Updated on - 27 Jan 2026
Walnuts are considered one of the most nutritious foods you can include in your diet. They are easy to carry, convenient as a snack and packed with heart-healthy benefits. Regular consumption may help lower LDL (bad) cholesterol and increase your intake of essential minerals, vitamins, fibre and protein. Walnuts are also rich in anti-inflammatory and antioxidant compounds that can help slow ageing and protect against degenerative changes.
However, eating them in excess may lead to certain side effects. This blog explains the potential side effects of walnuts and how many you should consume each day for optimal health.
What are the side effects of walnuts?
Consuming too many walnuts can lead to the following side effects:
1. Diarrhoea and stomach discomfort
Excessive consumption of walnuts can lead to digestive distress, including diarrhoea, bloating and stomach cramps. Walnuts are high in fibre, which benefits digestion in moderate amounts, but consuming too much can upset the stomach.
2. Kidney stones
Walnuts contain a high level of oxalates—compounds found in many plant foods. For some people, high oxalate intake can contribute to the formation of kidney stones. If you’re prone to kidney stones or have a history of calcium oxalate stones, it’s best to enjoy walnuts in moderation.
While this doesn’t mean you must cut them out completely, you should be mindful of your overall oxalate intake.
3. Nutrient absorption issues
Too many walnuts can interfere with the body’s ability to absorb certain essential nutrients. Walnuts contain phytic acid, an "anti-nutrient" that can bind to minerals like iron, calcium and zinc, reducing their absorption.
If you consume large amounts of walnuts, it could lead to deficiencies in these minerals over time. This is particularly important for individuals struggling with iron or calcium deficiencies.
4. Allergic reactions
Some people may have an allergy to walnuts, which can cause symptoms ranging from mild itching to severe anaphylaxis. If you notice any unusual symptoms like swelling of the lips, tongue or throat after consuming walnuts, seek medical attention immediately.
5. Weight gain
Walnuts contain high calories, and excessive consumption can contribute to weight gain if it is not balanced with the overall caloric intake.
6. High omega-6 intake
Although the omega-3 fatty acids in walnuts are highly beneficial, these nuts also contain omega-6 fatty acids. An imbalance of omega-3 to omega-6 ratios in the diet can lead to arthritis, increasing the chances of chronic conditions like heart disease and inflammation.
7. Mouth irritation
Walnuts consist of tannins, which might cause a puckering and dry sensation in the mouth when they are consumed in large quantities. Some people might also experience minor throat or mouth irritation.
8. Increases the risk of acne
The high fat content found in walnuts, particularly if it is consumed in excess amounts, can trigger acne outbreaks in some people who are prone to skin-related issues.
9. Interaction with medications
Consuming too many walnuts might interfere with specific medications like blood thinners because of their high vitamin K content. Those taking such medications should consult with their physician before increasing their walnut intake.
If you experience any side effects after consuming walnuts, make sure to seek medical help immediately. Since medical treatments and medications can be expensive, it might be difficult to manage funds on your own. For such reasons, getting a health insurance policy can be a good option. It is primarily because health insurance policies can offer you financial protection by covering the cost of medication, treatments and even hospitalisation.
How many walnuts should you eat daily?
A daily intake of approximately 1 ounce (28 grams), or about ¼ cup, of walnuts is appropriate. However, consuming 1.5 to 2 ounces (43–57 grams) may provide additional benefits. Given their high caloric density, aiming for a small handful per day is recommended to obtain their health benefits.
Conclusion
Walnuts are known as a nutrient-rich superfood that may greatly benefit your health when they are consumed in moderation. However, overindulgence can lead to several side effects, such as allergic reactions, acne risks, weight gain and even digestive issues. Once you have a good understanding of the risks and adopt mindful eating habits, you can enjoy the benefits of walnuts without compromising your health.
Besides that, having the right health insurance plan, whether individual health insurance, family floater plan, senior citizen plan or critical illness cover, can help you stay financially protected if any health issues arise, even those linked to excessive walnut consumption. If you want customised advice and support in choosing the most suitable plan, fill out the form on this page today.
FAQs
1. Are walnuts safe for children?
Walnuts are highly nutritious, and they are generally safe for children. However, make sure that the kids are not allergic to them and serve them in age-appropriate portions. Before serving them walnuts, you should consult with a medical expert to learn about the correct portion.
2. Is it okay to consume walnuts each day?
Yes. You can eat walnuts each day, but in moderation. It is advised that you consume around 1/ to ½ cup or 1 to 2 ounces of walnuts each day. However, you should be mindful of the portion sizes because of their high calorie content.
3. Who should avoid eating walnuts?
Individuals who have a tree nut allergy, certain digestive problems like IBS or are prone to kidney problems must limit or avoid walnuts. Apart from that, individuals who are taking blood-thinning medication and have a low-calorie diet should consult with a physician before consuming walnuts.
4. Can walnuts cause gas?
Yes. Walnuts can cause bloating and gas, particularly if you eat way too many or if you are not used to a high-fibre diet.
Disclaimer: The information provided in this blog is for educational and informational purposes only. It is not intended as a substitute for professional advice, diagnosis or treatment. Please consult a certified medical and/or nutrition professional for any questions. Relying on any information provided in this blog is solely at your own risk, and ICICI Lombard is not responsible for any effects or consequences resulting from the use of the information shared.