Our heart works 24 hours, continuously, without breaks, throughout our lives. We must protect and nurture it. How? The answer is saying “yes” to sustainable, healthy eating habits and regular physical activities. Small and consistent efforts over time give massive results. The DASH diet is one such approach towards making your heart healthy. This article deals with the DASH diet, how it helps protect our heart, heart enlargement, symptoms, risk factors, causes, diagnosis, complications of heart enlargement, and how the DASH diet prevents heart enlargement.
What is the DASH diet?
DASH stands for Dietary Approaches to Stop Hypertension, and was first introduced by researchers from the National Heart, Lung, and Blood Institute (NHLBI), and has also been studied extensively by Fung et al. and others. It is a dietary pattern designed to lower blood pressure (BP), but it has several beneficial effects on heart health too.
The DASH diet focuses on:
- The consumption of vegetables, fruits, whole grains, nuts, fish, low-fat dairy, and poultry
- Decreasing the intake of red meat, sweets, saturated fats, cholesterol, and sugary beverages
- Reducing salt intake1
- Increasing the intake of foods rich in potassium, magnesium, and calcium2
- How does the DASH diet help in protecting heart health?
The DASH diet improves lipid profiles, insulin sensitivity, and lowers blood pressure.2
The high fibre obtained from the consumption of fruits and vegetables is a rich source of antioxidants that improves insulin resistance. The high fibre reduces appetite, keeps you satiated, and in a calorie deficit, thereby reducing body weight. The triglycerides, blood pressure, and waist circumference decrease with a reduction in body weight.2,5
The electrolytes like potassium, magnesium, and calcium help regulate blood pressure by increasing the urine output and blood vessel dilatation. The high fibre ferments in the intestine and enhances the absorption of potassium and magnesium. Magnesium regulates the tone of blood vessels by altering intracellular calcium levels.1,5 Moreover, reducing saturated fats lowers the LDL and VLDL levels.5
What is heart enlargement?
An average adult heart measures 12–13 cm in length, 8–9 cm in breadth, and 6 cm in thickness. Its diameter is approximately 4–5.6 cm, with an average weight of 250–300 grams. Cardiomegaly, or heart enlargement, occurs when the heart weighs more than 450 grams, has a diameter of more than 5.6 cm, and is longer than 15.5 cm. A chest X-ray helps diagnose heart enlargement.3
Clinical features of heart enlargement
The symptoms vary from
- Fainting
- Swelling, especially in the legs, feet, or abdomen
- Fatigue
- Abnormal cardiac rhythm
- Weakness
- Shortness of breath while lying down or waking up early morning3
Risk factors for the development of heart enlargement
- Family history of an enlarged heart
- Heavy alcohol intake
- Tobacco use.
- High blood pressure
- Lack of exercise
Causes of heart enlargement
Whenever the heart encounters stress, be it physiological or due to diseases, it has to work harder. In order to compensate for the increased workload, it has to increase its size. The following table illustrates some examples of conditions causing heart enlargement.
Pathological causes
- Congenital heart defects (e.g., defects in the atrial or ventricular septum)
- Cardiomyopathies (diseases of the heart muscle), including:
- Dilated cardiomyopathy
- Hypertrophic cardiomyopathy
- Restrictive cardiomyopathy
- Valvular heart defects (affecting the valves separating atria, ventricles, and blood vessels), such as:
- Mitral stenosis
- Tricuspid regurgitation
- Pericardial effusion (collection of fluid between the layers around the heart)
- Fat around the heart
- Hypertension
- Pulmonary hypertension
- Hemochromatosis (accumulation of iron in the heart)
- Amyloidosis (deposition of amorphous material in the heart)
- Thyroid disorders
- Anaemia
Physiological causes
- Exercise
- Pregnancy
- Post-heart attack (myocardial infarction)
Cardiac enlargement induced by exercise or pregnancy is mild and reversible. However, the pathological enlargement causes heart dysfunction and failure. In such conditions, there is a compensatory increase in the size of the heart because of increased workload on the heart. Whenever there is cardiomegaly, there is a mismatch between oxygen demand and supply, which predisposes to heart attack, disturbed rhythm, stroke, and even death. At the cellular level, the heart muscle cells increase in size, and there is enhanced protein synthesis.6
The status of an enlarged heart and its activity can be judged by:
- Chest X-ray: It provides information about the dimensions of the heart
- CT scan: It shows the heart's muscles and all of its chambers
- Transthoracic echocardiogram: It is combined with ultrasound to check the blood flow of the heart
- Electrocardiogram (EKG): It studies the electrical activity of the heart
- Exercise stress test: It is used to assess the function of the heart in response to stress induced by exercise and medicines
- MRI: It provides images of the inner structures of the heart
- Genetic testing: Its purpose is to rule out the hereditary reasons of an enlarged heart
Complications of an enlarged heart
- Heart failure: The heart is not able to pump a sufficient amount of blood, which is required to meet the requirements of our body. Usually, it occurs when the left ventricle gets enlarged
- Blood clots: When the heart is not able to contract or relax properly, there is stasis of blood in the chambers of our heart, which leads to the formation of blood clots. These blood clots can migrate to various organs of our body through circulation. This phenomenon is called embolism. Depending upon the site, where these clots lodge, you may suffer from a heart attack, pulmonary (lungs) embolism, and even stroke
- Valvular dysfunction: Whenever there is an increase in the size of the heart, the heart valves don’t close properly, and the blood from one chamber of the heart can leak back to another chamber. It’s called regurgitation, and it produces abnormal heart sounds called heart murmurs when heard on a stethoscope
- Abnormal heart rhythm (Arrhythmias): The heartbeat becomes irregular and disordered, which may lead to fainting, a heart attack, or sudden death
Treatment of heart enlargement
The treatment depends on the underlying cause. Lifestyle modifications combined with pharmacological treatment, along with surgery, can reduce morbidity and mortality. The heart medications, such as Antiarrhythmics, Angiotensin-converting enzyme (ACE) inhibitors, Angiotensin II receptor blockers (ARBs), Anticoagulants, Beta-blockers, and Diuretics, are prescribed to lower the blood pressure, prevent the formation of blood clots, prevent the accumulation of fluid in our body, and maintain the normal rhythm of the heart. The surgical approach includes implantation of a pacemaker, cardioverter defibrillator (ICD), repair of a damaged heart valve, Coronary artery bypass surgery, or stent placement.
