Diabetes and your heart
Having diabetes increases your risk of several health problems, including problems with your heart and circulatory system. Heart problems include heart disease, heart attacks and angina, which – along with conditions including high blood pressure, stroke, peripheral arterial disease and vascular dementia – are all grouped under the term cardiovascular disease.
Cardiovascular disease, says the NHS, affects around seven million people in the UK and is a significant cause of disability and death (i). According to Diabetes UK, many of these people also have diabetes (ii):
Every week 530 people with diabetes have a heart attack – that’s more than 27,000 every year
Diabetes causes around 100,000 cases of heart failure every year
One in five of all strokes are caused by diabetes
A quarter of people in hospital for a stroke, heart attack or heart failure also have diabetes
Heart problems are very common, both in people with diabetes and those who don’t have diabetes. For instance, heart disease was the most common cause of death in this country for many years, though the latest figures suggest dementia and Alzheimer’s disease are our biggest killers, accounting for 12.7 per cent of all registered deaths in 2018 (heart disease, however, is still the leading cause of death in men) (iii).
What are the risk factors for heart disease?
Besides having diabetes, there are several other risk factors that put you at risk of developing heart problems, including
High blood pressure (especially if you also have diabetes)
Being overweight or obese
Eating foods that contain a lot of saturated fat or salt
What are the symptoms of heart disease?
Since your risk of heart problems are higher if you have diabetes, it’s a good idea to know the symptoms to look out for that might suggest your heart is struggling:
Chest pain, tightness or pressure (this may be angina)
Rapid heartbeat (this may feel like fluttering in your chest)
Feeling faint or fainting
Feeling dizzy or lightheaded
Pain in one or both arms, or in your neck, jaw, throat, back or upper abdomen
Feeling extremely tired
If you experience any of these symptoms, speak to your GP as soon as possible or call 999 for an ambulance if you have chest pain, are struggling to breathe or are fainting.
How does diabetes affect your heart?
Having higher-than-normal levels of sugar in your blood over time can damage your blood vessels, which can lead to complications with your heart. According to Patient UK, even a mildly raised blood sugar level can affect your blood vessels in the long term, even if it doesn’t cause any immediate problems (iv).
If your diabetes isn’t well controlled, all that sugar that your body can’t use builds up in your arteries by sticking to your red blood cells. The damage this causes to the lining of your arteries can make it more easy for cholesterol to stick to it too. All of this can block and damage the blood vessels that transport blood to your heart, making your heart work harder and preventing it from getting all the oxygen and nutrients it needs to stay healthy. High sugar levels in our blood can also damage the nerves in your body, including those that control your heart and blood vessels.
There is also some evidence that high blood sugar levels may drive up levels of inflammation in your blood vessels (v), which could lead to increased cholesterol build-up and hardening of your arteries – both of which hinder blood flow to the heart.
Meanwhile, research funded by the British Heart Foundation has found diabetes may cause subtle structural changes in the heart, making all four chambers of the heart smaller. (vi). The study discovered the left ventricle of the heart in people with diabetes was smaller and had thicker walls, which can lead to heart failure. The scientists also found the other three heart chambers were smaller in participants with diabetes, and have suggested these changes may be the heart’s way of dealing with the early damage caused by diabetes.
What is the connection between diabetes, blood pressure and cholesterol?
It’s widely acknowledged that there’s a link between high blood sugar levels and heart health. But many people with diabetes also have high blood pressure and/or high cholesterol, which can also cause blood vessel damage.
According to Patient UK, high blood pressure is more common in people with diabetes, with around three in 10 with type 1 diabetes and eight in 10 with type 2 diabetes developing it at some point (vii). Some people with diabetes are even more likely to develop high blood pressure if they have any of the following risk factors:
Being of African-Caribbean or Indian origin
Having a family history of high blood pressure
Eating too much salt
Drinking too much alcohol
Having a poor diet
This is why it’s important to keep having your blood pressure checked as often as your doctor or specialist recommends. Find out more about it, including how to keep yours healthy, by reading our guide to blood pressure.
Meanwhile, according to Heart UK, the cholesterol charity, people with diabetes are more likely to have a condition called dyslipidaemia, which is when you have lower levels of HDL (‘good’) cholesterol and higher levels of LDL (‘bad’) cholesterol (viii). This means your arteries are more likely to become narrow or blocked, which is a condition called atherosclerosis – the most common cause of heart attacks. As a result, people with diabetes are often advised to keep their cholesterol within a healthy range that’s lower than that for other people.
There’s lots more information with tips that may help you keep your cholesterol levels healthy in our guide to cholesterol.
The heart and type 1 vs type 2 diabetes
There are two main types of diabetes, namely type 1 and type 2 diabetes. But is either type more associated with heart disease than the other?
Type 1 diabetes:
Type 1 is when your body completely stops making insulin – the hormone that regulates your blood sugar levels. About eight per cent of people with all types of diabetes have type 1, which works out at around one in 300 people (ix).
