Sodium Intake and Your Health: A Tale of Two Standards

When it comes to making food pleasurable to the taste buds, adding salt to a cuisine definitely helps make that a reality. Salt has been known not just as a food additive for flavor enhancement, but for thousands of years, it has also been used as a preservative to extend the shelf-life of food.

However, as with many things in western society, the use of salt has become excessive. Simultaneously, the prevalence of obesity has also been on the rise along with the associated negative health consequences, such as, diabetes, renal (kidney) disease, and cardiovascular disease. For all of these outcomes, in one way or another, the common denominator is hypertension (high blood pressure), so controlling this risk-factor is paramount in maintaining good long-term health.

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Clinicians advise that for good cardiovascular health, we maintain a resting blood pressure reading of 120/80 or less. So what does that readout actually mean? The top number, 120, represents the pressure that blood vessels are subjected to when the heart pumps, and the bottom number, 80, represents the pressure on the blood vessels when the heart is at rest.

Important blood pressure levels to consider
Hypertension: 140/90 and above
Prehypertension: 121-139/81-89
Normal: 120/80 and below

A primary factor that influences blood pressure is sodium, and the most common form of sodium consumption is salt. Although there is a common misconception that the two substances are synonymous, on a molecular level, salt in the form of NaCl (sodium chloride) is 40 percent sodium and 60 percent chloride, so salt is not purely sodium.

Without getting too detailed with the molecular chemistry of NaCl (sodium chloride), this is a simplified representation of the salt molecule at an atomic level.

Taking this into consideration, it is clear that tracking sodium intake is prudent to the regulation of blood pressure. Specific populations are more susceptible to the impacts of excessive sodium intake, such as adult populations over 50 years old, individuals with a history of cardiovascular complications, and individuals of African descent.

To help the general population gauge how much sodium they should be consuming, the USDA has established guidelines for daily sodium intake, with 2300mg being the upper limit for the general population, and 1500mg for more salt-sensitive groups.

However, just because there are guidelines in place, does not mean that we actually abide by them. Unfortunately, it is estimated that about 90 percent of Americans are ingesting too much sodium, and according to the CDC, the average American consumes more than 3400mg of sodium per day! It’s no wonder that with the over-indulgence of this element, cardiovascular-related disorders and diseases are the leading cause of death, not just in the United States, but also in the world!

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So how are we consuming so much sodium? I mean, we’re talking thousands of milligrams per day, so is it that hard to stay within the suggested limits? The figure below, courtesy of the CDC, may give you an idea of how quickly your sodium intake can add up.

Breads, canned goods, processed foods, fast foods, and packaged snack foods contain some of the highest levels of sodium that can be potentially introduced into our diets, so avoiding these where possible is strongly advised when striving to follow a low-sodium regimen.

Now, if we go back to the sodium intake guidelines we notice that in the context of ethnic groups, only African-descended people are advised to shoot for the lower sodium limit, which begs the question, “Why?”

There is no one over-arching smoking gun, but one link that has been made pertains to the angiotensin converting enzyme (ACE) gene, which manifests itself in multiple variants/forms. This ACE gene is responsible for inducing the release of a hormone called angiotensin, which regulates the level of constriction of the blood vessels and, by proxy, regulates blood pressure.

Some of these ACE variants which exist in people of African-descent are more sensitive to sodium, and exposure to certain levels of this element can result in an over-constriction of the blood vessels, leading to an elevated systolic blood pressure.

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However, with this in mind, African-descended people who may be nutrition facts-conscious and track their sodium consumption may need to be wary of another revelation: The nutrition facts label assumes that your daily limit of sodium is capped at the general population’s recommendation of 2300mg.

Oops.

So instead of going by the percent of daily value, people of African descent and other susceptible groups need to pay attention to the number of milligrams of sodium, and align it with their 1500mg limit.

Some of these group-specific nuances have a history of being overlooked or ignored, as we have highlighted in previous publications regarding dairy consumption, or even calcium and vitamin D daily recommendations.

