Eat your way to a healthy heart

Coronary heart disease is a major cause of disability and death in the UK, and is among some of the diseases that could be avoided if we adjust our diet and lifestyle. If you are over 40, then you can get a free health check with the NHS, and it is worth it because you may not know your risk, particularly if you feel fit and healthy, as most of the warning signs do not display symptoms!

There are three essential things we need to do to ensure that our hearts stay in good condition: keep our weight down, control our blood pressure and check that our cholesterol levels are healthy. There are many other lifestyle factors that are linked to heart disease such as physical inactivity, stress, poor sleep and cigarette smoking, but for the purposes of this article, we’ll concentrate purely on how food and nutrition can help keep our hearts to top condition.

Weight control

Firstly, let’s look at healthy weight control because if you are overweight, then this will need to be addressed first as it will make tackling all of the other factors easier. So what is a “healthy weight”? Well it depends upon three factors: your age, your gender and your ethnicity. One other crucial factor that we’ll need to look at is where the weight is distributed, because weight held around the waist has repeatedly shown in research to have a direct link with risks of diabetes and heart disease. We frequently think of the waist as the area where our trousers or skirt sits, but in healthcare, we consider the widest part of our abdomen as being the waist, and this is typically the line around the navel or belly button. Knowing how to correctly measure your waist could be important, particularly if you are only moderately overweight.

So the first thing we need to measure is what is known as the body mass index or BMI. This is a figure that gives us an understanding of how much our weight relates to our height, and can be calculated by using the app on the NHS choices website

You can also use table 1 if you already know your BMI, and want to see whether you are of normal weight, underweight, overweight, obese or morbidly obese.

OK, so what if your weight is within the normal or overweight zone (BMI of under 30)? What is the real risk? This is where you need to correctly measure your waist. To do this, you may need help from a partner, and definitely a good tape measure. First, feel for your hip bone and your lowest rib, and then take the tape measure and measure the distance between these two points. Then find the midway point and place one end of the tape measure there and wrap the tape around your waist. Ensure the tape is nice and even (not sloping to one side) and tight against the skin with no slack (but not pressing into the skin) and keep your back straight (you will probably find yourself bending forward to see what you’re doing). Once you have your measurement, table 2 shows you the risk associated with your waist measurement.

Table 1: Body Mass Index and risk of heart disease
Classification	BMI (Kg/m2)	Asian BMI (Kg/m2)	Risk
Underweight	<18.5	<18.5	Low
Normal range	18.5-24.9	18.5-22.9	Average
Overweight	25-29.9	23-27.4	Increased risk
Obese class I	30-34.9	27.5-32.4	Moderately increased risk
Obese class II	35-39.9	32.5-37.4	Severely increased risk
Obese class III	40+	37.5+	Very severe

Table 2: Waist Circumference in centimetres and risk of heart disease
	Men	Asian Men	Women	Asian Women
Increased risk	>93cm		>79cm
Substantially increased risk	>101cm	>89cm	>87cm	>79cm

It might seem unfair that Asian populations have their own smaller ranges, but this is based on obesity having a more dangerous effect on people of certain ethnicities at a lower BMI range and therefore the World Health Organisation set out these guidelines.

The two biggest causes of obesity nutritionally are: eating energy-dense foods and eating large portion sizes. These need to be managed first before the rest of the diet can be adjusted. One good way of doing this is to eat more dietary fibre and to start using smaller plates/bowls to eat from. Following any of the formal dietetic plans like the DASH (lower blood pressure) or Portfolio diet (lower cholesterol) can also help lose weight.

Blood pressure control

Blood pressure is measured by an instrument that detects the force by which blood places upon its blood vessels during two phases of the heartbeat, and thus gives two numbers. The larger or top number (called the systolic) is a measurement of the blood pressure as the heart squeezes to push blood out and around the body; the lower or bottom number (called the diastolic) represents the pressure as the heart rests before the next beat. The perfect blood pressure measurement is 120/80 or slightly lower, and the Blood Pressure UK chart below shows whether your blood pressure is in the high risk range. If your blood pressure is higher, then it means the heart is having to work harder to do its job, and places additional strain on the blood vessels. This can lead to diseases of the kidney, eyes, cause stroke and heart attacks.

How do you know if you have high blood pressure?

You might not! High blood pressure rarely presents with symptoms and therefore it is wise to get a nurse or other trained health professional to measure it for you. Like raised cholesterol, symptoms are fairly unusual and therefore they are sometimes called “the silent killers”.