Type 1 diabetes is associated with a two-to-four-times higher risk of cardiovascular disease in adults who are aged 40 or older, especially if they also have kidney disease (x) (this is also a common complication of diabetes – find out more in our guide to diabetes and kidney disease.
Having type 1 diabetes also makes you more than four times more likely to have a heart attack four-and-a-half times more likely to develop heart failure than someone who doesn’t have diabetes (ii).
Type 2 diabetes:
Type 2 diabetes is more common in people aged 40 or older, though younger people are increasingly being diagnosed with the condition. It happens when your body does make insulin but not enough to keep your blood sugar levels under control, and/or when your body can no longer use the insulin you produce properly (this is a condition called insulin resistance). It’s also more common in people who are overweight or obese. Around 90 per cent of people with diabetes have type 2 diabetes (xi).
People with type 2 diabetes are two-and-a-half times more likely to have a heart attack or develop heart failure than people without diabetes (ii).
Cardiovascular disease is the leading cause of death in people with type 2 diabetes (xi).
There is also some research that suggests people with type 1 diabetes may have a higher risk of developing heart disease than those with type 2 diabetes (xiii).
How to keep your heart healthy
If you have diabetes, the good news is there are a number of things you can do to reduce your risk of developing heart problems.
First, try to make sure your blood sugar levels are managed as well as possible – this includes taking any diabetes medications you’ve been prescribed regularly and as instructed, and having regular blood sugar tests. You may have to do this several times a day or far less frequently, depending on various aspects of your condition – your doctor or a member of your diabetes care team will advise you about testing your blood sugar.
You should also have a special test that measures your HbA1C – that is, your average blood sugar levels for the last two to three months – at least once a year (this test is usually part of your annual diabetes review). Other tests that are part of your annual review include blood pressure and cholesterol tests. Having these tests regularly can also reduce your risk of having heart problems, because if either is too high you can be prescribed medication for them and advised about lifestyle measures that can help keep them healthier.
Some of the other things you can do include the following:
How does smoking affect your heart?
Avoid smoking, as smoking affects your circulatory system, including your heart. According to the NHS, diabetes also worsens the effects of smoking on your heart, so if you’re a diabetic it’s even more important to consider quitting if you’re a smoker. Find out more about giving up, including details of products that can help with nicotine cravings in our guide to stopping smoking.
Is being active good for your heart?
Be active whenever you can during the day – take the stairs instead of the lift, for instance, or walk to the local shops instead of taking the car and generally try to spend less time sitting. Also aim to do 150 minutes of moderate exercise every week (or 75 minutes of vigorous exercise) and some strengthening activities that work all your major muscle groups at least twice a week. If you’re 65 or older, the NHS recommends that you do activities that improve your balance and flexibility too.
Does weight loss improve heart health?
Lose weight if you need to – check if you’re overweight by using the NHS BMI healthy weight calculator and read our guide to the facts about weight loss for some helpful advice. Losing weight can be useful because if you’re carrying too much weight it puts extra strain on your heart. However even a small reduction in your weight can be effective.
What diet is best for heart health?
Eat a nutritious, balanced diet that includes at least five portions of fruit and vegetables every day, as well as wholegrains, oily fish, lean protein and lower-fat dairy foods. Try to cut back on saturated fat – butter, for instance, or full-fat dairy products – and replace it wherever possible with healthier versions such as sunflower, olive and rapeseed oils and spreads. Since too much salt is considered bad for your blood pressure, it’s important to limit salty foods too (the UK recommendation for adults is to have a maximum of 6g salt a day).
How does drinking alcohol affect heart health?
Try to make sure you don’t drink too much alcohol. In this country, we’re advised by the government to drink no more than 14 units of alcohol each week on a regular basis, spreading your drinks evenly over three or more days. Find out more about cutting back on alcohol and how many units are in popular drinks by reading our guide to alcohol misuse.
How does stress affect heart health?
Take steps to reduce your stress levels, as stress hormones can have an effect on your blood pressure, and aim to get plenty of good-quality sleep. Discover how you can help keep your stress levels more manageable by reading our guide to stress symptoms and signs. If you have occasional or more regular problems with sleeping well, there’s also lots of advice you may find useful in our guide to sleep and insomnia.
Natural support for blood sugar control
For further support in keeping the risks to your heart as low as possible, you may want to consider taking nutritional supplements that have been found to help with blood sugar control. It is, however, important to note that supplements should never be used as an alternative to conventional diabetes medicines or medical care.
Meanwhile if you have diabetes always check with your GP before taking these or any other supplements, as there’s a risk your blood sugar could dip too low and put you at risk of a serious complication called hypoglycaemia (hypo).
Find out more about hypos in our guide to diabetes.
One supplement you may want to try first is a good-quality multivitamin and mineral, as it may help make sure your body is getting all the nutrients it needs to stay healthy – with or without diabetes.
If you’re interested in finding out more about multivitamin supplements and the variety of different formulations available, try reading our guide to multivitamins and daily requirements.