How does the DASH diet prevent heart enlargement?
The DASH diet not only improves heart health, but it has several other benefits too. The DASH diet indirectly affects factors responsible for cardiac enlargement, such as hypertension. Over time, it leads to blockage of blood vessels by causing injury to the inner layer of blood vessels (endothelium) and promoting the formation of atherosclerotic plaques. These changes put a load on the heart, eventually leading to heart failure. The consumption of fruits and vegetables as recommended in the DASH diet provides antioxidants, which scavenge free radicals and prevent inflammation. The consumption of fish provides omega-3 polyunsaturated fatty acids, which are cardioprotective.4
Clinical trials have shown that the DASH diet is effective in reducing blood pressure and low-density lipoprotein cholesterol levels and can prevent heart failure. A study by Fung et al. (2008) found a significant correlation between the DASH diet and the incidence of coronary heart disease and stroke.7
If untreated, high blood pressure can lead to heart enlargement, mainly the left ventricle. The low-salt DASH diet can help lower blood pressure in obese or overweight persons, even if they don't take medicines.1
Obesity is one of the major risk factors for developing high blood pressure and metabolic syndrome. The DASH diet aids in weight loss, thereby reducing the risk of cardiovascular mortality.
Summary
Keeping your heart healthy is simpler than you might think. Lifestyle modification and wise food choices are all that's required for good heart health. By emphasising the consumption of foods rich in fibre, minerals like potassium, calcium, magnesium, and limiting salt intake, the DASH diet reduces risk factors associated with heart enlargement and heart failure, such as high LDL-Cholesterol (low density lipoprotein), and triglycerides. It improves insulin sensitivity, relaxes blood vessels, and promotes weight loss. These factors prevent the thickening of the heart muscles, lower blood pressure, and lessen the strain on the heart.
References
- Çapar AG, Yılmaz M. Which is more effective in hypertension?: Salt-free diet vs DASH diet. Medicine 2025;104:10(e41636).
- Liu J, Yang R, Ma P, Zhu X. Association between DASH diet and metabolic syndrome in US adults: a cross-sectional study. Front Public Health. 2025;13:1524399. doi:10.3389/fpubh.2025.1524399.
- Ayalew AM, Enyew B, Bezabh YA, Abuhayi BM, Negashe GS. Early-stage cardiomegaly detection and classification from X-ray images using convolutional neural networks and transfer learning. Intell Syst Appl. 2024;24:200453. doi:10.1016/j.iswa.2024.200453.
- Jiang R, Wang T, Han K, Peng P, Zhang G, Wang H, et al. Impact of anti-inflammatory diets on cardiovascular disease risk factors: a systematic review and meta-analysis. Front Nutr. 2025;12:1549831. doi:10.3389/fnut.2025.1549831.
- Dina C, Tit DM, Radu A, Bungau G, Radu A-F. Obesity, dietary patterns, and cardiovascular disease: a narrative review of metabolic and molecular pathways. Curr Issues Mol Biol. 2025;47(6):440. doi:10.3390/cimb47060440.
- Samak M, et al. Cardiac hypertrophy. Med Sci Monit Basic Res. 2016;22:75–79. doi:10.12659/MSMBR.900437.
- Levitan EB, Wolk A, Mittleman MA. Consistency with the DASH diet and incidence of heart failure. Arch Intern Med. 2009;169(9):851–857. doi:10.1001/archinternmed.2009.56.
- Young B, O’Dowd G, Woodford P. Wheaters Functional histology: a text and color atlas. 6th edition; 2013.
