18 Foods Scientifically Shown
💗 To Lower Blood Pressure 💗
Is your blood pressure too high?
For
those in countries like the US, UK and Australia, 1 in 3 people over
the age of 30 get diagnosed with high blood pressure (known medically
as hypertension).
That means 1 in 3 can benefit from lowering their blood pressure, especially considering it is responsible for 1,000 deaths per day in the US alone.
In
fact, correcting high blood pressure is the single most important thing
you can do to improve your cardiovascular health and lifespan. Rather
than always cutting foods out, research shows you may really benefit
from eating more of certain foods.
This 4,000 word article summarizes the science behind 18 of the most prominent foods.
1. Hibiscus tea is proven to reduce high blood pressure
🍈
While a group receiving no treatment would have been nice for the
sake of comparison, what’s really impressive is that numerous other
studies have replicated these results (2, 3, 4).
As
tea, about one gram of dried calyx (the part of the flower directly
beneath the petals) should be brewed. It should be enjoyed either once
in the morning or twice per day but with at least 8 hours between doses.
Alternatively, hibiscus supplements are also an option, and should be
dosed according to their anthocyanin content.
A
daily 10 mg dose of hibiscus anthocyanins – equivalent to 1g of a 1%
extract or 500 mg of a 2% extract – is optimal. Higher doses may be
toxic.
Summary: Hibiscus
tea has been repeatedly shown to lower blood pressure in those with
existing high blood pressure by around 10% systolic and 12% diastolic.
The effect may be noticeable after just two weeks.
2. Nitrates in beetroot can lower blood pressure
Nitrates are compounds that play a big role in our metabolic system.
The body can convert them into a signalling molecule called Nitric Oxide,
which is a major mechanism related to blood flow. It signals to the
cells in your arteries to soften and relax (vasodilation), an action
that can greatly reduce blood pressure.
Here is a basic illustration of the action nitric oxide has.
The largest source of nitrates (and therefore nitric oxide) in the human diet is vegetables. Beetroot is the best of the bunch, with most research focusing on beetroot juice supplementation.
A
2013 review study of 254 participants found that beetroot juice intake
reduces blood pressure by 4-10 points (mm Hg) in just a few hours. To
put that into perspective, a reduction of at least 5 points is said to
reduce your risk of a life-ending stroke by 14% and cardiovascular
diseases by 9%.
While long-term effects have not yet been examined, it seems highly unlikely beetroot juice would be dangerous.
Summary: Beetroot is a rich source of nitrates that play an important role in our metabolic health. The weight of evidence suggest beetroot juice can reduce high blood pressure by 4-10 mm Hg in a matter of hours.
3. Curcumin in turmeric may help improve blood flow
Turmeric is a popular Indian curry spice that has been traditionally used in both cooking and medicine.
The main active ingredient in turmeric is curcumin, which studies show have impressive medicinal properties (9).
In
a study of 32 post-menopausal women, supplementing 150 mg of curcumin
for 8 weeks successfully improved blood flow to levels seen in those who
exercise three times per week.
Another
human study using 500 mg turmeric three times per day (22.1 mg curcumin
each time) reported large decreases in blood pressure in subjects with a
form of kidney disease known as nephritis (11).
The benefit that curcumin has on blood flow and blood pressure are
believed to be related to nitric oxide, similar to beetroot.
Supplementation of curcumin has shown to increase circulating nitric
oxide, in some cases by up to 40% in just four weeks.
However there is just one problem with curcumin…
Humans are very bad at absorbing it. For any noticeable health
benefits, it’s essential to consume curcumin with an enhancer such as Black Pepper.
Summary: Turmeric is very rich in curcumin, shown to improve blood flow and decrease blood pressure in those with existing kidney problems. The benefits are thought to be related to nitric oxide.
4. Pomegranate can lower blood pressure and improve other heart health markers
Much like beetroot and curcumin, pomegranate is also a fantastic source of artery-relaxing nitrates.
Softer arteries remain thin and elastic, and encounter less resistance, which enables the heart to pump at reduced pressure.
In
fact, just 50 ml (1.7 oz) of pomegranate juice per day has been linked
with a 30% reduction in carotid artery thickness; the artery that
supplies the head and neck (14).
The more thin and elastic, the better.
