14/12/2014
Study Suggests Sugar Is Worse For Blood Pressure Than Salt: Really?
In recent years, salt has become somewhat less of a culprit in heart disease, and sugar has, at least in some researchers’ eyes, taken its place. Now, authors of a new study in Open Heart argue that sugar consumption may be considerably worse for blood pressure than salt intake. In fact, they say, “It is time for guideline committees to shift focus away from salt and focus greater attention to the likely more-consequential food additive: sugar.” Whether it’s really valuable to pit one white crystal against the other is unclear, but what we do know is that neither salt nor sugar, in high amounts, is very good for anyone’s heart. For people who already have heart disease or high blood pressure, it’s probably best to keep an eye on both.
But here’s the rationale for the argument that sugar is worse for blood pressure than salt. Sugar, in high amounts, has many well-documented negative effects on the body, and in particular, on one’s metabolic profile. There’s an established link between sugar and metabolic syndrome, a conglomeration of cardiovascular markers that includes insulin resistance, high cholesterol, high blood pressure, high triglycerides (blood fats), and excess weight, especially in the form of belly fat.
Sugar also seems to lead, in a series of steps, to an increase in blood pressure per se. “Consuming sugar increases insulin levels,” study author James DiNicolantonio tells me, “which activates the sympathetic nervous system, leading to increases in heart rate and blood pressure.” It also apparently reduces the sensitivity of the receptors that regulate our blood pressure. Finally, sugar depletes ATP, cells’ energy stores, which, again through a cascade of events, constricts blood vessels, and increases blood pressure.
Some studies have also suggested that consuming a high-sugar diet for just two weeks may have a measurable effect on blood pressure. “Twenty-four hour ambulatory blood pressure studies,” adds DiNicolantonio, “indicate an increase of BP of around 7mmHg/5mmHg with a high-sugar diet. That’s much stronger than what we see with sodium, which is perhaps around 4mmHg/2mmHg.” Other studies comparing the effects of drinking a single 24-oz fructose-sweetened drink, vs. a sucrose-sweetened drink, have shown effects on blood pressure and other cardiovascular markers in the hours following.
So, the authors argue, reducing sugar may be a more meaningful way of reducing blood pressure than reducing salt. And because too little sodium in the diet has been linked to adverse health effects, the argument goes, it’s all the more important to keep a moderate, rather than a very low, salt intake.
“The best thing people can do for their health,” says DiNicolantonio, “is eat real whole food and avoid added sugars – worrying less about the salt.”
Jennifer Haythe, a cardiologist at New York-Presbyterian/Columbia, who was not affiliated with the study, says we should use some discretion when interpreting studies like the current one. “It doesn’t need to be a comparison,” she says. “We don’t need to pit one against the other.”
Looking at a patient’s history and current diet is important – what’s not advisable is to let salt off the hook and turn our attention completely to sugar. She does say that high-fructose corn syrup (HFCS) isn’t good for anyone? “It’s a driving force for metabolic syndrome. And excess sugar intake leads to insulin problems. It’s hard not to pay attention to fact that people who eat a lot of sugar are at higher risk for metabolic syndrome and obesity, which are serious risk factors for heart disease.”
As with most things, for better or for worse, it’s all about moderation. For people with existing high blood pressure or who have had cardiovascular disease in the past, salt intake is certainly worth keeping an eye on. But to say we should trade concern for salt for that of its sweeter crystalline counterpart, may not be advisable at all. In the end, it may do more harm than good.
“Which white thing is worse for you? That’s not really the right question to ask,” says Haythe. “I certainly wouldn’t tell my heart failure patients that salt isn’t bad for them.”