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As is typical with science, opposite findings have been revealed when tipping the scale to the other extreme of very little sodium consumption. There are also instances where lower sodium intake may not show benefits to cardiovascular health, and some of these findings are presumptively gathered and disseminated as a devil’s advocate rebuttal to the promotion of a diet lower in sodium.

However, what is often overlooked is that the studies supporting this rebuttal are composed of majority or entirely Caucasian participants; this means that we don’t really know if these claims hold the same weight for African descendants, Hispanics, Asians, or any other non-Caucasian groups (remember those ethnic group nuances we mentioned earlier?). According to the American Heart Association (AHA), 500mg of sodium is the minimum requirement for physiological health (healthy bodily function). In this day and age, barring an extreme circumstance, it is pretty difficult to not eclipse that threshold.

These representative images are derived from 4 studies cited in the rebuttal article “6 Little-known Dangers of Restricting Sodium Too Much”
Study 1
Study 2
Study 3
Study 4

Claims of a low sodium diet not being beneficial may only be relegated to individuals with a history of congestive heart failure, or in very extreme instances of voluntary (diet) or involuntary (starvation) sodium restriction. These claims should not be irresponsibly dispersed as this may mislead and misinform the readers. Any study findings that have shown a lack of benefit from lower sodium intake (within physiologically relevant levels, such as 1000mg-2000mg) have been relegated to almost exclusively Caucasian participants.

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So, besides the typical recommendations of avoiding sodium-laden foods or suppressing the urge to add excess salt when cooking (and at the dinner table), are there any other ways to help individuals of African descent reduce sodium intake? Definitely!

• Consume more potassium-rich foods. Potassium and sodium are fierce competitors for some of the same targets, so the blood pressure-raising effects of sodium can be offset by the presence of this element. Bananas, orange juice, sweet potatoes, and spinach are excellent sources of potassium, for example.

• Consider using a proportion of potassium chloride with traditional sodium chloride salt. Some food companies have done this, like Smartfoods, with their bagged popcorn.

• Transition to a more contemporary salt alternative, such as SODA-LO with their salt microspheres. Simply put, it is your traditional sodium chloride salt, but with a twist; it’s engineered as hollow spheres instead of dense flakes or granules, so the density of salt (and concentration of sodium) is up to 50% less! This Tate & Lyle’s ingredient has garnered recognition for its innovative goal of helping reduce our sodium intake, while apparently retaining that same magnificent salty taste (*wink wink*). Hopefully, this product can be approved for adoption worldwide, if it hasn’t already.

• Make sure to consult your primary care physician or personal dietician for guidance in implementing the aforementioned suggestions, as well as other alternatives I haven’t mentioned here.

With the daily grind of work, family, and recreation, it can be challenging to plan and execute your goals of reducing sodium intake. Meal planning and cooking take time, I get it. But believe me, it’s worth the effort. Not only will your body thank you for it, but so will your loved ones; not just for sticking around, but for maintaining a higher quality of life while you’re still here.

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Science Lion Featured Guest: Raven Hardy and Sickle Cell

Science Lion recently had the pleasure of having a PhD candidate, Raven Hardy, drop by to speak with us about her upcoming event for sickle cell advocacy. To preface awareness of this event and the cause behind it, she also shed some light on her journey through graduate school, in addition to how she became interested in sickle cell research.

Raven is a neuroscience PhD candidate at Emory University, working in the lab of Dr. Hyacinth, which is part of the Aflac Cancer and Blood Disorders Center. In particular, she looks at the profile of inflammation in sickle cell patients, and the impact that it may have on brain structure, and subsequently on cognitive deficiencies (dysfunction of the brain) and cell proliferation (cell division and growth).

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  The sickle-like shape of the red blood cell wreaks havoc on the circulatory system, causing blockages in the blood vessels and inducing inflammation.

