Nutrition and heart health
When it comes to heart health, public information can become quite confusing, one moment butter is the best thing for us and the next day it’s the worst - but do we really know what nutrition and lifestyle factors positively influence vascular and heart health?
Structure of the Cardiovascular System
The cardiovascular system is made up of the heart, arteries, veins and capillaries. The heart is one of the body’s largest muscles responsible for pumping blood around the body. It’s made up of 4 chambers, the right and left atrium, and the right and left ventricle. The right side of the heart receives deoxygenated blood, and the left hand receives oxygenated blood.
Blood pumps around the body through a series of arteries and veins. Veins carry deoxygenated blood back to the heart; the main vein is called the superior vena cava. Arteries carry oxygen and nutrients away from the heart; the main artery is called the aorta. Arteries are incredibly elastic to cope with increased pressure and force expelled upon them by the heart. Blood pressure in the arteries is much higher than in the veins. Veins are malleable and require contractions from the surrounding muscle to return the blood back to the heart. Aside from structure, one of the main differences between arteries and veins is that arteries don't contain valves whereas veins do. Valves stop the blood flowing back in the opposite direction from the heart.
Common ailments in the Cardiovascular system
- Cardiovascular disease-This is an umbrella term for conditions affecting the heart and or blood vessels. Including Coronary heart disease, strokes, transient ischemic attacks, aortic disease and peripheral aortic disease.
- Coronary heart disease (CHD)- The most likely cause is atherosclerosis (discussed below). Symptoms include shortness of breath, faintness and chest pain. Coronary heart disease is one of the leading causes of death in the UK, according to the British heart foundation (BHF), resulting in 63,000 deaths/year in the UK.
- Peripheral arterial disease (PAD)- Also caused by atherosclerosis (discussed below). Causes of PAD is include a sedentary lifestyle, obesity, alcohol consumption and smoking. Common symptoms include numbness and weakness of the legs, ulcers and muscle wastage. According to the BHF, approximately 1/5 people over 60 in the UK have some degree of PAD.
- Atherosclerosis- this is a disease in which the arteries become filled with fatty substances called atheromas. This changes the structure, diameter and function of the arteries. Atherosclerosis causes the arteries to narrow and harden which may cause an increase in blood pressure. It’s thought that ~2.6 million UK people have some form of narrowing of the arteries. If extremely narrow, blood cannot flow through the vessels which can lead to heart attacks and strokes. The NHS states that a combination of lifestyle factors such as an unbalanced diet, smoking, sedentary lifestyle and alcohol consumption may be the cause.
- Varicose Veins- Most common in the legs, veins become swollen and enlarged. This occurs when the valves in the veins stop working efficiently allowing blood to flowback and pool in the legs. Resulting in sore and heavy legs. The causes are varied, including, genetic predisposition, a standing job and pregnancy.
- Hypertension- this is the formal term for high blood pressure. The NHS states around a third of UK adults have hypertension. The ideal blood pressure is 90/60mmHg-120/80mmHg, anything over 140/90mmHg would be considered high. The onset of hypertension is multifactorial, including a high-salt diet, a low potassium diet, genetic predisposition, lack of exercise, highly caffeinated diet, excessive alcohol consumption, and smoking.
Nutrition for a healthy heart
Nutrition plays a large part in the prevention of many cardiovascular diseases. We all know that maintaining a healthy diet helps to maintain a healthy body, but let us delve deeper into how nutrition supports cardiovascular health.
Vitamins and Minerals
B1 or Thiamine carries an approved claim for its contribution to ‘the normal function of the heart’. This is highlighted by rare Vitamin B1 deficiency, Beri Beri. Common symptoms include an enlarged heart and heart failure. Across numerous studies 21%-98% of patients with heart failure demonstrated poor vitamin B1 status. Be mindful this is in a severe deficiency state.
This collection of 3 vitamins are needed in homocysteine metabolism. Evidence demonstrates that high levels of homocysteine are associated with coronary events and heart disease. Vitamin B12 converts homocysteine to methionine, and vitamin B6 coverts homocysteine to cysteine, therefore reducing whole body homocysteine concentrations.
