Most processed foods and pre-prepared meals contain high amounts of salt, or sodium. Sodium causes the body to retain excess fluid, and this leads to an increase in blood pressure.
A person's blood pressure usually drops slightly after they have eaten. Learn more about blood pressure readings and see a blood pressure chart here. When a person eats, their body redirects blood to the digestive tract to aid with digestion. This causes a temporary decrease in blood pressure elsewhere in the body.
What causes blood pressure to change after eating?
Increases in blood pressure can be the result of many different things, but what people may not realize is that blood pressure change after eating. As many doctors, dieticians, and nutritionists can tell you, there is a response to consuming food that can cause an increase or decrease in blood pressure.
Before we get into blood pressure after eating, it is important to establish how we measure blood pressure. When blood pressure is evaluated, the diastolic and systolic pressure is looked at. These measure a high value and low value of pressure of blood on artery walls. Just to be clear, diastolic is the low value that can be calculated when the heart rests between beats. Systolic is the high value that is measured when the heart pumps blood.
The proper way to read pressure is systolic over diastolic. The ideal high and low for blood pressure is 120 and 80. This is why you would hear a healthcare provider read it out loud as, “120 over 80.” When blood pressure goes above or below the average, it is considered to be high blood pressure. High blood pressure is often called hypertension, while low blood pressure is referred to as hypotension.
Types of foods and changes in blood pressure in elderly
If you are wondering, how does blood pressure increase after eating, the fact is that it is not exactly cut and dry. For instance, aging can impact different systems in our body, such as the endocrine system. As a result, elderly people are left in a position where they can experience blood pressure changes after a meal. After eating a meal that is rich in lipids and carbohydrates, an elderly person might find that their mean arterial blood pressure (MAP) actually decreases. This can be related to a decrease in arterial blood flow. Sometimes, when there are changes in splanchnic circulation, which involves the gastric system, an increase in cardiac output, stroke, and heart rate are observed. It is interesting that young people can consume lipids and carbohydrates without a decrease in blood pressure, yet some still experience increases in cardiac output, stroke, and heart rate.
In a lot of cases, hypertension is linked to an autonomic failure. An autonomic failure is a degenerative disorder of the autonomic nervous system. Autonomic issues have also been associated with hypotension though. For example, orthostatic hypotension is when a person experiences a fall in blood pressure with standing.
Increase in blood pressure after eating
If blood pressure goes up after eating or blood pressure drops after eating, it can be a little unsettling; however, having a better understanding of the digestive process and how pressure can change can put minds at ease.
While there are a lot of factors that impact blood pressure, including the thickness of blood vessels and arteries and flow of blood, our digestive system also plays an important role. When we eat, our bodies need to break down the food. In order for this to happen, we need oxygen to help release digestive acids and enzymes. This means that oxygenated blood must flow to the blood vessels in the gut.
During this process, the body is telling the heart more blood is needed in the gastric system (stomach), so naturally, there is going to be a faster cardiac output. This may account for a blood pressure increase after eating. The kind of food we eat can also impact blood pressure. For instance, oil, butter, and other foods that contain fat can decrease blood flow, thus increasing cardiac output. Additionally, foods that are high in sodium lead to more pressure on the heart and lungs. Adding to this is the water retention that sodium causes. Extra water also puts pressure on lungs and the heart. Research has long demonstrated that a low fiber, high fat diet impacts blood flow and therefore affects blood pressure.
Is the increase in blood pressure considered normal?
Now you must be wondering, does blood pressure go down after eating? A slight rise in blood pressure after eating meals is temporary. Once the digestive process is complete, blood pressure should return to normal, unless there are other health factors involved. So, yes, a spike during meals is normal. If blood pressure doesn’t return to normal after about two hours, it is time to seek medical attention.
As established earlier, normal is 80 over 120. High blood pressure or hypertension would be 140 over 159 in what is known as stage 1. Stage 2 hypertension is 160 or more over 100 or more.
Decrease in blood pressure after eating
Just as blood pressure can increase after eating, low blood pressure after eating can occur. If someone experiences a lightheaded feeling or dizziness after having a meal, it could be postprandial hypotension. This decrease in blood pressure can be accompanied by nausea or even chest pain. This happens because the heart fails to respond properly to the eating of food. Sometimes, more blood just flows to the digestive system, leading to a reduction in blood pressure of the other parts of the body.
A decrease in blood pressure after eating could be related to a gene mutation, a chronic disease, such as diabetes, nerve damage of some sort, or simply be due to aging.
Including foods that are digested slowly, drinking an adequate amount of water before a meal, and avoiding strenuous activity right after a meal can help those who have experienced low blood pressure after eating.
Now that you have a better understanding of how eating impacts blood pressure, you are likely thinking about your own diet. Eating a healthy, balanced diet that is low in fat, low in sodium, and includes healthy carbohydrates as opposed to refined carbs is recommended to help maintain good blood pressure. A final tip: consuming water is important, as we pointed out, but relieve yourself prior to getting your blood pressure taken since a full bladder can actually impact blood pressure results.