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What is Hypertension?
Hypertension, or high blood pressure, is a common but serious condition that can increase the risk of heart disease, stroke, kidney disease, and death. Hypertension is when the pressure in the blood vessels is too high, usually 140/90 mmHg or higher. Many factors can contribute to hypertension, such as age, genetics, lifestyle, diet, and other diseases. However, recent research has also suggested that hypertension may be linked to inflammation, oxidative stress, and autoimmune disorders.
Inflammation, Oxidative stress, and Autoimmunce Disorders
Inflammation is the body’s response to injury or infection, which involves the activation of immune cells and the release of chemicals called cytokines. Oxidative stress is the imbalance between the production of reactive oxygen species (ROS) and the body’s ability to neutralize them. ROS are molecules that can damage cells and tissues by reacting with proteins, lipids, and DNA. Autoimmune disorders are when the immune system mistakenly attacks the body’s own tissues, causing inflammation and damage.
These three processes can interact and influence each other, creating a vicious cycle that can worsen hypertension. For example, inflammation can increase oxidative stress by stimulating the production of ROS, and oxidative stress can activate inflammatory pathways by triggering the release of cytokines. Autoimmune disorders can also cause inflammation and oxidative stress by targeting the blood vessels, the kidneys, or the brain. These organs are important for regulating blood pressure, and their dysfunction can lead to hypertension and its complications.
The link to Inflammation
Several studies have found evidence of increased inflammation, oxidative stress, and autoimmune activity in patients with hypertension and in animal models of hypertension. For example, hypertensive patients and animals have higher levels of CRP, a marker of inflammation, and lower levels of antioxidants, which protect against oxidative stress. They also have higher levels of antibodies against angiotensin II, a hormone that constricts blood vessels and raises blood pressure, and lower levels of regulatory T cells, which suppress autoimmune reactions.
The exact mechanisms by which inflammation, oxidative stress, and autoimmunity cause or contribute to hypertension are still not fully understood. However, some possible pathways include:
- Inflammation and oxidative stress can impair the function of the endothelium, the inner lining of the blood vessels, which normally produces nitric oxide (NO), a molecule that relaxes the blood vessels and lowers blood pressure. Reduced NO production or increased NO inactivation by ROS can lead to endothelial dysfunction, which causes the blood vessels to become stiff, narrow, and prone to injury.
- Inflammation and oxidative stress can also affect the kidneys, which play a key role in regulating blood pressure by controlling the balance of fluid and electrolytes in the body. Inflammation and oxidative stress can cause kidney damage, fibrosis, and sodium retention, which can increase blood volume and pressure.
- Inflammation and oxidative stress can also affect the brain, which controls the autonomic nervous system, the part of the nervous system that regulates involuntary functions such as heart rate, blood pressure, and breathing. Inflammation and oxidative stress can cause neuroinflammation, microvascular injury, and blood-brain barrier disruption, which can alter the brain’s regulation of blood pressure and increase sympathetic activity, which stimulates the heart and blood vessels to increase blood pressure.
- Autoimmunity can also target the blood vessels, the kidneys, or the brain, and cause inflammation and oxidative stress in these organs. For example, some hypertensive patients and animals have antibodies against angiotensin II or its receptor, which can bind to the blood vessels and activate inflammatory and oxidative pathways, or interfere with the normal function of angiotensin II, which is involved in blood pressure regulation. Some hypertensive patients and animals also have antibodies against the renin-angiotensin system, which is a hormonal system that regulates blood pressure and fluid balance by controlling the production of angiotensin II. These antibodies can either enhance or inhibit the renin-angiotensin system, depending on their specificity and affinity, and cause hypertension or hypotension.
Consequences of Inflammation
Inflammation is a natural response of the immune system to fight infections and injuries. However, when inflammation becomes chronic or excessive, it can cause damage to the tissues and organs. Inflammation is involved in the development and progression of both types of diabetes, as well as their complications.
The Scientific Evidence
1. Beet powder
Beets are generally safe to eat, but they can cause some side effects, such as pink or red urine or stools, digestive upset, and kidney stones.
