High blood pressure (also known as hypertension) is one of the key risk factors for heart disease. The lifetime risk of developing high blood pressure is estimated to be 90% and is predicted to affect 1.56 billion people worldwide by 2025.
Research has shown that maintaining blood pressure within a normal range reduces the risk of cardiovascular complications, both for those with high blood pressure and those with moderately high blood pressure.
Blood Pressure Readings
A blood pressure reading has two numbers. The top number, known as systolic, refers to the amount of pressure in your arteries during the contraction of your heart muscle. The bottom number, called diastolic, refers to your blood pressure when your heart muscle is between beats.
Normal systolic pressure is below 120. A reading of 120-129 is elevated, 130-139 is stage 1 high blood pressure and 140 is stage 2 high blood pressure.
Normal diastolic blood pressure is below 80. However, even if your diastolic number is lower than 80, you can have elevated blood pressure if the systolic reading is 120-129. A reading of 80-89 is stage 1 high blood pressure and 90 or more is stage 2 hypertension.
As there is such a large number of people with high blood pressure, it is not realistic to be able to treat all of them with antihypertensive drugs. International guidelines, therefore, promote dietary and lifestyle interventions to reduce blood pressure levels.
Advice includes reducing salt and alcohol intake, becoming more physically active and eating more fruit and vegetables. Supplementation can also help to enhance the effects of these strategies.
Helpful Supplements for High Blood Pressure
Cocoa
Cocoa extract is comprised of xanthine molecules (theobromine and caffeine) and procyanidins. These contain compounds, including procyanidins, epicatechin and flavanols.
A large number of dietary flavonoids have a beneficial impact on heart health, including antioxidant, anti-inflammatory effects and improving nitric oxide metabolism and endothelial function. A higher intake of these is also associated with a lower risk of heart disease.
A meta-analysis of 20 double-blind, placebo-controlled randomised-controlled studies of 856 people found that cocoa flavonoids had a statistically significant lowering effect on blood pressure, when taken over a period of between 2 and 18 weeks and when between 3.6 and 105g of cocoa products were consumed per day.
How to take cocoa
The standard dose for cocoa flavonoids is 500 – 1,000mg a day, taken with meals. Intake can also be boosted through the consumption of dark chocolate. However, this must be at least 85% cocoa solids to have a beneficial effect.
Omega-3 polyunsaturated fatty acids (PUFAs)
The two major classes of polyunsaturated fatty acids (PUFAs): omega-3 and omega-6 fatty acids. Like all fatty acids, PUFAs are comprised of long chains of carbon atoms with a carboxyl group at one end of the chain and a methyl group at the other. They are different from saturated and monounsaturated fatty acids because they have two or more double bonds between carbons within the fatty acid chain.
A number of different mechanisms have been proposed for the ability of PUFAs to lower blood pressure. This includes decreasing insulin resistance, regulating vascular tone via stimulating the parasympathetic nervous system and suppressing the renin-angiotensin-aldosterone system.
There is a large body of evidence demonstrating the effectiveness of PUFA supplementation in lowering blood pressure. A meta-analysis of 70 randomised controlled studies showed that omega 3 PUFA consumption of between 300mg and 15000mg per day for between 4 and 26 weeks significantly reduced blood pressure. The largest effects were observed in those with untreated high blood pressure levels (those not taking medication). No safety concerns have been found other than mild gastrointestinal discomfort at high doses.
How to take PUFAs
Although lower doses can lower systolic blood pressure, an intake of 2000mg per day of PUFAs is needed to reduce diastolic blood pressure. If you experience any gastrointestinal issues, lower the dose slightly to alleviate these effects.
L-Arginine
L-arginine is a conditionally essential amino acid found in the diet. It is often used by athletes because it produces nitric oxide, via the nitric oxide synthase enzymes, which increases blood flow.
A meta-analysis of 11 double-blind, placebo-controlled randomised controlled trials involving 387 participants showed that a dose of 4 to 24g daily over 2 to 12 weeks significantly lowered systolic and diastolic blood pressure. Results indicated that a 4 week treatment period was sufficient to produce a beneficial effect.
How to take l-arginine
A dose of 6g daily is recommended to reduce blood pressure. Intakes of less than 3g tend not to be effective and over 10g daily is associated with gastrointestinal issues.
Potassium
Potassium is a mineral that is hugely important for heart health. The recommended daily intake is 4700mg.
Doubling intake of potassium is associated with a reduction of between 4 and8mmHg in systolic blood pressure and 2.5 and 4in diastolic blood pressure. Higher potassium intake is also associated with a lower incidence of cardiovascular and cerebrovascular incidents, type 2 diabetes, left ventricular hypertrophy, heart failure and cardiac arrhythmias.
