Ask pretty much anyone — including health professionals — what can be done to reduce blood pressure, and chances are one of the first answers you’ll get is to reduce salt and sodium intake. As David Spero noted in a blog entry earlier this year on diabetes and hypertension (high blood pressure), the American Diabetes Association (ADA) recommends a “dietary pattern including reducing sodium and increasing potassium intake; moderation of alcohol intake; and increased physical activity.” And as we noted in a Diabetes Flashpoints post from October, the Centers for Disease Control and Prevention (CDC) recommends that many people with an elevated cardiovascular risk — including people with diabetes — consume less than 1,500 milligrams of sodium each day, far less than the average American intake of over 3,400 milligrams. Everywhere you look, the conversation seems to be about salt.
But a new research review concludes than sugar is a far worse culprit than salt in causing high blood pressure as well as death from cardiovascular disease. Published earlier this month in the journal Open Heart, the review emphasizes that recommendations to lower salt and sodium intake are not based on strong evidence. According to an article on the review at MedPage Today, the researchers write that the lowest risk for cardiovascular disease is found among people who consume 3,000 to 4,000 milligrams of sodium per day, which is basically the average American intake and far higher than most recommendations. They note that sodium intake has remained stable over the last 50 years, but that hypertension has become more common over that time period as the consumption of processed foods has increased. To back up their claims, the researchers cite a study from earlier this year that found a shockingly strong connection between sugar intake and death from cardiovascular disease. Compared with study participants who got less than 10% of their daily calories from sugar, those who got between 10% and 25% of their daily calories from sugar were 1.3 times as likely to die from cardiovascular disease, while those who got over 25% of their daily calories from sugar were a whopping 2.75 times as likely to die from cardiovascular disease.
So what do the studies say about salt? Some have, of course, shown that lowering salt intake can reduce blood pressure. But a study from the late 90’s — which analyzed research conducted over several decades — showed that this effect was relatively small, with a maximum drop of around 4.8 mmHg systolic (the top number) and 2.5 mmHg diastolic (the bottom number) blood pressure. Furthermore, a study from 2011 that examined urinary sodium levels in people with diabetes actually found that a higher sodium intake was associated with a lower risk of death, both from cardiovascular disease and from all causes.
In fairness to groups like the American Heart Association and the American College of Cardiology — which write the commonly used guidelines for reducing blood pressure — their recommendations put and even greater emphasis on overall dietary patterns, like following the DASH diet or Mediterranean diet, than on salt intake alone. Both of these recommended diets are low in sugar. But by not putting special emphasis on sugar as a stand-alone nutrient the way they do with salt, these groups’ guidelines may be sending the public the wrong message about the most important steps they can take to reduce their blood pressure and cardiovascular risk.
Have you been told to reduce your salt intake because of elevated blood pressure or cardiovascular risk? If so, have you ever been instructed to do the same with your sugar intake? Does this research review make you reconsider the common mantra that “carbs are carbs” for people with diabetes, whether they’re in the form of starch or sugar? Have you found it difficult or unpleasant to reduce your salt intake? Do you think reducing your sugar intake would be easier or harder? Leave a comment below!