High Blood Pressure.
Elevated blood pressure increases the risk of developing conditions such as heart attacks and stroke. Although this condition is very common, it doesn’t usually cause any symptoms.
High blood pressure is often caused by high levels of a hormone called insulin, which is directly impacted by the food we eat.
Insulin.
One of insulin’s roles is to regulate blood sugar levels. High blood sugar is toxic, so when levels increase insulin is released to bring them back to normal.
If we regularly eat foods that spike blood sugar, insulin levels remain high. Over time, cells stop responding as well to insulin - this is called insulin resistance.
High blood pressure is a result of both elevated insulin, and insulin resistance.
Think of your blood vessels like hose pipes.
The pressure inside the hose can be increased by:
Adding more water (turning up the tap), or by
Narrowing the hose
High insulin works on our blood vessels in both of these ways.
How insulin increases blood pressure.
1. More water in the blood
High insulin increases levels of another hormone (aldosterone) which tells the kidneys to keep salt in the blood, rather than removing it in urine. Water follows salt, so more water also stays in the blood, which leads to increased blood pressure.
2. Narrowed blood vessels
Insulin instructs the cells lining the inside of blood vessels to grow bigger. This narrowing increases the pressure of blood passing through them.
Blood vessel walls also contain muscles, which narrow the vessels when they contract.
Insulin causes a mild stimulation of our “fight or flight” nervous system causing these muscles to contract.
Insulin resistant blood vessel cells produce less of a muscle relaxing chemical (nitrous oxide).
The amount of sugar in your diet is more important than the salt.
What next?
Avoiding blood sugar spikes allows insulin to fall, enabling blood vessels to relax, and excess salt and water to be removed from blood.
So, to reduce blood pressure, we need to know which foods spike blood sugar.
Although there are some obvious ones (think lollies and chocolate!), some of the other foods may surprise you!
The science.
Read the high quality evidence linking high insulin and insulin resistance to high blood pressure.