Fructose, a fruit-derived sugar present in many sweetened beverages and processed foods, has been associated with epidemic levels of diabetes, obesity, metabolic syndrome and hypertension in the U.S. and around the world.
New research presented at the Experimental Biology 2016 meeting in San Diego further supports this link, finding that high levels of fructose similar to amounts consumed within the American diet may predispose individuals to fast-onset, salt-sensitive hypertension. "A majority of American adults consume 10 percent or more of total calories from added sugars with a subset taking in more than 25 percent of total calories from added sugars," said lead author Kevin Gordish, PhD. Because beverages are the most common source of added sugars in the American diet, the research team gave rats drinking water with 20 percent fructose-to simulate excessive human soft-drink consumption-and compared them with rats who received plain water in addition to their food for two weeks. During the second week, the rats receiving 20 percent fructose were also given additional salt in their diets.
"The specific combination of fructose and high salt introduced in the second week rapidly increased blood pressure, resulting in hypertension. Fructose-linked hypertension was associated with increased sodium retention, decreased sodium excretion and diminished factors that help rid the body of excess salt. This observation of fructose-linked hypertension was only seen a diet with fructose and high salt and not a normal salt diet," Gordish said. "Fructose intake, similar to amounts consumed within the American diet, predisposed normal rats to a rapid onset of salt-sensitive hypertension. Fructose-linked hypertension was unambiguously due to fructose (and not glucose). Further, fructose had distinct deleterious effects in the kidney not seen with the same amount of glucose."
Our results suggest enhanced fructose and salt consumption increases sodium retention and oxidative stress. High salt can induce elevations in blood pressure in 20% fructose-fed rats within just one week. Increased blood pressure appears to associate with increased sodium retention and positive cumulative sodium balance. Overall, fructose combined with high salt in the diet contributes to the accelerated development of salt-sensitive hypertension.