[Last updated 23rd July, 2019]
For some reason we like to think nutrient deficiencies don’t exist in Western countries.
But food quantity and food quality rarely go together.
Nutrient deficiency is a part of the high blood pressure puzzle that I’ve always found quite fascinating. Several nutrients are shown to play a key role in blood pressure regulation, yet can often be overlooked by your doctor or dietitian.
Research shows that having sufficient levels of the following 4 nutrients is important for maintaining a healthy blood pressure.
Similarly, if we are deficient in these nutrients, managing blood pressure becomes all the more difficult.
1. Coenzyme Q10
Coenzyme Q10 (CoQ10), also known as ubiquinone, is a molecule that acts as an antioxidant in our cells.
Most CoQ10 is made by the body itself, although there are some dietary sources too.
The reason we can be deficient in a self-produced nutrient is because several factors can deplete CoQ10 levels overtime. Long-term use of certain pharmaceutical drugs is the main one, with cholesterol-lowering statin drugs the usual culprit (1).
Several disease states are also thought to cause a deficiency including post-myocardial infarction (experienced by 7% of heart attack sufferers), fibromyalgia, depression, Peyronie’s disease, Prader-Willi syndrome and Parkinson’s disease. In fact, CoQ10 supplementation is normally advised by doctors for anyone with these diseases.
Through a mechanism related to nitric oxide, CoQ10 appears to protect the blood vessels and enhance blood flow, which influences blood pressure (much in the same way as beetroot juice). This is why a deficiency could be problematic for someone who needs to lower blood pressure.
The current weight of evidence indicates that CoQ10 supplementation in those with high blood pressure may lower readings by up to 11mm Hg systolic and 7mm Hg diastolic (2, 3). Note that we are still lacking larger more well-designed studies.
How to correct CoQ10 levels
There are tests available to check CoQ10 levels, but they’re not particularly cheap nor easy to access.
The best course of action is to ensure you regularly eat foods rich in CoQ10. There are no official dietary recommendations to follow, but a ballpark figure to aim for is at least 5 mg per day.
Supplemental CoQ10 is also an option – especially if you have any of the diseases mentioned above or regularly use a statin drug for lowering cholesterol – but you should speak with your doctor first. The standard dose ranges from 90-200 mg and should be taken with meals due to its reliance on food for absorption.
Summary: CoQ10 is thought to influence blood pressure and flow through a mechanism related to nitric oxide. Although most of our CoQ10 is produced by the body itself, certain disease states and long-term statin drug use can cause a deficiency. Eating a diet rich in cruciferous vegetables, nuts, oily fish and beef will help, although in some cases a supplement is necessary too.
Potassium is an essential mineral required for the body to function.
In the context of blood pressure regulation and heart health, potassium works in tandem with sodium to regulate the electrical activity of the heart.
Human trials consistently show that being deficient in potassium intake can raise blood pressure. Likewise, they show that correcting low potassium markedly lowers blood pressure in those with existing high blood pressure (4, 5).
The effect is even greater when coupled with reduced sodium consumption.
How to correct potassium levels
For treating high blood pressure we should aim to get at least 4,700 mg of potassium per day.
Fruits and vegetables are the greatest source of potassium in our diet. Things like potatoes, bananas, legumes, mushrooms and spinach are the best choices. Coffee is also high in potassium, but I wouldn’t recommend it in large amounts.
I like to place emphasis on eating more root vegetables throughout the week, such as potato, sweet potato, parsnips and pumpkin.
As illustrated by Dr. Stephan Guyenet, replacing grains in the diet with root vegetables dramatically increases potassium intake. 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.
To calculate your daily intake, record everything you eat for three consecutive days in a food diary and then work out the average using a food database tool.
Potassium supplements are an option too, but you must consult with your doctor first as excessive potassium can be harmful.