Studies on subjects with high blood pressure show that consuming
around 150 ml (5 oz) of pomegranate juice daily for 2 weeks can lower
both systolic (top reading) and diastolic (bottom reading) blood
pressure by clinically significant amounts.
Additionally, the unique fatty acid in pomegranate – Punicic acid – has been shown to protect against several other factors in the heart disease process. These include improving triglyceride:HDL ratio and lowering LDL cholesterol.
Summary: Pomegranate juice is a strong source of nitrates, which is thought to help keep blood vessels soft and elastic. Studies suggest that 150 ml (5 oz) of pomegranate juice daily for 2 weeks can markedly lower both systolic and diastolic blood pressure.
5. Cashews and almonds can dramatically reduce your blood pressure
Magnesium
is an essential mineral involved in over 300 bodily process, including
blood pressure regulation and blood sugar control (19).
A
lack of magnesium in the diet (deficiency) is very strongly associated
with blood pressure complications. This holds true whether you are
overweight or not (20).
As
you would expect then, correcting low magnesium has been shown to
significantly reduce high blood pressure in numerous studies.
Given that approximately two-thirds of US adults eat below the recommended intake of magnesium, you can see how the addition of magnesium-rich foods to your diet could make a huge difference.
Alongside spinach, almonds and
cashews are among the best sources of magnesium in the human diet.
Several handfuls provides over 20% of our daily requirements (25):
Magnesium supplements are also alternative, but where possible we should always choose natural whole foods first.
Summary: Having low magnesium levels is very strongly linked to high blood pressure. Cashews and almonds are very high in magnesium, with one small handful providing 20% of your daily requirements.
6. Potatoes and sweet potatoes are loaded with potassium
In the context of blood pressure and heart health, potassium works in tandem with sodium (salt) to regulate the electrical activity of the heart.
Human trials show that an increased potassium intake significantly reduces high blood pressure (except for those with chronic kidney disease),
especially individuals deficient in potassium. In fact, a combination
of potassium and magnesium can lower blood pressure as much as
medications.
Unfortunately
we no longer eat much potassium. The average American now eats roughly
400% less than our hunter-gatherer ancestors, which is unsurprising
considering that the greatest food source of potassium in our diet is fruit and vegetables (29).
It
goes without saying we can all benefit from eating more vegetables, but
I like to place emphasis on eating more root vegetables (such as
potatoes and sweet potatoes). They tend to replace other starchy carbs on the plate that have far less potassium and far more sodium.
For example, replacing grains in the diet with root vegetables dramatically increases potassium intake, as illustrated by Dr. Stephan Guyenet. The graph shows how much of our recommended daily potassium intake (%) is met with a 100-calorie portion of each food.
You can see that grains
and rice – even whole grains – cannot compete with the potassium in
root vegetables, or other vegetables for that matter. Consider swapping
more pasta, rice and sandwich dishes for potato-based meals.
Summary: Increasing your potassium intake is a fundamental aspect of treating high blood pressure (unless you have chronic kidney disease). Root vegetables like potatoes are one of the best food sources, and can easily be substituted for other starchy carbs at meal times.
7. Ergothioneine in mushrooms helps to protect arteries
Ergothioneine is a powerful antioxidant that protects cells from oxidative damage (otherwise known as ageing).
In
particular it appears to protect and preserve nitric oxide, which is
fundamental to healthy blood flow and pressure. In fact, the role of
ergothioneine is so unique to cardiovascular health that many believe it
should be classified as a whole new vitamin (30, 31).
Mushrooms are by far the richest source of ergothioneine in our diet, and are actually ranked in the top 5 for antioxidant capacity when compared with 29 other common vegetables. Considering mushrooms are also one of the best sources of potassium (more than bananas per gram), it only makes sense to eat them often.
Summary: Mushrooms are the greatest food source of ergothioneine, a powerful antioxidant that protects and preserves nitric oxide. Combined with their high potassium content, mushrooms are undoubtedly beneficial to cardiovascular health.
8. Dark chocolate may help manage high blood pressure
The words ‘chocolate’ and ‘healthy’ in the same sentence sounds almost too good to be true, right?
Well it’s not… but it’s close.
Chocolate contains cocoa extracted from the cocoa plant. The active ingredients within cocoa are the flavanols, which may lower blood pressure through inhibition of angiotension converting enzyme (ACE)- much like ACE inhibitor drugs (32 ).