A number of different mechanisms have been proposed for the ability of potassium to lower blood pressure. This includes improved sympathetic nervous system function and increased excretion of sodium in the urine. Potassium must be taken with caution in patients with renal impairment and in those who are taking medications which increase potassium retention.
How to take potassium
Potassium cannot legally be sold in high amounts due to safety concerns. In order to gain the benefits of potassium for reducing blood pressure without any risk of adverse effects, a dose of 500mg daily is recommended. Intake can also be boosted by eating more fruits, vegetables, and beans.
Magnesium
Magnesium is another mineral that is beneficial for reducing blood pressure. It is one of the most common dietary deficiencies after vitamin D. A lack of magnesium is associated with increased blood pressure and poorer insulin sensitivity.
A meta-analysis of randomised controlled trials with between 3 and 24 weeks of follow up has shown that magnesium supplementation is associated with a decrease in systolic blood pressure of between 3 and 4 mmHg and decrease of diastolic blood pressure of approximately 2.5 mmHg. Results are optimised when both potassium and magnesium are taken in those with high blood pressure.
A number of mechanisms have been proposed for the effect of magnesium in lowering blood pressure, including calcium channel blocking, increasing prostaglandin (PG) E and increasing nitric oxide synthesis.
How to take magnesium
The optimal dose of magnesium is between 500mg and 1000 mg per day. It is best to obtain this from a chelated supplement because this improves absorption and has a lower risk of gastrointestinal issues, such as diarrhoea and bloating. However, magnesium supplements should be avoided in patients with severe renal insufficiency.
Intake can also be boosted through food, including nuts and green leafy vegetables.
Vitamin C
Vitamin C is an essential vitamin with antioxidant properties. It has a number of different functions in the body, particularly those relating to the immune system. Deficiencies in vitamin C are a risk factor for high blood pressure.
The level of vitamin C in the blood is inversely correlated with blood pressure.
In a meta-analysis of clinical trials with a 500mg dose of vitamin C over an 8 week period in participants with high blood pressure, systolic blood pressure was reduced by 4.8mmHg but diastolic blood pressure was not reduced. Some studies have also shown that vitamin C supplementation can enhance the effectiveness of antihypertension drugs such as amlodipine.
How to take vitamin C
To obtain the benefits of vitamin C for lowering blood pressure, it is recommended to take 500mg to 1000mg per day. It is not associated with any side effects. Intake can also be boosted by eating more green leafy vegetables, berries and citrus fruits.
Resveratrol
Resveratrol is a polyphenol that is in particularly high amounts in grapes. A number of studies have shown that it is effective in lowering blood pressure in preclinical models. This is thought to be due to its antioxidant effects, its ability to stimulate nitric oxide production, inhibits vascular inflammation and the prevention of platelet aggregation.
One study of 11 participants found that 150mg resveratrol daily reduced systolic blood pressure by 6mmHg and diastolic by 1mmHg. In a meta-analysis of 6 randomised controlled trials of 247 participants, only higher doses (over 150mg daily) were able to significantly reduce systolic blood pressure.
How to take resveratrol
A daily dose of between 150mg and 445mg is recommended to lower blood pressure. Further research is needed to establish the most optimal dose.
Coenzyme Q10
Coenzyme Q10 (also known as ubiquinone) is a potent lipid phase antioxidant, which is particularly high in raw meat and fish. It is a free radical scavenger, reduces oxidative stress; regenerates other vitamins and antioxidants, reduces the oxidation of low-density lipoprotein. It is also a cofactor and coenzyme in mitochondrial oxidative phosphorylation, which lowers blood pressure and is often low in those with high blood pressure.
A meta-analysis of placebo-controlled randomised controlled trials found that treatment with more than 100mg of coenzyme Q10 in participants with systolic blood pressure greater than 140mmHg or a diastolic blood pressure of over 90mmHg taken over 4 weeks, decreased systolic blood pressure by an average of 11 and diastolic blood pressure by an average of 7.
How to take coenzyme Q10
A daily dose of 10 mmHg per day is recommended to lower blood pressure. It is a fat-soluble compound so it is recommended to take it with food for better absorption.
Lycopene
Lycopene is a carotenoid, a natural pigment that gives vegetables and fruits their red color. It is an antioxidant and therefore protects against cell damage.
A recent meta-analysis of randomised controlled trials found that between 10 and 50 mg per day of lycopene significantly reduced systolic blood pressure. This enhanced the blood pressure lowering the effect of antihypertensive medications.
