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Sodium Potassium Ratio

December 18, 2009 Written by JP    [Font too small?]

The best way for me to learn is to understand the logic behind a lesson. I need to comprehend not only what is happening, but why. This helps me quite a lot when it comes to the study of natural medicine and nutrition. It’s not enough for someone to tell me that fruits and vegetables protect against cancer or that exercise “does a body good”. I have to be aware of the mechanisms that justify such statements. Very often, these explanations are based on incomplete information and, therefore, need to be modified over time. But even so, at least they provide a reasonable underpinning upon which one can hang a concept.

Ordinary table salt is a common villain in the field of cardiology. You’ll often hear experts recommend limiting sodium intake by reducing consumption of processed foods and using a lighter hand with the salt shaker. But for whatever reason, the message isn’t getting across very well. This is evidenced by the ever increasing sodium content found in many commercial foods and by the excessive levels of sodium consumed by many populations. In addition, there are even some unconventional nutritionists and physicians who believe that sodium has unjustly received a bad reputation. That’s why I’ve decided to review the latest scientific data relating to salt intake and human health in today’s column. (1,2)

2009 began with an intriguing study which forms the foundation for my personal view of this topic. In essence, it discovered that the level of sodium in one’s body is less of an issue than the “sodium to potassium” ratio. Higher levels of sodium and lower levels of potassium appeared to play a significant role in the incidence of cardiovascular disease in two separate trials involving almost 3,000 participants. It’s important to note that the levels of these essential minerals were quantified by measuring urinary output. This is a more accurate testing method than what has typically been used in the past. (3)

The DASH diet (Dietary Approaches to Stop Hypertension) is perhaps the most popular nutritional approach for addressing the cardiovascular effects associated with the over consumption of sodium. This particular menu plan is rich in fresh fruits and vegetables, low-fat dairy products and whole grains. The DASH program also suggests avoiding most processed foods, saturated fat and sugar. A study in the October 2009 issue of the Journal of Human Nutrition and Dietetics applied this specific diet to a group of volunteers from the United Kingdom. Oxford researchers asked 14 healthy participants to eat a DASH-style diet, which was “adapted to fit UK food preferences and portion sizes” for a 30 day period. Blood pressure readings and food diaries were collected at the beginning and end of the trial. The results indicate the following:

  • The diet was well received and tolerated by the study volunteers.
  • Daily intake of sodium decreased by approximately 860 mg per day.
  • Diastolic and systolic blood pressure declined by 3.9 and 4.6 mmHg.

A newly released study presented in the Journal of Human Hypertension goes on to add an important detail to the DASH story: this diet not only lowers blood pressure, but can also decrease oxidative stress and “vascular stiffness”. This lends credibility to the hypothesis that a lower-sodium, higher-potassium diet may actually preserve the condition of the cardiovascular system via improved arterial health. (4,5)

Another trial from October 2009 found that older adults (aged 48-73) on low sodium diets demonstrated substantially better circulation as assessed by a test known as “brachial artery flow-mediated dilation”. The authors of that research concluded that “dietary sodium restriction may be an effective intervention for improving vascular endothelial function”. A presentation in the December issue of the American Journal of Hypertension contributes yet another piece to the sodium/high blood pressure puzzle. Scientists from Tulane University School of Public Health commented that their research “suggests that individuals who were more sensitive to a high sodium diet might benefit more from a low sodium and/or high potassium intervention aimed at lowering BP levels”. This may give salt sensitive patients a most welcome option: either lower dietary sodium or, at least, increase dietary sources of potassium. (6,7)

A shift to a more balanced sodium to potassium ratio isn’t a modern discovery at all. In fact, it’s more of a “blast from the past”. A recent review from the McGill University School of Dietetics and Human Nutrition focuses on the rather dramatic dietary changes that have occurred over the past 10,000 or so years. They note that modern man tends to eat fewer fruits, meats, seafood and vegetables than his paleolithic predecessors. In addition, 21st century eating frequently includes denatured and hydrogenated fats, lower fiber intake and more sodium. What’s more, recent interventional trials using paleolithic style diets have revealed that they generally promote higher potassium levels, lower sodium concentrations and improvements in various markers of cardiovascular health. This has lead some scientists to suggest a return to a more “stone age” way of dining. (8,9,10,11,12,13)

The Effects of a High or Low Salt Diet on Blood Pressure
Source: Hypertension. PMC 2009 November 2. (link)