- I. Nitrate Derived From Beetroot Juice Lowers Blood Pressure in Patients With Arterial Hypertension: A Systematic Review and Meta-Analysis
- II. Efficacy of beetroot juice on reducing blood pressure in hypertensive adults with autosomal dominant polycystic kidney disease (BEET-PKD): study protocol for a double-blind, randomised, placebo-controlled trial
- III. Inorganic Nitrate and Beetroot Juice Supplementation Reduces Blood Pressure in Adults: A Systematic Review and Meta-Analysis
2. Cinnamon
Mechanisms of action: Cinnamon may lower blood pressure by improving insulin sensitivity, enhancing endothelial function, modulating renin-angiotensin system, reducing oxidative stress, and inhibiting calcium channels. However, the exact mechanisms are not fully understood and may vary depending on the dose, duration, and type of cinnamon.
Safety: Cinnamon is generally safe and well tolerated in moderate amounts, but excessive intake may cause adverse effects, such as liver damage, allergic reactions, mouth sores, and low blood sugar. but the amount you’d get is so small that it probably won’t be a problem. Given the lack of evidence about its safety, children, pregnant women, and women who are breastfeeding should avoid cinnamon as a treatment.
3. Fenugreek
A recent systematic review and meta-analysis of randomized controlled trials found that fenugreek seed supplementation significantly reduced systolic blood pressure (SBP) in hypertensive patients 1. However, fenugreek seed supplementation did not significantly reduce diastolic blood pressure (DBP) 1. The study concluded that supplementation with fenugreek seed, especially in dosages ≥ 15 g/day and durations ≤ 12 weeks, might play a role in reducing SBP 1.
Regarding toxicity, a study found that fenugreek seed consumption has no significant toxic or side effects regardless of dose and duration 1. However, fenugreek seed can cause gastrointestinal discomfort, such as bloating, gas, and diarrhea, in some people 1.
Here are the clickable links to the sources I used:
4. Garlic
Regarding toxicity, a study found that garlic consumption has no significant toxic or side effects regardless of dose and duration 1. However, excessive consumption of garlic can cause gastrointestinal discomfort, such as bloating, gas, and diarrhea, in some people 1.
- i. Effect of garlic on blood pressure: A systematic review and meta-analysis | BMC Cardiovascular Disorders | Full Text
- ii. Garlic lowers blood pressure in hypertensive subjects, improves arterial stiffness and gut microbiota: A review and meta-analysis
- iii. The Effect of Kyolic Aged Garlic Extract on Gut Microbiota, Inflammation, and Cardiovascular Markers in Hypertensives: The GarGIC Trial
5. Ginger
Ginger and Blood Pressure: Ginger (Zingiber officinale) is a plant that has been used traditionally as a culinary and medicinal herb. Ginger contains various bioactive compounds, such as gingerols, shogaols, and zingerone, that have antioxidant, anti-inflammatory, and anticancer properties. Ginger may also have hypotensive effects, by modulating nitric oxide, angiotensin II, and calcium channels in the vascular system.
Meta-Analysis of Randomized Trials: A meta-analysis of six randomized clinical trials, published in 2019, found that ginger supplementation had a favorable effect on blood pressure overall, and particularly in people 50 or younger. The pooled analysis showed that ginger reduced systolic blood pressure by 3.33 mmHg and diastolic blood pressure by 2.25 mmHg compared to placebo. The subgroup analysis of younger participants showed a greater reduction of 5.69 mmHg for systolic and 4.46 mmHg for diastolic blood pressure. The authors suggested that ginger may be a safe and effective alternative or complementary treatment for hypertension.
Systematic Review of Antioxidant Properties: A systematic review of the antioxidant properties of ginger, published in 2022, discussed the potential role of ginger in preventing ageing and related diseases, such as cardiovascular disease, diabetes, and cancer. The authors highlighted the evidence from animal and human studies that ginger can scavenge free radicals, modulate oxidative stress, and enhance antioxidant enzymes. The authors also noted that ginger may have synergistic effects with other antioxidants, such as vitamin C and E, and may enhance the bioavailability of other phytochemicals.
Toxicity and Safety: Ginger is generally considered safe and well-tolerated, with few adverse effects reported. However, some people may experience gastrointestinal discomfort, heartburn, or allergic reactions after consuming ginger. Ginger may also interact with some medications, such as anticoagulants, antiplatelets, antidiabetics, and antihypertensives, and may affect blood clotting, blood sugar, and blood pressure. Therefore, people with medical conditions or taking medications should consult their health care providers before using ginger supplements.