Meanwhile you may also want to consider one or more of the following:
A natural remedy that’s been used in traditional Chinese medicine for centuries, cinnamon is a spice that’s also often recommended by natural therapists for people with type 2 diabetes, as there is some evidence it may help improve blood sugar levels (xv).
Alpha lipoic acid
There’s also evidence to suggest this fatty acid and powerful antioxidant could help control blood sugar levels (xvi) as well as improve insulin sensitivity in people with type 2 diabetes (xvii). However, if you have diabetes always consult your GP before taking alpha lipoic acid as it may enhance insulin activity.
Some researchers have found that people who have diabetes may have low magnesium levels (xviii), possibly because having diabetes or taking the medicines used to treat it may cause magnesium deficiency. Others have also discovered magnesium may even help with blood sugar control (xix).
This curry spice contains a compound called curcumin that’s believed to have a number of potential health benefits, including the ability to reduce blood sugar levels (though to date most studies have been carried out in animals rather than humans, meaning the available evidence isn’t as strong as it could be). However, one study has found that curcumin may help improve blood sugar level control after investigating its effects in people with diabetic foot ulcers (xx).
High-strength fish oils
Omega-3 fatty acids – particularly two called EPA and DHA found in oily fish such as salmon, trout, sardines and mackerel as well as fish oil supplements – are widely considered helpful for general health and wellbeing. Studies also suggest taking omega-3 fish oil supplements may reduce the risk of heart attacks and other types of cardiovascular disease (xxi). Studies of the possible beneficial effects of omega-3 supplements in people with diabetes and cardiovascular disease, however, have produced mixed results. But some researchers believe this is because many studies have used too low a dose of fish oils, and that benefits may only be seen in people taking higher doses (xxii). This suggests that, if you want to try taking a fish oil supplement, it’s a good idea to take a high-strength one. Meanwhile vegetarians and vegans can get the same beneficial omega-3 fats by taking supplements that contain EPA and DHA derived from marine algae instead of fish.
Fenugreek seeds have a long tradition of use in some parts of the world, including in Ayurvedic medicine. These days herbal practitioners often recommend fenugreek seeds to people with diabetes, as they may help the body to produce insulin. There’s also some evidence fenugreek seeds may be helpful in controlling type 2 diabetes and reducing insulin resistance, though supporting studies to date are small in scale (xxiii). However, don’t take fenugreek if you’re pregnant or breastfeeding.
Best known for helping the body to absorb calcium, vitamin D is also thought to play an important part in regulating the immune system. Meanwhile researchers have found lower vitamin D levels in people with prediabetes and diabetes are associated with an increase in cardiovascular events – though they didn’t find out whether or not increasing vitamin D levels with supplements would reduce that risk (xxiv). Scientists elsewhere have, however, suggested vitamin D deficiency could affect the development of type 2 diabetes, and that daily supplements may improve blood sugar control (xxv).
Vitamin D deficiency is common, including in the UK. Indeed, Public Health England advises adults and children over the age of one year old to consider taking a daily supplement containing 10mcg of vitamin D, particularly during autumn and winter (xxvi).
However if your skin is rarely exposed to the sun – if you spend most of your time indoors, for instance, or if your skin is always covered when you’re out and about – you may need to take vitamin D throughout the year. People with dark skin from African, Afro-Caribbean and South Asian backgrounds should consider taking vitamin D all year round too, PHE advises.
The recommended form of vitamin D is vitamin D3 or cholecalciferol, as it’s the natural form of vitamin D that the body makes when it’s exposed to sunlight. Vitamin D3 supplements are available in tablet form, and now you can get them in veggie-friendly drops too. However most vitamin D3 supplements are made from the fat of lamb’s wool, which means they’re unsuitable for vegans. The good news is that vegan vitamin D3 supplements sourced from lichen are now more widely available.
Found in dark-skinned fruits such as blueberries, cranberries, raspberries, blackberries and red grapes – as well as vegetables such as red cabbage, red onions and aubergines – anthocyanidins and their derivatives anthocyanins are potent antioxidant compounds. These substances haven’t been linked with blood sugar control, but they may be helpful in that they may strengthen and repair the walls of blood vessels by protecting collagen in the body (collagen being the structural protein that gives blood vessels their strength).
Anthocyanidins are also available in supplement form (choose a product that combines anthocyanidins with vitamin C, as vitamin C supports the body’s ability to produce collagen).
If you have diabetes you’re more susceptible than others to a range of complications, including problems with your heart and the rest of your cardiovascular system. But this guide aims to show how keeping control of your blood sugar as well as other factors such as managing blood pressure and cholesterol can go a long way to keeping your heart as healthy as possible. For more information on a range of heart health issues, take a look at our pharmacy library’s heart health section.
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Disclaimer: The information presented by Nature's Best is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications.
Christine Morgan has been a freelance health and wellbeing journalist for almost 20 years, having written for numerous publications including the Daily Mirror, S Magazine, Top Sante, Healthy, Woman & Home, Zest, Allergy, Healthy Times and Pregnancy & Birth; she has also edited several titles such as Women’ Health, Shine’s Real Health & Beauty and All About Health.