The most fundamental way to improve the sodium/potassium ratio is to eat fewer packaged products and a diet that consists primarily of fresh, whole foods. However, this doesn’t necessarily mean that you have to follow a low fat, mostly vegetarian, DASH style diet. There are many foods that are high in fat that also provide substantial quantities of potassium and minimal amounts of sodium. Avocados, chicken, fish, meat and a variety of nuts and seeds all fall into this category. (14,15)

The use of potassium supplements is rarely called upon because said pills and tablets often cause digestive irritation and upset. Fortunately, there are some low sodium, salt substitutes that are easily found in health food stores and markets. Such food additives are typically rich in potassium and have been shown in numerous studies to lessen arterial stiffness and lower blood pressure. (16,17,18,19,20,21)

The cardiovascular system gets the lion’s share of the attention in relation to salty foods. However, other organs and systems in the body such as the kidneys and the skeletal system can similarly be affected by an imbalanced sodium/potassium ratio. If you combine the prevalence of heart and kidney disease with osteoporosis, it would seem that nearly everyone should become conscious of how much sodium and potassium their typical menu provides. (22,23,24,25,26,27)

One of the hottest debates about salt is whether sodium is to blame for its bad rap. Some alternative and integrative practitioners believe that highly processed table salt is what is truly at fault. On the other hand, they claim that natural, minimally processed sea salt is actually health promoting. Sea salt is, indeed, a more natural product which contains trace minerals that are absent from conventional table salt (sodium chloride). This is why some of the biggest names in modern medicine, such as Dr. Andrew Weil and Dr. Mehmet Oz, recommend its use. But there’s very little debate about one thing: sea salt contains about as much sodium as conventional salt. I should also point out that I’ve only seen one study that has compared the effects of sea salt versus sodium chloride. That animal trial actually found that sea salt was more likely to produce hypertension in a group of lab rats. (28,29,30,31)

In my opinion, the healthiest ways to reduce sodium intake is to: a) eat more whole foods and reduce intake of pre-packaged products; b) add more antioxidant-rich herbs and spices to recipes to your diet; c) consider a potassium-based salt substitute in consultation with your physician – this may not be appropriate for those on certain medications or with compromised kidney function and; d) be consistent with your nutritional game plan. Please keep in mind that your chosen dietary strategy is serious medicine. It can work in your favor or against you. But one way or another, the food you eat is affecting your body and mind 24 hours a day, 7 days a week. A recent example is a study that found that eating high amounts of sodium can actually “contribute importantly to resistance to anti-hypertensive treatment”. I wonder how many people are finding incomplete or unsatisfactory response to their medications because they don’t know or apply this information. If they did know, it might even provide an opportunity to use less medication or none at all. The only way to find out the potential of a given therapy, whether conventional medication or natural diet, is to try it out. But balancing your sodium/potassium ratio offers at least one distinct benefit over medication: it’s highly unlikely to cause any adverse reactions or side effects. (32,33,34,35)

Note: Please check out the “Comments & Updates” section of this blog – at the bottom of the page. You can find the latest research about this topic there!

Be well!

JP


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Posted in Bone and Joint Health, Heart Health, Nutrition

14 Comments & Updates to “Sodium Potassium Ratio”

  1. Nina K. Says:

    Good Morning JP!

    its a wonderful morning, it snows the sky is blue and its sunny and very cold -11°C! (off topic 🙂 )

    my hubby and i try always to watch our sodium intake. we both read books about low carb and one of the scientists says, that to much salt (and sugar) is an cancer supporting environment. the arguments for that are going to far for posting here.

    im very sodium sensitive, to much and my eyes get puffy and my fingers swollen. so we looked for foods which are high in potassium to give our meals a little spice.

    here my suggestions:

    to increase potassium use Coconutwater – it contains 240 mg potassium / 100 ml!

    fresh herbs like parsley, dill, thyme, rosemary contain very much potassium

    here is my fav summer (-high potassium) salad – eaten in a very good restaurant:

    fennel grated (or grinded – hope thats the right word?), carrot grinded and as green salad leafs use unchopped parsley and dill in great amounts like it where romain lettuce or lettuce. don’t panic, these very aromatic herbs taste in those amounts very very good, if they where not choped the taste develops in mouth by chewing them. Only add olive oil and balsamico and very little breeze of herb salt.

    this salad is often combined with smoked fish or grilled meat. i love it and i had never thought that parsley and dill maks such a wonderfull salad. iv available you can add fresh young dandelion to the salad, than its more a diuretic than a salad 😉 😉

    the best thing to lower sodium is to cut all sodium out for a few days and then reintroduce small amounts, because the sense of taste is mostly adapted to high sodium content. after a pause everything tastes salty, even with very less salt.