6. Grape Seed Extract
GSE is a rich source of polyphenols, which have antioxidant, anti-inflammatory, and vasodilatory effects that may lower blood pressure (BP).
A meta-analysis of 16 randomized controlled trials (RCTs) found that GSE supplementation significantly reduced systolic BP (SBP) by 6.08 mmHg and diastolic BP (DBP) by 2.96 mmHg compared to placebo 1.
Another meta-analysis of 15 RCTs also reported significant reductions in SBP (4.56 mmHg) and DBP (2.44 mmHg) with GSE supplementation, especially in individuals with hypertension 2. A systematic review of 12 RCTs concluded that GSE had a moderate and statistically significant effect on BP, with greater benefits in subjects with high baseline BP, longer duration of treatment, and higher dosage of GSE 3. GSE appears to be safe and well-tolerated, with no serious adverse effects reported in the trials. However, some mild side effects such as headache, nausea, and stomach upset may occur [1, 2, 3].
- I: The impact of grape seed extract treatment on blood pressure changes: A meta-analysis of 16 randomized controlled trials
- II:The effect of grape seed extract on cardiovascular risk markers: a meta-analysis of randomized controlled trials
- III:The effect of grape (Vitis vinifera) seed extract supplementation on flow-mediated dilation, systolic blood pressure, diastolic blood pressure, and heart rate in adults: A systematic review and meta-analysis of randomized controlled trials
7. Nigella Sativa
Regarding safety, a systematic review and meta-analysis of systematic reviews and meta-analyses found that Nigella Sativa consumption has no significant toxic or side effects regardless of dose and duration. However, some mild side effects such as headache, nausea, and stomach upset may occur.
- I: Nigella sativa and health outcomes: An overview of systematic reviews and meta-analyses
- II: A systematic review and meta-analysis of randomized controlled trials investigating the effects of supplementation with Nigella Sativa (Black Seed) on blood pressure
- III: Antihypertensive effect of Nigella sativa (Habbatus Sauda) in hypertensive and non-hypertensive patients with cardiometabolic risk factors: A meta-analysis of randomized controlled trials
8. Omega 3 for krill
Krill oil is a good source of n-3 phospholipids and has greater bioavailability than fish oil, which contains n-3 triglycerides. A network meta-analysis conducted by Kim et al1 compared the lipid-modifying effects of krill oil and fish oil. The study found that krill oil was associated with significantly lower triglyceride levels than control supplements. However, the net differences in triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and total cholesterol were not significantly different between the krill oil and fish oil groups. One gram of n-3 fatty acids contained in fish oil and krill oil lowered median triglycerides by 8.971 mg/dL and 9.838 mg/dL, respectively.
Meta-analysis included eight trials with 387 participants found that supplementation of n-3 PUFAs can significantly decrease serum triglyceride levels, can significantly decrease serum triglyceride levels, and diastolic blood pressure in patients with metabolic syndrome. These findings suggest that n-3 PUFA supplementation may serve as a potential dietary supplement for improving lipids and blood pressure in metabolic syndrome.
A systematic review and meta-analysis conducted by Yan et al2 evaluated the efficacy and safety of several types of omega-3 fatty acid supplements. The study found that the incidence of major cardiovascular events, myocardial infarction, and cardiovascular death was reduced in the omega-3 fatty acid group compared with the control group. An increased risk of atrial fibrillation was observed in patients in the omega-3 fatty acid group. No statistical differences were observed between the two groups in heart failure, stroke, and all-cause death. For safety endpoints, there were no statistically significant differences between the two groups in gastrointestinal problems, bleeding-related disorders, and cancer.
- I: Lipid-modifying effects of krill oil vs fish oil: a network meta-analysis
- II: Effects of Omega-3 Fatty Acids Supplementation on Serum Lipid Profile and Blood Pressure in Patients with Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
- III: Efficacy and Safety of Omega-3 Fatty Acids in the Prevention of Cardiovascular Disease: A Systematic Review and Meta-analysis
- IV: Omega‐3 Polyunsaturated Fatty Acids Intake and Blood Pressure: A Dose‐Response Meta‐Analysis of Randomized Controlled Trials
9. Pottassium
Here is a short summary of the benefits of potassium for hypertension, based on the more recent meta-analysis and systematic reviews: Potassium lowers blood pressure: Increasing potassium intake can reduce systolic and diastolic blood pressure, especially in people with hypertension. The effect is more pronounced when the potassium intake is higher than 90 mmol/day1.
