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Fructose Connection with Kidney Function

Kidney doctor

With a rise in kidney illnesses, it is more important than ever to look for the underlying causes to slow its occurrence. One of the easiest ways we can influence our kidney function is to be mindful of how much sugary drinks like soda (soft drinks) we consume on a daily basis. This can decrease our propensity for obesity, diabetes, and other metabolic disorders that can place undue stress on our kidneys.


This study was done to check that consuming soft drinks during and following exercise in the heat elevates biomarkers of acute kidney injury in humans. This involved 12 healthy adults who were given two liters of assigned beverage during four hours of exercise in the heat. The two drinks offered were water and soda. Elevated serum creatinine was found in 75% of soda drinkers compared to 8% of water drinkers. Creatinine mostly comes from metabolism of muscles and meat products we eat. Production of creatinine is almost constant so the level of this in the blood shows the kidneys ability to excrete waste. In addition, a biomarker of acute kidney injury was higher during the overnight collection period after the soft drink trial as opposed to the water. Thus this test showed that drinking soda with or after exercise in heat causes acute kidney injury in the patients of the trial (Chapman et al, 2019).

Is there a correlation?

This study explored the connection between drinking soda, unsweetened fruit juice and high levels of uricemia-or a high level of uric acid found in the blood. There has been a shift in dietary patterns leading to a sharp increase in consumption of sugar-sweetened soda. This proactive has led to not just elevated uricemia but weight gain, obesity, and metabolic changes, and elevated uric acid levels. The relationship between high uricemia, sweetened beverage, and dietary fructose is not fully understood. So this study was arranged to check out the association between drinking of sugar-sweetened soda, fructose and natural fruit juices and prevalence of high uricemia. A few things found were strange. Alcohol consumption increased the frequency of high uricemia in men but no change found in women. In men, higher consumption of meat, coffee, and sugar-sweetened soda showed high uricemia while in women it was higher consumption of fruits and vegetables. One thing that came through even after the adjustment for socio-demographic variables there was a significant correlation between sugar-sweetened soda to high uricemia. This can lead to kidney stones, kidney infections and gout in joints (Siqueira et al, 2018).

Recently studies have found that diets have had an increase in the intake of sucrose and high fructose corn syrup. Fructose or fruit sugar is a natural sugar found in fruit, honey, and some vegetables. Currently, the majority of sugar found in our diets comes from table sugar (fructose and glucose) and high fructose corn syrup-sugar made from corn starch that contains 42% to 53% fructose combined with glucose. This consumption of fructose has also widely considered being a contributor to worldwide issues with obesity. While fructose was initially embraced by diabetics as it was a natural sugar, it has since come under scrutiny as it tends to lead to insulin resistance. In addition, high fructose corn syrup intake can create a risk factor for kidney disease. Fruit is good for you but high fructose corn syrup is not. Caution needs to be taken with the drinking of fruit juice as some of them have as much fructose as soda. High fructose in diets has been found to have a negative impact on health. This includes metabolic syndrome, non-alcoholic fatty liver, hypertension, kidney disease, and cognitive impairment (Salem, 2018).

Other health issues influencing kidney function
Caffeine is consumed in many beverages, not just coffee. It has been estimated that approximately 89% of adults in the US consume caffeine daily be it tea, coffee, or soda. The specific cause of mortality was examined. They found no significant interaction between caffeine consumption and chronic kidney disease regarding all-cause mortality but in patients who consumed caffeine in the form of soda, however, showed an inverse association.

The study didn’t find a significant correlation between chronic kidney disease and urinary albumin-creatinine ratio leading them to state they felt consumption of caffeine and the stages of chronic kidney disease could be done without effect. And while coffee is shown to decrease the uric acid levels there was an association between higher estimated glomerular filtration rate and coffee consumers. Considering the limitations of the study that the 24-hour recalls were what they based their data on. Future research should focus on the benefits of other components found ni coffee and other caffeine-containing beverages. The results of this study need to be confirmed by other studies before advising patients with chronic kidney disease to drink caffeine-containing beverages (Vieira et al, 2018).

In the past 40 years, there has been an ever increasing risk of adults developing a kidney stone. Studies have shown there are two reasons for this. One is a rise in conditions such as obesity, metabolic syndrome, diabetes, and hypertension. The other one is environmental; hot environments such as the southern US also influence the chance of nephrolithiasis (kidney stone) and even chronic kidney disease. And while an increase in fructose has been linked to both kidney disease and obesity the actual mechanisms that cause these conditions are not known at present. This study did find that as the body breaks down fructose it generates uric acid increases the serum uric acid content.