Summary: Potassium is an essential mineral that plays a key role in heart function and blood pressure regulation. Correcting low potassium levels greatly reduces high blood pressure, especially if sodium intake is reduced at the same time. This is best achieved by regularly consuming potassium-rich foods such as potatoes, legumes and other vegetables.
Magnesium is an important mineral involved in more than 300 bodily processes. Regulating blood pressure is one of the most prominent.
In fact, research has proven that a magnesium deficiency is strongly linked with elevated blood pressure. This remains true regardless if you are overweight or not (6).
As you would expect then, correcting low magnesium has been shown to significantly reduce high blood pressure (7, 8, 9, 10).
Given that almost 60% of US adults do not meet dietary magnesium recommendations, it’s easy to see how more magnesium-rich foods in our diet could make a big difference to blood pressure.
How to correct magnesium levels
Magnesium levels can be tested by your doctor, and usually come as part of a routine blood test.
Regardless of your levels, magnesium-rich foods are a healthy addition to any diet. Several tasty foods are brilliant sources of magnesium… Namely almonds, cashews and spinach.
The current recommended daily intake (RDI) for magnesium in the US is 310-420 mg (11). Just half a cup of almonds or cashews provides a whopping 180 mg; what I recommend to clients in order to maintain optimum levels.
Magnesium supplements are also an option, but only under the guidance of your doctor.
Summary: Magnesium deficiency is very strongly associated with high blood pressure. Many studies have shown replacing this magnesium deficiency will significantly improve blood pressure, especially if you already have high blood pressure. Cashews and almonds are very high in magnesium, with one cup providing your daily requirements.
4. Omega-3 Fats
Omega-3 fats are a type of dietary fat that are extremely beneficial to human cardiovascular health.
The best source of Omega-3 fats are fatty fish species such as salmon, tuna and mackerel. Fish oil supplements are also a concentrated source, with studies proving them to be an effective treatment for high blood pressure (12, 13, 14, 15, 16).
It is thought that a diet low or deficient in Omega-3 fats is undesirable for heart health, including blood pressure regulation.
The mechanism of its effects are not clear, but most experts believe it is to do with the Omega-6: Omega-3 ratio.
Put simply, the more Omega-3 fats in your diet compared to Omega-6 fats, the better for your heart health. A 1:1 ratio is ideal, however today’s average diet contains a ratio of up to 16:1 (17, 18). In other words, for every 16 grams of Omega-6 fats eaten, we only consume 1 gram of Omega-3.
Improving that ratio to just 4:1 is associated with a 70% decrease in cardiovascular-related death (19).
How to correct Omega-3 levels
The best way to ensure you are not deficient in Omega-3 fats (unless you are pregnant) is by eating more fatty fish.
At least 2 grams per day is desirable, equal to around 3 oz (85 grams) of fresh salmon or canned tuna. For vegetarians, it’s 1 oz of walnuts, 1/3 oz of flax seeds or ¼ oz of chia seeds; but note that marine sources of Omega-3 are much better utilised by the body than plant sources (20, 21).
If fish is difficult to access in your situation, fish oil supplements are an effective and often more affordable alternative. With a goal of lowering blood pressure, 2-3 grams of (total) fish oil per day is recommended. Fish oil pills tend to be 1 or 2 grams total, depending on the brand. If you plan on taking more than 3 grams per day, consult with your doctor first.
Note that quality matters when it comes to supplements, and fish oil is no exception. Anecdotal reports suggest that budget/cheap fish oil varieties are less effective than premium brands.
Summary: A diet low in Omega-3 fats is thought to be bad for high blood pressure. This is likely due to the importance our dietary Omega-6: Omega-3 ratio has on heart health. For this reason, there is strong evidence that increasing Omega-3 fats in the diet can help lower blood pressure. Fresh fish is the best source, but supplements are a great alternative.
Any effort to lower blood pressure will be maximised if you stay on top of those 4 nutrients.
Basically, we’ve just been given 4 additional reasons to include more fish, nuts and vegetables into our weekly diet.