Cholesterol Control

Cholesterol is a substance that is carried in the blood by a protein called “lipoproteins”. Therefore, when we have our cholesterol tested, we’re having a test for the amount of these carriers we have in our blood. Some of these carriers are often known as either “bad cholesterol” or “good cholesterol”, although in reality cholesterol isn’t bad at all! We need it and could not be living, functioning humans without it; but we can have too much of it. These carriers of cholesterol take cholesterol away from the liver where it is made and deliver it to the cells where it is used; any excess is taken away from the cells and back to the liver for processing. The carrier that takes cholesterol to the cells is known as low density lipoprotein (LDL), and this is the one often called “bad cholesterol” because too much of it can be unhealthy. The carrier that removes cholesterol and takes it back to the liver is thought of as the good cholesterol and is known as “high density lipoprotein (HDL)”. The figures you will be given by your doctor will be the “total cholesterol” figure, which is the sum of all the different carriers that transport cholesterol around the body, and the good cholesterol, HDL figure. If your doctor doesn’t tell you the results, then ask for them. It’s useful to know your results so you can keep track yourself. Total cholesterol should be lower than 5, and HDL should be higher than 1.

Nutritional strategies

In nutrition and dietetics, there are a number of different diet plans that have been developed to improve heart health including the DASH diet, Portfolio diet and the UCL Plan; many of which are based on the Mediterranean diet, so the principles among these are relatively similar. These diets tend to be plant-based, which means ensuring that the largest part of our diet comes from plants

such as fruit, vegetables, whole grains and pulses; eating a little lean meat and fish, and including some dairy. Plants contain natural sources of sterols and stanols, which compete with cholesterol for absorption into the body from the gut. We will look at the highlights of these for preventing heart disease.

Fat

The type of fat we eat has been horribly confusing recently. There have been several headlines over the last year or two suggesting that scientists have had it all wrong about saturated fats, and that it’s OK to eat butter, lard and other sources of saturated fats, because they do not lead to heart disease. This lead to a campaign against carbohydrates, and making them the villain; fats were suddenly hailed as being healthy. Yet government health departments in most countries have not changed their stance around advice for saturated fat, and those that did, quickly changed back again.

So why? It’s all to do with how you read and understand the science literature. The truth is, saturated fats in food such as butter, ghee and fat in meat are not a single entity. There are different types of saturated fats and, moreover, they all affect different types of blood cholesterol carriers. This is a complicated field and not an easy one to explain to the public without being technical. Simply put, your cholesterol is packaged up into little bundles so that it can be transported around the body. Cholesterol is really important to us, as we need it to make hormones, to make vitamin D and create the skeleton that holds cells together. However, too many of these packages that carry cholesterol can clog up arteries that feed the heart; specifically, too many of these packages that carry cholesterol away from the liver. As discussed, proteins that carry cholesterol back to the liver are considered “good”, and are often called “good cholesterol”. Some types of saturated fats raise the group of proteins that take cholesterol to the cells, often termed (wrongly) as “bad cholesterol”, and over time, these can accumulate in the blood vessels forming a plaque that can eventually block it and stop blood from reaching the heart muscle, which can cause a heart attack.

Some science suggests that when you remove saturated fats from the diet and replace these with carbohydrates, the risk of heart disease does not change, and that is why carbohydrates became the demon and saturated fats were considered healthy. However, if you replace saturated fat with non-saturated fats, such as those found in plants and fish, the risk of heart disease falls.

Therefore, trained dietitians and nutritionists will always advise you to keep saturated fats in your diet at a low level (less than 10% of total daily calories), and where you can, replace them with plant oils such as olive oil, rapeseed or groundnut oil. Experiment with walnut or avocado oils for salads or add to the end of cooking (they don’t react to heat so well). You can still use butter or coconut oil, but these should be used much less frequently. For meat, choose lean cuts and for poultry, avoid the skin, and try and eat fish at least twice a week to get some of these great polyunsaturated fats into your body, as these are known to be heart protective. Best fish are small oily fish like mackerel, salmon, herring and sardines because these are great sources of omega-3 oils, and tend to have lower levels of ocean pollutants than larger fish like marlin or swordfish

Trans fats

There is one type of fat that can be hidden in our food where there’s no doubt causes bad health-effects and that’s trans saturated fats. These fats occur naturally in nature where their effect is benign, but they can also be manufactured by subjecting liquid oils to very high temperatures to produce a solid fat. The only way you can tell if this is in the food you buy is to look for the ingredient “hydrogenated vegetable oil” or “partially hydrogenated vegetable oil”. Thankfully, British manufacturers have largely removed them from their products, but you may still see them around, so it is worth looking at the ingredient list of your most frequently bought food items to ensure you’re not consuming too much. To avoid them when eating out, choose foods that have not been fried or foods (such as pastries and cakes) that are not high in fat.