It is often debated whether it is better to take in lycopene through food or via supplementation. Although foods such as tomatoes are high in lycopene, for blood pressure management, rather than for general health purposes, supplementation is recommended.
How to take lycopene
To obtain the benefits of lycopene for lowering blood pressure, it is recommended to take 10mg per day. Intake can be further boosted by consuming lycopene-rich foods, such as tomatoes.
Pycnogenol
Pycnogenol is bark extract of Pinus pinaster (French maritime pine) and is a natural angiotensin-converting-enzyme (ACE) inhibitor. It protects cell membranes from oxidative stress, increases nitric oxide and improves endothelial function, all of which have a beneficial impact on human health.
Clinical evidence has shown that supplementing with 100 mg Pycnogenol for 12 weeks allowed nearly half of participants to reduce the dose of their blood pressure medication.
How to take pycnogenol
To get the benefits of Pycnogenol for lowering blood pressure, it is recommended to take 100mg per day.
Melatonin
Melatonin is a hormone that is secreted from the pineal gland at night. It acts as a signal of darkness so plays a key role in the physiological regulation of circadian rhythms, including sleep. It is thought to influence blood pressure by protecting blood vessels from oxidation, improving nitric oxide metabolism and endothelial function.
A meta-analysis of double-blind, placebo-controlled randomised controlled trials consisting of 221 people who were taking between 2mg and 5mg of melatonin for between 7 and 90 days reported a significant decrease in both systolic blood pressure and diastolic blood pressure.
As beta-blockers inhibit the body’s natural melatonin secretion, this supplement also improves sleep in people taking this medication for high blood pressure. Melatonin has also been used as an adjunct to the treatment of refractory hypertension (treatment-resistant high blood pressure) with positive results.
How to take melatonin
To obtain the benefits of melatonin it is recommended to take 2mg daily. In order to optimise results, it is best to take a controlled-release rather than a fast-release supplement.
Garlic
Garlic (Allium sativum) is a food product that can improve immunity as well as heart health. It also has anti-aging properties. The molecule alliin is responsible for garlic’s main mechanism.
Garlic enhances the regulation of endothelial nitric oxide, which causes smooth muscle cell relaxation, vasodilation and a reduction in blood pressure. There are a number of dietary and genetic factors which influence these pathways and thus contribute to the development of high blood pressure.
Dry aged garlic is particularly effective for reducing blood pressure as it has ACE inhibition and calcium channel blocking activities. Both of these reduce catecholamine sensitivity, increase bradykinin and nitric oxide, improving arterial functioning.
A recent meta-analysis of nine randomised controlled trials, including 482 individuals treated with aged garlic extract for between 8 and 26 weeks, found that both systolic and diastolic blood pressure were reduced more effectively than by a placebo. The average reduction in systolic blood pressure was 9mmHg and the average reduction in diastolic blood pressure was 4 mmHg. These effects seem to be over and above those obtained through taking blood pressure medications.
How to take garlic
To obtain the benefits of garlic for blood pressure, it is recommended to take 600mg per day. This can be divided into several doses if preferred. Aged garlic is the preferable form to take, not only for its effectiveness but also because of its lack of scent. Intake can also be boosted with food. However, it is important not to microwave garlic as this destroys its beneficial compounds.
Probiotics
Probiotics contain live microorganisms that have a range of health benefits. The most common are bacteria that belong to groups called Lactobacillus andBifidobacterium.
A meta-analysis of randomised controlled trials found that consuming probiotics moderately reduced blood pressure. Effects were more significant in those with high blood pressure initially, those ingesting multiple strains of probiotics and when taking them for more than 8 weeks.
Another meta-analysis of 14 randomised controlled trials, involving 702 participants, found that, compared with placebo, probiotic fermented milk produced a significant reduction of an average of 3mmHg in systolic blood pressure and 1mmHg in diastolic blood pressure. Similarly to the other meta-analysis, results were also more pronounced in those with higher blood pressure at the start.
How to take probiotics
It is recommended to take at least 10 colony-forming units (CFU) per day in order to reduce blood pressure. Intake can also be boosted by eating foods containing probiotics, such as yogurts.
The Bottom Line
It is clear that there is a range of supplements that can help to reduce high blood pressure, which can have benefits for those who are taking prescription high blood pressure medication and those without.
However, if you are taking prescription medication for high blood pressure, you will want to check with your doctor before using any dietary supplements as there could be interactions.
Supplementation can be used alongside making diet and lifestyle changes. These modifications include increasing your intake of foods high in potassium, calcium and magnesium, such as nuts and leafy green vegetables. Being more physically active can also help to lower blood pressure, particularly increasing cardiovascular exercises, such as walking, swimming and jogging.