Last updated by Dr Sarah Brewer on
Diet and heart disease are so closely linked that almost one in three heart attacks could be prevented by following a heart-friendly diet. The large INTERHEART study, which involved over 16,000 people in 52 countries concluded that following an unhealthy diet accounts for almost one in three heart attacks (30%) worldwide.
By eating the right foods you can reduce your future risk of a heart attack even if you have already experienced one, and it’s never too late to start. A review published in the British Medical Journal concluded that even starting from the age of 50, eating certain selected foods regularly could potentially increase life expectancy by six and a half years for men, and five years for women. The protective foods they identified were:
- Fruit and vegetables – 400g per day
- Fish – one portion (114g) four times a week
- Almond nuts – a handful (68g) per day
- Garlic – two to three fresh cloves (2.7g) per day
- Dark chocolate – one medium bar (100g) per day
- Wine – one glass (150ml) per day.
The researchers calculated that frequently including these foods in the diet could reduce the risk of heart attack and stroke by more than 75 percent. These benefits were due to protective effects on blood pressure, cholesterol balance and arterial elasticity. What’s more, these findings were based on the robust Framingham Heart Study data and were reviewed for accuracy by the US National Heart, Lung, and Blood Institute (NHLBI). It’s good to know that you can enjoy sensible intakes of wine and dark chocolate without feeling guilty.
- Fruit and veg protect against heart disease
- Oily fish protect against heart disease
- Nuts and heart disease
- Garlic and heart disease
- Dark chocolate and heart disease
- Wine and heart disease
- Tea and heart disease
- Salt and heart disease
- Trans-fats and heart disease
- Wholegrains and heart disease
- Tomatoes and heart disease
- Coenzyme Q10 and heart disease
- Magnesium and heart disease
- Vitamin K2 and heart disease
- Vitamin D3 and heart disease
Fruit and veg protect against heart disease
Fruit and vegetables protect against heart disease by supplying key vitamins and minerals, fibre and other beneficial substances such as sterols, isoflavones, coenzyme Q10 and antioxidant polyphenols.
Another meta-analysis of 16 studies, involving over 56,00 people found that each serving of fruit lowers the risk of cardiovascular disease by 5%, while each serving of vegetables reduces the risk by 4% up to a total of five combined servings of fruit and vegetables per day – more than this did not seem to provide any additional benefits.
Oily fish protect against heart disease
Oily fish are an important part of the Mediterranean, Japanese and Inuit Diets – three ways of eating that are associated with a lower risk of heart disease.
Oily fish are a rich source of long chain omega-3 fatty acids called EPA and DHA. These have beneficial effects on blood pressure, blood stickiness, triglycerides and heart rhythm, as well as reducing the low-grade inflammation associated with circulatory damage.
In the Diet and Reinfarction Trial (DART), men who were advised to eat fatty fish after a heart attack were 29% less likely to die over the two-year follow-up period than those who did not receive this advice.
Eating oily fish twice a week, or obtaining at least 1g omega-3 fish oils per day from pharmaceutical grade supplements (made to a standard known as GMP) has consistently been shown to reduce blood pressure and the risk of sudden cardiac death by around 40%.
The latest review of all the evidence concluded that taking omega-3 fish oil supplements may help to prevent a heart attack in people at high risk of coronary heart disease, such as those who have recently had a heart attack (secondary prevention).
Nuts and heart disease
Nuts provide protein, fibre, vitamins, minerals, isoflavones, antioxidants and cholesterol-lowering plant sterols. They are also a good source of healthy omega-3s and monounsaturated fats which are similar to those found in olive oil.
Eating a handful of unsalted nuts per day (including Brazil nuts, walnuts, peanuts, pecans, almonds and macadamias) can improve coronary heart disease risk factors such as cholesterol balance, blood pressure and blood stickiness. The beneficial effect is so great that substituting just 28g of nut oils per day for the equivalent calories from carbohydrate can reduce your risk of coronary heart disease by 30%, while for women with type 2 diabetes the benefits are even greater with a 44% reduced risk.
