January 2025 – Dr. Stefano Picca, Nephrologist
During the holiday season or nights out with friends, it’s easy to indulge in some dietary excess or have one drink too many. While an occasional episode might seem harmless, it’s important to understand how these behaviors can impact kidney health, especially when repeated over time.
The function of the kidneys
The kidneys are vital organs that filter the blood, remove toxins, regulate bodily fluids, and maintain the balance of essential substances like glucose, proteins, and minerals such as sodium, potassium, calcium, or phosphorus. However, excessive consumption of salty, fatty, or protein-rich foods, or alcohol abuse, can impair kidney function, sometimes irreversibly (Chronic Kidney Disease – CKD). In severe cases, this can lead to dialysis or kidney transplantation. Water plays a crucial role in preventing such damage.
Does what we eat affect kidney function?
Yes.
Long-term studies show that red meat, processed meat, high-fat cheeses, and sugary soft drinks are associated with an increased risk of CKD, while dairy products, vegetables, and legumes reduce this risk. The DASH diet (Dietary Approaches to Stop Hypertension) and the Mediterranean diet, rich in fruits, vegetables, and whole grains, have proven effective in preventing CKD (1).
Does how much water we drink affect kidney function?
Yes.
Drinking insufficient water causes dehydration, a condition linked to serious health issues, especially in older adults, such as urinary tract infections, kidney stones, strokes, and heart attacks. Reduced thirst perception in older adults and social or environmental factors like isolation or embarrassment to use the restroom can exacerbate the risk (2).
Can alcohol damage the kidneys?
Yes.
Excessive alcohol consumption leads to dehydration and high blood pressure, both of which severely harm the kidneys. High blood pressure is, alongside diabetes, one of the leading causes of dialysis and kidney transplantation (3).
How to protect kidney health
Prevention is key. Here are practical tips from the Italian Society of Nephrology (4):
- Limit salt intake and avoid preserved or pre-cooked foods. Maintain adequate salt levels during periods of illness to prevent low blood pressure and poor organ perfusion, particularly in the kidneys.
- Choose fruits and vegetables, which are high in fiber and have alkalizing properties.
- Reduce animal protein intake, replacing some with plant-based proteins like legumes, paired with grains, as emphasized in the Mediterranean diet.
- Maintain proper hydration: about 30 ml per kg of body weight, roughly 2 liters for a 70 kg adult.
Conclusion
Taking care of your kidneys means taking care of your overall health. If you have questions or wish to check your kidney health, I would be happy to assist you. Schedule an appointment with me, Dr. Stefano Picca, nephrologist at the Aventino Medical Group. Together, we can work to protect your kidney health.
References
- Van Westing et al., Diet and Kidney Function: a Literature Review. Current Hypertension Reports (2020) 22:14.
- Hooper L et al., Water-loss dehydration and aging. Mechanisms of Ageing and Development 136-137 (2014) 50–58.
- National Kidney Foundation, Alcohol and Your Kidneys (2024).
- Italian Society of Nephrology, “Christmas, Mediterranean Diet, and Holiday Menus: A Guide for Kidney Health,” Adnkronos (2024).