Heart-friendly diet

Written by: 
Dr Sarah Brewer

Researchers have found that almost one in three heart attacks worldwide can be linked to eating an unhealthy diet. [1] In contrast, following a heart-friendly diet can reduce your risk of having a heart attack in the future, even if you’ve already experienced one. [2] It’s therefore never too late to start eating for a healthier heart.

Heart-friendly super foods 

Some foods have a greater impact on the health of your heart than others. Scientists have suggested that regularly consuming certain foodstuffs, so-called ‘super foods’, can reduce the risk of cardiovascular incidents (heart attacks and strokes) by as much as 76 per cent. They even predict that consuming these items on a regular basis, from the age of 50, could potentially increase your life expectancy by six and a half years for men, and five years for women. [3] 

The super foods that scientists have identified are: 

  • Fruit and vegetables - 400g/14oz per day
  • Oily fish - one portion (114g/4oz) twice a week (pregnant women should eat no more than two portions a week and avoid shark, swordfish and marlin)
  • Almonds - a handful (68g/2.4oz) per day
  • Garlic - 2.7g/0.1oz (two to three fresh cloves) per day
  • Dark chocolate - one medium bar (100g/3.5oz) per day
  • Wine - one glass (150ml/5fl oz) per day.

Below you can also read about other foods that have an important influence on your heart health:

Fats

Salt

Tea

Whole grains

Soya

Fruit and vegetables 

Fruit and vegetables were an important component of the Stone-Age diet on which our ancestors evolved. They supply vitamins, minerals, fibre and other beneficial substances such as sterols, isoflavones and antioxidant polyphenols. These substances have beneficial effects on blood pressure, cholesterol balance and blood stickiness (an increase in blood stickiness can lead to clots forming), as well as on levels of inflammation and homocysteine (an amino acid; too much homocysteine can damage the artery linings and lead to atherosclerosis). 

Eating at least five portions of fruit and vegetables a day can lower your blood pressure by 4/1.5mmHg. [4] Although this may seem a small amount, it significantly reduces your risk of a heart attack or stroke. 

A large analysis of 12 studies found that people who increase their fruit and vegetable intake from fewer than three portions per day to over five daily servings lower their risk of a heart attack by 17 per cent. [5] Each additional portion of fruit eaten per day reduces the risk of a stroke by 11 per cent, while each additional daily portion of vegetables reduces the stroke risk by 3 per cent. [6] 

Fish

Oily fish, such as salmon, herring, trout and mackerel, is an important component of the Mediterranean diet, the Japanese diet and the Inuit diet. All three diets are associated with a reduced risk of heart disease. Oily fish is a rich source of long-chain omega-3 fatty acids called EPA and DHA (eicosapentaenoic and docosahexaenoic acids). These omega-3 oils help to balance the harmful inflammatory effects of dietary omega-6 fatty acids. They can also reduce blood pressure and blood stickiness, and are highly effective at lowering raised levels of triglycerides. [7] In addition, they appear to protect against certain abnormal heart rhythms, especially in people whose heart muscle has a poor blood supply. [8]

An intake of at least 1g of omega-3 fish oils per day on average (from eating oily fish twice a week, or from taking daily pharmaceutical-grade supplements) has consistently been shown to reduce the risk of sudden cardiac death by 40 to 45 per cent. [9, 10] As a result, the American Heart Association and the European Society of Cardiology recommend a daily intake of 1g of omega-3 fish oils, both to prevent a first heart attack (this is called primary prevention) and to avert a second heart attack if you have already experienced one (secondary prevention). [9] 

Almonds 

Nuts generally are an excellent source of omega-3 and monounsaturated fatty acids. Walnuts are particularly rich in omega-3s, while almonds, macadamias and hazelnuts are particularly good sources of monounsaturated fatty acids. They also contain fibre, vitamins, minerals, isoflavones and antioxidants. Pecan nuts, for example, contain almost twice as many antioxidants as blueberries (17,940 ORAC units per 100g/3.5oz versus 9,260). [11] 

Eating a handful of nuts every day (including walnuts, peanuts, pecans, almonds and macadamias) can improve coronary heart disease risk factors such as cholesterol balance, blood pressure and blood stickiness. [12-15] The beneficial effect is so great that substituting just 28g/1oz of the saturated fat in the diet for nut oils can reduce the risk of coronary heart disease by 45 per cent. [13] 

Garlic 

Garlic is another important component of the Mediterranean diet. It is a source of allicin, an antioxidant that helps to make your arteries more elastic and reduces blood stickiness. 