A
large analysis of 20 previous studies concluded that consumption of
cocoa (usually very dark chocolate or cocoa supplementation) is
associated with a small 2-3 point reduction of systolic blood pressure.
An earlier analysis of 13 relevant studies made a similar conclusion,
noting that cocoa products were most effective in those with high blood
pressure or pre-hypertension (33, 34).
If we dig deeper it seems benefits are only seen with dark chocolate
or a cocoa extract equivalent to around 500-1000 mg of flavanols per
day. This suggests that for chocolate to have any benefits it must
be really dark, equal to about 25-40 grams of 85% dark chocolate
(typically shown on the package as 85% cocoa).
According to Calorieking,
30 grams (1 ounce) of 70-85% dark chocolate has 179 calories (750
kilojoules) and 7.2 grams of sugar. The same amount of milk chocolate
has more than double the sugar (not to mention half the potassium and a
fraction of the flavanols).
The lower the percentage of cocoa,
the higher the sugar. Below is the nutrition facts of dark chocolate
(left) and milk chocolate (right):
Therefore, in order for
chocolate to be (potentially) beneficial, it must be at least 85% cocoa.
Otherwise the health benefits are cancelled out by the increased amount
of added sugar.
Summary: Dark chocolate (must be
85% cocoa or more) may help lower blood pressure, although the effects
are quite weak. At least we know it does not make things worse.
9. Green tea can greatly improve blood flow
Traditionally from China, green tea is loaded with many powerful compounds and antioxidants; a combination that is unrivalled by any other food.
The reason tea – in particular green tea – is beneficial is because of its polyphenols. One particular type called catechins are linked to improved blood flow and pressure, related to nitric oxide.
Looking
at high blood pressure treatment, test tube studies show promise, but
actual experimental studies on humans have either been too small, poorly
executed, or finding contradictory results. Plus they all use green tea
extract or supplements, rather than actually drinking brewed tea.
But a large review of green tea confirmed that two cups per day (500 mL) can increase arterial diameter by up to 40% (39).
Just like wider pipes will increase water flow, wider and more relaxed
blood vessels increase blood flow, which should (in theory) reduce
pressure.
It’s also hard to argue with the benefits of green tea
when you consider that regular green tea drinkers have up to a 31% lower
risk of cardiovascular disease (40, 41).
Summary: The
catechins in green tea have been shown to increase the diameter of
arteries by up to 40%. This results in improved blood flow and is likely
to reduce blood pressure too.
10. Kale may benefit blood pressure more than other leafy greens
While very few “superfoods” live up to the hype, kale does quite well.
Similar to spinach and other greens, it’s loaded with vitamins, minerals, antioxidants,
and other compounds known to help prevent disease. But the reason kale
stands out for cardiovascular health is because it’s rich in magnesium,
potassium and vitamin C (42).
We’ve
already established the benefits of magnesium (almonds and cashews) and
potassium (potatoes), but the reason I give preference to kale over spinach is because it has four times morevitamin C.
Similar
to the potassium-magnesium relationship, vitamin C appears to increase
the blood pressure lowering effects of magnesium as well as increase
potassium in the blood (43, 44).
This incredibly unique nutrient profile makes it stand out from the other leafy greens when it comes to high blood pressure.
Summary: Kale
has an incredibly unique nutrition profile that is rich in magnesium,
potassium and vitamin C. The research suggests that both potassium and
vitamin C enhance the blood pressure-lowering properties of magnesium.
11. Garlic can reduce blood pressure and LDL cholesterol
Did you know garlic was not traditionally used for cooking?
All the major civilizations throughout history actually used it for medicinal purposes, and now there’s science to back it up.
The active ingredient in garlic is a sulphur compound called allicin, which is formed when a garlic clove is crushed, chopped or chewed.
Several
studies on hypertensive patients have shown that garlic supplementation
significantly improves blood pressure. One study even found its effects
comparable to that of prescription medication after 24 weeks (46, 47, 48, 49).
Benefits were seen with supplementation of 600-1,200 mg per day, equal to eating at least two garlic cloves daily.
Summary: Garlic supplementation equal to two cloves per day can help lower blood pressure long-term.
12. Fish oil can help those with high blood pressure
Fish oil refers to the natural fatty acids found in certain fish species such as salmon, tuna and mackerel.
