Eat healthy for healthy kidneys

March 9 was commemorated as World Kidney Day under the theme “Kidney Health for All: Preparing for the unexpected, supporting the vulnerable!” It is critical to better improve our diet to keep our kidneys healthy and functioning.

Kidneys are about the size of your fists. They are situated at the bottom of your ribcage on both sides of the spine. The kidneys remove waste, excess water, and other impurities from the blood. They remove acid that your cells produce. They maintain the balance of water, salts, and minerals such as sodium, calcium, phosphorous ,and potassium in your blood.

They help in the regulation of your blood pressure and control the production of red blood cells. Your kidneys activate a form of Vitamin D and so help your body absorb calcium for building bones. Eating foods to benefit your kidneys is important to your overall health.

A high-salt diet is deleterious to the functioning of your kidneys. Eating too much salt raises your blood pressure, and this interferes with the kidneys’ function of eliminating water. Limit sodium intake to less than 2300mg or 1 teaspoon of salt per day. High blood pressure on its own will damage your kidneys and is the chief cause of chronic kidney disease in Jamaica. Your blood pressure should be 120/80 mmHg. If it is higher, you may have hypertension, and you should visit your health centre or family doctor for investigations.

THINGS TO AVOID

Avoid processed foods. Most packaged or canned foods are high in salt even if they are sweet. Bread, biscuits, and crackers are preserved with high levels of salt. Processed meats such as frankfurters, ham, bologna, and salami contain high levels of salt and preservatives, which are detrimental to kidney health.

Avoid sodas. Sugary drinks and carbonated beverages have been shown to damage the kidneys. Cola beverages contain phosphoric acid that promote kidney stones. A study published in Epidemiology (2007) suggested that drinking two or more colas per day is associated with an increased risk of chronic kidney disease.

Limit meat intake. Eating too much meat (pork, beef, lamb) increases acid in your blood. This affects the kidney negatively. It is a good idea to replace meat sometimes with fish or with peas or beans. Eat no more than 90 to 120 g (three to four ounces) of meat per meal. Try not to have meat more than three to four times per week. Ask your health practitioner to refer you to a nutritionist who will design a regime to fit your needs and circumstances.

Limit eggs to two to four per week. Eggs are superfoods. An egg contains 7g of protein but only 75 calories. Eggs are rich in vitamin B2, B12, D, selenium, and iodine, other essential minerals, and trace elements. Egg yolks are a rich source of phospholipids, which are incorporated into the high-density cholesterol (good cholesterol) of our blood. However, the egg yolk contains saturated fats as well as cholesterol. So while eggs should be enjoyed, they should not be had in excess.

Restrict sugar intake. Your kidneys respond to high levels of sugar in the blood (in excess of 10 mmol/L or 180 mg/dl) by spilling sugar into the urine. But people with uncontrolled diabetes maintain high levels of sugar in the blood. This causes damage to the blood vessels of the kidneys and impairs their function of removing impurities. It is important for people suffering from diabetes to maintain normal levels of blood sugar.

Review water intake. How much water do you need for healthy kidneys? How much will vary with your level of activity, the environment, and your overall health. The usual recommendation is six to eight cups daily, and this includes soups, watery fruits, and juices. Yellow urine usually means you could drink more water except in cases where medications such as vitamins colour the urine. Your urine should be colourless or light yellow. Drink water when you are thirsty, before, during and after exercise, with each meal, and between meals. Avoid drinking excess water because then, the kidneys become overburdened. The sodium levels fall, resulting in a life-threatening condition.

Reduce alcohol consumption. Too much alcohol reduces the kidneys’ ability to filter blood. Alcohol affects the ability of your kidneys to regulate fluid and minerals in the body. You may have noticed that alcohol has a drying effect on the body. This drying action can affect the normal functioning of your kidneys. It is best to choose not to drink at all. Women who choose to drink should restrict alcohol intake to one ounce of rum (40 per cent alcohol) or four ounces of wine (12 per cent alcohol) or 8 ounces of beer (five to seven per cent alcohol). Men who choose to drink should limit intake to no more than two times this amount.

OPTIMAL PERFORMANCE

After age 40, the filtration ability of your kidneys decline slightly each year as you age. What can you do to keep your kidneys at optimal performance? Here are some suggestions for foods you can include in your meals that will promote healthy kidneys.

• Choose whole-grain carbohydrates. These are unprocessed grains, which provide a source of dietary fibre, vitamins, minerals, and antioxidants. Examples are brown rice, oats, and millet. Persons with impaired kidney function who require food with low potassium and phosphorous content should choose bulgur, popcorn, and wild rice.

• Choose root vegetables. These are foods that grow under the ground. They include carrots, Irish potatoes, sweet potatoes, cassava, turnips, and yams. They are high in fibre, vitamins, and antioxidants. Persons with chronic kidney disease (CKD) who have been advised to lower their potassium intake should double boil these root vegetables to reduce the potassium content.

• Choose beans and peas. These are low in fat and do not contain cholesterol. They are high in fibre, protein (6-8 g in ½ cup) and provide significant amounts of iron, potassium, and magnesium. People with CKD can have beans. They should seek the advice of a kidney dietician on how much and which beans have low levels of potassium. Fortunately, the phosphorous and potassium from beans are not well absorbed. Persons with CKD should be wary of absorbing too much phosphorous and potassium from animal sources or from phosphate and potassium food additives.

• Choose leafy greens. Dark green leafy vegetables contain vitamins, minerals, and antioxidants, which are excellent for overall health, including your kidneys. They include pak choy (bok choy), callaloo, spinach, and mustard greens. Persons with chronic kidney disease may be advised to avoid these foods because they contain high levels of potassium. Such persons can have lettuce and raw green cabbage, which are low in potassium.

Choosing to eat foods that promote your overall health and especially the health of your kidneys is your responsibility and your privilege. You owe it to your kidneys!

- Dr Pauline Williams-Green is a family physician and a member of Caribbean College of Family Physicians. Send feedback to ghapjm@gmail.com or columns@gleanerjm.com.