A large two-country study of 2,696 people has revealed that swilling a lot of sugary drinks every day may be bad for your blood pressure. The study authors found that blood pressure climbed with every added regular soda or fruit drink participants slurped each day. They also reported that high blood pressure, or hypertension, was more widespread among people who swigged sugary drinks and ate a lot of salt. Their findings are part of the International Study of Macro/Micronutrients and Blood Pressure (INTERMAP) and were published February 28, 2011, in the journal Hypertension.
The study’s first author, Ian Brown of Imperial College, London, said that sugars common to drinks sweetened with high fructose corn syrup might play a role in keeping blood vessels from stretching. A healthy elastic blood vessel can expand to accommodate increased fluids, controlling blood pressure. In an unhealthy, inflexible vessel, on the other hand, increased volume just results in the increased pressure we measure as high blood pressure.
The people who took part in the study, hailing either from the U.S. or the U.K., were all between the ages of 40 and 59. They reported to researchers what they’d eaten over the course of four days, gave up two days’ worth of urine for analysis, and allowed their blood pressure to be measured eight times.
In addition to pumped-up blood pressure, sugary drinks also were linked to ballooning caloric intake. People who had more than one regular-sugar drink a day tended to take in more daily calories on average—about 400 more. To put that into perspective, that’s about the same as having a McDonald’s McDouble cheeseburger added to your diet every day.
Diet soda consumption, on the other hand, was associated with a drop in blood pressure. People who didn’t drink sweet, sugary sodas and fruit juices also had lower BMIs than people who did.
Study author Brown warned that this research provides only “piece of the evidence in a jigsaw puzzle that needs to be completed. In the meantime,” he said in a press release, “people who want to drink sugar-sweetened beverages should do so only in moderation.”
What kind of moderation, exactly? Well, the American Heart Association has your answer: if you’re female, no more than 100 calories a day from added sugars, and no more than 150 if you’re male. Your average non-diet soda has between 100 to 140 calories or so. Whether your source is the American Heart Association or INTERMAP, the conclusion seems to be the same: In in interest of good blood pressure and a healthy diet, keep the sugary drink consumption to no more than one a day.
Dr. Emily Willingham came to EarthSky from The Biology Files. Her background includes a PhD in biological sciences, a bachelor's degree in English, and a published book: The Complete Idiot's Guide to College Biology. She is a scientist, writer, editor, teacher, autism & ADHD parent, and "all around opinionator." Says Emily: "Got an English BA & biology PhD, & I'm not afraid to use them, often together."