Introduction

Cardiovascular health includes the well-being of the heart and the connected blood vessels.² A disease associated with this is cardiovascular disease (CVD), where fat can start to build-up in the arteries, increasing the risk of blood clots in the brain, heart, eyes, and kidneys.³ This can lead to various heart conditions such as coronary heart disease, heart failure, heart arrhythmias, strokes, and heart valve problems.

This is linked to high blood pressure and blood cholesterol levels. CVD affects 620 million people globally and is becoming an increasing issue due to changes in lifestyle and a growing population. There are various foods that can assist cardiovascular health, such as blueberries. Blueberries are linked with various cardiometabolic benefits, which will be discussed in this article.

Nutritional composition of blueberries

Blueberries have many nutritional benefits. For every 100g, the nutritional composition includes:⁴

• 14.6 g Carbohydrates
• 9.36 g Sugar
• 84.2 g Water
• 12 mg Calcium
• 0.34 mg Iron
• 6.2 mg Magnesium
• 13 mg Phosphorus
• 86 mg Potassium
• <2 mg Sodium
• 0.09 mg Zinc
• 0.046 mg Copper
• 0.423 mg Manganese
• 8.1 mg Vitamin C
• <3.7 µg Biotin

From above, it is seen that blueberries have a high potassium content. This is pivotal for heart and bone health, reducing the risk of stroke and coronary heart disease.⁵ Plus, as shown above, there is a high phosphorus and vitamin C content. Phosphorus strengthens the bones and teeth.⁶ At the same time, vitamin C is an antioxidant which improves endothelial function (the layer of cells along the heart and blood vessels), reduces blood pressure, and decreases the risk of arterial stiffness.⁷

Additionally, blueberries are rich in anthocyanins, an antioxidant, which are also responsible for the pigmentation of the fruit.⁸ This pigment possesses many properties, such as:⁹

• Antidiabetic
• Anticancer
• Anti-inflammatory
• Antimicrobial
• Anti-obesity effects
• Preventing cardiovascular disease

These are also considered to be flavonoids. These are known for their role in reducing blood pressure, increasing peripheral blood flow (the transport of blood in the body) and increasing cerebral blood flow (the rate of delivery of arterial blood to capillaries in the brain).¹⁰

Cardiovascular health benefits

Maintaining a healthy cardiovascular system reduces the likelihood of risk factors. One of these includes lowering blood pressure, which in turn lowers the risk of heart disease, strokes, and death.¹¹ This can be controlled through the consumption of blueberries, as it contains anthocyanins. These can help reduce blood pressure, as shown in a study.¹²

In this experiment, individuals with hypertension (high blood pressure) took a range of anthocyanin plants, where their blood pressure was lowered. However, these results might vary depending on the dosage, number of dosages and patients’ medical history. In addition, anthocyanins aid cardiovascular health as they can regulate different signalling pathways (how cells communicate with each other to carry out a function), which can lead to CVD.¹³

Moreover, blueberries contain high levels of potassium. This is beneficial to cardiovascular health as it can lower blood pressure. Potassium can relax the walls of the blood vessels, reducing muscle cramps and blood pressure.¹⁴

Furthermore, this fruit can control cholesterol levels. There are two types of cholesterol, LDL (low-density lipoprotein) and HDL (high-density lipoprotein). LDL is known to be harmful cholesterol; this can increase the risk of heart diseases and strokes as deposits build up in the arteries, which can lead to blood clots¹⁵, while HDL is helpful cholesterol.

This absorbs cholesterol and returns it to the liver, where it can be discarded. This can lower the risk of heart disease and strokes.¹⁶ Blueberries are a source of soluble fibre, allowing the removal of bile and the management of cholesterol.¹⁷ Soluble fibre can bind to salt, minerals, cholesterol, and other components which are removed through the body’s waste. 

“Soluble fibre is a natural cleansing system, helping keep your cholesterol levels down.” – Julia Zumpano, a registered dietitian at the Cleveland Clinic in Ohio.¹⁵

Antioxidant effects

Antioxidants can stop oxidant formation, which causes cellular damage)¹⁸, interfere with oxidants when formed, and repair any damage caused by oxidants.¹⁹ This is prominent in coronary heart disease, where antioxidants can inhibit the progression of this disease.

