Does consuming oil improve kidney disease?

A doctor reminds us that correct fat intake is crucial for kidney patients to maintain kidney function. He offers 5 key recommendations, including completely avoiding 1 type of fat, and recommends 1 type of cooking oil suitable for daily use that has kidney-protective and anti-inflammatory effects.

Nephrologist Dr. Hong Yong-xiang stated in a Facebook post that to improve kidney disease, besides paying attention to protein intake, consuming good fats is actually beneficial for kidney health. He suggests kidney patients can refer to the following 5 key points regarding fat intake for kidney protection:

How to Consume Fats to Protect Kidneys?

1. Avoid Trans Fats

Trans fats are artificially refined fats that are even more prone to clogging blood vessels than saturated fats, offering no health benefits. Most trans fats are created by artificially "partially hydrogenating" vegetable oils, altering their structure into a semi-solid state that is more stable, resistant to high-temperature frying, and less prone to spoilage, extending food shelf life and improving texture. Due to its lower cost, it's widely used.

However, its downside is that it's harder to metabolize, easily accumulates in blood vessel walls, causes atherosclerosis, and worsens kidney function. Therefore, it's recommended that kidney patients "do not eat a single bite."

• Common Trans Fat Foods:
  • Fried Foods: French fries, doughnuts, chips, fried chicken cutlets, salt and pepper chicken, fried stinky tofu, etc.
  • Cakes & Pastries: Swiss rolls, cream cakes, cheesecakes, biscuits, cookies, cream puffs, muffins, etc.
  • Puff Pastry Items: Egg tarts, pies, pizza, pineapple cakes, Chinese flaky pastries, etc.
  • Bread
  • Cream-based Items: Margarine, non-dairy creamer, ice cream, etc.
  • Spreads: Peanut butter, bread spreads.
  • Western Dishes: Baked/casseroles, creamy soups, risotto, pasta, etc.
  • Others: Curry roux blocks, chocolate, instant noodles, popcorn, candy, etc.

2. Increase Omega-9 Intake

The American Heart Association recommends that monounsaturated fatty acid (Omega-9) intake should be 1.5 times that of polyunsaturated fatty acids, which helps cardiovascular health, lowers bad cholesterol, fights inflammation, and stabilizes blood sugar.

Omega-9 is also an excellent cooking oil. Because polyunsaturated fatty acids are easily metabolized by the body and are heat-stable, they are suitable as household cooking oils, benefiting vascular health, lowering bad cholesterol, fighting inflammation, stabilizing blood sugar, and protecting kidney function.

• Omega-9 Sources: Olive oil, camellia oil, avocado oil, avocado, nuts.

3. Total Fat Intake Should Be 25-35% of Daily Calories

Since the kidney disease diet restricts protein and reduces low-nitrogen starches, consuming more good fats is necessary to supplement the required calories.

4. Adjust the Omega-6 to Omega-3 Intake Ratio

When the Omega-6 to Omega-3 ratio exceeds 10:1, it increases inflammation risk. The modern diet typically has a ratio as high as 20:1. The American Heart Association recommends that the intake ratio of polyunsaturated fatty acids Omega-6 to Omega-3 must be reduced to below 4:1; some studies suggest the healthiest ratio is even 1:1. This is because Omega-6 is metabolized in the body into arachidonic acid, which further produces pro-inflammatory substances (like prostaglandin PGE2, leukotrienes), prompting immune cells to release inflammatory signals, leading to chronic inflammation.

Modern diets widely use soybean oil, corn oil, sunflower seed oil, grapeseed oil, etc. Being cheap and easily available, they are commonly used in processed foods, fast food, and baked goods. These oils are extremely high in Omega-6, with ratios potentially as high as 50:1 to 70:1. Additionally, modern animal farming often uses corn and soybeans as feed, grains rich in Omega-6, leading to increased Omega-6 and decreased Omega-3 in meat.

Kidney patients' bodies are often in a state of inflammation. It is recommended to reduce the use of oils rich in Omega-6 and increase intake of Omega-3 sources, such as fish oil and flaxseed. Increasing intake of high-concentration fish oil to supplement sufficient Omega-3 helps lower cholesterol, protect the heart and blood vessels, fight inflammation, and reduce proteinuria.

5. Saturated Fat Should Be Less Than 5% of Total Calories

Saturated fat increases blood levels of bad cholesterol. Excessive intake may accelerate kidney function deterioration. It is recommended that patients with heart or kidney disease control their low-density lipoprotein (LDL, bad cholesterol) below 70 mg/dL.

• Saturated Fat Sources:
  • Animal Fats: Lard, butter, chicken fat, etc.
  • Some Vegetable Oils: Coconut oil, palm oil, etc.
  • Minced Meat Products: Potstickers, dumplings, wontons, pan-fried buns, soup dumplings, etc.
  • Chinese Breakfast: Rice balls, baked sesame cakes with fried dough sticks, etc.
  • Sauces: Thousand Island dressing, satay sauce, chili sauce, sesame sauce, etc.
  • Thickened Dishes: Rice with gravy, thick soups, chowders, etc.

What Are the Signs of Chronic Kidney Disease? 9 Changes in Urine to Watch For

According to Hospital Authority information, the main functions of the kidneys are to excrete waste products from metabolism, regulate body fluids, electrolytes, acid-base balance, and blood pressure, produce erythropoietin, and assist in vitamin D production. Diseases like diabetes, glomerulonephritis, and high blood pressure can cause long-term severe damage to the kidneys, leading to chronic kidney failure. Poor kidney function allows waste to accumulate, triggering numerous health problems.

Kidney disease and chronic kidney failure have less obvious symptoms in the early stages, which may include:

• Urinary Symptoms: Blood in urine/tea-colored urine (hematuria), foamy urine (proteinuria), cloudy urine (urinary tract infection), painful and frequent urination, difficulty urinating, passing small stones, or having increased urine output, decreased urine output, nocturia (nighttime urination).
• Other Symptoms: Lower back or abdominal pain, swollen ankles or eyelids, high blood pressure.

When kidney function declines to the kidney failure stage (less than 25% of normal function), the following uremic symptoms may appear:

• Nocturia, decreased urine output.
• Loss of appetite, nausea, vomiting.
• Fatigue, pale complexion (anemia).
• Itchy skin.
• High blood pressure.
• Shortness of breath.
• Edema (swollen ankles or eyelids).
• Confusion, convulsions, coma.