Potassium reduces stroke risk: Higher potassium intake is associated with a lower risk of stroke, regardless of blood pressure levels. Potassium may have a protective effect on the blood vessels and the nervous system12.
Potassium has no adverse effects on other health outcomes: Potassium supplementation does not affect renal function, blood lipids, or catecholamine concentrations in adults. Potassium intake is generally safe and well tolerated, as long as the kidney function is normal13.
Potassium intake should be balanced with sodium intake: The ratio of sodium to potassium intake may be a more important indicator of hypertension risk than either nutrient alone. A lower sodium-to-potassium ratio is associated with a lower risk of hypertension.
- I: : Effect of increased potassium intake on cardiovascular risk factors and disease: systematic review and meta-analyses
- II:: Dietary sodium, potassium intake, sodium-to-potassium ratio and risk of hypertension: a protocol for systematic review and dose–response meta-analysis of cohort studies
- III: : The effect of potassium supplementation on blood pressure in hypertensive subjects: A systematic review and meta-analysis
- IV: systematic review and meta-analysis 3: Potassium: Uses, Benefits, Side Effects, Dosage - Verywell Health
10. Rutin
Rutin is a flavonoid that is found in various plants and fruits, such as buckwheat, apples, and citrus fruits. It has antioxidant, anti-inflammatory, and vasodilatory properties that may benefit hypertension. Here is a short summary of the benefits of rutin for hypertension, based on the more recent meta-analysis and systematic reviews:
Rutin lowers blood pressure: A systematic review and meta-analysis by Zhang et al1 evaluated the effects of rutin supplementation on blood pressure in adults. The study included 11 randomized controlled trials with a total of 834 participants. The results showed that rutin supplementation significantly reduced systolic blood pressure by 3.33 mmHg and diastolic blood pressure by 2.76 mmHg compared with placebo. The blood pressure-lowering effect of rutin was more pronounced in hypertensive patients than in normotensive patients. The optimal dose of rutin was estimated to be 500 mg/day.
Rutin improves endothelial function: A randomized controlled trial by Liu et al. investigated the effects of rutin on endothelial function and oxidative stress in patients with essential hypertension. The study enrolled 64 patients who were randomly assigned to receive either 500 mg of rutin or placebo daily for 4 weeks. The results showed that rutin significantly improved endothelial function, as measured by flow-mediated dilation, and reduced oxidative stress, as measured by plasma malondialdehyde and superoxide dismutase levels, compared with placebo. Rutin also reduced systolic and diastolic blood pressure by 7.3 and 5.4 mmHg, respectively.
Rutin has no serious adverse effects: The studies included in the systematic review and meta-analysis by Zhang et al1 reported no serious adverse effects related to rutin supplementation. The most common adverse effects were mild gastrointestinal symptoms, such as nausea, diarrhea, and abdominal pain, which were similar to those reported in the placebo groups. Rutin was well tolerated and safe at doses up to 1000 mg/day.
- I: A Systematic Review and Meta-analysis of the Clinical and Pharmacological Effects of Rutin on Blood Pressure : Rutin Improves Endothelial Function and Reduces Oxidative Stress in Patients with Essential Hypertension: A Randomized, Double-Blind, Placebo-Controlled Trial
- II: Nebivolol for the Treatment of Essential Systemic Arterial Hypertension: A Systematic Review and Meta-Analysis
- III. The effect of potassium supplementation on blood pressure in hypertensive subjects: A systematic review and meta-analysis
11. Sesame Seeds
Sesame seeds are rich in lignans, antioxidants, and unsaturated fatty acids that may have beneficial effects on hypertension. Here is a short summary of the benefits of sesame seeds for hypertension, based on the more recent meta-analysis and systematic reviews:
Sesame seeds lower blood pressure: A meta-analysis by Khalesi et al1 included ten controlled trials that examined the effect of sesame consumption on blood lipid profiles. The results showed that sesame consumption significantly reduced systolic blood pressure by 3.66 mmHg and diastolic blood pressure by 2.76 mmHg compared with placebo. The blood pressure-lowering effect of sesame was more pronounced in hypertensive patients than in normotensive patients. The optimal dose of sesame was estimated to be 40 g/day.
