CSN-CommunityPost-Breaking Study Examines Impact of Low-Salt Diets and the Keto Diet

A study has developed a novel test that identifies individuals who are the most likely to experience adverse health effects if they eat a high salt diet. This new test and a second study show that the ketogenic diet helps diabetes symptoms were introduced today at the 71st AACC Annual Scientific Meeting & Clinical Lab Expo and could empower people to transform their health through dietary changes.

Numerous contradictory dietary guidelines have come out in recent years, leaving the public frustrated about what is truly healthy to eat. The American Heart Association suggests an ideal upper salt intake limit of 1.5 g/day for adults to prevent cardiovascular disease and high blood pressure. In 2013, the Institute of Medicine came out on cutting sodium levels below 2.3 g/day. So which is correct? The result turns out based on an individual's genetically determined salt sensitivity. 14% of Americans are salt sensitive, which indicates that too much salt increases their cardiovascular disease risk. However, another 11% of Americans are inverse salt sensitive and—paradoxically—have high blood pressure and too little salt intake.

In the previous, the only method to find salt sensitivity was by placing a person on a stringent, 2-week salt-restricted diet. A more convenient, the faster test has been developed by a team of researchers led by Kwabena Sarpong,e Ph.D., of the University of Virginia School of Medicine in Charlottesville. This new test finds salt sensitivity by measuring a patient's dopamine one receptor (D1R) recruitment, which plays a crucial role in determining the kidneys to excrete salt.

To verify this test, Sarpong's team used controlled dietary salt changes to identify one group of salt-sensitive individuals and a second control group of salt-resistant individuals whose blood pressure does not fluctuate significantly in response to changes in sodium intake. The investigators then isolated kidney cells known as renal proximal tubule cells (RPTCs) from participants' urine. Sarpong's team revealed the RPTCs to salt and saw how much D1R the cells mobilized in reply. Salt sensitive people had the least D1R recruitment, salt-resistant individuals had moderate D1R recruitment, and inverse salt-sensitive individuals had high D1R recruitment.

"If you understand that you are salt sensitive, you can manage this condition through therapeutic interventions or lifestyle modifications," said Sarpong. "But if you don't comprehend your salt sensitivity index, you could potentially decrease your lifespan by as much as 20 years. Accordingly, there will be profound advantages that come from knowing salt sensitivity and improving robust tools for diagnosing it."

The ketogenic (keto) diet is a different health trend on which experts' views vary. Developed about 100 years ago to treat drug-resistant epilepsy, this deficient carbohydrate diet has grown in popularity because of its reputation for speeding up weight loss. Specialists caution that very little evidence shows that the keto diet is efficient over a long time for anything except controlling epilepsy—but some studies recommend that this diet could help with other medical conditions like diabetes.

Investigators from CARE Hospitals in Visakhapatnam, India, have shown that the keto diet reduces blood sugar in type 2 diabetes patients, supporting the latter theory. Started by Kanchana Lakshmi Prasanna Angati, MD, the investigator recruited 115 Indian type 2 diabetes patients to follow the keto diet for three months. At the beginning of the study, participants' mean hemoglobin A1c (HbA1c) levels and blood glucose —both of which indicate blood sugar levels—were 7.8% and 169 mg/dL, respectively. By the end of the research, mean HbA1c and blood glucose levels had dropped for 110 participants, going down to 6.43% and 137 mg/dL, respectively.

"[The ketogenic] diet over three months managed to a remarkable reduction in HbA1c levels and great improvements in symptoms linked with type 2 diabetes," said Angati. "This is an especially powerful finding for diabetes people in India because, with the Indian diet, people consume carbohydrates morning, noon, and night, and we want to encourage and counsel people to change these dietary habits."