The study’s authors concluded: “All diabetics should consider reducing salt intake at least to less than 5-6 g/day in keeping with current recommendations for the general population and may consider lowering salt intake to lower levels, although further studies are needed.”
Lead researcher Rebecca Suckling, from the Blood Pressure Unit at St. George’s Hospital Medical School, London, told FoodNavigator: “There is substantial evidence for the role of lowering salt intake in blood pressure in individuals with normal and raised blood pressure and this has lead to government backed campaigns to lower the salt intake of the general population to less than 6g/day.”
Reducing salt intake by just 2g a day has the same effect on blood pressure as medication for hypertension, according to the researchers from St George’s Hospital Medical School and Barts and the London School of Medicine and Dentistry.
A 2g a day reduction of salt in the diet of diabetics reduced their systolic blood pressure by an average of 7 mmHg and diastolic blood pressure by 3 mmHg after about a week.
The reductions were similar in patients with type-1 and type -2 diabetes.
In addition to significantly lowering blood pressure, diabetic patients who adopt a low-salt diet are also less likely to progress to chronic kidney disease, said the researchers.
The meta-analysis of 13 studies included 254 patients with type-1 and type-2 diabetes. Participants in the study agreed to a large reduction in their daily salt intake for one week to see how the change would affect their blood pressure.
High dietary salt intake is widely recognized as a major factor for increased blood pressure. For diabetic patients, high blood pressure can lead to serious health problems, including stroke, heart attack and diabetic kidney disease.
“Tight control of BP (blood pressure) in diabetics lowers the risk of strokes, heart attacks and heart failure and slows the progression of diabetic kidney disease,” according to the report summary. “Currently there is no consensus in restricting salt intake in diabetic patients.”
Suckling said that the research team was surprised to find so few studies focusing on the effects of modest salt reductions in the diets of diabetic patients.
Meanwhile, diabetes is estimated to affect 285m people worldwide this year, according to the International Diabetes Federation. That number is expected to reach 438m within 20 years.
The five countries with largest numbers of diabetic patients are Russia, India, China, the United States and Brazil.
Study source: The Cochrane Library, published by the Cochrane Collaboration.
“Altered dietary salt intake for preventing and treating diabetic kidney disease”
Authors: R. Suckling, F. He, G. MacGregor