Tuesday, 1 November 2016

Evidence Poor for Restricting High-Potassium Foods

The normal advice to dialysis patients is to reduce intake of high potassium foods, to reduce the risk of hyperkalemia, a problem which is already raised as renal failure is the most common cause of hyperkalemia. But new research is challenging this view.

An article in Journal of Renal Nutrition, which is reported on here suggests that there are several other reasons for high potassium levels. The summary says:
"Experimental studies of potassium kinetics show that serum potassium is affected by nervous and endocrine signals, chemical concentrations in and out of cells, circadian rhythms, and organ system functionality. For example, some evidence links acidosis to hyperkalemia in kidney disease patients. Intracellular and extracellular shifts in potassium occur in response to acid-base changes. Insulin also plays a role.

Furthermore, inadequate potassium excretion may contribute to hyperkalemia. When excess potassium is not removed by kidneys, it may be excreted through the bowel. Constipation, a common problem among patients, would hinder excretion."

It is suggested that there is no actual evidence to suggest that high potassium foods such as bananas, kiwis, baked potatoes, tomatoes, and oranges are likely to cause problems with potassium levels, and that more research is required to check whether other factors are more important such as prolonged fasting, hyperosmolality, metabolic acidosis, tissue breakdown, constipation, and medications. Dialysis modality and prescription are yet another influential variable.

"Ultimately, we conclude that this approach is not evidence-based and may actually present harm to patients,” Dr St. Jules and the other authors concluded. “However, given the uncertainty arising from the paucity of conclusive data, we agree that until the appropriate intervention studies are conducted, practitioners should continue to advise restriction of high-potassium foods.”

With this research going against the normal advice, clearly more research is required. So don't rush out to eat foods you have been recommended to avoid just yet. Changes like this have to be confirmed first, rather than immediately jumped upon as a new solution. Wait for conclusive proof from follo-up research which will surely take place.