Analysis of the results from ten trials suggests that garlic extracts can reduce blood pressure by an average of 16.3/9.3mmHg in people with high blood pressure, also called hypertension. [16] Although some studies suggested that garlic may also lower blood cholesterol levels, analysis of data from 13 trials showed garlic to have no overall effect on cholesterol or triglyceride levels. [17]

Dark chocolate 

Dark chocolate is one of the richest dietary sources of antioxidants. It provides an extraordinary 103,971 ORAC units per 100g/3.5oz - over ten times more than is obtained from eating pomegranates (10,500 ORAC units). [11] 

Eating 100g/3.5oz of dark chocolate per day has been shown to improve the elasticity of blood vessels and to reduce blood pressure by an average of 5.1/1.8mmHg. This in turn corresponds to a 27 per cent lower risk of circulatory problems. [3]

Research in 2009 suggested that eating just 45g (1.5oz) of dark chocolate per day significantly improves blood flow through the coronary arteries, regardless of its effects on blood pressure and blood fat levels. [18] 

There are no benefits from eating white chocolate, which contains few antioxidants and lots of fat and sugar. Instead, you are advised to select dark chocolate containing at least 70 per cent cocoa solids, and cut back on energy intake from less healthy foods to accommodate the extra calories (a small bar - 45g/1.5oz - of dark chocolate contains 200kcal of energy). 

Wine

Wine was originally thought to contribute to the lower risk of heart disease found in the Toulouse region of France, an area where dietary intakes of fat are high.

Wine, especially red wine, contains antioxidants such as resveratrol that help to reduce blood stickiness. [19] In fact, alcohol in general appears to have a blood-thinning effect, as well as increasing blood levels of ‘good’ HDL-cholesterol. [20]

People who drink a daily glass of red wine reduce their relative risk of cardiovascular disease by 32 per cent compared with non-drinkers. [21] 

Drinking alcohol is not recommended as a ‘treatment’ for heart disorders, however, as too much alcohol increases the risk of problems. Excess alcohol intake is associated with high blood pressure, enlargement of the heart and abnormal heart rhythms. [23] If you wish to enjoy one or two units per day, though, this is unlikely to have an adverse effect on the health of your heart. 

Interestingly, the benefits of having a moderate amount of alcohol are mostly seen in those with a poor diet, people who exercise very little or who smoke. People who do not smoke, who eat fruit and vegetables daily and who exercise for three or more hours per week get few additional advantages from alcohol. [22] 

Other important dietary factors

Many other foods have been shown to have an important influence, for better or for worse, on the health of your heart and blood vessels. 

Fats

Eating too much fat, in general, is associated with weight gain and can have adverse effects on your blood fat levels. Eating excess saturated fat, and trans fats in particular, has also been associated with an increased risk of coronary heart disease. [24] 

Trans fats are formed when oils are partially hydrogenated to solidify them. These trans fats increase the risk of heart disease because of their harmful effects on blood cholesterol levels, and because they increase inflammation and calcification of the arteries. [25] So it is advisable to cut back on your overall intake of fat and to check labels so that you can select foods with the lowest levels of trans fats (often labelled as partially hydrogenated fats rather than trans fats). 

It is important to concentrate instead on obtaining sources of healthy fats such as monounsaturates (for example, olive, rapeseed, macadamia, hazelnut, almond and avocado oils) and omega-3s (found in, for instance, fish and walnut oils). 

Eating foods containing pre-formed cholesterol, such as eggs, has little effect on blood cholesterol levels. Most people are therefore able to eat them in moderation, unless they are following a very low-cholesterol diet. 

Salt

Eating too much salt increases fluid retention and raises blood pressure. Studies involving the so-called DASH diet (Dietary Approaches to Stop Hypertension) show that, whatever type of diet you follow, those who consume the least salt have significantly lower blood pressure than those with a high salt intake. [26] 

Many people on typical modern diet eat between 9g and 12g salt daily. Any reduction in this amount can lower your blood pressure and thus reduce your risk of cardiovascular disease. Restricting your average salt intake to just 3g per day could reduce your risk of a stroke by a third and of coronary artery disease by a quarter. [27] 

Tea

Both green and black tea contain powerful antioxidant polyphenols similar to those found in dark chocolate and red wine. Research suggests that drinking three cups of green or black tea per day may reduce the risk of a heart attack by 11 per cent [28] and a stroke by 21 per cent.[29] Although there has been less extensive research on it to date, white tea, picked from younger leaves, may also be beneficial.

