The amount of unnatural chemicals in food, air and water is only increasing in a dramatic way, with thousands of new chemicals being introduced every year, many of them insufficiently tested. A recent UN report points out that every third child in the world, or 800 million children, have lead levels in their blood that exceed the limit of five micrograms per deciliter. Because of that, it is wise to try to reduce their exposure to chemicals as much as possible. Many deodorants contain aluminum, which effectively clogs the sweat ducts under our arms so that we do not sweat or smell, but if we ask our bodies, they would probably not want this substance under our arms preventing our sweat ducts from functioning as they are intended.

The reason you sweat under your arms is to get rid of some of the excess heat. An alternative to spraying or rolling aluminum under your arms is to make your own deodorant based on a common kitchen baking ingredient, baking soda (sodium bicarbonate) and any essential oil, such as lavender or eucalyptus.

Baking soda removes odors

What is the reason for odor under our arms? Nasty-smelling sweat can occur from consuming certain foods and beverages or if we have diseases and take medicines. Normally, sweat does not smell, but the smell arises from naturally existing bacteria that live under our arms. When the bacteria eat old skin cells in our armpits, an acidic substance called trans-3-methyl-2-hexenoic acid (TMHA) is released. When TMHA is mixed with both water in the form of our sweat, and air, the reaction causes body odor.

Baking soda reacts with the acidic TMHA to neutralize the odor while forming carbon dioxide. Everything you need to make your own deodorant can be bought at the grocer or local discount store, in USA for example Walmart, Target and Whole Foods.

▶ 100 ml bottle (3 oz). Purchase in the UK via Essential Oils Direct. Cost: £0.54. Purchase in the US via Amazon. Cost: $9.99 for 3-pack (includes spray pump).
▶ Spray pump for the bottle. Purchase in the UK via Essential Oils Direct. Cost: £0.5.
▶ 0.5 kg (16 oz) baking soda. Purchase in the US via Amazon. Cost: $8. Enough for about 250 100 ml deodorant bottles.
▶ Essential oil of your choice, for example lavender 10 ml. Purchase in the UK via Essential Oils Direct. Cost: £6.78. Purchase in the US via Amazon. Cost: $7.49. Enough for about 100 100 ml deodorant bottles.

Deodorant recipe: Fill the 100 ml (3 oz) bottle with water. Add 2 grams (2 ml, just a little under ½ teaspoon) baking soda and about 5 drops of essential oil. Choose the essential oil and number of drops depending on how strong you want your deodorant to smell. Shake the bottle slightly before use.

Other areas of use for bicarbonate:

▶ Mouth spray. If you have bad breath, a spray of baking soda can be an environmentally friendly and efficient solution. (same mix as above, but skip the essential oil)
▶ Bathroom shower. Spray throughout the bathroom after you have relieved yourself to neutralize the odor.
▶ Shoes, gym bag. Bad odor in shoes, gym bags and backpacks can easily be neutralized by spraying them with a baking soda solution.
▶ Flower shower. Spray the flowers if you have problems with infestation, as baking soda causes the leaves to have a higher pH, which retards fungal growth. Mix 1 tablespoon (15 grams) of baking soda in 1 liter (1 quart/32 oz) of water. Skip the essential oil.
▶ In the fridge. Put an opened box of baking soda in the fridge. The odor in your fridge consists of food particles that circulate in the regrigerated air, and instead of sticking to other food they can stick to the baking soda. Change after a couple of months.
▶ Recycling. Place an opened box of baking soda under the sink or wherever you keep your trash or recycling, as the foul-smelling air particles bind to the baking soda. Change after a couple of months.
▶ Get rid of pesticides. Soak fruit or other food that has been sprayed with pesticide in a baking soda bath to remove the pesticide. Use 1 tablespoon (15 gram) of baking soda to 1 liter (1 quart/32 oz) of water.

A study shows that baking soda is more effective at removing pesticide residues in apples than the commercial rinse aid Klorox. After 15 minutes in a baking soda bath, almost all pesticide was neutralized.

We have large amounts of baking soda in our bodies

From the study above we can conclude that baking soda is not only effective against odor, but also fungi, bacteria and pesticides. Furtermore we have large amounts of baking soda, or bicarbonate as it is also called, in our body. A person weighing 70 kg (155 lbs) normally has about 120 liters of carbon dioxide in his or her body. How can we have 120 liters of something in the body, you may wonder. That is because carbon dioxide is a gas, and gas does not weigh as much or take up as much space as liquid. For example, a Sodastream® gas cylinder, which is relatively small, contains about 360 liters of carbon dioxide. The pressure is, admittedly, much higher in the Sodastream® cylinder than in our bodies, so the comparison is not quite appropriate, but t it gives you the idea of how a lot of carbon dioxide can be stored in a small space.

Most of the carbon dioxide, 70-80 %, travels around in our bodies as bicarbonate. The large amount of bicarbonate is an important buffer for the body to be able to maintain the correct pH value in different parts of the body. The stomach should have pH 1.5-3, the skin a pH of 5-5.5, the small intestine a pH of 7-9, the blood a pH of 7.4, and so on.

If bicarbonate is effective against all of these things outside our bodies, a relevant question is whether it can have similar functions inside our bodies? It is absolutely conceivable. But what happens if we have less bicarbonate in our bodies than desirable? It is possible (likely?) that our ability to deal with fungi, bacteria, pesticides and other chemicals we are exposed to decreases.

Impaired breathing reduces our bicarbonate buffer

An important purpose of our breathing is to maintain a balance between oxygen and carbon dioxide. Many people have a lifestyle that means that the carbon dioxide pressure, and, thus, the bicarbonate buffer in the body is lower than what is optimal. On the one hand, it is common to breathe faster than desirable, which means that we exhale too much carbon dioxide. On the other hand, it is common for us to engage in too little physical activity, which means that the production of carbon dioxide decreases. This is because carbon dioxide is formed during metabolism, which is higher when we move around compared to when we are inactive.

As we discussed initially, food and drink as well as diseases and medications can affect our sweat odor. Could it be that the body odor we emit is affected by our bicarbonate buffer too? I do not know. I admit that I am speculating here, but it is conceivable that certain types of food, drinks and medication lcan ead to impaired respiration, which lowers the carbon dioxide pressure, and the lower levels of bicarbonate in the body that is the reason why the "smell" cannot be taken care of inside the body, but instead, we sweat it out.