of fat:
Saturated fats are found in dairy products, meat, ghee, and coconut oil, and have experienced very bad press over the past 60 years. Their association with an elevated risk of heart disease was a theory propagated in the 1950s, however much disagreement exists among experts about the results of studies regarding the link between saturated fat intake and elevated CVD (Cardiovascular disease) risk. Some argue that saturated fats are the preferred source of fuel for the heart and that they are in fact essential for a healthy functioning body, due to the fact that 50% of the cell membrane is made up of saturated fat3.
This controversy now even has its own Wikipedia page which summarises a number of the conflicting studies and their authors4. The jury is out on saturated fat and it is an ongoing debate with arguments on both sides. If you choose to include animal fats in your diet, try and purchase the highest quality you can afford, going for organic and grass fed meat where possible.
Unsaturated fats can be separated into monounsaturated and polyunsaturated fats.
Monounsaturated fats are found in avocados, nuts and olive oil. Extra virgin olive oil is rich in protective compounds called polyphenols that are linked to disease prevention5.
Polysaturated fats are found in seed oils; including sunflower, flax, chia, sesame and walnut, and are very beneficial for heart health. They do however need to be produced via a heat-free process to preserve their goodness, so always look for ‘cold pressed and unfiltered’
Two types of polyunsaturated fats are omega-3 and omega-6, and these are ‘essential’ fatty acids, meaning they are not made in the body so need to be consumed through the diet.
Omega-3 fatty acids are found in oily fish and shellfish, and plant foods such as walnuts, flaxseed and algae. Omega-3 is highly beneficial for heart health; it helps prevent blood clots, improves blood triglyceride levels (a type of fat in your blood) and boosts circulation.
Omega-6 fatty acids are also important for health, and can be found in vegetable oils. However, the ratio of our omega-3 to 6 is important, and, unfortunately, the Western diet leans heavily towards omega-6 intake. It is, therefore, important to make sure we include omega-3 in our diet to balancing out this ratio.
These fats really need to be avoided and have no place is the diet, let alone one that is concerned with looking after heart health. Trans fats are chemically modified fats called hydrogenated fats, used widely in processed foods. They increase your ‘bad’ cholesterol and arterial inflammation6. Long-held beliefs that CVD is caused primarily by the consumption of animal fat are now being challenged, with trans fats becoming the real villains.
A note on heating oils
Heating vegetable oils releases high concentrations of chemicals called aldehydes, linked to CVD, cancer and dementia. According to research by De Montford University (2015)7 sunflower oil and corn oil produced aldehydes at levels 20 times higher than recommended by the World Health Organisation. Olive oil, rapeseed oil, butter and goose fat produced far less of these harmful chemicals but the best for high-temperature cooking are lard, goose fat, ghee, and coconut oil7.
Not all cholesterol is bad. There are two types of cholesterol; LDL which carries fat and cholesterol to the body tissue, and HDL (‘good’ cholesterol) which carries fat and cholesterol away from body tissues and back to the liver. LDL has been shown to attach to arterial walls and begin the process of plaque formation, leading to heart problems. However, LDL cholesterol is not alone in contributing to heart disease and must be considered in conjunction with other factors, one of the most important being sugar consumption.
Sugar vs saturated fat
Newer thinking suggests that sugars in the diet are more closely correlated to CVD risk than saturated fat intake, and there is a significant relationship between added sugar consumption and increased risk for CVD mortality.8
Studies have shown that when saturated fats are replaced with refined carbohydrates, and specifically with added sugars (like sucrose or high fructose corn syrup), the end result is unfavourable for heart health. Such replacements lead to changes in LDL cholesterol that can contribute to heart problems.
There are studies that claim dietary guidelines should shift focus away from reducing saturated fat, and from replacing saturated fat with carbohydrates, specifically when these carbohydrates are refined. 9
Fruit and vegetables
The risk of heart disease is considerably reduced by a diet rich in plant foods. For every extra 200g of fruit and vegetables you eat a day, you may be able to reduce your risk of ischaemic stroke by a third.10
Fruit and vegetables contain hundreds of antioxidant compounds. There are some studies that show vitamin E contributes to heart health, especially when combined with vitamin C11. Antioxidants help LDL cholesterol stay in circulation, making sure it is only delivered to where it is required in the body.
Fibre is an excellent way to manage your cholesterol and help lower blood glucose and insulin levels post-meal. Fibre can also contribute to lower LDL cholesterol levels and blood pressure and can increase HDL cholesterol and levels of B vitamins which keep heart-damaging homocysteine in check. Homocysteine is an amino acid which promotes narrowing of the arteries
Magnesium is involved in several essential processes which regulate cardiovascular function. Essentially what magnesium does is help relax your blood vessels, increasing blood flow around the body. There have been favourable associations between magnesium intake and lower calcification of the coronary arteries, thereby reducing the risk of heart problems.12
The effect of stress cannot be underestimated as a cause of heart problems. Long-term stress increases heart rate and blood pressure, leading to atherosclerotic plaques which are a key contributor to heart disease.13
Exercise is a great way to reduce stress and it also reduces LDL cholesterol and blood pressure, as do foods rich in potassium.
Which foods should I include in my diet?
- Monounsaturated fats – avocado, nuts, olive oil
- Omega-3 - oily fish such as herring, mackerel, sardines, salmon
- Nuts and seeds – sunflower seeds, flaxseeds, chia seeds, almonds, walnuts
- Potassium rich foods – lentils, kidney beans, chickpeas, banana, avocado, raw carrots
- Fibre – oats, lentils, artichokes, broccoli
- Magnesium rich foods – wholegrains, pulses, white almond butter
- A range of fruit and vegetables. Try to make your diet as colourful as possible which helps ensure you are getting a range of plant goodness.
What foods should I avoid?
- Foods with added sugar - For both adults and children, WHO recommends reducing the intake of free sugars to less than 10% of total energy intake.14
- Processed meats
- Cakes and biscuits (We have lots of healthy recipes on the VITL Life blog!)
- Fried foods such as chips and fried chicken
- Margarine – use butter instead