What are the side effects of using curd?

December 2, 2025 •

4 min read

While often hailed as a probiotic powerhouse, a significant portion of the population experiences adverse reactions when consuming curd due to lactose intolerance or allergies. What are the side effects of using curd, and how can you mitigate potential risks to your digestive and overall health?

Quick Summary

Curd can cause digestive distress for the lactose intolerant, trigger allergies, increase acidity, and worsen respiratory issues, particularly when consumed excessively or improperly. Adverse reactions also include inflammatory flares and weight gain, depending on individual sensitivities.

Key Points

Lactose Intolerance: Curd can cause bloating, gas, and diarrhea for people who are lactose intolerant, though it's generally better tolerated than milk.
Allergic Reactions: Some individuals may have a milk protein allergy to casein or whey, leading to severe reactions like hives, swelling, and wheezing.
Acidity Trigger: Aged or sour curd has a higher lactic acid content and can worsen acid reflux, especially when combined with incompatible foods.
Respiratory Issues: As per Ayurveda, curd can increase mucus production, aggravating respiratory conditions like asthma or cold, particularly when eaten at night.
Weight Gain Risk: Excessive intake of high-fat curd, especially with a sedentary lifestyle, can contribute to weight gain.
Inflammatory Response: People with inflammatory conditions like arthritis may experience increased joint pain and stiffness from frequent curd consumption.
Improper Pairings: Combining curd with certain foods like fish, mangoes, or oily items can disrupt digestion and create an imbalance.

Digestive Distress and Intolerances

For many, curd is a digestive aid, but for others, it can be a source of significant discomfort. The most common cause of digestive issues is lactose intolerance, a condition where the body lacks the enzyme lactase needed to break down lactose, the sugar found in dairy.

Symptoms of lactose intolerance can range from mild to severe and typically appear within a few hours of consumption. These include:

Abdominal bloating and pain
Excessive gas or flatulence
Diarrhea or, in some cases, constipation
Nausea and stomach rumbling

While curd contains less lactose than milk due to the fermentation process, which breaks down some of the sugar, it is not entirely lactose-free. This means that individuals with a high degree of sensitivity may still experience symptoms. Additionally, even without a formal intolerance, consuming too much curd can overwhelm the digestive system, leading to temporary bloating and indigestion.

Curd and Acidity: A Double-Edged Sword

Curd's role in managing acidity is complex. While fresh curd can have a cooling, soothing effect on the stomach, aged or sour curd can have the opposite effect, especially according to Ayurvedic principles.

This is because as curd ferments, its lactic acid content increases, making it more acidic. For individuals already prone to acid reflux, consuming sour curd can aggravate their condition. Furthermore, Ayurveda suggests that the heating nature of fermented foods can increase body heat, contributing to acid-related discomfort.

Allergic Reactions

Distinct from lactose intolerance, a milk protein allergy involves an immune system response to the proteins in milk, specifically casein and whey. Symptoms of a milk allergy can be more severe and involve multiple body systems.

Immediate symptoms of an allergy can include:

Hives and other skin rashes
Wheezing or difficulty breathing
Swelling of the lips, tongue, or throat
Vomiting

In rare but severe cases, a milk allergy can trigger anaphylaxis, a life-threatening reaction. If you suspect a milk allergy, it is crucial to consult a healthcare professional. Individuals with a confirmed milk allergy should strictly avoid curd and other dairy products.

Potential Respiratory Concerns

Ayurveda has long associated curd consumption, especially during colder months or at night, with increased mucus production. This can be problematic for individuals with pre-existing respiratory conditions such as asthma, chronic sinusitis, or frequent colds and coughs.

While modern science links colds and coughs to viral infections rather than curd itself, some people report that dairy products can thicken mucus, worsening their symptoms. For this reason, those with respiratory sensitivities are often advised to consume curd in moderation, at room temperature, and preferably during the day.

