How Food Contributes To Heart Healt

Article by Emilia Fish, ANutr, MSc, BSc

Cardiovascular disease (CVD) is the most common cause of death worldwide, with an estimated 17.9 million people dying from it each year1. However, it is important to know that CVD can be prevented through changes in our lifestyles1,2 including dietary adjustments and increased physical activity3.

What is cardiovascular disease?

CVD is the term given to a group of conditions which affect our heart or blood vessels2. Blood vessels include our veins, arteries, and capillaries4.

CVD is associated with atherosclerosis, which is a narrowing of our arteries caused by the build-up of fatty deposit in our arteries2.

It is a normal consequence of ageing and/ or a response to damaging stimulus (e.g. high cholesterol)5,6.

Types of cardiovascular disease

There are four main types of CVD, which are2:

1. Coronary artery disease (CAD). This is where a blockage in the vessels supplying the heart reduce oxygen-rich blood reaching our hearts. It can lead to, angina, heart attacks or heart failure.

2. Stroke or transient ischemic attack (TIA). This is where there is a complete blockage in the vessels stopping supply of blood to the brain. A TIA is similar but is only temporary.

3. Peripheral arterial disease. This is where there is a blockage in the vessels supplying the limbs.

4. Aortic disease. This is a group of diseases effecting the aortic blood vessel, the largest blood vessel in the body.

Risk factors of cardiovascular disease

The risk of CVD increases with: Aging, smoking, high blood pressure, high cholesterol level, diabetes and physical inactivity1,2.

This is not an exclusive list, visit the NHS website to read more about what increases our risk of CVD2.

How can food have a positive effect on health ?

Unsaturated Fats.

Research finds that replacing saturated fats with unsaturated fats, in particular polyunsaturated fats, can reduce CVD and coronary heart disease risk, reduce total cholesterol and LDL-C and insulin resistance7.

Examples of foods containing unsaturated fats include8:

· Oils such as rapeseed and olive.

· Nuts and seeds such as almonds and sunflower.

· Oily fish such as salmon and sardines.

Fibre.

We need cholesterol to make bile acids. Fibre binds bile acids so more cholesterol is diverted to make bile acids. This in turn reduces our LDL-C levels. So, increasing fibre consumption reduces a risk factor of CVD9,10.

The recommended daily intake for fibre for adults is 30g11.

Examples of foods which are a source of fibre include12:

· Wholemeal bread and wholegrain pasta.

· Pulses such as beans and lentils.

· Fruit and vegetables.

Polyphenols.

Polyphenols are a compound found in several plant-based foods. There is a large body of research showing that polyphenols are protective against CVD13. While the exact mechanism by how this works is unclear, it is clear that they have a cardioprotective effect14.

Consumption of polyphenols is in line with the governments recommendations to eat 5 portions of fruit and vegetables a day13.

Examples of foods often containing polyphenols include13:

· Dark chocolate.

· Green Tea.

· Berries.

Remember, just because these foods have a positive effect on our heart health, does not mean they will stop us getting CVD. There are plenty of risk factors, as we talked about before. These foods are associated with reducing the risk of CVD.

How can food have a negative effect on heart health?

Saturated and Trans Fats.

Diets that are high in saturated fats have been associated with increased low-density lipoprotein cholesterol (LDL-C) which is a strong risk factor of CVD15. Trans fat intake has been associated with all-cause mortality, coronary heart disease and coronary heart disease mortality16.

It is recommended that total fat, saturated fats and trans fats should not contribute to more than 35%, 11% and 2%, respectively to our daily energy intake11,17.

The reference intake per day for total fats is 70g, of which saturated is 20g11.

Examples of foods containing saturated and trans fats include8,18:

· Dairy products including butter and cream.

· Hydrogenate spreads.

· Processed meat such as pies.

Sugar.

Research has shown adults consuming excess sugar are at higher risk of CVD than those consuming less19.

It is recommended that free sugars, such as honey and table sugar, should not contribute to more than 5% of our daily energy intake11,20.

The reference intake per day for total sugars (including free sugar and those naturally found in food such as fruit), is 90g11,21.

Examples of foods which tend to be high in added sugar include20:

· Dried fruit including raisins and apricots.

· Chocolate and cakes.

· Condiments such as tomato ketchup.

Salt.

High salt intake is associated with increasing blood pressure, and high blood pressure is a risk factor of CVD22. Since the 1970’s Finland has worked with food companies as part of a cohort study, to reduce salt intake and increase awareness. They have observed a decrease in blood pressure, coronary heart disease prevalence and a 5-6-year increase in life expectancy23,34.

The reference intake for salt is 6g per day11.

Examples of foods which tend to be high in salt include25:

· Processed meat such as ham and bacon.

· Sauces including tomato ketchup and soy cause.

· Salted nuts and crisps.

Remember, just because these foods contribute to cardiovascular disease risk does not mean that you cannot eat them. It is all about moderation and balance.

Advice on heart health

1. Increase our fibre intake. Swap refined white grains for wholemeal cereal and cereal products, try to include more legumes such as tinned lentils and chickpeas and aim to have five-a-day.

2. Consider eating foods rich in polyphenols. This may be increasing berries intake; frozen fruits are a great option.

3. Swap unsaturated fats in and unsaturated fats out. A swap may be using extra virgin olive oil instead of butter.

4. Decrease our trans fat intake. This does not mean completely cut it out. Continue to enjoy it just be aware and try to reduce the amount we consume.

5. Reduce our salt and sugar intake. Be aware of hidden salt and sugar for example in readymade meals and fruit juices.

Resources

· National Health Service. Cardiovascular Disease2.

· British Heart Foundation. Information and Support26.

· National Institute on Aging. Heart Health and Aging27.

This blog post was written by Emilia Fish, a registered associate nutritionist, Food Science and Nutrition BSc graduate and current Clinical and Public Health Nutrition MSc student at UCL. She has worked in several nutrition internship roles, has experience in Food Science labs and enjoys sharing simple, evidence-based nutrition on @nutritionnourishment. Emilia enjoys sharing others nutrition journeys in her podcast, The Nutrition Nourishment Podcast: Sharing Our Journeys.

References:

(1) https://www.who.int/health-topics/cardiovascular-diseases/#tab=tab_1

(2) https://www.nhs.uk/conditions/cardiovascular-disease/

(3) https://academic.oup.com/cardiovascres/article/73/2/326/486833

(4) https://www.nhsinform.scot/illnesses-and-conditions/heart-and-blood-vessels/about-the-heart/understanding-how-your-heart-functions

(5) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3366686/

(6) https://pubmed.ncbi.nlm.nih.gov/15893363/

(7) https://www.gov.uk/government/publications/saturated-fats-and-health-sacn-report

(8) https://www.nhs.uk/live-well/eat-well/different-fats-nutrition/

(9) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5731843/

(10) https://pubmed.ncbi.nlm.nih.gov/23628720/

(11) https://www.nutrition.org.uk/attachments/article/234/Nutrition%20Requirements_Revised%20Oct%202016.pdf?