Garlic and heart disease
Garlic contains a unique amino acid, called allicin, whose powerful antioxidant improves arterial dilation and reduces blood stickiness. Allicin has also been found to protect heart cells from injury when oxygen levels are low, to reduce the risk of a heart attack and abnormal rhythms.
The results from ten trials, involving over 400 people, suggest that garlic extracts can reduce blood pressure by an average of 16.3/9.3 mmHg in people with hypertension. Other researchers have found that taking the equivalent of 2.7mg garlic per day is sufficient to reduce the risk of a heart attack or stroke by as much as 25%.
Dark chocolate and heart disease
Dark chocolate and cacao are among the richest dietary sources of antioxidant polyphenols. Researchers have consistently found that eating 100g dark chocolate per day can improve arterial dilation enough to lower blood pressure by an average of 5.1/1.8 mmHg and reduce your risk of a heart attack by 27%. Researchers have also found that eating a smaller amount of 45g dark chocolate per day can significantly improve blood flow through the coronary arteries. Select dark chocolate containing at least 70% cocoa solids, and cut back on energy intake from less healthy foods as even a small bar (45g) of dark chocolate contains 200 kcals energy.
Wine and heart disease
Wine contains antioxidant polyphenols, such as resveratrol, which reduce blood stickiness to help prevent unwanted blood clots. Alcohol itself also has a blood thinning effect and increases liver production of ‘good’ HDL-cholesterol. As a result, those who drink a daily glass of wine are 32% less likely to experience a heart attack than non-drinkers.
Although drinking alcohol isn’t recommended as a ‘treatment’ for heart problems, enjoying one glass of wine per day is unlikely to have adverse effects on heart health. Interestingly, the benefits of moderate alcohol intake are greatest in those who follow a poor diet with little fruit or vegetables, exercise for less than three hours per week or who smoke.
As excess alcohol increases blood pressure, can cause heart rhythm abnormalities and weaken heart muscle (cardiomyopathy linked with heart failure), avoid binge drinking and aim to have two or three alcohol-free days per week to give your liver a rest, too.
Tea and heart disease
Both green and black tea provide powerful antioxidant polyphenols similar to those found in dark chocolate and red wine. Drinking tea – at least three cups of green or black tea per day – can reduce your risk of a heart attack by 11% and of a stroke by 21%. Don’t, whatever you do, add sugar to your tea, however, or your risk of diabetes and heart disease will increase.
Salt and heart disease
Excess salt raises blood pressure partly by increasing fluid retention and partly through a direct effect on arterial walls and heart muscle. Studies involving a way of eating known as the DASH diet (Dietary Approaches to Stop Hypertension) show that people who consume the least salt have a blood pressure that is significantly lower than those with a high sodium intake.
Restricting average salt intakes by 9g per day (eg from 12 grams to 3g daily) can reduce your risk of a heart attack by a quarter and your risk of a stroke by a third.
Trans-fats and heart disease
Trans-fats are formed when oils are partially hydrogenated to solidify them when making spreads and margarines. Trans-fats have harmful effects on blood cholesterol levels and increase inflammation and calcification of artery walls to increase the risk of heart disease.
Artificially hydrogenated trans-fats are mostly found in processed and convenience foods. While manufacturers are reducing the level of trans-fats in their products, it’s worth checking labels to select those with the lowest content of partially hydrogenated fats.
Concentrate on obtaining sources of healthy fats such as monounsaturates (eg olive, rapeseed, macadamia, hazelnut, almond and avocado oils) and omega-3s (eg fish and walnut oils).
Wholegrains and heart disease
Wholegrains are an important source of fibre, vitamins and minerals. They have less of an impact on blood glucose levels than processed grains and are an important part of a low glycemic diet.
