Why electrolytes matter for cardiovascular health

As a health educator, I’ve spoken to countless folks about heart disease prevention. For instance, I spoke at length about cardiovascular health on my podcast with Dr. Bill Cromwell, Chief Medical Officer of Precision Health Reports. Precision Health Reports analyzes over 40 risk factors to calculate a risk score and identify ways to keep your ticker healthy.

Most of my focus has been on modifiable risk factors—blood sugar, body weight, cholesterol, triglycerides, and blood pressure—that respond to diet and lifestyle adjustments. Diet is easily the most meaningful input for all of these modifiable risk factors. And one crucial—and often misunderstood—component to the heart health nutrition conversation is electrolytes.

Sodium, potassium, magnesium, and calcium status can influence well-documented cardiovascular disease (CVD) risk factors like blood pressure, inflammation, and the rate at which calcium accrues in the arteries. If you want to stave off the number one killer globally and live a longer and better life, it makes sense to optimize your electrolyte intake.

In this article, I’ll summarize how heart disease progresses, a few risk factors, and the importance of electrolytes (spoiler alert: you may need more than you think). If you’re short on time, jump to the end for my recommended electrolyte intake targets.

Electrolytes and Heart Disease Risk Factors

The buildup of plaque in the arteries (atherosclerotic heart disease) is a slow process. It accumulates over a lifetime, often culminating suddenly in a heart attack, stroke, or death. Although the plaques accumulate slowly, certain risk factors make them pile up faster. These include:

• Chronic inflammation
• Hypertension (high blood pressure)
• Hypercalcemia (high blood calcium)

Of course, that’s not the whole story. Other risk factors like smoking and oxidized or high levels of low-density lipoproteins (LDLs) also influence plaque formation. But the 3 risk factors above relate more closely to electrolytes. Let’s discuss a few specific electrolytes now.

Sodium and Heart Disease

Why are we told to limit our sodium intake?

Let’s rewind a bit. The US government has recommended salt restriction for nearly 50 years. The genesis of this advice is largely attributed to 1960s research by Lewis Dahl, in which he bred a line of rats whose blood pressure was sensitive to salt. How? He fed them the human equivalent of 560 grams of salt… per day. 

Much of Dahl’s research has since been called into question due to unaddressed confounders, a lack of controls, and poor study design. Regardless, his work spurred a controversy around salt, culminating in the 1980 US Dietary Guidelines advising salt restriction for heart health.

So why do governing bodies like the FDA and the WHO perpetuate this idea? I have a two-part hunch: 1) processed foods contribute about 70% of the US population’s sodium intake, and 2) people who eat more processed foods are more likely to live sedentary lifestyles. In other words, sodium isn’t the causative factor. Rather, overeating refined foods (that happen to be high in salt) and avoiding exercise results in insulin resistance, diabetes, high blood pressure, obesity, and many other health issues that impair our cardiovascular systems.

If governing bodies want to reduce the occurrence of chronic inflammatory conditions–like heart disease–they should stop devoting resources to reducing sodium in processed foods. Instead, they should disincentivize processed foods themselves and help make whole foods desirable and accessible. 

With that rant out of my system, we’ve seen a lot of research since Dahl’s days. The underlying question remains: Is limiting sodium intake good for your heart?

Is salt restriction an effective treatment for high blood pressure?

The relationship between sodium and blood pressure is more complicated than “less is more.” Yes, eating a lot of salt results in a transient (momentary) increase in blood pressure. And yes, some observational data link salt restriction to lower blood pressure. But not all the data tell the same story.

Avoiding sodium can also raise blood pressure by stimulating sodium-retention hormones like aldosterone. This may explain the Framingham Offspring Study, which suggests that low-sodium diets lead to higher blood pressure in people without hypertension.

Furthermore, the Intersalt Study showed no link between high blood pressure and salt consumption in 10,000 people across the globe. And in 2020, a Cochrane Collaboration Review found that when study participants were put on low-salt diets, they achieved a mere 0.4 mmHg drop in mean arterial pressure for normotensives and about a 4 mmHg drop for hypertensives.

What about specific CVD events? The authors of a 2011 paper published in the Journal of the American Medical Association found that people consuming 4–6 grams of daily sodium had fewer heart events (cardiac arrest, strokes, death) than those consuming fewer than 3 grams per day. This study’s population consisted of people with established CVD or diabetes—people typically urged to limit sodium. The results make me question the logic of universal salt restriction.

How can I get my blood pressure under control?

