Author + information
- Christopher M. O’Connor, MD, FACC, Editor-in-Chief, JACC: Heart Failure∗ ()
- ↵∗Address for correspondence:
Dr. Christopher M. O’Connor, Editor-in-Chief, JACC: Heart Failure, American College of Cardiology, Heart House, 2400 N Street NW, Washington, DC 20037.
Salt consumption has been studied intensely by a number of investigators across the world. In this issue of JACC: Heart Failure, we have a Perspective article from Food and Drug Administration (FDA) colleagues (1) with the new initiatives of FDA to improve restricting sodium consumption to <1,500 mg a day, as recommended by the American Heart Association to reduce hypertension. Despite the pathophysiological reasoning for sodium resulting in increased blood pressure, left ventricular hypertrophy, and cardiovascular disease, the data and observational databases in randomized clinical trials have been conflicting. Although it is believed that excessive dietary salt consumption over a long period of exposure is associated with increased blood pressure and cardiovascular disease, the definitive data by cardiovascular standards are inconclusive.
The balance between salt consumption and salt restriction is sensitive and has a well-defined pathophysiological mechanism related to the renin-angiotensin system. Although, historically, sodium consumption may have been important to conserve blood pressure in times of traumatic and hemorrhagic shock, as the human species has survived acute illnesses and now faces chronic health conditions, an excess of sodium intake may have unintended harm. There continues to be conflicting data from epidemioligical studies on a whether high-sodium diet or low-sodium diet has adverse effects on patients with pre-existing cardiovascular disease. Several observational studies have suggested that more liberal sodium diets have no harmful effects in patients with congestive heart failure, leading to confusion in the recommendations from the Centers for Disease Control (CDC), society guidelines, and the European Union World Health Organization. In 2014, investigators from the Cochrane study group demonstrated that salt reduction prevented cardiovascular disease, but the magnitude of effect was uncertain and uncoupled from blood pressure reduction. Entities such as the World Health Organization have encouraged reducing global salt consumption by 30% through 2025. The CDC and ADA have encouraged Americans to reduce salt consumption.
The body of evidence on surrogate endpoints and observational studies suggest lower sodium consumption reduces blood pressure and is better for cardiovascular health. However, do we have enough evidence to definitively recommend a very low-sodium consumption? All of us who eat have a in restaurants know that consumption of a healthy salad, appetizer, fish, or chicken may result in over 3,000 mg of sodium in 1 sitting. What should we do as a community of heart failure clinicians?
I would propose the following:
1. The HF community should recommend a simple large randomized controlled trial using registry trial design methodology. This design would feature simple data collection, central follow-up with low effort, 5,000 to 10,000 patients, and <$5 million to answer the question of whether standard sodium consumption (3,400 mg per day) versus a moderate sodium restriction (<2,300 mg per day) versus a low-sodium consumption diet (<1,500 mg a day) is better for chronic heart failure patients. The target should be an endpoint of cardiovascular events and cardiovascular death.
2. Should we begin the advocacy of nutritional labeling in restaurants of sodium?
The FDA is making efforts to improve nutrition labeling in restaurants; however, there are few restaurants that provide transparent open labeling of sodium. Let us as a community advocate for both of these initiatives and finally answer the question: what is the threshold of sodium intake that is harmful for our patients?
- 2017 American College of Cardiology Foundation