Supporting this, a study was carried out with anthocyanins, the leading antioxidant in blueberries, where 93,600 women were examined to show their relationship between the consumption of anthocyanin and myocardial infarction (a heart attack).²⁰ Results showed 32% of those who had an increase in consumption were at a lower risk of heart attacks.

As well as anthocyanins being the main antioxidant in blueberries, they contain other antioxidant components, such as²¹

• Quercetin- supports cardiovascular health and has anti-inflammatory properties²²
• Kaempferol- improves cardiac function²³
• Myricetin- cardioprotective, anti-hypertensive and anti-hyperglycaemic properties²⁴
• Chlorogenic acid- reduces hypertension, heart failure and myocardial infarction²⁵

Anti-inflammatory properties

These antioxidants are also important in conveying anti-inflammatory properties. There are free radicals, which are produced by various processes.²⁶ If these free radicals outweigh the antioxidants in the body, the body can lose control, which is known as oxidative stress, which can lead to various diseases. These reactive substances therefore, cause inflammation when they are not balanced.

Inflammation can be caused when the body goes through injury or illness, as it helps destroy bacteria and helps the healing process.²⁷ A build-up of cholesterol and fatty deposits in the arteries can also cause an inflammatory response, as it encourages the growth of plaques and triggers blood clots, which can lead to heart attacks and strokes. There are various ways to reduce inflammation, through lifestyle changes,

• Quit smoking- these damage the blood vessels
• Lose weight- the excess stomach fat releases a substance which causes inflammation
• Exercising more- doing at least a 20-minute work-out can decrease inflammation
• Eating a balanced diet- processed food causes inflammation, whilst healthy food carries anti-inflammatory properties 

Incorporating blueberries into a heart-healthy diet

The consumption of 150g of blueberries can reduce the risk of cardiovascular disease by 15%.²⁸

How can blueberries be incorporated into your daily diet? Here are some ways in which this fruit can squeeze into your dishes:

• Eat them as a snack: Blueberries are sweet and crisp as they are, great as a snack
• Smoothies: Put them in your smoothies with other fruits and vegetables and enjoy the benefits of this superfood
• Pancakes or waffles: These go great in any pancake or waffle batter or even as a topping
• Ice cubes: Combine water and whole blueberries in an ice tray and freeze like normal; this can be great when drinking water and very refreshing 
• Jam: Blueberry jam is a great sweet treat for toast and bake
• Muffins: Incorporate blueberries in your muffin batter for a tasty twist
• Yoghurt: This is a great breakfast or snack option and easily accessible in all shops
• Mocktails: Blueberries go great with mocktails, either as a syrup or as a whole, which can make any drink not only tasty but packed with antioxidants
• Fruit salad: This can be incorporated into any fruit salad by simply being sprinkled on top
• Cereal or porridge: This can simply be used as a breakfast topping in simple dishes to start the day

Blueberries can be incorporated into many foods and drinks. This versatile fruit is suitable for both sweet and savoury insert foods.

Considerations and precautions

Some allergies can arise from blueberries; whilst this is a beneficial fruit and safe, symptoms can occur.²⁹ These include:

• Itching
• Tingling
• Swelling of the lips, mouth, or throat
• Abdominal pain
• Nausea
• Diarrhoea 

Some special considerations include:³⁰

• Pregnancy and breastfeeding: Blueberries are safe if consumed as much as in food. However, enough is not known about the safety of consuming a more significant amount 
• Diabetes: Blueberries can lower blood sugar levels for those with diabetes (hypoglycaemia). Patients with diabetes may need to adjust their medication dosage based on individual cases
• Surgery: blueberries affect blood glucose levels and also interfere with blood sugar control; it is recommended to stop using this product 2 weeks before surgery

If any of these conditions apply to you or you exhibit any side effects, please consult your doctor. 

Summary

Blueberries play a significant role in cardiovascular health. They are packed with various antioxidants, vitamins and minerals, directly linked to studies showing they reduce heart attacks, strokes, etc. Cardiovascular health focuses on the risk of both blood pressure and cholesterol levels, which blueberries assist.

They are also packed with a range of antioxidants and exhibit anti-inflammatory properties. Blueberries are versatile as they can be included in many dishes and drinks, making them an easy ingredient to incorporate into any meal. On the other hand, there are some special considerations to consider, and some may be allergic to this fruit; however, this can be addressed through a simple consultation with your doctor.