These fatty acids – such as omega-3 fats – are linked to numerous health benefits… not all of which are true.
But fish oil does appear to benefit human
cardiovascular health, especially those who have already developed a
problem. Many human trials and reviews have found fish oil
supplementation to be an effective treatment for high blood pressure,
however the mechanism of effect remains unclear.
Many experts believe it’s related to our Omega-6: Omega-3 ratio; the more omega-3 fats in your diet compared to omega-6 fats, the better for your cardiovascular health.
The
ideal ratio is said to be less than 2:1, however today’s average diet
has a ratio of around 16:1. Put another way, we only consume 1 gram of
omega-3 fats for every 16 grams of omega-6 fats.
Increasing your omega-3 fat intake is one of the best ways to correct this imbalance.
If accessing fatty fish
is not a barrier for you, then it’s advised to have 2-3 servings per
week. Alternatively, fish oil supplements make an effective and often
more affordable option.
Summary: There is strong
evidence that fish oil supplementation improves blood pressure in those
with elevated blood pressure. Eating whole fish is best, but supplements
are a great alternative.
13. Green coffee beans may decrease blood pressure
Coffee
beans are naturally green in colour, but roasting turns them brown. So
in essence, green coffee is just another name for unroasted coffee.
While roasted coffee beans have a similar chemical composition to green coffee beans, the roasting process destroys much of itsChlorogenic acid (53). This is the active ingredient that gives green coffee beans additional health properties.
Now green coffee bean extract may not be the “weight loss miracle”Dr Oz claimed, but it does appear to benefit blood flow in one way or another; at least in the short-term (54).
One
12-week study using 480 mg of green coffee extract (equal to 140 mg of
chlorogenic acid) found it reduced heart rate and blood pressure by
about 8%. These benefits were maintained for 12 weeks of
supplementation, but only in those with high blood pressure to start
with. What’s more, benefits were lost once supplementation stopped (55).
For the majority of us caffeine has no influence on blood pressure,
so drinking more green coffee should have much of the same benefits as
supplementing, theoretically. You could try swapping your regular coffee
for green coffee, but I wouldn’t count on it making a big difference.
Summary: Green
coffee contains chlorogenic acid, the active ingredient with most of
the health properties. Chlorogenic acid supplementation has been shown
to reduce blood pressure after 12 weeks in those with existing
hypertension.
14. Stevia may help lower blood pressure long-term
Stevia is one of the few sweetener alternatives that most experts agree is the safest and most “natural” option.
Its two active ingredients are called Stevioside and Rebaudioside A, which is what most studies focus on.
A
one year trial on participants with high blood pressure found those
given 750 mg stevioside per day decreased their blood pressure by 8.1%
(systolic) and 13.8% (diastolic) after 3 months. They were able to
maintain this reduction for the next nine months (56).
Another
study using high doses of stevioside (1,500 mg per day) found benefits
after 2 years of use, while several other studies on healthy individuals
failed to find any health benefits (54, 55,57).
If
you are looking to replace sugar, or already using another type of
sweetener, stevia appears the best choice for those with blood pressure
problems. It’s not guaranteed to help, but at least will not make it
worse.
Summary: Long-term use of stevia is linked to
reduced blood pressure in those with existing high blood pressure. It
is not likely to be beneficial in small doses, but certainly not
harmful.
15. Fermented foods contain Vitamin K2 that improves vascular health
Vitamin K2 (also known as menaquinone) has a close relationship with vascular health.
It works to keep calcium in your bones while removing it from blood vessels where it can cause arterial stiffness and calcification (60).
While
no studies have measured the direct effect of vitamin K2 on blood
pressure yet, a study of 244 post-menopausal women found that vitamin K2
supplementation for three years significantly reduced stiffening of the
artery walls. This makes sense given its relationship with vascular
health.
Animal foods (like meat, full-fat dairy, egg yolks) and fermented foods (like sauerkraut, nattoand miso) are
by far the best food sources of vitamin K2. I prefer to recommend
fermented foods as they also supply your gut with healthy bacteria known as probiotics. New research suggests our gut bacteria has a direct influence on blood pressure via kidney regulation.
If you are particularly vulnerable to arterial calcification – such as diabetics or
those with a family history of high cholesterol and blood pressure
– then it is recommended you include more fermented foods in your diet,
or consider a vitamin K2 (MK-7) supplement.