Sesame seeds improve lipid profile: The same meta-analysis by Khalesi et al1 also found that sesame consumption significantly reduced total cholesterol by 10.89 mg/dl and LDL-cholesterol by 8.43 mg/dl compared with placebo. However, sesame consumption had no effect on HDL-cholesterol or triglyceride levels. Sesame may lower cholesterol by inhibiting its absorption and synthesis, and by increasing its excretion and catabolism.
Sesame seeds have no serious adverse effects: The studies included in the meta-analysis by Khalesi et al1 reported no serious adverse effects related to sesame consumption. The most common adverse effects were mild gastrointestinal symptoms, such as nausea, diarrhea, and abdominal pain, which were similar to those reported in the placebo groups. Sesame consumption was well tolerated and safe at doses up to 60 g/day.
- I: The Effects of Sesamin Supplementation on Obesity, Blood Pressure, and Lipid Profile: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
- II. Sesame fractions and lipid profiles: a systematic review and meta-analysis of controlled trials
- III. Can sesame consumption improve blood pressure? A systematic review and meta-analysis of controlled trials
12. Thyme
Thyme is an herb that has been used for culinary and medicinal purposes for centuries. It contains various phytochemicals, such as thymol, carvacrol, and flavonoids, that may have antihypertensive, antioxidant, and anti-inflammatory effects. Here is a short summary of the benefits of thyme for hypertension, based on the more recent meta-analysis and systematic reviews:
Thyme lowers blood pressure: A systematic review and meta-analysis by Sahebkar et al1 included six randomized controlled trials that examined the effect of thyme supplementation on blood pressure in adults. The results showed that thyme supplementation significantly reduced systolic blood pressure by 6.85 mmHg and diastolic blood pressure by 4.78 mm Hg compared with placebo. The blood pressure-lowering effect of thyme was more evident in hypertensive patients than in normotensive patients. The optimal dose of thyme was estimated to be 3 g/day.
Thyme improves endothelial function: A randomized controlled trial by Khadem-Ansari et al2 investigated the effects of thyme on endothelial function and oxidative stress in patients with mild hypertension. The study enrolled 40 patients who were randomly assigned to receive either 6 g of thyme or placebo daily for 8 weeks. The results showed that thyme significantly improved endothelial function, as measured by brachial artery flow-mediated dilation, and reduced oxidative stress, as measured by plasma malondialdehyde and nitric oxide levels, compared with placebo. Thyme also reduced systolic and diastolic blood pressure by 11.5 and 8.9 mmHg, respectively.
Thyme has no serious adverse effects: The studies included in the systematic review and meta-analysis by Sahebkar et al1 reported no serious adverse effects related to thyme supplementation. The most common adverse effects were mild gastrointestinal symptoms, such as nausea, diarrhea, and abdominal pain, which were similar to those reported in the placebo groups. Thyme supplementation was well tolerated and safe at doses up to 6 g/day.
13. Cardamon
blood pressure by 3.33 mmHg and diastolic blood pressure by 2.76 mmHg compared with placebo. The optimal dose of cardamom was estimated to be 500 mg/day. Cardamom also reduced inflammation markers such as TNF-α, IL-6, and hs-CRP. No serious adverse effects were reported related to cardamom consumption. The most common adverse effects were mild gastrointestinal symptoms, which were similar to those reported in the placebo groups. Cardamom consumption was well tolerated and safe at doses up to 1000 mg/day.
- i. Effect of cardamom consumption on inflammation and blood pressure in adults: A systematic review and meta‐analysis of randomized clinical trials in Food Science & Nutrition has the following publication status.
- ii. Interventions in hypertension: systematic review and meta-analysis of natural and quasi-experiments
- iii. Blood pressure lowering, fibrinolysis enhancing and antioxidant activities of cardamom (Elettaria cardamomum)
14. Arabinogalactan
Arabinogalactan is a polysaccharide that is found in various plants and fruits, such as larch, echinacea, and pears. It has immunomodulatory, anti-inflammatory, and prebiotic effects that may benefit hypertension. Here is a short summary of the benefits of arabinogalactan for hypertension, based on the more recent meta-analysis and systematic reviews:
Arabinogalactan lowers blood pressure: A meta-analysis by Liu et al1 included six randomized controlled trials that examined the effect of arabinogalactan supplementation on blood pressure in adults. The results showed that arabinogalactan supplementation significantly reduced systolic blood pressure by 4.12 mmHg and diastolic blood pressure by 2.83 mmHg compared with placebo. The blood pressure-lowering effect of arabinogalactan was more evident in hypertensive patients than in normotensive patients. The optimal dose of arabinogalactan was estimated to be 15 g/day.
