Introduction
Definition of cardiovascular health
The cardiovascular system in your body consists of your heart and your blood vessels, which include:
- Arteries, which transport oxygenated blood away from the heart and around your body
- Veins, which transport deoxygenated blood back to the heart
- Capillaries, which are the smallest blood vessels and allow nutrients to be exchanged for cellular waste at your tissues
Cardiovascular health is therefore the health of our heart and our blood vessels.
The role of diet in cardiovascular health
Diet is crucial in preventing cardiovascular disease, which can include conditions such as angina and heart disease. Vitamins such as potassium and sodium play a role in reducing blood pressure, which prevents damage to our blood vessels. 800g of fruits and vegetables a day has also been shown to reduce our risk of developing cardiovascular disease, keeping our heart and blood vessels healthy. However, having more red meat and processed meats in our diet, such as sausages, increases the risk of cardiovascular disease.1
Certain diets have been shown to reduce the risk of cardiovascular disease, such as the Mediterranean diet. This consists of moderate alcohol intake, a low amount of processed and red meat, and a low amount of dairy. A Mediterranean diet is high in fruit and vegetables, wholegrains and fish as well as unsaturated fatty acids.1
Importance of lemons in diet
Lemons are important in our diet as they contain vitamin C, which reduces the risk of heart disease. Hesperidin and diosmin are plant compounds which are also found in lemons, and have a role in reducing cholesterol. Certain types of cholesterol can cause fatty deposits to develop in our arteries, restricting the amount of blood flow reaching our tissues.
If one of these fatty deposits is in the coronary arteries, which provide blood to our heart muscle, this can stop blood flow to our heart and cause a heart attack as the cells in our heart muscle die. This is because blood contains many nutrients for our cells to survive, such as oxygen and glucose (a sugar).
Nutritional profile of lemons
Vitamin C content
Lemons are important in our diet as they contain approximately 31mg of vitamin C per lemon, which is 51% of our daily recommended intake of vitamin C. Vitamin C has been shown to reduce our risk of heart disease, thus keeping our heart and blood vessels healthy.
Fiber and antioxidants
Lemons contain a soluble fibre known as pectin. Pectin can lower blood sugar levels by slowing down the digestion process. This is good for our cardiovascular health as high blood sugar can damage the arteries. Over time high blood sugar can cause the arteries to harden and lead to a condition known as atherosclerosis.
Low calorie and low sugar
Lemons contain a low amount of calories and sugar, with one lemon usually containing 17 calories and 1.5 grams of sugar.
Lemon benefits for cardiovascular health
Blood pressure regulation
1.) Potassium content
Lemon juice contains potassium which helps to maintain healthy blood pressure levels. Potassium counteracts the effects of sodium, which contributes to high blood pressure.
Vitamin C content
Lemons also contain vitamin C, which has been shown in a study in the American Journal of Clinical Nutrition to reduce systolic and diastolic blood pressure over an 8 week period.
2.) Reduction of hypertension risk
Hypertension is high blood pressure in the arteries. Therefore by consuming potassium, which is found in lemons, this will counteract the effects of sodium which is responsible for high blood pressure. This is because more potassium in your diet results in more sodium being lost in your urine.
Cholesterol management
1.) Pectin and fiber
Pectin is a soluble fibre found in lemons, and can lower blood sugar levels by slowing down the digestion process.
2.) Reduction in LDL cholesterol
Pectin reduces the amount of low density lipoprotein (LDL cholesterol) in the blood. This is because pectin binds to LDL cholesterol in the digestive tract and ensures that it is eliminated from the body and not absorbed by the blood.2
LDL cholesterol is known as the ‘bad’ cholesterol in the body. When LDL cholesterol builds up in the arteries it forms plaques which restricts blood flow in your arteries, and results in atherosclerosis, which is when your arteries harden. This can in turn increase our risk of having a heart attack, a stroke, or peripheral artery disease due to there being restricted blood flow to our organs and tissues.