Summary: Vitamin
K2 appears to inhibit the progression of arterial stiffness,
which protects cardiovascular health. Animal foods and fermented
foods are the best source of vitamin K2.
16. Herring, salmon and other fatty fish species are rich in CoQ10
The benefits of fatty fish are not just limited to Omega-3 fats.
They are also one of the best food sources of Coenzyme Q10 (CoQ10). Also known as ubiquinone, CoQ10 is a molecule that acts as an antioxidant in our cells involved with blood flow and pressure.
The current weight of evidence indicates that CoQ10 supplementation in those with high blood pressure may lower readings by up to 11 points systolic and 7 points diastolic (64, 65).
Note that we are still lacking larger more well-designed studies, but a
diet lacking in CoQ10 could be very problematic for individuals with
high blood pressure.
Additionally, fish is also a very strong
source of potassium. In fact, per 100 grams it has more potassium than
potato (but is much more expensive and calorie-dense of course).
Summary: Fatty
fish are one of the best food sources of CoQ10, a molecule that helps
mediate blood flow and pressure. They are also rich in potassium and
Omega-3 fats, which is why they are so heart healthy.
17. Spirulina has been shown to lower blood pressure
Also known as blue-green algae, spirulina is an organism that grows in both fresh and salt water..
It became popular when NASA proposed it could be grown in space and used by astronauts to supplement their diet.
It
is thought to influence blood pressure and cardiovascular health by an
increased production of the signalling molecule nitric oxide (66).
In
healthy individuals, a daily dose of 4.5 grams for six weeks was shown
to lower blood pressure. Given this finding, it’s likely to be even more
effective in those with high blood pressure, although more clinical
trials are necessary (67).
Summary: A
high dose of spirulina has been shown to lower blood pressure in health
individuals, which suggests it may be even more useful for those with
existing high blood pressure.
18. Extra virgin olive oil is linked with improved blood pressure and heart health
Forget coconut oil, olive oil is probably the healthiest oil in the world.
It’s a staple of Mediterranean-style diets, and is rich in heart-healthy monounsaturated fats (MUFAs) and phenolic antioxidants. ‘Extra-Virgin’ olive oil has the highest levels of beneficial components because it is the least processed form of olive oil.
In
a six-month study of 23 subjects with high blood pressure, the extra
virgin olive oil group (MUFA) reduced reliance on blood pressure
medications by 44% more than the sunflower oil group (PUFA). Regular
olive oil intake even cut the need for blood pressure medications in 8
of 11 subjects (68).
It
comes as no surprise then that a major study found regular consumption
reduced heart attacks, strokes and death by a whopping 30% (69).
Add extra-virgin olive oil to salads, and safely cook with it on almost all occasions… it’s the best choice.
Summary: Frequent
consumption of olive oil has been heavily linked with cardiovascular
benefits for many years. Small studies have shown extra virgin olive oil
can significantly reduce blood pressure compared to sunflower oil.
Diet is just the beginning…
If
you’re struggling to manage high blood pressure – with or without
pharmaceutical drugs – consuming more of the above foods could really
make a difference to your health.
Just remember that many other
lifestyle changes help to lower blood pressure too, including sodium
restriction, physical activity, adequate sleep, sun exposure, meditation and other stress management practices.
But
in the end, what goes into your mouth is certainly the most influential
factor at play. Becoming better educated in this area of nutrition is
fundamental, particularly if you have family history of high blood
pressure or heart disease.
Joe Leech is a Clinical Dietitian from Sydney, with a Master's
degree in nutrition and dietetics. He has spent the last decade reading,
researching and writing about health and nutrition, especially diet-related disease.
He believes that conventional medicine and natural medicine do not have
to be mutually exclusive, and draws from the best of both areas when
discussing nutrition science or giving dietary advice to treat
conditions.
Disclaimer
This article is for informational purposes only, and is educational in nature. Statements made here have not been evaluated by the FDA. This article is not intended to diagnose, treat, cure or prevent any disease. Please discuss with your own, qualified health care provider before adding in supplements or making any changes in your diet.
This article is for informational purposes only, and is educational in nature. Statements made here have not been evaluated by the FDA. This article is not intended to diagnose, treat, cure or prevent any disease. Please discuss with your own, qualified health care provider before adding in supplements or making any changes in your diet.
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