Do you need to restrict protein intake to protect your kidneys?
If your kidneys are healthy, you do not need to restrict your protein intake. If you have chronic kidney disease, discuss with your doctor and dietitian whether a protein-restricted diet is worthwhile, because too little protein is also dangerous.
If your kidneys are healthy, you do not need to restrict your protein intake. The NHANES cohort study (27,604 participants) actually found that people with normal kidney function who eat less than 0.6 grams of protein per kilogram of body weight per day had a higher risk of mortality. Reviews confirm that, in the presence of healthy kidney function, there is no association between protein intake and long-term decline in kidney function.
Chronic kidney disease is a different matter. A high protein intake increases pressure in the small filtering structures of the kidney, which can accelerate deterioration. In the same NHANES study, people with reduced kidney function who ate 1.4 grams of protein per kilogram or more had a 37% higher risk of mortality; this is an association, not a proven cause. Multiple reviews and guidelines support a protein-restricted diet of 0.6 to 0.8 grams per kilogram per day in kidney disease without dialysis, but the largest study in this field (the MDRD study) did not produce a clear-cut result. In research, people with severe kidney disease (kidney filtration capacity below 30) were sometimes given an even stricter plant-based diet supplemented with keto analogues, special amino acid substitutes; in that study (Garneata 2016, n=207) the outcome was clearly better, but only 14% of screened patients were randomised at all. Always discuss this with your doctor, as this is not an approach for self-treatment.
This is a medical topic: it concerns diet as a treatment strategy, not a supplement. On the label of a protein product you will find 'Proteïne' or 'Protein' with grams per serving; for kidney disease the issue is not what you buy, but what you restrict. A significant risk of protein restriction is malnutrition with muscle loss, particularly in kidney disease. Guidance from a dietitian is essential. Plant-based protein produces less acid than animal protein and is considered less taxing on the kidneys, although the exact magnitude of this difference has not yet been well established.
The claims are based on multiple reviews, a randomised trial (PMID 26823552), and a large non-indexed cohort study (PMID 33742197, NHANES). No meta-analysis was used as a direct source. The MDRD study is cited for context but falls outside the direct sources.
How do I keep my kidneys healthy as I age?
The two best-supported steps to limit kidney damage as you age are keeping your blood pressure under control and exercising regularly. Moderate salt intake and a healthy weight demonstrably contribute to both.
Do your kidneys age at a different rate than your liver?
The kidneys age measurably faster than the liver, but for most healthy people that decline only has major consequences when dosing medications at an advanced age. If you also have high blood pressure or diabetes, it is wise to have your kidney function checked regularly.
Which supplements are risky in the presence of kidney damage?
Yes, multiple supplements are demonstrably risky in the presence of kidney damage. Herbal preparations (particularly those containing aristolochic acid), germanium supplements, and high doses of vitamin D or C stand out the most; if you already have kidney problems, discuss every supplement with your doctor.
Can I prevent or slow down early hearing loss?
Hearing loss caused by noise and by certain medications is very preventable, but for age-related hearing loss no proven interventions yet exist. The greatest gain comes from protecting your ears from loud sounds now.
How do I keep my eyes healthy and prevent cataracts or macular degeneration?
Protect your eyes with UV-filtering glasses, a diet rich in vegetables and fruit, good diabetes management and regular eye check-ups. If cataracts have advanced significantly, surgery is the only proven solution.
What really keeps your mouth and gums healthy?
Daily brushing supplemented with interdental brushes is the best foundation for a healthy mouth; if you have diabetes, regular gum care pays extra dividends for your blood sugar.