Rather than picking on transient and intermediate factors in hypertension (like sodium intake), let’s talk about the root causes. I recently listened to an interesting conversation between longevity expert Dr. Peter Attia and nephrologist (kidney specialist) Dr. Rick Johnson that may shed some light on this topic. 

Rick makes a strong case that kidney inflammation—likely due to high uric acid levels—increases sodium retention and salt sensitivity, driving hypertension. Too much salt isn’t the problem. Too much uric acid is. (Even this is downstream of the likely cause: insulin resistance.) There is a lot to be said on the topic of metabolic health, but all of that is beyond the scope of this article.

For now, understand this: If you’re not eating an appropriately portioned whole foods diet, avoiding sugar, exercising, managing stress, and sleeping well, you’re doing yourself a disservice in the blood pressure department. 

Potassium and Heart Disease

Potassium is less controversial than sodium. It’s clear that higher potassium intakes reduce the risk of high blood pressure and CVD risk. Some supporting data:

• Multiple population studies suggest that hypertension risk falls as potassium intake rises.
• In a study of nearly 250,000 people over 5–19 years, stroke risk decreased 21% for every 1.6 grams of additional potassium consumed daily.
• Rats fed more potassium have less kidney inflammation.
• A meta-analysis of randomized controlled trials found that potassium supplementation lowered blood pressure in people with hypertension.

Another point of interest: The modern diet is low in potassium-rich whole foods and high in salty processed foods. Is widespread hypertension due to our collective sodium intake, or is it that we’re eating too much unhealthy food that is also lacking in potassium? I lean toward processed foods and potassium deficiency.

Beyond blood pressure, potassium intake is inversely correlated with diabetes risk. (Metabolic derangement, a cluster of conditions that disturb or disrupt the normal order of the body and metabolic processes of the metabolism, is closely linked to heart disease.) But we can’t say for sure that potassium causes this effect. People on a high-potassium whole foods diet also tend to engage in healthy behaviors—such as exercise—that improve metabolic health. My blood sugar stats might look good because I eat plenty of potassium, or maybe because I rarely miss a jiu jitsu session. (I’d spar on an international flight if it was socially acceptable.) Probably a bit of both.

Magnesium and Heart Disease

Magnesium influences most of the cardiovascular system. It influences calcification, clotting, heart rhythms, blood vessel relaxation, and inflammation, as I alluded to earlier.

Inflammation advances heart disease. Excess immune particles can incite an inflammatory cascade that accelerates plaque formation in the arterial walls. And, of course, more arterial plaque increases the risk of heart attack, stroke, and death.

Back to magnesium. Magnesium-deficient people (about 30% of the population) have higher levels of inflammation, so optimizing magnesium intake is a reasonable step to reduce CVD risk. Magnesium supplementation (compared to placebo) has also been shown to reduce CVD risk by preventing cardiac arrhythmias.

Calcium and Heart Disease

Calcium is best stored in your skeleton, not your arteries. Calcium in the arteries is a sign of advanced heart disease—indicating that particles have broken into the inner lining of the blood vessels called the endothelium. High blood calcium levels (hypercalcemia) cause this calcification, which stiffens and narrows your arteries.

A quick route to high blood calcium levels is to consume calcium in great excess. This may explain why calcium supplements (but not dietary calcium) are linked to higher CVD risk. Swallowing a calcium pill causes transient hypercalcemia, but distributing your calcium over several meals does not.

One last point on calcium: Coronary calcium doesn’t track perfectly with heart disease risk. Many people have heart attacks and strokes with zero measurable calcification. But all else equal, less coronary calcium is generally a good thing.

Electrolyte Intakes for Heart Health

How much electrolytes should you consume for heart (and general) health? Based on the available evidence[*][*][*][*], I can suggest baseline ranges that work for many people in many situations:

• Sodium: 4–6 grams/day
• Potassium: 3.5–5 grams/day
• Magnesium: 400–600 mg/day
• Calcium: 1 gram/day (from dietary sources)

I recommend tracking your electrolyte intake with an app for a few days. Once you better understand your current diet, you can experiment with different ranges and adjust your regimen to suit your needs.

Electrolytes: A Heart Health Tactic

I spend a lot of time pondering how to reduce CVD risk because it affects so many of us. We need a strategy to slow down this silent assassin and live longer and better lives.

Our tactics should include exercising, sleeping well, a whole foods diet, and—as I hope this article made clear—optimizing electrolyte intake.

Fortunately, getting enough electrolytes is simple enough. Just focus on eating nutrient-dense whole foods and then supplement as needed. Your ticker will appreciate it.