Reducing High Blood Pressure to Support the Immune System.

Last week I chatted briefly about a condition called metabolic syndrome (MetS), and how it’s inflammatory effects can alter the normal functioning of lymphatic tissues involved in the immune response.

Now there are 5 risk factors that fall under the banner of metabolic syndrome, but in today’s post, I’m going to concentrate on High Blood Pressure, also known as hypertension.

First and foremost, something to keep in mind is that high blood pressure is an inflammatory disease that impairs immune function.  That being said, a compromised immune system also leads to inflammation, so it works both ways.

When the immune response becomes dysregulated, it causes the sympathetic nervous system (a fancy way to describe our ‘fight or flight’ stress response), to go into overdrive. This raises our heart rate and blood pressure (which is fine in the short term), but over the long-term, can lead to oxidative damage causing arterial stiffening and hardening of the arteries.

Picture a rusty pipe and this is pretty much what oxidative damage does to our inner piping, so definitely something we want to avoid!

What Exactly Is High Blood Pressure?

Whilst definitions may vary slightly depending on the source, high blood pressure is defined as blood pressure equal to or greater than 140/90 mmHg and is the most common condition managed by Australian general practitioners. It affects one in three Australians over the age of 24, and a staggering 25–43% of the world’s adult population equating to over 1-billion people which is mind-blowing!!

Keeping your blood pressure check is important because if it is too high, it affects the blood flow to the organs which increases your chances of developing many chronic diseases such as cardiovascular disease, stroke, kidney failure, type 2 diabetes to name a few.

What Causes High Blood Pressure?

There are many causes of high blood pressure but stress, weight gain, nutritional deficiencies and poor sleep can all be contributing factors.

Sounds like the life of a shift worker doesn’t it?

Whilst there are many treatment options available including pharmaceuticals, it’s important to understand that they are not always effective, and often come with side effects.

So what can we do from a nutritional, environmental and lifestyle perspective to help keep our blood pressure in check whilst working 24/7. 

Lots of things!

NUTRITIONAL – certain nutritional deficiencies and excesses can contribute to high blood pressure and include, but are not limited to things like:

  • Magnesium Deficiencymagnesium helps to keep blood pressure down by aiding blood vessel relaxation and dilation. It also helps to moderate production of aldosterone, a hormone which causes the kidneys to hold on to sodium and water, thereby affecting blood pressure. Supplementation is often required to boost magnesium levels, however, incorporating foods that contain magnesium such as green leafy vegetables, nuts and seeds is a great starting point.
  • A Low Intake of Omega-3 Fats and Fish Oil – omega-3 fats help to relax the blood vessels and make them more pliable.  Salmon, walnuts and chia seeds are a great source of omega-3 fatty acids. I’m also a big fan of cod liver oil as I don’t eat a lot of fish.
  • High Sodium and Low Potassium Diet – if your diet consists of mostly refined and processed foods your salt intake is likely quite high.  This is because poor quality salt is added to most processed foods to enhance palatability. When we have too much salt in our blood it draws water into the blood, raising blood volume and thereby blood pressure.
  • Potassium is also an important mineral in lowering blood pressure as it helps to increase vasodilation (widening of the blood vessels as opposed to restricting them), along with enhancing the urinary excretion of sodium.
  • Studies have shown the DASH diet to be beneficial in reducing blood pressure, which is short for Dietary Approaches to Stop Hypertension.  Whilst I’m not really a fan of any “diets” per se, nor strict calorie counting as that can be super stressful, it is however, low in sodium and high in potassium (and magnesium) foods such as fresh fruits and vegetables, whole grains, nuts and seeds.  Click Here to learn more about the DASH diet.


  • Test For Heavy Metal Toxicity – lead and mercury, especially, can damage the inner lining of the blood vessels.  They also lead to an increase in production of the stress hormone, adrenalin, putting the body into that ‘fight or flight’ mode which makes the heart beat faster.  This in turn, raises blood pressure.


  • Lose Weight – when we’re overweight it puts a strain on our heart as we need to pump more blood to supply oxygen to our tissues.  This also adds pressure on the walls of the arteries.  

    In one study involving over 13,000 obese individuals, weight loss showed to be a major factor in reducing the risk of uncontrolled hypertension. Additionally, in a meta-analysis incorporating over 25 studies, 1-kg loss of body weight was associated with an approximate 1-mm Hg drop in blood pressure.  

    This means by simply shedding some kilograms (I know this can often be easier said than done!) – it will help to bring blood pressure down.
  • Make Sleep a Priority – insufficient sleep and circadian desynchronicity (welcome to the wonderful world of shift work!) also increases sympathetic activity and proinflammatory cytokines further driving inflammation.

    If you’ve read a lot of my blog posts previously, you will know I’m a HUGE fan of sleep which is actually one of the best forms of blood pressure medication … and it’s absolutely free!
  • Incorporate More ‘Rest and Digest’ Activities – to stimulate the parasympathetic arm of the nervous system.  This calming arm of the nervous system (which is the opposite of the ‘fight and flight’ arm) helps to shift the body out of a stressed state, and into more of a relaxation one.  Just 15-minutes of mind-body exercises like yoga and tai chi have been shown to help reduce blood pressure.  Click Here for more information on this.

So there you go!  Lots of different ideas to help keep your blood pressure in check and support your immune system at the same time.

Next week I’m going to talk about how to reduce abdominal adiposity or belly fat, which is also helps to optimise immune function.

Audra x

Please note: The information contained in this article is for general information only. Please get in touch via the link below, or consult with your own health care provider for specific health advice.


Anderson, C, Murphy, K & Luz Fernandez M 2016, ‘Impact of obesity and metabolic syndrome on immunity’, American Society for Nutrition, vol. 7, no, 1, pp. 66-75.

Appel, L, Moore, T, Obarzanek, E, Vollmer, W, Svetkey, L, Sacks, F,
et al. 1997, ‘A clinical trial on the effects of dietary patterns on blood pressure’, The New England Journal of Medicine, vol. 336, no. 16, pp. 1117-1124.

Britt H, Miller G, Charles J, et al. 2008, ‘General practice activity in Australia 2006–07’, Australian Institute of Health and Welfare,

Houston M 2011, ‘Role of mercury toxicity in hypertension, cardiovascular disease, and stroke, Journal of Clinical Hypertension, vol. 13, no. 8, pp. 621-627.

Kulkarni, K, Schow, M & Shubrook, J 2020, ‘Shift workers at risk for metabolic syndrome’, The Journal of the American Osteopathic Association, vol. 120, pp. 107-117.

Neter, J, Stam B, Kok F, Grobbee D, Gelseijnse J, 20023’, ‘Influence of weight reduction on blood pressure: a meta-analysis of randomized controlled trials’, Hypertension, vol. 42, pp. 878-884.

Rodriguez-Iturbe, B, Pons, H & Johnson, R 2017, ‘Role of the immune system in hypertension’, Physiological Reviews, vol. 97, no. 3, pp. 1127-1164.

Singh, M, Chapleau, M, Harwani, S.C, Abboud F 2014, ‘The immune system and hypertension, Immunologic Research, vol. 59, pp. 243-253.


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