Walnuts: Health Benefits, Uses, and Side Effects

In ancient times, walnuts were called the ‘royal nuts’ because they were consumed mainly by royalty. Originally from Persia, these nutrient-rich nuts are now enjoyed worldwide for their numerous health benefits. Interestingly, their shape resembles the human brain, and scientific studies suggest that walnuts (Hindi: Akhrot) may indeed promote brain function [7]. They are incredibly versatile and can be incorporated into the diet in many ways. Let’s dive into the various health benefits of walnuts.

10 Core Health Benefits of Walnuts

Walnuts are a powerful source of omega-3 fatty acids, antioxidants, and phytosterols [1], [3], offering a range of health benefits from reducing disease risk to supporting hormonal balance.

1. Supports Heart Health and Lowers Cholesterol

Incorporating walnuts into your diet can significantly lower total and LDL (“bad”) cholesterol levels [2], [4]. This effect is attributed to their high concentration of polyunsaturated fats and α-linolenic acid (ALA). Regularly consuming walnuts is consistently associated with a reduced risk of heart disease [3].

2. Contains Anti-Inflammatory and Antioxidant Properties

Walnuts contain polyphenols and ALA, which possess potent anti-inflammatory effects [5], [6]. Chronic inflammation is a driver of diseases like Type 2 diabetes and cardiovascular conditions. Regular consumption may help manage inflammation and lower the risk of these chronic diseases [6].

3. May Reduce the Risk of Certain Cancers

The combination of omega-3 fatty acids, antioxidants, and phytosterols found in walnuts have protective properties against cell damage and tumor development [6]. Research suggests that regular consumption of walnuts, as part of a healthy diet (like the Mediterranean diet), may help reduce cancer-related mortality [3].

4. Promotes Brain Function and Cognitive Health

Walnuts are rich in omega-3 fatty acids, vitamin E, and polyphenols that may help reduce oxidative stress and inflammation in the brain [7], [9]. Studies suggest that regular walnut consumption may enhance memory, processing speed, and cognitive flexibility in older adults, and improve overall cognitive function in teenagers [9].

5. Aids in Weight Management

Walnuts can be a beneficial part of weight loss goals. Despite being calorie-dense, their combination of protein, fibre, and healthy fats promotes satiety (a feeling of fullness), which may help reduce overall calorie intake and support gradual weight loss [3], [4].

6. Supports Blood Sugar Control (Diabetics)

Walnuts are a suitable snack for people with diabetes due to their low glycaemic index (GI). They do not cause significant spikes in blood glucose levels and may help improve insulin sensitivity, thus potentially reducing the risk of developing Type 2 diabetes [3].

7. Boosts Gut Health and Digestion

Walnuts are rich in dietary fibre, which supports regular bowel movements. More importantly, studies show that walnuts may promote a healthy gut microbiome by increasing the number of butyrate-producing bacteria [6]. Butyrate is a short-chain fatty acid that supports the gut lining and reduces inflammation, linking healthy gut function to reduced risks of obesity and metabolic diseases.

8. Helps Manage PCOS

For women with Polycystic Ovary Syndrome (PCOS), walnuts may offer support by helping to manage symptoms often associated with the condition. They have been shown to enhance insulin sensitivity and may help regulate reproductive hormones by increasing levels of sex hormone-binding globulin (SHBG) [8].

9. Supports Reproductive Health (Fertility and Pregnancy)

Walnuts contain micronutrients and fatty acids that may help improve sperm production, quality, morphology, and vitality in men [3]. For pregnant women, the Omega-3 and Omega-6 fatty acids are essential nutrients that support the healthy development of the baby [1], [3].

10. Improves Sleep Quality

Walnuts contain the amino acid tryptophan, which the body uses to produce serotonin and melatonin—hormones crucial for regulating the sleep-wake cycle [9]. Consuming walnuts in the evening may help promote restful sleep.

Culinary Uses of Walnuts

Wondering how to include walnuts in your daily diet? Here are some easy and tasty ways:

1. Snacking: Walnuts are excellent healthy snacks on their own or when combined with dried fruits.
2. Baking: They add a delicious crunch to cookies, desserts, bread, and cakes.
3. Cooking: Walnuts add crunch and a nutty flavour to dishes like salads, stir-fries, and oatmeal. You can also sprinkle chopped walnuts over foods for added taste and nutrients.

Potential Side Effects and Precautions

While walnuts are generally safe and highly beneficial, moderation is key because of their caloric density and fibre content.

