Several scientific studies have examined the health benefits of baking soda and lemon juice separately, but there is not much research to support the combined effects of these two ingredients.
This article discusses some of the potential health benefits of consuming baking soda and lemon juice mixtures.
A note about pH
A baking soda solution is alkaline, while lemon juice is acidic.
The idea of combining baking soda and lemon juice draws on basic principles of acidity and the pH scale.
Scientists use the pH scale to measure the acidity of a solution. A solution can have a pH level between 0 and 14.
The lower the pH, the more acidic the solution, so:
- pH levels below 7 indicate an acidic solution
- pH levels above 7 indicate an alkaline, or base solution
- neutral solutions, such as pure water, have a pH of 7
Baking soda, also known as sodium bicarbonate, is a base. This means that when people dissolve baking soda in water, it forms an alkaline solution. For example, a 0.1 molar solution of baking soda has a pH of around 8.3.
Lemon juice contains citric acid and has a pH of around 3. Adding baking soda to lemon juice will raise the pH to produce a more neutral solution.
Usually, the skin has a weakly acidic pH of about 5.7. Bases, such as baking soda, will increase the pH of the skin. Higher pH levels can disrupt the barrier function of the skin, which may lead to dryness, excess oil production, and acne.
Lemon juice appears to have obvious skincare applications because it contains concentrations of vitamin C and citric acid, which both provide powerful skin benefits. Citric acid is an alpha-hydroxy acid (AHA) that manufacturers commonly use in chemical peels.
However, skin cells naturally repel water-soluble molecules, such as vitamin C. This means that very little vitamin C will actually penetrate the skin.
The high acid content of lemon juice can lower the pH level of the skin. Low pH levels may cause skin irritation, hyperpigmentation, and UV light sensitivity.
Using a homemade mixture of baking soda and lemon juice may potentially be harmful to the skin. Instead, a person can try using neutral cleansers or chemical peels that contain AHAs, such as glycolic acid.
Neutralizing stomach acid
Citrus fruits are a rich source of citric acid.
Many people with excess stomach acid take over-the-counter (OTC) antacids to relieve their symptoms. Consuming baking soda and lemon juice together may also neutralize stomach acid in a similar fashion as an antacid.
A 2017 study examined the antacid effects of various foods. The authors of this study created artificial stomach acid with a pH of 1.2. Although lemon juice by itself had almost no effect, sodium bicarbonate successfully neutralized the synthetic stomach acid.
Many OTC antacids contain sodium bicarbonate and citric acid. Lemons and other citrus fruits are rich sources of naturally-occurring citric acid.
When a person mixes lemon juice and baking soda, the citric acid reacts with the sodium bicarbonate to produce a buffer called sodium citrate. A buffer refers to a weak acid or base that prevents drastic pH changes. Although lemon juice does not neutralize stomach acid, it may help stabilize the pH level inside the stomach.
Using baking soda and lemon juice to combat excess stomach acid may be a good home remedy, as effective OTC antacids contain similar ingredients.
However, mixing the correct proportions of baking soda and lemon juice can be difficult.
Consuming a mixture with too much baking soda may cause diarrhea and gas, whereas too much lemon juice could trigger acid reflux and make symptoms worse. Purchasing an antacid at the drug store is often much safer.
Other home remedies for reducing excess stomach acid include:
- avoiding or reducing acidic foods and beverages
- limiting caffeine intake
- limiting alcohol consumption
- eating smaller meals
- drinking more water
- getting enough sleep
People with severe or persistent acid reflux or heartburn should speak to a doctor or gastroenterologist.
Many oral care products contain baking soda due to its antibacterial properties, and its ability to remove plaque without eroding tooth enamel.
Baking soda may also help remove surface-level tooth stains, making it an effective and affordable alternative to traditional teeth whitening. However, there is little evidence to suggest that adding lemon juice to baking soda will enhance the dental benefits of baking soda.
A 2017 report that reviewed 21 studies concluded that toothpaste containing baking soda safely and effectively removed tooth stains. However, the report did not include any studies involving lemon juice.
It is also important to note that lemon juice contains high concentrations of citric acid and ascorbic acid, or vitamin C. Acidic compounds can erode enamel and lead to tooth decay. However, combining baking soda and lemon juice should produce a more pH-neutral solution.
People interested in whitening their teeth should contact their dentist. The American Dental Association (ADA) have also approved several types of baking soda toothpaste. To acquire an ADA Seal, manufacturers must provide scientific evidence to prove their product is safe and effective.
General risks and considerations
Baking soda can cause side effects, including thirst and headaches.
Baking soda contains sodium bicarbonate, which is an active ingredient in some medications, such as antacids, and can potentially interact with other medications. People who intend on regularly consuming baking soda for health purposes should speak to a doctor first.
People who have kidney disease or high blood pressure must avoid sodium bicarbonate because it can increase sodium levels in the blood.
Side effects of sodium bicarbonate can include:
- nausea and vomiting
- stomach pain
- excess gas
- frequent urination
- swelling of the lower limbs
Lemons contain many essential vitamin and minerals. Lemon juice also contains compounds that have beneficial antibacterial and antioxidant properties.
However, lemon juice is acidic and using too much can cause side effects. These can include:
- enamel loss
- tooth decay
- acid reflux
- nausea and vomiting
Baking soda and lemon juice mixtures are popular health hacks, with people using them for things that include skin care, teeth whitening, and treating heartburn and indigestion. However, there is limited scientific evidence currently to support the health benefits of these mixtures, making it difficult to draw definitive conclusions.
Both baking soda and lemon juice possess several health benefits on their own. However, combining these two ingredients without specific dosage or usage guidelines may cause adverse side effects.