Dietary cholesterol

If you know that you have too much cholesterol in your blood, you may need to reduce it to safer levels. Food sources of cholesterol do not appear to influence blood levels very much, but if you have very high cholesterol or you have been told you have a genetic condition called familial hypercholesterolaemia, then it’s probably sensible to limit cholesterol to 300mg per day. This means limiting the consumption of shellfish, offal, eggs and avoid fatty meat. For everyone else with raised cholesterol, discuss this with your doctor or dietitian, since you probably will not need to restrict eggs or shellfish (only egg yolk has cholesterol and the most popular shellfish like mussels, clams, scallops and oysters contain very little).

Salt

Salt is partially responsible for driving up blood pressure. Adults should ideally keep their daily salt intake to less than 6g, or one level teaspoon – but there are initiatives to bring this down to half that at 3g! Research suggests that many of us consume an average of 8g per day, so there’s a long way to go to get the nation’s love of salt under control. Many food manufacturers are slowly reducing the amount they use, because a sudden change will make food taste too bland to consumers; if it is gradually reduced, it is unlikely that many of us would notice. Reducing salt suddenly is problematic, because our taste receptors are used to flavours the way they are, and therefore they have to be slowly educated, and thus salt should be reduced little by little.

Foods highest in salt include:

-bread, breakfast cereals, crackers

-cheese

-ready meals

– dried meals (like noodle-based snacks)

-processed meats

-cooking sauces and ketchups

-stock cubes, bouillon, sauce packets

Advice:

* Avoid using salt at the table and, start to think about putting less into cooking little by little until you are used to the new flavour.

* Flavour foods with herbs, spices and, for the adventurous, a pinch of dried seaweed such as nori flakes.

* Look for foods with less than 0.3g of salt per 100g.

Carbohydrates

Free sugars are the biggest problem in our diet. These are the sugars that we add to our food, or found in processed foods such as jarred sauces, ketchups, ready meals, tinned foods, yoghurts and desserts. Eating foods high in sugar can prevent our cells from responding to the hormone insulin, which is responsible for taking sugar out of our blood and into our cells. This is called “insulin resistance”, and over a period of time can lead onto type 2 diabetes and then heart disease.

We need carbohydrates, eliminating them from our diets is not particularly healthy, because removing them means we remove our only source of dietary fibre, a wide range of vitamins and minerals, and the preferred source of energy for our body: glucose. However, the type of carbohydrates we should choose is important, and that is where the concept of “glycaemic index (GI)” or “glycaemic load (GL)” comes in. If we choose foods that are low in GI/GL, then we reduce our risk of heart disease and diabetes. Choose whole grains, whole fruits and vegetables (rather than juices), nuts and seeds, and pulses such as beans, lentils and chickpeas.

Soy

Soy is something that is associated with Asian cuisine, vegetarians and vegans – yet it is a good source of plant-based protein that we could all introduce into our diet from time-to-time. Evidence shows that exchanging 15-25g of animal protein (meat/dairy) for soy protein lowers LDL (bad) cholesterol. You can introduce soy into your diet by using tofu, tempeh, or soy milk. Tofu has a bland flavour and therefore does not overpower any dish you add it to. You can increase the protein of smoothies or soups, for example, by blending in a little tofu and you’d never know it was there; but your body would.

Vitamins and minerals

It is always preferable to get vitamins and minerals from the diet rather than supplements, but there are occasions when it might be necessary to supplement. It’s advisable to follow the advice of a healthcare provider rather than self-medicate, because taking too many supplements can result in toxic levels of some compounds in the blood. Moreover, if you are already on medication, there can be interference between different drugs, supplements, herbal preparations or natural/holistic medicines.

A blood constituent called homocysteine (a type of amino acid that can damage the inside of blood vessels) has been linked with high risk of heart disease, and keeping this low could be important. A diet with good sources of B vitamins and folate is important for this, so eating dark green leafy vegetables, whole grains and pulses will certainly help. Blood pressure could be improved by potassium and magnesium in foods, which include fresh fruit and vegetables.

If you have high blood pressure, it is advisable to avoid liquorice and liquorice-based products as its possible this raised blood pressure in some people.

Vitamins and minerals in food

Good sources of potassium: greens (beet greens, kale and spinach), beans (pinto beans and broad beans), baked potato, herbs (parsley and coriander), portabello mushrooms.

Good sources of magnesium: seeds (pumpkin or squash, flax, sesame), peanut butter and nuts (brazil, almonds, cashew), herbs (marjoram, tarragon and thyme) and whole grains (oats, bran, brown rice and quinoa).

Good sources of folate: dark leafy greens (spinach, kale, turnip greens, collards, endive, rocket) seaweed (kelp), asparagus, okra, artichokes and beans.