Sodium, also known as salt, is a mineral that plays a crucial role in regulating fluid balance and muscle function in the human body. We all need sodium to survive. But most people get a lot more sodium than they need! Too much salt has been linked to high blood pressure, heart disease, and stroke. If you have heart failure, you likely have been told to “cut out the salt” with the typical recommendation of less than 1500mg per day.
Some people find this really hard to do and struggle to stay within the guidelines. Others are “all in” and cut their sodium intake low– extremely low. Is this the way to go? Should you get your sodium intake as low as possible? Possibly not! Too low may be a problem too. Let’s take a closer look at this debate.
Top Questions I Get as a Dietitian Specializing in Heart Failure
- Is sodium restriction necessary?
- Is a severe sodium restriction healthy?
- What is the optimal sodium intake for you?
The research can seem conflicting, and the debate is ongoing. Are you confused? It is confusing. I get it! We’re going to dive in and make some sense of it all.
The Great Salt Debate
While the general consensus is that reducing sodium intake can lead to significant health benefits and should be a public health priority, others question the evidence supporting this notion and suggest that excessive sodium restriction did not improve disease outcomes and can actually have negative health effects.
If you google this, you can find a ton of information from reputable sources like the American Heart Association outlining the benefits of a low sodium diet and the health dangers of a diet with too much salt. However, there is some real research showing potential problems with a very low sodium intake.
Still, others insist that abandoning the notion of low sodium intake altogether is the best way to approach things, even for people with heart problems. (This one makes me nervous because processed foods, snack foods, and restaurant foods are loaded with sodium. The more you have, the more you develop a taste for it. I think this advice is treading into dangerous water and has the potential to do harm, so you won’t find me recommending it!)
Dangers of Excessive Sodium Intake
Whether or not you have heart failure, excessive sodium intake can have negative health consequences! This is well established. And it’s particularly for individuals with hypertension, heart disease, and kidney problems. Here are some of the potential dangers that you may or may not know about.
High Blood Pressure
Excessive sodium intake is a major risk factor for developing high blood pressure, also known as hypertension. High blood pressure can increase the risk of heart attack, stroke, and other cardiovascular diseases.
Increased Risk of Heart Disease
High sodium intake has been associated with an increased risk of heart disease, including heart attack and heart failure. A meta-analysis of 13 studies published in the American Journal of Hypertension found that high sodium intake was associated with a 20% higher risk of developing heart disease.
Negative Impact on Kidney Function
Excessive sodium intake can increase the workload on the kidneys, leading to decreased kidney function and an increased risk of developing chronic kidney disease. And if you already have kidney disease, too much sodium makes it worse. This is not debated!
Increased Risk of Stroke
High sodium intake has been linked to an increased risk of stroke, particularly in individuals with hypertension. A study published in the Journal of the American College of Cardiology found that high sodium intake was associated with a 24% higher risk of stroke.
Negative Impact on Bone Health
High sodium intake can increase the amount of calcium excreted in the urine, which can lead to decreased bone density and an increased risk of osteoporosis.
The WHO says the World has a Salt Problem
I found this March 2023 article published in the Wall Street Journal about a report from the WHO (World Health Organization). The article warns that people all over the world are eating way too much salt, and it could lead to negative health consequences.
Let’s sum it up!
Seven million people could die of diseases linked to excessive salt consumption before the end of the decade unless governments immediately pass tighter restrictions on salt. Specifically, the WHO is calling on governments to:
- Implement stricter sodium targets for food
- Mark salt content more clearly on packaging
- Boost public awareness of the health dangers of salty food.
Francesco Branca, director of the WHO’s Department of Nutrition for Health and Development as of 2023, said governments could save many lives by introducing mandatory limits on the amount of salt the food industry is permitted to add to processed foods.
The WHO hopes to reduce global salt intake by 30% from 2013 levels, a target agreed to by all 194 of its member states at the time, but which none are on track to meet, it said Thursday.
How Does Sodium Affect Heart Failure (CHF)?
Sodium restriction is crucial for people with heart failure because consuming too much salt can cause the body to retain fluids, which puts a strain on the heart. This can lead to complications and speed up the progression of their disease.
If you have heart failure, your doctor has probably recommended a low sodium diet. I have seen recommendations vary from 1500mg per day to 2300mg or less. It can depend on the physician, the stage of your heart failure, your body’s tolerance of sodium, and your current symptoms.
The general advice is to avoid processed and packaged foods, cook at home with fresh ingredients, and use herbs and spices to flavor food instead of salt. Much of this website is dedicated to low sodium and heart healthy eating. See my articles The Best Diet for Heart Failure Patients and Salt Shockers: Discovering the Hidden Sources of Sodium in Your Diet for more information.
We know that heart failure patients who eat too much sodium can experience negative effects on their health. This is really up for debate with the vast majority of experts in total agreement, even if the details of their recommendations vary a bit.
Consuming excess sodium can cause the body to retain fluids, leading to swelling, shortness of breath, and difficulty breathing. This puts additional strain on the heart can worsen symptoms of heart failure, and significantly affect quality of life.
Dangers of a Sodium Intake that is Too Low
While there is little doubt that a low sodium diet can be beneficial for individuals with heart failure, excessively low sodium intake can have negative health consequences. Here are some potential consequences of having too little sodium in your diet.
Hyponatremia
Hyponatremia is a condition where the sodium levels in the blood become dangerously low, leading to symptoms such as nausea, headaches, confusion, seizures, and even coma. Very low sodium diets can increase the risk of developing hyponatremia, particularly in individuals who engage in strenuous exercise or who take diuretic medications.
Adverse Effects on Cognitive Function
Low sodium intake has been associated with impaired cognitive function, particularly in older adults. A study published in the American Journal of Clinical Nutrition found that older adults with a low sodium diet performed worse on cognitive tests compared to those with a moderate sodium intake.
