Lemon water in the morning is a popular habit worldwide, appreciated for its refreshing effects and benefits for digestion and detoxification. Many consider it a miraculous remedy for supporting immunity and weight loss. However, there is an important category of people who should avoid this ritual. In certain conditions, regular consumption of lemon water on an empty stomach can worsen symptoms or even lead to complications.
Who Should NOT Drink Lemon Water in the Morning?
1. People with Gastroesophageal Reflux Disease (GERD)
The high acidity of lemon can irritate the esophageal mucosa, causing heartburn, acid reflux, or nausea. Even in small amounts, lemon juice can exacerbate symptoms already present in gastroesophageal reflux disease. Consumed on an empty stomach, this mixture aggravates mucosal irritation, leading to increased gastric acidity and a feeling of retrosternal burning.
Explanation: The citric acid in lemon stimulates gastric acid secretion. In healthy individuals, this can be beneficial for digestion. However, in those with reflux or gastritis, this excess acid can reach the esophagus, causing unpleasant symptoms.
Study: A study published in Journal of Neurogastroenterology and Motility (2019) analyzed the effects of acidic foods on reflux symptoms. The research, conducted on patients with GERD, concluded that foods and drinks rich in citric acid (including lemon juice) increased the frequency and intensity of heartburn. Participants who avoided these foods for 6 weeks reported a significant reduction in symptoms. The study also highlighted that morning consumption on an empty stomach led to greater discomfort compared to consumption during meals.
2. People with Gastric or Duodenal Ulcers
In these cases, citric acid can irritate already inflamed or eroded areas in the stomach and duodenum. Even a small amount of lemon juice can cause intense abdominal pain, cramps, or a burning sensation. Additionally, it can worsen existing inflammation, delaying the healing process and increasing the risk of bleeding.
Explanation: The protective mucus of the stomach is already compromised in patients with ulcers, and the additional acid can easily penetrate these vulnerable areas, exacerbating the lesions.
Study: In research published in Alimentary Pharmacology & Therapeutics (2021), it was shown that frequently consumed acidic foods, including natural juices, increase the rate of gastric irritation in ulcer patients. The study was conducted on 102 patients with active gastric ulcers, and 84% of them reported an increase in pain after consuming citrus. Participants who excluded lemon from their diet experienced significant symptom relief after 4 weeks.
3. People with Dental Erosion or Sensitive Enamel
Daily consumption of lemon water in the morning, especially on an empty stomach, promotes enamel erosion. Citric acid is one of the most aggressive acids for teeth, and repeated exposure can lead to thinning and sensitivity of the enamel, resulting in pain and even cavities.
Explanation: Enamel does not regenerate, and once it is damaged, the tooth becomes much more vulnerable. In the absence of foods that can neutralize the acid, the acid comes into direct contact with the teeth and has a stronger effect.
Study: A study published in British Dental Journal (2020) evaluated the effects of daily consumption of acidic beverages on dental enamel. In a group of 30 individuals who consumed lemon water daily, signs of dental demineralization were observed in just 6 weeks. Direct application of the juice, without using a straw or protective method, led to significant enamel damage, especially on the upper incisors.
4. People with Kidney Problems (especially Oxalate Stones)
Although lemon is often promoted for preventing kidney stones, in cases where the patient already has a high level of oxalate or suffers from oxalate kidney stones, frequent consumption of citrus can worsen the condition.
Explanation: Lemon contains a small amount of natural oxalates, which in certain cases can contribute to the formation of calcium-oxalate stones. In predisposed individuals, this additional intake can be problematic.
Relevant Study: In a study published in Clinical Journal of the American Society of Nephrology (2018), researchers observed that patients with a history of oxalate kidney stones had a higher incidence of recurrences when consuming citrus-rich beverages daily. Although lemon can help alkalinize urine, in certain forms of lithiasis, the effect is opposite to the desired one.
When is lemon beneficial for the kidneys:
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Lemon contains citrate, a compound that inhibits the formation of calcium stones (including calcium-oxalate).
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Consuming diluted lemon juice (not concentrated, and not on an empty stomach) can help increase citrate levels in urine, reducing the risk of forming new stones.
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Especially for individuals with hypocitraturia (low citrate levels in urine), lemon juice can be a recommended natural aid.
When can it be contraindicated:
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If the patient already has a high level of oxalates in urine, daily and excessive consumption of citrus can increase this intake, promoting the formation of stones, especially in combination with other sources of oxalates (spinach, chocolate, nuts).
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In some individuals, the effect of citric acid on urinary pH may not be sufficiently alkalinizing, especially in the absence of other dietary factors (e.g., magnesium and calcium intake).
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If lemon juice is consumed on an empty stomach, it can affect the gastric mucosa and temporarily disrupt the metabolic processes involved in renal filtration.
Other Possible Adverse Effects of Consuming Lemon Water on an Empty Stomach:
- Irritation of the throat, especially in individuals who consume concentrated lemon.
- Imbalance of stomach flora, in some cases, due to excessive acidity.
- Interactions with antacids or stomach treatments.
Sources:
- Journal of Neurogastroenterology and Motility Dietary Impact on GERD: Citrus Fruits and Reflux Symptoms
- Alimentary Pharmacology & Therapeutics Effect of dietary acidity on gastric ulcer healing and symptom severity
- British Dental Journal Acidic Beverages and Dental Erosion: Long-Term Observations
- Mayo Clinic Reflux Disease and Triggers: Acidic Drinks and Foods