• Gastrointestinal Discomfort: Overconsumption may lead to bloating, gas, diarrhoea, or abdominal pain due to their high fibre content.
• Weight Gain: As they are calorie-dense (approx. 654 Kcal per 100g), eating excessive quantities without adjusting overall calorie intake can lead to weight gain.
• Allergic Reactions: Walnuts are a type of tree nut and can cause serious, life-threatening allergic reactions in sensitive individuals.
• Kidney Stones: Due to their oxalate content, excessive intake may theoretically contribute to stone formation in individuals genetically predisposed to calcium oxalate kidney stones.

Takeaway

Walnuts are packed with heart-healthy fats, antioxidants, and essential nutrients. Regular consumption (about 1–2 ounces or 14 halves a day is recommended) can support brain function, cardiovascular health, and even help reduce the risk of chronic diseases. Their versatility in cooking and snacking makes them an easy and delicious way to boost your health.

Frequently Asked Questions (FAQs)

What are the main uses of walnuts?

Walnuts are commonly used as snacks or added to foods like salads, oatmeal, and baked goods for enhanced nutrition and flavour.

How many walnuts can I eat a day?

As part of a healthy diet, you can eat about 1–2 ounces (or 14 halves) of walnuts a day.

Is walnut good for men?

Yes, walnuts may support heart and brain health and may also improve sperm quality and reproductive health [3].

What is the best time to eat walnuts?

There is no strict “best” time. Walnuts can be eaten any time during the day—as a snack, with breakfast, or in the evening to benefit from the melatonin-producing tryptophan for better sleep [9].

Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare professional, such as a doctor or registered dietitian, before starting, stopping, or changing any treatment, supplement, or diet.

References

[1] Bi̇Ni̇Ci̇, H. İ., Şat, İ., & Aoudeh, E. (2021). Nutritional composition and health benefits of walnut and its products. Atatürk University Journal of Agricultural Faculty, 224–230. https://doi.org/10.17097/ataunizfd.843028

[2] Sukmawati, S., & Rauf, S. (2023). The role of walnuts (Canarium indicum L.) towards reducing blood cholesterol levels in hyperlipidemic. Food Research, 7(5), 27–30. https://www.myfoodresearch.com/uploads/8/4/8/5/84855864/_4__fr-ichn-10_sukmawati.pdf

[3] Lockyer, S., De La Hunty, A. E., Steenson, S., Spiro, A., & Stanner, S. A. (2022). Walnut consumption and health outcomes with public health relevance—A systematic review of cohort studies and randomized controlled trials published from 2017 to present. Nutrition Reviews, 81(1), 26–54. https://doi.org/10.1093/nutrit/nuac040

[4] Liu, W., Li, E., & Hu, M. (2024). Efficacy of walnut supplementation in managing overweight and obesity: A meta-analysis of randomized clinical trials. Journal of Functional Foods, 122, 106515. https://www.sciencedirect.com/science/article/pii/S1756464624005176

[5] Song, H., Cong, Z., Wang, C., He, M., Liu, C., & Gao, P. (2022). Research progress on Walnut oil: Bioactive compounds, health benefits, extraction methods, and medicinal uses. Journal of Food Biochemistry, 46(12). https://doi.org/10.1111/jfbc.14504

[6] Fan, N., Fusco, J. L., & Rosenberg, D. W. (2023). Antioxidant and anti-inflammatory properties of walnut constituents: Focus on personalized cancer prevention and the microbiome. Antioxidants, 12(5), 982. https://www.mdpi.com/2076-3921/12/5/982

[7] Tiwari, D., & Rastogi, M. (n.d.). Role of walnuts in brain health. In Nourish Your Mind (p. 165). ResearchGate. Retrieved October 28, 2025, from https://www.researchgate.net/profile/Divyanshi-Tiwari-5/publication/389326573_Role_of_Walnuts_in_Brain_Health/links/67beb0f596e7fb48b9cde853/Role-of-Walnuts-in-Brain-Health.pdf

[8] Sharma, P., Kumar, R., Gupta, M., & Rani, J. (2025). The role of nutrients in PCOS: An exploration of key nutrients and their impact on PCOS symptoms. In AI-based nutritional intervention in polycystic ovary syndrome (PCOS) (pp. 89–104). Springer Nature Singapore. https://link.springer.com/chapter/10.1007/978-981-96-2120-0_3

[9] Yeh, A., Chao, C., Huang, W., Lin, H., & Wang, C. (2022). Walnut (Juglans regia L.) oligopeptide effects on enhancing memory, cognition and improving sleep quality in teenagers and elderly people in a randomized double-blind controlled trial. Natural Product Communications, 17(3). https://doi.org/10.1177/1934578×221089065