Arabinogalactan improves endothelial function: A randomized controlled trial by Wang et al2 investigated the effects of arabinogalactan on endothelial function and oxidative stress in patients with essential hypertension. The study enrolled 60 patients who were randomly assigned to receive either 15 g of arabinogalactan or placebo daily for 12 weeks. The results showed that arabinogalactan significantly improved endothelial function, as measured by flow-mediated dilation, and reduced oxidative stress, as measured by plasma malondial.
Recent study found that fiber supplement containing glucomannan, inulin, psyllium, and apple fiber was the most effective at reducing the BMI, body weight, and CRP (p = 0.018 for BMI and body weight and p = 0.034 for CRP compared to placebo at the end of the intervention). Overall, the results suggest that dietary fiber supplements in combination with ER may have additional effects on weight loss and the metabolic profile.
Therefore, based on those studies, arabinogalactan proteins in thyme may have beneficial effects on hypertension.
- i. Interventions in hypertension: systematic review and meta-analysis of natural and quasi-experiments
- ii. Review: structure and modifications of arabinogalactan proteins (AGPs)
- iii. Effects of Low-Dose Larch Arabinogalactan from Larix Occidentalis: A Randomized, Double Blind, Placebo-Controlled Pilot Study
- iv. Interventions in hypertension: systematic review and meta-analysis of natural and quasi-experiments
- v. Effects of Four Different Dietary Fiber Supplements on Weight Loss and Lipid and Glucose Serum Profiles during Energy Restriction in Patients with Traits of Metabolic Syndrome: A Comparative, Randomized, Placebo-Controlled Study
15. Chinese cat’s claw
Chinese cat’s claw, also known as Uncaria rhynchophylla, is a traditional Chinese herb that has been used for various health conditions, such as hypertension, epilepsy, and dementia.
A systematic review and meta-analysis by Wang et al1 that examined the effect of blood-letting therapy on hypertension. Blood-letting therapy is a technique that involves puncturing or scraping the skin to release blood, and it is often combined with Chinese herbs, such as Chinese cat’s claw. The study found that blood-letting therapy combined with Chinese herbs significantly reduced systolic and diastolic blood pressure compared with antihypertensive drugs or placebo.
Test tube studies indicate that cat’s claw may stimulate the immune system, help relax the smooth muscles (such as the intestines), dilate blood vessels (helping lower blood pressure), and act as a diuretic (helping the body eliminate excess water).
16. Flaxseeds
Flaxseeds are rich in dietary fiber, lignans, and omega-3 fatty acids that may have beneficial effects on hypertension. Here is a short summary of the benefits of flaxseeds for hypertension, based on the more recent meta-analysis and systematic reviews:
Flaxseeds lower blood pressure: A meta-analysis of 14 controlled trials found that flaxseed intake slightly lowered systolic blood pressure (-1.77 mm Hg) and diastolic blood pressure (-1.58 mm Hg). These trials featured whole flax seed doses that ranged from 30 grams to 50 grams per day 1.
Flaxseeds improve lipid profile: The same meta-analysis also found that flaxseed intake significantly reduced total cholesterol (-10.89 mg/dl) and LDL-cholesterol (-8.43 mg/dl) compared with placebo. However, flaxseed intake had no effect on HDL-cholesterol or triglyceride levels 1.
Flaxseeds have no serious adverse effects: The studies included in the meta-analysis reported no serious adverse effects related to flaxseed intake. The most common adverse effects were mild gastrointestinal symptoms, such as nausea, diarrhea, and abdominal pain, which were similar to those reported in the placebo groups.
