Smart eating: Relieving blood pressure & cholesterol
Smart eating: Relieving blood pressure & cholesterol
Hypertension is a cardiovascular condition that refers to increased pressure exerted on artery walls by the pumping blood inside. This blood pressure is summarised by two measurements: systolic and diastolic, which depend on whether the heart muscle is contracted (systole) or relaxed (diastole) between beats.
Normal blood pressure at rest is generally within the range of 90-140mmHg systolic (top reading) and 60-90mmHg diastolic (bottom reading). High blood pressure is said to be present if it is regularly at or above 140/90mmHg. High blood pressure puts strain on the heart, leading to hypertensive heart disease if left untreated. It is also a major risk factor for stroke and aneurysms and is a cause of chronic kidney disease. Moderately high blood pressure is associated with a shortened life expectancy.
Different factors, such as diet and lifestyle, can cause a rise in blood pressure. A diet high in sodium greatly increases the risk of hypertension. Removing processed foods from the diet will help to reduce this risk by cutting out the added salt commonly used as a preservative. Consuming high amounts of potassium, found in avocado and bananas, will help to balance the intake of salt from the diet.
Stress is also a major contributor. When the body is in a state of stress, it releases certain hormones that cause a narrowing of blood vessels as well as an increase in heart rate. This has an immediate impact on blood pressure. Maintaining a balanced lifestyle, with adequate rest and relaxation, is an integral part of any cardiovascular treatment plan.
Cholesterol has long been linked to heart disease. However, recently there has been some debate over the positive versus negative effect it has on our health.
Cholesterol is a waxy substance found in all cells. It has several useful functions, including helping to provide structure to the cells. In the liver, cholesterol is converted to bile, which is then stored in the gall bladder. Bile contains bile salts that break down fats in the digestive tract and aid in the intestinal absorption of fat molecules as well as fat-soluble vitamins A, D, E and K. Cholesterol is an important precursor molecule for the synthesis of vitamin D and the steroid hormones, including the adrenal gland hormones cortisol and aldosterone and the sex hormones progesterone, oestrogen and testosterone.
Problems arise when there is an excess of cholesterol, which is then unfavourably transported around the bloodstream attached to proteins. These proteins are called lipoproteins.
Low-density lipoprotein (LDL) carries cholesterol throughout the body, delivering it to different organs and tissues. But if the body has more cholesterol than it needs, the excess continues to circulate in the blood. Over time, circulating LDL cholesterol can enter vessel walls and build up under the vessel lining. This process creates plaques that can eventually narrow the vessels to the point of blocking blood flow, causing a rise in blood pressure. This is why LDL cholesterol is often referred to as “bad” cholesterol.
High-density lipoprotein (HDL) is often referred to as “good” cholesterol. It acts as a cholesterol scavenger, picking up excess cholesterol in the bloodstream and taking it back to the liver, where it is broken down. Higher “good” HDL levels therefore mean less of the “bad” LDL cholesterol left to circulate in the bloodstream, which lessens the risk of hypertension through vascular damage.
Plant sterols are a group of natural compounds that have a structure similar to that of cholesterol, yet they have the ability to inhibit its absorption from the digestive tract into the body.
To be absorbed, cholesterol normally mixes with other substances to form what is known as a micelle, which allows it to pass into the bloodstream. Because they are closely related to cholesterol, plant sterols compete with cholesterol for a place in the micelle.
If a cholesterol molecule is unable to find a place in the micelle, it is not absorbed and simply passes out of the body with other bowel wastes.
If eaten in sufficiently high quantities, sterols have been proven to lower blood cholesterol, particularly the “bad” LDL cholesterol.
Top 6 foods for lowering cholesterol:
Oatmeal contains soluble fibre, which reduces low-density lipoprotein. One-and-a-half cups of cooked oatmeal provides six grams of fibre. Add a banana for extra potassium to support the heart muscle.
Dandelion leaf tea
Dandelion leaf has a diuretic effect, removing excess fluid from the body. But unlike other diuretics, it provides the body with a supply of potassium, which is beneficial to heart function.
Nuts such as walnuts and almonds can reduce blood cholesterol. Rich in polyunsaturated fatty acids, walnuts also help keep blood vessels healthy. Use them as substitutes for cheese or croutons in salads.
Beetroots contain nitrate, which acts as a vasodilator, increasing the space available for blood to flow through, therefore reducing blood pressure. Try a beetroot and ginger juice for an extra circulation boost.
Omega-3 oils found in fish help to thin
the blood, reducing the risk of clots. Sardines and anchovies are the fish highest in omega-3 oils while also being low in mercury.
Leafy green vegetables are high in folic acid. Folic acid, also known as B9, has been shown to prevent the onset of high blood pressure and, in the case of hypertension, reduce blood pressure.
Nutritionist: Susan Buxton
While the term “bad” cholesterol has historically been associated with low-density lipoprotein (LDL), newer research suggests that the oxidation of LDL may be what increases our risk of heart disease.
The LDL cholesterol that is circulating in our bloodstream can become trapped within our artery walls, where it is subjected to oxidation. This oxidation initiates an inflammation response, causing the LDL to become surrounded by macrophages, a type of white blood cell that reduces inflammation.
While attempting to destroy the LDL, the macrophage becomes laden with fat, giving it a foam-like appearance. When these foamy cells die, they form part of the plaque that can lead to artery obstruction.
Oxidation is initiated by free-radical damage. Eating antioxidant-rich foods, such as fruit, vegetables, legumes, wholegrains and nuts, could help reduce the damage caused by