Increased Risk of Falls
Sodium is essential for maintaining fluid balance in the body, which is important for preventing falls. A study published in the Journal of the American Geriatrics Society found that older adults on low sodium diets had a higher risk of falls compared to those with a moderate sodium intake.
Negative Impact on Athletic Performance
Sodium is important for maintaining hydration and electrolyte balance in athletes. Very low sodium diets can lead to dehydration, muscle cramps, and decreased athletic performance.
Potential Increase in Insulin Resistance
A study published in the Journal of Clinical Endocrinology & Metabolism found that individuals on a very low sodium diet had a higher risk of developing insulin resistance, which can lead to type 2 diabetes.
Research on Extremely Low Sodium Intake and Heart Failure
Here is a February 2023 headline from the American College of Cardiology.
“Too Little Sodium Can be Harmful to Heart Failure Patients:
Cutting sodium below current recommendations could be counterproductive, study finds”
Wow! This seems to turn everything upside down!
A new meta-analysis (analysis of many studies) presented at the American College of Cardiology’s Annual Scientific Session suggests that restricting dietary sodium intake to below 2300mg per day for people with heart failure does not bring additional benefits and may even increase the risk of death.
The study analyzed nine trials that looked at different levels of sodium restriction for people with heart failure. It included data on rates of death and hospitalization. The researchers found that patients following a diet with a sodium intake target below 2500mg grams per day were 80% more likely to die than those following a diet with a target of 2500mg per day or more.
I wonder if all the studies compensated for the fact that the more severely restricted people were likely experiencing more severe or advanced heart failure. Would a meta-analysis of so many different studies account for the stages of heart failure, the comorbidities etc? Were they relying on self reporting? Were all of the patients able to accurately report their salt intake?
It isn’t always easy to track your intake or remember everything you are eating! Food recalls are notoriously incorrect.
The researchers acknowledged that this isn’t one size fits all. We need studies to find the optimal targets for sodium intake and identify subgroups of heart failure patients who might benefit from more or less restriction.
Here’s an important note! Many people experience more severe symptoms when they eat too many salty foods. They feel short of breath or develop edema. This is important as far as quality of life!
Should People with Heart Failure Limit Salt or Not?
That is the question!
And for now, my answer is an unequivocal yes.
That article I mentioned above does not mean everyone should throw their sodium restriction out the window. Please don’t! And according to the CDC, Americans consume over 3400mg of sodium per day on average, so 2500mg is a lot less.
And the problems with high sodium intake are well known. What we are really talking about is whether or not the current recommendations are too low, not whether or not there should be a limit.
Researching humans is complicated, and a meta-analysis like this conclusion often raises more questions than answers. And we don’t know much about the individuals in the studies.
Were they eating a healthy plant based, Mediterranean, or DASH diet, or were they just limiting salt? It’s unlikely that we know anything at all about them. There are plenty of ways to eat low sodium but still be unhealthy. I see it all the time.
(Don’t do this! It takes more than a low sodium diet to improve your heart health.) Check out The Best Diet for Heart Failure Patients and 5 Ways a Plant Based Diet May Benefit the Heart
While this meta-analysis raises important questions, it is by no means the final word on the subject. Even the authors of this article admit that more research is needed.
Here is my Expert Recommendation:
- Discuss this with your physician. (Your physician knows you and is familiar with your overall health, your stage of heart failure, and your symptoms.)
- Avoid Excessive Intake: Even if your physician doesn’t limit salt, be sure that your intake is not excessive. Except in rare instances, your body has no need for more than 2500mg per day.
- Don’t go too low. Don’t drop your intake super low. I’ve seen people who are getting less than 500mg per day. Going this low may not give your body the proper balance of electrolytes.
- Pay attention to your symptoms.
Are you salt sensitive?
Do you swell up and feel breathless whenever you overdo it?
Are you often hospitalized or needing to increase your medications?
- Keep Up with any New Research
- Commit to a Heart Healthy Diet. More than just limiting sodium, a heart healthy diet rich in vegetables, whole grains, fruits, healthy oils, and legumes is naturally balanced in sodium, potassium, and other electrolytes important for heart health. If the foundation of your diet is good, there is room for an occasional indulgence. See my article on nutrition for heart failure. I link it again. The Best Diet for Heart Failure Patients
Remember, your overall health is my number one goal.
I hope you enjoyed this article. I always try to present both sides of a debate. If you have questions or comments, let me know. And don’t forget to sign up for my email list so you don’t miss out on important updates and new articles.
References:
He FJ, MacGregor GA. Salt reduction lowers cardiovascular risk: meta-analysis of outcome trials. Lancet. 2011;378(9789):380-382.
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Mente A, O’Donnell MJ, Rangarajan S, et al. Associations of urinary sodium excretion with cardiovascular events in individuals with and without hypertension: a pooled analysis of data from four studies. Lancet. 2016;388(10043):465-475.
Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. 2018;71(19):e127-e248.
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Stolarz-Skrzypek K, Kuznetsova T, Thijs L, et al. Fatal and nonfatal outcomes, incidence of hypertension, and blood pressure changes in relation to urinary sodium excretion. JAMA. 2011;305(17):1777-1785.
Graudal N, Jurgens G, Baslund B, Alderman MH. Compared with usual sodium intake, low- and excessive-sodium diets are associated with increased mortality: a meta-analysis. Am J Hypertens. 2014;27(9):1129-1137.
Sands, Leo. We have a huge salt problem. Millions will die without action, WHO warns. https://www.washingtonpost.com/wellness/2023/03/09/salt-excessive-diet-who/ Accessed 3/10/23.