Tomatoes and heart disease
Tomatoes contain the red antioxidant pigment, lycopene, and people who regularly eat tomato products are 30% to 47% less likely to develop heart disease than those who eat them infrequently. Data from twelve studies suggests that taking lycopene in a dose of 25mg or more per day can reduce LDL-cholesterol levels by around 10% – equivalent to low dose statin drugs. Lycopene also has significant blood pressure lowering effects, reducing systolic blood pressure by around 5.6 mmHg.
The clear jelly around tomato seeds contains over 35 substances that help to reduce the spikiness of blood platelets to reduce unwanted blood clots. A tomato extract now has an authorised EU health claim that it ‘Helps maintain normal platelet aggregation, which contributes to healthy blood flow.’
Coenzyme Q10 and heart disease
Coenzyme Q10 is needed for oxygen processing and energy production in cells – especially heart muscle cells which need a constant supply for energy for contraction. Your production of coenzyme Q10 starts to decline in your mid-20s and, by the age of 50, may contribute to reduced heart muscle strength. If you are taking a statin drug, it is important to know that statins suppress natural coenzyme Q10 production as well as cholesterol synthesis.
In people who have experienced a heart attack, taking coenzyme Q10 (120 mg/day) for one year was found to significantly reduce the risk of experiencing a recurrent non-fatal heart attack compared with placebo (13.7% vs. 25.3%). The most effective form of coenzyme Q10 is ubiquinol, which is twice as bioavailable (absorbed for use) as the ubiquinone form.
Coenzyme Q10 is now a recognised treatment for heart failure in some countries, such as Japan. The usual dose is 100mg ubiquinol per day, which is equivalent to around 200mg of the ubiquinone form.
Magnesium and heart disease
Magnesium plays an important role in muscle contraction and blood vessel dilation. Magnesium deficiency chas been linked with spasm of coronary arteries, increased blood pressure and abnormal heart rhythms.
Research from 40 trials involving over 1 million people, shows that each 100 mg per day increment in dietary magnesium intakes was associated with a 22% lower risk of heart failure and a 7% reduced risk of stroke.
Good sources of magnesium include whole grains, nuts, seeds, dark green leaves, seafood and dark chocolate. Don’t have more than 400mg magnesium per day from supplements, however, as this can caused a laxative effect (which is not always a bad thing, of course).
Vitamin K2 and heart disease
Vitamin K2 is best known for its role in the production of blood clotting proteins. Less well-known is the fact that it helps to regulate where calcium is deposited in the body, and low levels can increase hardening of the arteries due to a build-up of calcium plaques in artery walls.
Research involving over 16,000 women show that every 10mcg increase in dietary intakes of vitamin K2 can reduce the long-term risk of coronary heart disease by 9%.
Vitamin K2 is found in liver, meats, egg yolk, butter, salmon, aged hard cheeses and natto (fermented soy beans). Supplements are also available, but look for those providing vitamin K2 rather than vitamin K1 which is preferentially used in the liver so that little is sent out to benefit your artery walls.
Vitamin D3 and heart disease
Vitamin D is also needed to regulate calcium, improves blood pressure control and helps to strengthen muscle fibres.
The results from 19 studies, involving almost 66,000 people, found that those with the lowest vitamin D levels were 52% more likely to have cardiovascular disease than those with the highest blood levels, and were also more likely to have a fatal heart attack.
You can make vitamin D in the skin on exposure to sunlight when the UV index is less than 3. In many parts of the world, vitamin D synthesis does not occur during autumn and winter, which may partly explain why heart attacks are less common during the warmer months of the year.
Food sources of vitamin D include oily fish, liver, eggs, fortified foods and mushrooms exposed to ultraviolet light. When taking a supplement, select those supplying vitamin D3 which has significantly greater bioavailability than vitamin D2.
Taking a statin drug to lower cholesterol also lowers vitamin D3 levels which may contribute to statin-associated muscle side effects.
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