Following my last posting on the use of baking soda for washing fruits and vegetables, I received questions regarding whether baking soda is good or bad for health. To answer, let’s look at what baking soda is.

What is baking soda?
Baking soda is a chemical compound, namely sodium bicarbonate (Formula: NaHCO3). It is also called bicarbonate of soda, or simply bicarb. According to the company history of Church & Dwight Co., Inc., John Dwight and Dr Austin Church started the first production of baking soda for household use in 1846 [1]. They subsequently launched a company to manufacture and market the product with the now classical “Arm and Hammer” brand. Church & Dwight has since grown to become a globally leading supplier of sodium bicarbonate, producing 9% of the global supply in 2016 [2].

So, is baking soda entirely man-make? Not quite. Just like table salt (sodium chloride), which can be produced in the laboratory, or extracted from natural sources (like seawater), sodium bicarbonate has its natural form. The naturally occurring sodium bicarbonate is a mineral either colourless or white. Called Nahcolite (basically, NaHCO-lite). Nahcolite is found in large deposits in many parts of the world, including the United States of America (California and Colorado), Botswana, Kenya, Uganda, Turkey, and Mexico [3].
Baking soda – a good friend
From baking to cleaning
Since its introduction more than 170 years ago, baking soda has found its way into a wide variety of household usage. Originally, baking soda is marketing as a leaving agent for baking. It releases carbon dioxide in the dough to produce the porous structure and increase volume in biscuits, cookies, and cakes. People soon find many other uses of this inexpensive white powder at home. It has also become an all-round product for cleaning, deodorising, and disinfecting, just to name a few. For example, baking soda is good for removing stains on clothes. It is also a common practice to put a box of baking soda in the refrigerator to eliminate odour.

For oral care
Researchers also found baking soda to have anti-bacterial properties , and it is a natural disinfectant that can eliminate many harmful bacteria [4]. For this reason, this versatile product also found its way into many natural oral care products, such as toothpaste, mouthwash, chewing gum, and denture cleanser. Dentists also use it for teeth polishing and whitening [5].
By simply dissolving half a teaspoon (2.5 g) of sodium bicarbonate in 250 ml of water, you can make a safe and effective mouthwash. Use it to rinse your mouth 3-4 times daily. It can help to neutralise the pH, moisturise, deodorise, and kill bacteria in the oral cavity. It is the right formula for keeping the mouth clean, prevent dental decay and oral infections [5].

In medicine
Bicarbonate is a weak alkali (or base) in water. As such, the natural use of sodium bicarbonate is an antacid to neutralise the excessing secretion of stomach acid for relieving heartburn and upset stomach [6]. Sodium bicarbonate is widely available as an over-the-counter medication (in tablet or mixture form) in pharmacies [7].

Bicarbonate also plays an essential part in regulating the pH in our blood and body system. When dissolved into water, bicarbonate ion forms a buffer system with carbonic acid (H2CO3). The solution has an equilibrium in pH. It is resisting to pH changes when acids or bases are added to it [8]. The body depends on the bicarbonate buffer system to maintain its acid-base balance. The blood pH, for example, is tightly regulated between the range of 7.35 to 7.45 [9]. Severe disruption of the acid-base balance can become life-threatening. Metabolic acidosis happens when blood pH to drop below 7.35. It is associated with kidney and heart diseases, as well as increased mortality. Sodium bicarbonate used in hospitals to treat such cases of over-acidity. However, some doctors have questioned its usefulness [10–12].
Furthermore, taking sodium bicarbonate supplement is also suggested for patients with chronic kidney disease [13]. It can help to slow the progression of kidney failure and improve the nutritional status of such patients. However, it must be used in proper dosage to achieve the desirable effects [14,15].
Sport performance
Another exciting use of baking soda is in the field of exercise and sport. During intense exercise, the muscles will begin to produce lactic acid due to insufficient oxygen. Accumulation of lactic acid in the body is also a form of metabolic acidosis [16]. Taking sodium bicarbonate before exercise has been found to increase the endurance and improve performance of the athletes [17]. Hence, don’t be surprise if you see sports drink made with baking soda.

Baking soda can be an ugly foe
Baking soda is generally considered safe for general use. However, this does not mean that there is entirely no risk. Among the side effects listed for its use as a medication include frequent urge to urinate, continuing headache, loss of appetite, mood change, muscle pain or twitching, nausea or vomiting, restlessness, slow breathing, swelling of feet, unpleasant taste, and unusual tiredness [18]. There are also some very severe case reports of sodium bicarbonate become toxic and harmful when it is used in excess quantity [19]. For patients with chronic conditions such as heart disease and kidney conditions, it is essential to consult a qualified health professional before taking sodium bicarbonate as an oral supplement.

Summary
In a nutshell, baking soda is useful not only for baking but also for cleaning, deodorising, and disinfecting at home. It is also suitable for maintaining oral health. As a medication, it is to relieve upset stomach and heartburn. Bicarbonate therapy is the medical term for using baking soda to correct over-acidity in the body, even though its effectiveness is questionable. Nonetheless, the use of baking soda as a supplement for sport is gaining popularity. Research has shown that it can improve the performance and endurance of athletes.
However, everything can become toxic when using in large quantity. If overuse, baking soda can cause a severe metabolic imbalance in the body. It can also pose a risk to patients with chronic conditions such as heart disease and kidney conditions if not correctly used. Hence, it is important not to overdose or misuse this useful and seemingly harmless substance.

Reference
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[2] Sodium Bicarbonate – Chemical Economics Handbook (CEH) | IHS Markit, (n.d.). https://ihsmarkit.com/products/sodium-bicarbonate-chemical-economics-handbook.html (accessed October 30, 2019).
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[12] S. Sabatini, N.A. Kurtzman, Bicarbonate Therapy in Severe Metabolic Acidosis, J. Am. Soc. Nephrol. 20 (2009) 692 LP – 695. doi:10.1681/ASN.2007121329.
[13] Oral bicarbonate supplements – Chronic Kidney Disease (Partial Update) – NCBI Bookshelf, (n.d.). https://www.ncbi.nlm.nih.gov/books/NBK328145/ (accessed October 31, 2019).
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[15] I. de Brito-Ashurst, M. Varagunam, M.J. Raftery, M.M. Yaqoob, Bicarbonate supplementation slows progression of CKD and improves nutritional status, J. Am. Soc. Nephrol. 20 (2009) 2075–2084. doi:10.1681/ASN.2008111205.
[16] Lactic Acidosis: Symptoms, Causes, Treatment, and More, (n.d.). https://www.healthline.com/health/lactic-acidosis (accessed October 31, 2019).
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