Weight Gain and Calcium Overload

While often praised for its health benefits, excessive consumption of full-fat curd can lead to weight gain due to its calorie density. A sedentary lifestyle coupled with a high intake of full-fat dairy can contribute to an unhealthy caloric surplus over time. Moderation is key to harnessing the benefits without gaining unwanted weight.

Additionally, though calcium is vital for bone health, overconsumption of dairy products, including curd, can be an issue. In individuals predisposed to kidney stones, particularly calcium oxalate types, an excessive calcium intake could potentially increase risk. A balanced diet with varied calcium sources is generally recommended.

Curd and Inflammatory Conditions

For some individuals suffering from inflammatory conditions like arthritis, regular curd consumption may exacerbate symptoms. The acidic nature of curd is sometimes linked to heightened joint pain and stiffness in sensitive individuals. As with any dietary change for a chronic condition, it's wise to monitor your body's response and consult a doctor or dietitian.

The Risks of Improper Consumption

Beyond individual sensitivities, how and when you consume curd can determine its effect on your health. Ayurveda and dietary experts highlight several practices to avoid:

Heating Curd: Cooking curd can destroy its beneficial probiotics and make it harder to digest, potentially creating 'ama' (toxic buildup).
Incompatible Food Combinations: Mixing curd with certain foods is thought to disrupt digestion. Common examples include pairing curd with fish, mangoes, onions, or oily fried foods.
Nighttime Consumption: As mentioned, eating curd at night can be harder to digest, potentially increasing mucus and sluggishness.

A Comparison of Fresh Curd vs. Aged/Sour Curd


Feature	Fresh Curd	Aged/Sour Curd
Lactic Acid Content	Lower	Higher
Acidity Level	Less Acidic	More Acidic
Effect on Stomach	More soothing, can help with acidity	Can trigger or worsen acid reflux
Digestive Impact	Easier to digest	Heavier, can slow digestion
Probiotic Activity	High	Can be diminished by excessive fermentation
Best Time to Consume	Day and night, in moderation	Best during the day; avoid at night

Conclusion

While curd is a highly nutritious and beneficial food for many, it is not without its potential drawbacks, which can significantly impact certain individuals. The side effects of using curd range from common digestive issues, particularly for those with lactose intolerance, to more specific concerns like increased acidity, respiratory problems, and inflammation.

Understanding your body's unique response to curd is paramount. By being mindful of consumption patterns, timing, and food combinations, you can minimize negative reactions. Listening to your body, consuming in moderation, and opting for fresh, plain curd can help you reap its benefits safely. If symptoms persist, seeking advice from a healthcare provider is the best course of action.

For more information on milk protein allergies, you can consult a reputable source like the Mayo Clinic Milk allergy - Symptoms and causes.

Frequently Asked Questions

Curd generally has a lower lactose content than milk due to the fermentation process, so some people with mild intolerance may tolerate it better. However, it still contains lactose, and those with severe intolerance may still experience symptoms like bloating and gas.

Curd does not cause viral infections like colds or coughs. However, some traditional systems and sensitive individuals report that curd, especially if cold or consumed at night, can increase mucus production and aggravate existing respiratory issues like a cough or sinus congestion.

The effect of curd on acidity depends on its freshness. Fresh, plain curd can be soothing, while aged or sour curd contains more lactic acid and can trigger or worsen acid reflux symptoms in sensitive individuals.

According to some traditions like Ayurveda, it is best to avoid curd at night as it is considered heavy and mucus-forming, potentially slowing down digestion. For better digestion, it's often recommended for daytime consumption.

Ayurveda advises against combining curd with several foods, including fish, oily fried foods, mangoes, onions, and milk, as these pairings can disrupt digestion and create imbalances.

While full-fat curd is nutritious, excessive consumption can contribute to weight gain, especially if combined with a sedentary lifestyle. It is important to monitor portion sizes.

Some people with pre-existing inflammatory conditions like arthritis report that the acidic nature of curd can aggravate joint pain and stiffness. If you have such a condition, it's important to monitor your body's response.