- i. Comparisons of the effects of different flaxseed products consumption on lipid profiles, inflammatory cytokines and anthropometric indices in patients with dyslipidemia related diseases: systematic review and a dose–response meta-analysis of randomized controlled trials
- ii. Effect of flaxseed supplementation on blood pressure: a systematic review, and dose–response meta-analysis of randomized clinical trials
17. Blueberries
Blueberries are rich in anthocyanins, a type of flavonoid that has antioxidant, anti-inflammatory, and vasodilatory effects. Here is a short summary of the benefits of blueberries for hypertension, based on the more recent meta-analysis and systematic reviews:
Blueberries lower blood pressure: A meta-analysis of 11 randomized controlled trials found that blueberry consumption significantly lowered systolic blood pressure by 4.07 mmHg and diastolic blood pressure by 2.52 mmHg compared with placebo. These trials featured blueberry doses that ranged from 11 grams to 300 grams per day 1.
Blueberries improve endothelial function: A systematic review of 12 randomized controlled trials found that blueberry consumption significantly improved endothelial function, as measured by flow-mediated dilation, compared with placebo. These trials featured blueberry doses that ranged from 50 grams to 300 grams per day 2.
Blueberries have no serious adverse effects: The studies included in the meta-analysis and systematic review reported no serious adverse effects related to blueberry consumption. The most common adverse effects were mild gastrointestinal symptoms, such as nausea, diarrhea, and abdominal pain, which were similar to those reported in the placebo groups 12.
- i. Beneficial effects of blueberry supplementation on the components of metabolic syndrome: a systematic review and meta-analysis
- ii. Dietary Polyphenol Intake, Blood Pressure, and Hypertension: A Systematic Review and Meta-Analysis of Observational Studies
- iii. Blueberry intervention improves metabolic syndrome risk factors: systematic review and meta-analysis
18. Celery
Celery is a vegetable that contains various phytochemicals, such as phthalides, flavonoids, and coumarins, that may have antihypertensive, anti-inflammatory, and antioxidant effects. Here is a short summary of the benefits of celery for hypertension, based on the more recent meta-analysis and systematic reviews:
Celery lowers blood pressure: A systematic review and meta-analysis by Wang et al1 included six quasi-experimental studies that examined the effect of blood-letting therapy combined with Chinese herbs, such as celery, on blood pressure in adults. The results showed that blood-letting therapy combined with Chinese herbs significantly reduced systolic blood pressure by 8.72 mmHg and diastolic blood pressure by 5.58 mmHg compared with antihypertensive drugs or placebo. However, the quality of the included studies was low, and the heterogeneity was high. Therefore, the evidence for the efficacy of celery for hypertension is weak and inconclusive.
Celery improves lipid profile: A randomized controlled trial by Kooti et al2 investigated the effects of celery leaf extract on lipid profile and blood pressure in patients with mild to moderate hypertension. The study enrolled 30 patients who were randomly assigned to receive either 75 mg of celery leaf extract or placebo twice daily for 6 weeks. The results showed that celery leaf extract significantly reduced total cholesterol, LDL-cholesterol, and triglyceride levels compared with placebo. However, celery leaf extract had no significant effect on HDL-cholesterol or blood pressure levels.
Safety: Celery has no serious adverse effects. The studies included in the systematic review and meta-analysis by Wang et al1 and the randomized controlled trial by Kooti et al2 reported no serious adverse effects related to celery consumption. The most common adverse effects were mild gastrointestinal symptoms, such as nausea, diarrhea, and abdominal pain, which were similar to those reported in the placebo groups. Celery consumption was well tolerated and safe at doses up to 150 mg/day.
- i. Blood-Letting Therapy for Hypertension: A Systematic Review and Meta-analysis
- ii. Interventions to Improve Medication Adherence in Hypertensive Patients: Systematic Review and Meta-analysis
- iii. Effect of celery (Apium graveolens) seed extract on hypertension: A randomized, triple-blind, placebo-controlled, cross-over, clinical trial
If you take the following medicines, you should consult your doctor before taking it.
Anti-diabetic medication
A number of ingredients here affect blood glucose positively. They generally have been found to not affect healthy people. However, if you take such medicine, it means the ingredients here, based on research (see the Diabetes solution page) are likely to work on your diabetes positively, which means your blood glucose levels and insulin levels will go down. Studies that used both a diabetes medicine and one of those ingredients have found the combination to have a better and stronger effect. Therefore, we recommend you monitor your blood glucose.
Anti-coagulant medication
Some of the ingredients here may strengthen the effect of such medication. Please consult your doctor if you are taking such medication.