What can I do to keep my heart and blood vessels healthy?

There is plenty of dietary advice out there – and lots of supplements that supposedly improve your health.

But only a very small number of these recommendations are based on high-quality research. So a lot of the advice can be ignored.

If you want to change your eating habits, it’s best to follow recommendations that are based on solid scientific evidence. Most experts agree that people shouldn’t eat or drink too much of the following:

• Foods containing a large amount of saturated and trans fatty acids
• Foods and drinks that are particularly high in sugar
• Heavily processed foods
• Salt
• Alcohol

There are various reasons for these recommendations. The most important thing is to keep an eye on your calorie intake. Eating and drinking products that contain sugar or are heavily processed can increase the long-term risk of becoming overweight. In addition, saturated fats and trans fatty acids are more likely than other fats to have a negative effect on cholesterol. Too much salt can make your blood pressure go up.

There's usually no need to completely cut out the things you like to eat. But there are good reasons to make sure you only eat unhealthy things occasionally and in moderation – and then really enjoy them! And, anyway, it's often difficult to be very strict about what you eat.

Many people overestimate the effect their diet has on their cholesterol. In fact, 90% of our cholesterol is produced inside the body and only about 10% comes from our food. So eating habits only have a limited effect on cholesterol levels.

It is sometimes claimed that drinking moderate amounts of alcohol (red wine, for example) is good for the heart, but there is no proof of this. On the contrary, alcohol is more likely to increase the risk of heart disease.

A person's total fat intake doesn't have a major impact on their risk of cardiovascular disease. But the type of fat is important. There are three different types:

• Saturated fatty acids tend to cause a rise in the level of LDL cholesterol in the blood. LDL cholesterol is harmful to the body. Saturated fatty acids are mainly found in animal fat but are also contained in some solid vegetable fats such as palm or coconut oil.
• Unsaturated fatty acids have less of an effect on LDL cholesterol. They're mainly found in vegetable oils and fats like olive oil, avocados, nuts and seeds.
• Trans fatty acids are an industrial byproduct of the process of solidifying vegetable oil. They can also occur when vegetable oil is heated to a high temperature to be used for deep-frying, for instance. Trans fatty acids resulting from food processing are considered to be particularly harmful.

In Germany and the rest of the EU, industrially produced trans fatty acids are not allowed to account for more than 2% of the total fat content of a food product. This has resulted in an almost total disappearance of trans fatty acids in certain products that used to contain large amounts of them – like margarine.

Dairy and meat products from cows, goats and sheep can also contain trans fatty acids. This is because special enzymes in their stomach convert unsaturated fatty acids into trans fatty acids. There are no legal limits on these natural types of trans fat. They have a different chemical makeup from industrial trans fatty acids and appear to have fewer disadvantages in terms of health.

Experts don't always agree on all aspects of fat in foods. For example, there are different views about the importance of where saturated fatty acids come from and their exact chemical makeup. One of the reasons for this is that it's difficult for researchers to produce reliable findings when it comes to diet.

Research has shown that people were able to lower their risk of cardiovascular disease by reducing their intake of saturated fatty acids – especially those found in sausages, high-fat meats and dairy products.

If you're thinking of making changes to your diet, it's important they're ones you can stick to. Research findings show that it takes two years for the health benefits to kick in.

The following table lists examples of food products that are high in saturated fatty acids – and alternative products.

The following tips can help you cut down on saturated fatty acids too:

• Check the fat content of dairy products. The lower the total fat, the fewer saturated fatty acids they contain.
• Cut off any visible fat on meats.
• Be aware when choosing fats and oils that saturated fats (like butter and palm/coconut oil) are solid at room temperature and unsaturated fats are liquid (olive or rapeseed oil, for example).

"Mediterranean diet" is the term given by nutritionists to a diet rich in vegetables, fruits, legumes, nuts, olive oil, whole grain products, fish and poultry. It meets many of the recommendations for a nutritionally balanced diet.

Research has shown that eating this type of diet helps reduce risk factors for cardiovascular disease. One major study also found that the risk of vascular disease decreased over a five-year period.

The vast majority of experts recommend regular exercise to strengthen your heart and vessels. As well as potentially positive impact on cholesterol levels, exercise and sports keep your vessels fit and make them more elastic. This can reduce blood pressure too. Exercise and sports can also help you lose weight, strengthen your muscles and bones and improve your general level of fitness and wellbeing.

The World Health Organization (WHO) recommends that adults should:

• do at least 150 to 300 minutes of moderate-intensity aerobic physical activity per week, or
• 75 to 150 minutes of vigorous-intensity aerobic physical activity per week, or
• a combination of the two,

and

• do muscle-strengthening activities (like weight training) on two days per week, and
• incorporate lots of physical activity into their day-to-day life and spend less time in a seated position.

"Aerobic physical activity" means things like Nordic walking, hiking, jogging, cycling or swimming. If you haven't done much in the past, it's best to increase your level of physical activity gradually. You can ask your doctor which types of sports would be good for you, whether there are any reasons not to take up certain sports and the best way to get started.

According to the WHO, any aerobic physical activity that lasts at least ten minutes is beneficial. It doesn't matter if you exercise for 30 minutes in one go or incorporate three ten-minute activities into your day.

Lots of people find it easier to stay motivated if they

• do physical activities with their families or friends,
• start off slowly and then gradually do more, and/or
• keep a record of their activities on a smartphone app or fitness tracker.

The important thing is to find something you like doing and that fits in with your day-to-day schedule.

Being very overweight increases the risk of cardiovascular disease. People are considered to be very overweight if they have a BMI of over 30. BMI stands for “body mass index” and the higher it is, the higher the risk of illness.

People with a BMI above 30 are recommended to lose 5 to 10% of their weight. This is only possible if they make permanent changes to their diet. Exercise can help but it’s not enough on it’s own. There are a number of programs available to help people lose weight.

Smoking can increase the amount of LDL cholesterol (“bad” cholesterol) in the blood. But it damages the blood vessels in other ways too. It can cause minor inflammation on their inner walls, leading to a higher risk of deposits on the walls and blood clots. Smoking also causes the coronary arteries (the vessels that supply the heart) to become narrower.

Research shows that smoking significantly increases the risk of cardiovascular disease and that the risk is higher the more a person smokes. But if they manage to give up, they can also prevent cancer and lung disease and increase their overall life expectancy.

Most smokers do manage to stop if they’re motivated enough but it often takes quite a few attempts. The right preparation, support and special products to help reduce withdrawal effects (like nicotine replacement therapy) can help.

There is a wide variety of products for sale that are meant to reduce cholesterol and promote cardiovascular health. Many of them are sold as highly concentrated dietary supplements in the form of capsules. But none of these supplements has so far been proven to provide protection against medical problems such as heart attacks or strokes.

Examples of supplements that have not been proven to be effective include:

• Artichoke extract
• Fish oil
• Garlic
• Guggul
• Policosanol (a sugar cane extract)
• Products containing soluble fiber such as psyllium husk
• Green tea extract (catechin extract)

There are even some supplements that experts advise against. For instance, good-quality, large-scale studies carried out in recent years have repeatedly shown that fish oil capsules containing omega-3 fatty acids can increase the risk of an irregular heartbeat ( atrial fibrillation).

In addition, even if a supplement does improve a person’s cholesterol levels, it doesn’t mean that it also decreases their risk of developing medical problems such as a heart attack. The cholesterol level alone cannot prove whether a treatment is effective.