Upon making these assessments, she observes how these effects track with age, from childhood to adulthood; these alterations of the brain appear to be culprits of the resulting strokes and neurological disorders that may manifest in sickle cell patients.

All of which are done in a mouse model that is humanized or genetically altered to mimic the expression of relevant human proteins in the brain. The purpose of humanizing in this case is to resemble as closely as possible what happens in a human brain, without having to use one.

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But how did Raven get here, in the first place, to do this kind of research? Many times, people draw inspiration and direction in life from tragedy, and this case stands true for Raven, as well. During her senior year of undergraduate studies, Raven’s sister, who herself lived with sickle cell, passed away at the age of 26 from brain death, extending from complications due to a preceding sickle cell crisis.  After managing to overcome that great loss and obtaining her degree, she began her unconventional path through graduate school.

Although she had a passion to learn more about sickle cell and its effects from a research standpoint, she initially entered a PhD program at Scripps Research Institute studying brain-related microorganisms called prions. She later transferred to Emory University, switching gears in her research, and focusing on brain imaging as it related to nutrition in predominately African American communities. However, her journey did not stop there.

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“Unfortunately, I had to leave that lab”, Raven reflected with a chuckle. “And as it would so have, I was able to join a lab that did sickle cell research, so I actually think that my path took a complete circle to get me right where I wanted to be.”

That lab would be her current research home with Dr. Hyacinth. “But I’m happy to be where I am”, she remarked with a smile on her face. “I feel as though when you’re meant to be somewhere you’ll end up there, and I think this is where I’m meant to be.”

So what is sickle cell disease? Sickle cell is a genetic blood disorder that can manifest itself if two parents carry the sickle cell trait. Within the context of the disease, red blood cells possess a “sickle-like” shape, inducing pain and inflammation – a response of immune cells – which can result in a “crisis event.” Unfortunately, these crisis events can lead to adverse outcomes such as stroke, or even death.

Punnett Square: This type of diagram outlines the possible combinations of alleles passed down from parents (alleles are variable forms of a given gene). Here we show what allele combinations correspond with which resulting phenotype (phenotype is the outward expression of genes – in other words, what we see!).

Bridging the conventional knowledge of the disease with what she is researching now in the neuroscience realm, Raven informs us that individuals with sickle cell can have high levels of behavioral and cognitive deficits. “So as far as blood is concerned, morbidities may stem from high levels of inflammation that induce the crisis (event) , and this inflammatory crisis may occur in the brain leading to different forms of brain damage.”

In addition to the amazing and intriguing research that she conducts in the lab, Raven really has a passion to advocate for closing the racial disparity gaps within health care, and of course in raising awareness of sickle cell disease, especially as it disproportionately impacts people of African descent.

“There is a lot of research and support for children with sickle cell, but when you reach adulthood and require a continuum of care, unfortunately it is not to the level where it should be”, Raven contends. “So, definitely there should be more physicians that are able to treat and manage individuals with sickle cell in crisis, and in general health.”

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Speaking of her endeavors in public health advocacy, this leads us to her current task of raising awareness of sickle cell in her local community by holding a “sickle cell gala” on her birthday, in honor of her late sister. The Dec. 6 art gala event includes a classy dinner at the Miller-Ward Alumni House in Atlanta, GA, and offers a social opportunity to network in a nurturing environment with other participating individuals. All proceeds toward the event will go to sickle cell causes.

If you would like to follow in Science Lion Media’s footsteps and donate to the cause of furthering sickle cell research and bettering the relevant public health policy, please visit her GoFundMe page. This way, she can allocate the funds to the most reputable organizations for maximum community impact. If you are interested in attending her art gala event, please reach out to Raven at blackbyrd1206@gmail.com for any remaining seats.

Be sure to check back soon for the uploaded, full podcast interview with Raven as the Science Lion Media team chopped it up with this outstanding young lady, who has personified perseverance in the face of an unconventional road to her PhD.

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