Whole grains

Whole grains are an important source of fibre, vitamins and minerals. They also have less of an effect on blood glucose levels than processed grains. Selecting ‘brown’ or wholemeal versions of rice, bread, pasta and other cereal products, in place of ‘white’ processed versions, may help to reduce the risk of heart disease. [30] Oats have also been shown to have beneficial effects in terms of cholesterol levels and glucose control. [31] 

Soya

Soya contains oestrogen-like isoflavones and fibre, which have a beneficial effect on cholesterol balance. Eating a diet rich in soya protein is associated with a reduced risk of cardiovascular disease. 

Even modest intakes of around 25g (1oz) of soya per day can lower LDL-cholesterol levels by 6 per cent. [32] As a result, a number of countries have approved food-labelling health claims for soya products. [33]

Eating more legumes in general, in place of some red meat, will help to lower your intake of saturated fat. In fact, among older people, the food most closely associated with a long life is the humble bean. A 20g (0.7oz) increase in your average daily intake of beans – try red kidney beans, pinto beans, red lentils, black beans and chickpeas - is linked with an 8 per cent lower risk of death from a medical cause at any age. [34]  

References: 

1. http://www.ncbi.nlm.nih.gov/pubmed/18936332

2. http://www.bhf.org.uk/keeping_your_heart_healthy/healthy_eating/what_is_...

3. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid...

4. http://www.ncbi.nlm.nih.gov/pubmed/12076551

5. http://www.ncbi.nlm.nih.gov/pubmed/17443205

6. http://www.ncbi.nlm.nih.gov/pubmed/16247045

7. http://www.circ.ahajournals.org/cgi/content/full/94/9/2337

8. Raitt MH. Cardiovasc Drugs Ther. 2009;23:1-3 http://www.ncbi.nlm.nih.gov/pubmed/19005746

9. http://www.ncbi.nlm.nih.gov/pubmed/17575803

10. http://www.ncbi.nlm.nih.gov/pubmed/17575805

11. http://www.ncbi.nlm.nih.gov/pubmed/15186133

12. http://www.ncbi.nlm.nih.gov/pubmed/12463111

13. http://www.ncbi.nlm.nih.gov/pubmed/11122711

14. http://www.ncbi.nlm.nih.gov/pubmed/19420347

15. http://www.ncbi.nlm.nih.gov/pubmed/17437143

16. http://www.ncbi.nlm.nih.gov/pubmed/19017826

17. http://www.ncbi.nlm.nih.gov/pubmed/19250134

18. http://www.ncbi.nlm.nih.gov/pubmed/18045712

19. http://www.ncbi.nlm.nih.gov/pubmed/16905951

20. http://www.ncbi.nlm.nih.gov/pubmed/18496264

21. http://circ.ahajournals.org/cgi/content/full/105/24/2836 (NB relative risk 0.68 = 32% reduction)

22. http://www.ncbi.nlm.nih.gov/pubmed/18791048

23. http://www.bhf.org.uk/keeping_your_heart_healthy/healthy_eating/alcohol_...

24. http://www.ncbi.nlm.nih.gov/pubmed/18937892

25. http://www.ncbi.nlm.nih.gov/pubmed/19345947

26. http://www.ncbi.nlm.nih.gov/pubmed/11806776

27. http://www.ncbi.nlm.nih.gov/pubmed/14610100

28. http://www.ncbi.nlm.nih.gov/pubmed/11549554

29. http://www.ncbi.nlm.nih.gov/pubmed/19228856

30. http://www.ncbi.nlm.nih.gov/pubmed/10479204

31. http://www.ncbi.nlm.nih.gov/pubmed/18301937

32. http://www.ncbi.nlm.nih.gov/pubmed/18534601

33. http://www.ncbi.nlm.nih.gov/pubmed/18492864

34. http://www.ncbi.nlm.nih.gov/pubmed/15228991