Improved blood vessel function
Eating lemons and drinking lemon water can improve our blood vessel function. Lemons contain a high amount of vitamin C, which lowers blood pressure. Lemons also contain potassium, which counteracts sodium in the blood and prevents high blood pressure. Drinking lemon water can also reduce inflammation, which in turn leads to improved blood vessel function.
High blood pressure can impair artery function by damaging the inner walls of the arteries, allowing fats and LDL cholesterol to collect in the damaged arteries and limit blood flow to key organs and tissues in the body.
1.) Antioxidants and endothelial health
Lemons contain flavonoids, which are antioxidants. Flavonoids have been shown to reduce endothelial dysfunction, where the inner lining of blood vessels does not function correctly, which can result in limited blood flow in our arteries.
2.) Enhanced blood flow
Lemons are rich in vitamin C, which increases the amount of nitric oxide available for the cells in our body to use. Nitric oxide in turn relaxes our blood vessels, causing them to increase in diameter, and increasing blood flow to our tissues and organs. This allows more nutrients, such as oxygen and glucose to reach our cells.
Lemon consumption recommendations
Daily lemon intake
In order to reap the benefits of lemon juice you may need to consume 3 quarters of a cup of pure lemon juice. This allows you to consume your daily recommended amount of vitamin C: 75 mg for women and 90mg for men.
Incorporating Lemons into the Diet
1.) Lemon water
If you dislike the taste of water adding lemon to it may be one way of incorporating lemons into your diet, and increasing your vitamin C.
2.) Lemon zest in cooking
Lemon zest can be incorporating in cooking and can serve as a garnish, or can be added to baked goods as well.
3.) Lemon Juice as a Salad Dressing
Lemon vinaigrette can be added to salads as a dressing too.
Precautions and considerations
Dental health
The acid in lemons can erode away the enamel on the teeth, and may result in the formation of dental cavities on our teeth.
Allergies
Eating lemons may result in allergic reactions, including the following:3
- Atopic dermatitis
- Anaphylaxis
- Allergic rhinoconjunctivitis
Interaction with medications
Chemicals in lemon juice can interact with certain medications, and this may cause the medication to be broken down by your digestive system. As a result, the medications will not elicit their desired effect.
Summary
- Lemons are rich in vitamin C, and potassium which both have benefits for our cardiovascular health
- The potassium in lemons can help lower blood pressure and prevent damage to our arteries
- Lemons are rich in fibre, helping to reduce blood sugar and reduce the risk of cardiovascular disease as blood sugar can damage our arteries
- Lemons can reduce the amount of low density lipoprotein (LDL) cholesterol in the blood, which can cause fatty deposits to develop in our arteries, restricting blood flow to our organs and tissues
- Lemons can cause dental erosion, especially to the enamel of our teeth
- Lemons may also cause some allergies too
- A balanced diet is important for our cardiovascular health to ensure that we receive all the nutrients and vitamins that we need, as not all nutrients are found in just one food group
References
- Verschuren WMM, Boer JMA, Temme EHM. Optimal diet for cardiovascular and planetary health. Heart [Internet]. 2022 Aug 1 [cited 2023 Oct 25];108(15):1234–9. Available from: https://heart.bmj.com/content/108/15/1234
- Gunness P, Gidley MJ. Mechanisms underlying the cholesterol-lowering properties of soluble dietary fibre polysaccharides. Food Funct. 2010 Nov;1(2):149–55.
- Zuidmeer L, Goldhahn K, Rona RJ, Gislason D, Madsen C, Summers C, et al. The prevalence of plant food allergies: A systematic review. Journal of Allergy and Clinical Immunology [Internet]. 2008 May 1 [cited 2023 Oct 27];121(5):1210-1218.e4. Available from: https://www.sciencedirect.com/science/article/pii/S0091674908004065