The body’s secret weapon – the blood buffer

In our day-to-day activities, we come across different forms of acids and bases. Well, you know to generally avoid these types of things but we are not always aware of the acidic things that we ingest. This can include acidic foods or alkaline dressings. Of course, it is important to limit how much of these foods that we eat daily, but we were never told why that is exactly (except that it can cause tooth decay). This article is going to look at the reason why we should avoid taking excessive amounts of acidic and basic foods and how the body reacts to the change in its conditions when we do take them in.


So to begin, you must be aware of the term acidic and basic and understand their basic meanings (no pun intended). An acid is a proton donor. In simple terms, this means that a solution can donate a hydrogen ion which is a proton. a base is a proton acceptor meaning that it can accept the proton being donated by the acid, and in terms of hydrogen ions, it can accept the hydrogen ions. acids have a pH ranging from about 0 to 6, bases have a range of 8 to 14 and pure water has a pH of 7. So, the higher the pH value the more alkaline the substance is or the less acidic it is. So we’d say that a more acidic substance has a high concentration of hydrogen ions whereas a substance that is more alkaline or basic has a high concentration of hydroxide ions. So, if you look at something like lemons, we know that it has a pH of around 5 this means that it has quite a high concentration of hydrogen ions. So what happens when you eat the lemon? Does it cause a change in our bodies and if so, what is that change? This all comes down to something called buffer action, a mechanism that is used to keep the body in check.


A buffer is a solution (or a substance) that can maintain pH and bring it back to its optimal value when there has been a small change in the pH. It does this by the addition or removal of hydrogen ions. They are made from a weak acid and the salt of this weak acid. Buffers working in the body fluid adjust the pH level of the blood if it rises or falls below 7.4, the human body’s pH level. If the pH of the blood falls below 7.4 and so becomes more acidic, the buffers act to use up hydrogen atoms and decrease the acidity of the blood. We have two natural buffers in our body—carbonate and bicarbonate— which play a vital role in regulating the body’s blood pH levels. When the blood becomes too acidic, the body produces bicarbonate to balance out the acidity. When the blood becomes too alkaline, the kidneys introduce carbonic acid (or carbonate) into the blood to bring down the excess alkalinity.


During exercise, the circulatory system cleans up the acid and carbon dioxide produced by taking it into the blood. This could result in a dangerous condition called acidosis, a process caused by increased acidity in the blood, but the bicarbonate buffer system maintains the blood pH at 7.4. When the blood becomes more acidic due to exercise, the additional protons from those acids are absorbed by the bicarbonate in the blood to form carbonic acid. The increase in carbonic acid in the blood stimulates the lungs to expel more carbon dioxide, which eventually causes the acid in the blood to be lowered back to a normal range.

So small changes in the value of the pH of our blood are ok as the body’s buffer system is able to shift the values back witihin the correct range. However, larger changes result in quite severe health issues. So let’s appreciate that we have these super power that means we can stay healthy and well. Where would we be without it?!

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