Sodium and Potassium
As you may know Sodium (chloride) is the chemical name for table salt. Sodium is essential in the body but within narrow limits. Excess sodium has a well-established relationship with cardiovascular health. Water moves to areas of high sodium concentration to dilute the concentration. In a high salt diet this leads to water movement into narrow blood vessels which increases volume and blood pressure. Studies demonstrate that when salt intake is reduced, blood pressure falls within a few weeks. Simply swap to low sodium options or try decreasing processed foods that may contain added salts.
Potassium is another dietary salt, but it doesn’t behave in the same way as sodium. Potassium carries an approved health claim as follows, ‘contributes to the maintenance of normal blood pressure’. Evidence shows an inverse relationship between potassium and sodium; the more potassium you consume, the more sodium is lost through urine. This relationship promotes relaxation and dilation of the blood vessels which may lower blood pressure. Great sources of potassium include fruits and vegetables.
Fats –saturated and unsaturated fats
For a very long time, fats and more specifically saturated fat has been demonised for its role in cardiovascular health. However, current research shows that the relationship may not be that straight forward. A recent Cochrane review looked at 15 studies and 59,000 participants, evidence found that reducing saturated fat reduced the risk of CVD by 21%. Saturated fats can be found in processed foods and animal-derived products. However, our understanding of the interaction of dairy foods has changed somewhat. A longitudinal study looked at the CVD in the highest dairy consuming countries. You would assume because of the density of saturated fat in these foods the rates of cardiovascular disease would be sky-high, right? Wrong! Studies showed that in a Dutch population, higher saturated fat intake was not associated with higher coronary heart disease. This is thought to be due to the interaction between calcium and saturated fat. Additionally, saturated fat has been shown to raise LDL (bad) cholesterol and total cholesterol. A relationship has been demonstrated between high cholesterol and risk of atherosclerosis and artery hardening.
That being said, fat is essential in the human body. Therefore, it’s less about quantity of fat but quality. By reducing dietary saturated fat, you are encouraged to replace this with unsaturated sources of fat. It’s recommended to focus on omega 3 oils in order to reduce the risk of cardiovascular disease. These do so by increasing HDL production in the liver and decrease triglyceride levels in the blood which in turn can help to reduce the risk of cardiovascular disease.
Plant stanols and sterols
These are compounds found in plant-based food. They are a natural and effective way of reducing cholesterol which can reduce cardiovascular illness risk. They work by blocking saturated fat absorption in priority of their own absorption. Research shows that 1.5 to 3 g of stanols/sterols per day can lower LDL by 7.5% to 12%.
According to the British medical journal there is an inverse relationship between total dietary fibre and cardiovascular disease. The study showed that the greater the intake of insoluble dietary fibre, the lower the risk of cardiovascular disease. Insoluble fibre sources include wheat, potatoes, legumes, beans and nuts.
Handy tips to take care of your heart
- Switch from white varieties of food to high fibre wholemeal and brown varieties. Such as bread rice and pasta.
- Opt for plant oils over animal fats.
- Opt for low sodium options. Anything over 1.5grams of salt per 100grams is considered a high salt food.
- Attend regular check-ups with your GP if you are over 50 years of age.
- Try out an Omega 3 oils supplement.
- Aim for a minimum 5 portions (~80g) of fruits and vegetables per day.
- Include at least 1-2 portions of oily fish a week.
- Include sources of B-vitamins in your diet or opt for a B-complex supplement which supplies all of them.
- Increase plant-based proteins in your diet such a legumes and beans.
- Don’t be afraid to tackle the nutrition labels. Any product with over 5grams of saturated fat/100grams is considered a high saturated fat item.
- Purchase a circulation device with electrical muscle stimulation.
- Include supplemental plant sterols, these can be found in powders or fortified foods.
- Seek advice from your GP, healthcare practitioner or the British Heart Foundation.