Chronic Kidney Disease: Cooked or raw foods?

Eating well when you have kidney disease will help you to stay as healthy and strong as possible. Including the rightkinds and amounts of foods each day suggested for healthy eating can help your kidneys to work more easily and keep you well for a longer time.

Sometimes having Chronic Kidney Disease (CKD) can make you feel unwell. Food may taste different and some people lose their appetite. When you have CKD, waste produced from the foods you consume build up in the blood because the  kidneys can no longer completely remove them.

The need to make adjustments to your diet plan largely depends on how well your kidneys are working. Because what is right for others may not be right for you.

Eating well

Eating well

What do we know so far? Your appetite for food may not be so good and food may taste a little different. This is because when you have CKD, waste and waste products produced from the foods you consume build up in the blood instead of being removed from the body by the kidneys.

The Kidney Foundation of Canada suggests to double boil high-potassium tuberous vegetables or root vegetables like yams, potatoes, sweet potatoes, and others because it is scientifically proven that the double boiling process helps remove potassium from these vegetables. Eating these vegetables raw may not be advisable. It is best to check with your doctor or dietitian how much and what kinds of double boiled high potassium root vegetables you may eat.

Kinds of Root Vegetables

  • Sweet potatoes and yams
  • Beets
  • Parsnips
  • Turnips
  • Rutabagas
  • Yuca root
  • Kohlrabi
  • Onion and garlic
  • Ginger

Trivia: A 2018 psychological study revealed that “[h]igher intakes of fruits and vegetables, rich in micronutrients, have been associated with better mental health. However, cooking or processing may reduce the availability of these important micronutrients.”

Important reminder: While double boiling vegetables is considered the best way to remove the most potassium from root vegetables, this food preparation process actually does not turn root vegetables into low-potassium food. It does, however, allow you to include these foods safely to your diet, that is, in moderation.

What do we know so far? The Kidney Foundation of Canada suggests to double boil high-potassium tuberous vegetables or root vegetables like yams, potatoes, sweet potatoes, and others because it is scientifically proven that the double boiling process helps remove potassium from these vegetables. Eating these vegetables raw may not be advisable. It is best to check with your doctor or dietitian how much and what kinds of double boiled high potassium root vegetables you may eat.

So how to double boil vegetables?

The National Kidney Foundation of Canada gives us some useful instructions:

1. Wash and peel the vegetable.

2. Dice or thinly slice the vegetable.

3. Place the diced or sliced vegetable in room temperature water. Use two times the amount of water to the amount of vegetable.

4. Bring the water to a boil.

5. Drain off the water and add fresh, room temperature water. Use two times the amount of

water to the amount of vegetable.

6. Bring the water to a boil again and cook until the vegetable is soft and tender.

Fact: Steaming vegetables helps to retain their flavor.

To give you more ideas, Food Revolution Network lists down foods which are more nutritious when cooked and foods which are more nutritious when raw.

More Nutritious When Cooked

    • Spinach and other leafy greens

    • Asparagus

    • Tomatoes

    • Mushrooms

    • Potatoes

    • Carrots, zucchini, celery, and green beans

    • Legumes

More Nutritious When Raw

    • Bell peppers

    • Broccoli, cauliflower, and kale

    • Onions

    • Garlic

Source: https://foodrevolution.org/blog/raw-vs-cooked-vegetables/

The Balancing Act 

Vegetables and fruits have low content of calories, fat, and sodium. Depending on the recipe and meal plan, cooking can add in fat, calories, sugar, and salt — but that isn’t necessarily a bad thing, especially when they are healthy fats, like those from olive oil and other plant-based oils.

What do we know so far? Vegetables more nutritious when cooked are: spinach and other leafy greens, asparagus, Mushrooms, potatoes, carrots, zucchini, celery, and green beans, and legumes.

So, which one is it—raw or cooked? Cooking actually destroys enzymes which aid in digestion. But cooked food, at the same time, are easier to chew and digest and as studies have suggested, increases some of the vegetables’ availability of antioxidants such as lutein (yes, the “eye vitamin”), beta-carotene (which helps us gain a healthy skin and immune system), and lycopene (which improves heart health and lowers the risk of certain types of cancer).

Trivia: There are more lycopene found in tomato paste and tomato sauce than in fresh tomatoes. Cooking allows the breaking of plant cell walls which meant more nutrients available for consumption.

The consensus among most nutrition experts, according to Food Revolution Network, is that we need both raw and cooked veggies to get the most food nutrients. There are, however, nutrients which are lost after the food is cooked—water-soluble vitamins like vitamins C and all B vitamins—but there are also those which become available to the body after the foods are cooked. Interestingly, the World Health Organization’s Five Keys to Safer Food Manual suggests to “separate raw” food from “cooked food.” 

While some types of food are better consumed after they are cooked and some better eaten raw, the bottom line is this: More fruits and vegetables on your diet definitely is better. Balance your intake.



SOURCES

Potassium and chronic kidney disease | The Kidney Foundation of Canada

https://www.kidney.ca/document.doc?id=945 


Why Double Boiling Is Good For Your Health | Michelin Guide

https://guide.michelin.com/en/article/dining-in/technique-thursdays-why-double-boiling-is-good-for-your-health


Raw vs Cooked: The Healthiest Ways to Eat Your Veggies | Food Revolution Network

https://foodrevolution.org/blog/raw-vs-cooked-vegetables/ 


Parenchyma cell microstructure and textural characteristics of raw and cooked potatoes | Science Direct

https://www.sciencedirect.com/science/article/pii/S0308814611016256 


Lycopene is more bioavailable from tomato paste than fresh tomatoes | ResearchGate

https://www.researchgate.net/publication/14010573_Lycopene_is_more_bioavailable_from_tomato_paste_than_fresh_to

matoes 


Intake of Raw Fruits and Vegetables Is Associated With Better Mental Health Than Intake of Processed Fruits and

Vegetables | ResearchGate

https://www.researchgate.net/publication/324408334_Intake_of_Raw_Fruits_