Fructose can directly increase the risk of kidney stones and with the altered pH and urinary oxalate and magnesium may help account why soda consumption predisposes someone to kidney stones. In addition, there is evidence that fructose tends to shift intracellular water leading to decreasing urine output. This lower urine output also can increase the risk of kidney injury from serum crystalluria. It also found low urine pH, soda, low urine volumes, and elevated serum osmolarity all predict the development of chronic kidney disease in addition to kidney stones. It is also possible that the protective effects of bicarbonate in chronic kidney disease may not be to neutralize the metabolic acidosis as much as an attempt to neutralize the pH of the urine (Johnson et al, 2018).

Possible ways to treat kidney damage
The balance between hepatic production of urate and intestinal or renal urate excretion is what determines a person’s serum urate levels. This balance can be affected by both genetic and environmental factors. Studies have found that 25% to 60% of the variation of serum urate levels can come from genetic factors. For centuries though diet has been spoken of as the major risk factor of developing gout. Consumption of red meat, shellfish, alcohol, sugary drinks and tomatoes have all been identified as items that can lead to elevated serum urate levels. Certain diets such as dietary approaches to stop hypertension (DASH) and the Mediterranean diet have proved useful in lowering these same levels.

Unfortunately, studies have not been done with enough subjects to confirm these findings. This study found 15 different food items that were significantly associated with serum urate levels. These included six already identified urate containing foods.

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The other nine included two less known food such as cheese and non-citrus fruit. It also included seven food items previously not associated with high serum urate levels. These were poultry, margarine, cold cereal, and eggs. However, it was found diet scores did little to explain the resulting data. Genetic variance was greater with serum urate levels than the expected dietary variants. This study did show that among the people of European ancestry had healthier dietary habits reduced the serum urate levels. In addition, this study results challenge the widely held perceptions that high uricemia is primarily caused by diet (Major et al, 2018).

Chronic kidney disease has a high risk of complications with cardiovascular disorders even before end-stage kidney disease requiring dialysis therapy. The connection between calciprotiene particles and chronic kidney disease has led to new assays to be developed to monitor it closely. Excess phosphorus intake from original phosphorus rich food and from fast food soft drinks and preservatives can enhance the formation of the particles resulting in a poor prognosis for patients with chronic kidney disease (Akiyama et al, 2018). Heat stroke is a concern throughout the world not just in the realm of exercise and marathon running. It affects our military and people who work outside for a living such as farm workers, electric workers, road construction workers, or airport workers who load and unload aircraft.

With heat stroke, there is an increased risk for multi-organ failure and death. There is a case to be made for chronic heat stress can result in chronic kidney disease. In spite of this, when workers rehydrate by drinking beverages with fructose in them such as soda, the stress on the already working hard kidneys creates a situation that the damage can be increased in severity. The heat and dehydration stress the renal injury in the proximal tubule where the fructose is metabolized. Indeed this study found that rehydrating with a sugary beverage resulted in worse tubular injury. When a comparison was made the group that rehydrated with fructose had higher body weight, higher serum osmolarity, and increased vasopressin levels. In addition, it was noted to have increased creatinine levels showing kidney function that was indeed impaired (Milagres et al, 2018).

Work Cited
Akiyama, K., Kimura, A. & Shiizaki, K. (2018). Biological and clinical effects on calciprotein particles on chronic kidney disease-mineral and bone disorder. International Journal of Endocrinology.

Chapman, C.L. et al. (2019). Soft drink consumption during and following exercise in heat elevates biomarkers of acute kidney injury. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology.

Johnson, R.J. et al. (2018). Fructose increases risk for kidney stones: Potential role in metabolic syndrome and heat stress. BMC Nephrology.

Major, T.J. et al. (2018). Evaluation of the diet wide contribution to serum urate levels: Meta-analysis of population-based cohorts. The BMJ (British Medical Journal).

Milagres, T. et al. (2018). Rehydration with fructose worsens dehydration-induced renal damage. BMC Nephrology,19 (180).

Salem, H.R. (2018). Negative impact of fructose overconsumption on health. World Nutrition,9(3).

Siqueira, J.H. et al. (2018). Sugar-sweetened soft drinks and fructose consumption are associated with hyperuricemia: Cross-sectional analysis from Brazilian longitudinal study of adult health. Nutrients,10(8).

Vieira, M.B. et al. (2018). Caffeine consumption and mortality in chronic kidney disease: A nationally representative analysis. Nephrology Dialysis Transplantation.