Risk factors for heart disease
A number of factors are associated with the build-up of fatty deposits in the coronary arteries, including cigarette smoking, lack of physical activity and a family history of the disease.
Other risk factors include:
- Type of fat eaten – saturated and trans fats increase blood cholesterol and heart attack rates. Polyunsaturated and monounsaturated fats lower the risk of heart attacks.
- Obesity – many overweight and obese people have diets high in fat, particularly saturated fat. A person who carries the bulk of their body fat around their stomach (an ‘apple’ shaped body) is at greater risk of heart disease than someone whose body fat tends to settle around their bottom, hips and thighs (a ‘pear’ shaped body).
- High blood pressure (hypertension) – blood pressure is the amount of pressure within the arteries (blood vessels that carry blood around the body). High blood pressure, or hypertension, means that the pressure in the arteries is higher than normal. This may be because the arteries are less elastic, there is more blood volume, or more blood is being pumped out of the heart.
Foods that help prevent heart disease
There is no ‘magic’ food to decrease the risk of developing heart disease. You need to eat a healthy diet and have plenty of exercise. High-salt diets increase blood pressure and the risk of heart attack and stroke.
Most of us consume more than ten times the amount of salt we need to meet our sodium requirements (salt contains sodium and chloride). However, there is evidence that plant foods – especially whole grain cereals, legumes, nuts, fruits, and vegetables – may decrease the risk of heart disease.
The foods that best protect against heart disease include:
- oily fish – such as mackerel, sardines, tuna and salmon which contain omega-3 fatty acids. This type of fat has been shown to decrease triglycerides and increase HDL-cholesterol levels, improves blood vessel elasticity and thins the blood, making it less likely to clot and block blood flow
- some vegetable oils – such as corn, soy, and safflower, which contain omega-6 fatty acids, and those containing omega-3 fatty acids such as canola and olive oil. All of these can help to lower LDL cholesterol when used instead of saturated fats such as butter
- fruit and vegetables – antioxidants in fruit and vegetables offer protection against heart disease. Fruit and vegetables are also important sources of folate, which helps lower the blood levels of the amino acid homocysteine, which appears to be linked to an increased risk of heart disease
- fibre – whole grain cereals and fruit and vegetables
- unrefined carbohydrate sources with a low glycemic index – foods such as whole grain breads and breakfast cereals, legumes, certain types of rice and pasta are important for people prone to diabetes because they help keep blood sugar levels in check
- legumes and soy – soy protein has been shown to lower LDL cholesterol levels, especially if blood cholesterol levels are high
- nuts and seeds – they should be eaten in small quantities, as they are high in kilojoules
- tea – some evidence suggests that the antioxidants in tea can help prevent the build-up of fatty deposits in the arteries. The antioxidants may also act as an anti-blood clotting agent and improve blood vessel dilation to allow increased blood flow
- alcohol – it is thought that a moderate intake of alcohol may have some potential health benefits. For example, some types of alcohol (such as red wine) may contain protective factors like antioxidants, although this is still being researched. Alcohol also increases the HDL (‘good’) cholesterol and this helps clear cholesterol from the body. However, a high intake of alcohol increases blood pressure and also tends to increase triglycerides (a type of fat) in the blood, increasing the risk of heart disease. Current guidelines for alcohol intake in Australia recommend no more then two standard drinks per day for men and one for women to reduce the risks of harm related to alcohol
- foods containing vitamin E – some studies indicate that vitamin E acts as an antioxidant, helping to protect against ‘bad’ cholesterol. Good sources of vitamin E include avocados, dark green vegetables, vegetable oils and whole grain products. It is better to eat foods containing vitamin E rather than take supplements, which do not have the same protective effects
- garlic – a compound in fresh garlic called allicin has been found in some studies to lower blood cholesterol
- foods enriched with plant sterols – a daily intake of 2–3 g of phytosterols/stanols lowers LDL cholesterol levels by approximately ten per cent in healthy people and in those with high cholesterol and those with diabetes. This intake can be achieved by the consumption of two to three serves of phytosterol-enriched foods like margarine spreads, reduced-fat yoghurts, milk and breakfast cereals.