Why unstable blood sugar harms kidneys

If high blood sugar isn't properly managed, it can lead to complications like kidney disease (nephropathy). To prevent high blood sugar from harming kidney function, a doctor points out that daily diet can employ 4 methods to stabilize blood sugar and prevent kidney disease. Notably, merely eating vegetables before rice is insufficient; a key additional method is crucial during meals.

Japanese nephrologist Dr. Uetsuki Masahiro explains that preventing diabetes requires controlling blood sugar and being mindful of daily carbohydrate intake. Excessive carbohydrates easily trigger blood sugar spikes—a rapid post-meal rise followed by a sharp drop. If blood sugar fluctuates repeatedly daily, insulin efficacy gradually weakens, leading to persistently high blood sugar. Beyond potentially causing or worsening diabetes, these fluctuations damage blood vessels throughout the body, accelerating atherosclerosis. The microvessels in the kidneys are particularly vulnerable, and as these tiny vessels get damaged, the progression of chronic kidney disease speeds up.

Therefore, to protect the kidneys, one must avoid excessive carbohydrate intake to prevent sharp blood sugar spikes and learn to eat slowly to allow blood sugar to rise gradually. The basic method for controlling carbs is reducing portions of high-carb staples like rice, bread, and noodles while increasing the proportion of side dishes like meat and vegetables. Mastering this principle can slow post-meal blood sugar rises.

While reducing carbs is healthy, extremely strict avoidance (e.g., completely cutting out rice or bread) is not recommended. Carbs from staples are an essential energy source for the brain and body. For the elderly, insufficient nutrient and energy intake is especially dangerous. A better approach is to adjust intake to slightly less than usual and cultivate the habit of moderately reducing staple food portions at each meal.

He proposes 4 dietary methods to control carbohydrates, which help stabilize blood sugar and protect kidneys, and are also suitable for patients with chronic kidney disease:

4 Key Dietary Tips to Protect Kidneys & Stabilize Blood Sugar:

1. Stop Drinking Sugary Beverages:
   • Many seemingly healthy or common household drinks contain large amounts of sugar: sweetened sodas, sports drinks, fruit juice drinks, lactic acid drinks, boxed vegetable juices, canned sweetened coffee/tea/yogurt drinks.
   • Habitual daily consumption easily leads to excess carb intake.
   • Solution: Replace them with sugar-free options like tea, water, or black coffee to drastically reduce carb intake. For kidney patients and those concerned about diabetes, fatty liver, or obesity, quitting sugary drinks should be the first step in reducing carbs.
2. Avoid Sweet Breads, Snacks, and Desserts:
   • Reducing sugar often starts with easily adjustable foods. Since reducing staples like rice/bread has limits, it's best to begin by controlling daily snacks and sweets: e.g., biscuits, rice crackers, steamed buns, pudding, jelly, small cakes, sweet breads, cream puffs.
   • Strategy: Complete fullness can feel painful. Instead, set flexible rules focusing on avoiding excess. For example: allow yourself a treat once a week, as a reward for work success, or eat only half and freeze the rest.
3. Eat Slowly and Chew Thoroughly:
   • The popular "vegetables first, then rice" eating sequence helps avoid rapid blood sugar spikes. However, if you eat too fast, the benefits of this sequence are greatly diminished. If a meal is finished in about 10 minutes, even vegetables eaten first will quickly mix with other food in the stomach.
   • Key Takeaway: To effectively slow post-meal blood sugar rise, the primary key is slowing down eating speed. Aim for 30-40 minutes per meal. This not only stabilizes blood sugar but also increases satiety, preventing overeating. Maintain the basic principle of slow eating over fast eating, while still keeping the sequence: vegetables first, then meat/fish, finally rice.
4. Increase Soluble Dietary Fiber Intake:
   • Dietary fiber is categorized into insoluble and soluble. Soluble fiber stays longer in the gastrointestinal tract, significantly helping suppress excessive carbohydrate absorption and stabilizing blood sugar.
   • While reducing staple food intake (rice, bread), increase fiber from vegetables, seaweed, and mushrooms. Examples: natto, okra, yam, nameko mushrooms, black fungus, kelp, wakame.

Uetsuki states these dietary habits are highly beneficial for maintaining and improving health. They are not only suitable for those worried about declining kidney function but also beneficial for those without obvious kidney damage or other health issues. He recommends cultivating these habits early and integrating them into daily life to extend kidney healthspan and lay a long-term foundation for overall well-being.

Early Symptoms of Kidney Disease/Failure: Watch for Changes in Urine

According to Hong Kong's Hospital Authority, early-stage kidney disease and chronic renal failure symptoms are often not obvious. Common symptoms include:

• Blood in urine / tea-colored urine (hematuria)
• Foamy urine (proteinuria)
• Cloudy urine (urinary tract infection)
• Painful, frequent urination
• Difficulty urinating, poor flow
• Passing small stones/sand in urine
• Polyuria, reduced urine output, nocturia
• Waist/abdominal pain
• Ankle or eyelid swelling
• High blood pressure

4 High-Risk Groups for Kidney Failure; Severe Cases May Require Dialysis

Patients with the following conditions have a higher risk of developing chronic kidney failure:

• Diabetes
• Glomerulonephritis (including lupus nephritis)
• Hypertension
• Congenital kidney disease or family history of kidney disease

When end-stage renal failure is reached, patients require dialysis or kidney transplantation to sustain life.