    Stay healthy!
    Wish everybody here a wonderful weekend 🙂

    Nina K.

  2. JP Says:

    Fantastic suggestions! Thank you, Nina! 🙂

    I think your final piece of advice is very good as well. Added salt, much like sugar, is an acquired taste. Sometimes we need to train our taste buds to truly appreciate smaller amounts of it.

    I hope your weekend is as beautiful as this morning turned out to be! Believe it or not, it’s about 70 degrees F over here! Where’s our Winter?! 🙂

    Be well!

    JP

  3. Bill Rawls, MD Says:

    Great discussion on sodium, JP! The taste of salt is only secondary to that of sweet in our natural drive to acquire the necessities of life. Like the irrepressible taste for sweet, our prominent taste for salt evolved over thousands and thousands of years when salt, like glucose, was very scarce in food sources. Because these substances were and are so essential for life, they receive preference over other substances in food. Today, we are naturally driven to eat foods that are almost nothing but glucose and salt.

    I like the taste of sea salt over regular salt, and it does offer benefit from other trace minerals, but you are right, it has just as much sodium. The trick is eating enough fruits, vegetables and other foods naturally high in potassium to balance the ratio of sodium to potassium.

  4. JP Says:

    Bill,

    Thank you for adding that historical context to this issue! 🙂

    My personal philosophy is in line with yours: We try to eat plenty of foods that are rich in potassium (we love avocados!) while limiting our intake of processed foods which are often loaded with added salt. In our home, we do include a bit of sea salt in our cooking and I frequently add a sprinkle or two of a potassium-based salt substitute to my protein shakes. I think overall we probably have a better sodium potassium ratio than most. Thankfully, our blood pressure reflects that as well.

    Thanks for all your valuable contributions on this site!

    Be well and happy holidays! 🙂

    JP

  5. Sue Says:

    JP, decreasing sodium doesn’t seem to lower diastolic and systolic by much at all. Low carb diets lower BP a lot more.

  6. JP Says:

    Good day, Sue. 🙂

    I think low carb diets can be another useful tool for lowing blood pressure. But keeping sodium in check appears to offer additional benefits along with the relatively modest BP modifying effect. Combining a low carb diet with a balanced sodium to potassium ratio is what I personally try to do. I think this offers a greater effect than either strategy alone.

    Be well and happy holidays!

    JP

  7. Nicolas Says:

    Thank you very much for this thoughtful and thorough article.

    I was investigating the potassium/sodium ratio to work out whether it was reputable enough to be worth applying. This article swung it for me.

    I wonder what the ideal ratio is and if, if you’re getting your full RDA of other vitamins and minerals from your diet, it is possible to have too little sodium. There’s very little info about that.

  8. JP Says:

    Nicolas,

    You’re welcome. I’m glad to know this column was of interest to you.

    I think you might find this interview to be useful:

    http://www.drpasswater.com/nutrition_library/Potassium%20_to%20_Sodium_Ratio.html

    Be well!

    JP

  9. Gardener Says:

    Excellent work on this article. It makes for an interesting and Thoughtful read.

  10. JP Says:

    Update 06/01/15:

    http://archpedi.jamanetwork.com/article.aspx?articleid=2272973

    JAMA Pediatr. 2015 Apr 27.

    Longitudinal Effects of Dietary Sodium and Potassium on Blood Pressure in Adolescent Girls.

    Importance: Identification of risk factors early in life for the development of high blood pressure is critical to the prevention of cardiovascular disease.

    Objective: To study prospectively the effect of dietary sodium, potassium, and the potassium to sodium ratio on adolescent blood pressure.

    Design, Setting, and Participants: The National Heart, Lung, and Blood Institute’s Growth and Health Study is a prospective cohort study with sites in Richmond, California; Cincinnati, Ohio; and Washington, DC. Participants included 2185 black and white girls initially aged 9 to 10 years with complete data for early-adolescent to midadolescent diet and blood pressure who were followed up for 10 years. The first examination visits were from March 1987 through February 1988 and follow-up continued until February 1999. Longitudinal mixed models and analysis of covariance models were used to assess the effect of dietary sodium, potassium, and the potassium to sodium ratio on systolic and diastolic blood pressures throughout adolescence and after 10 years of follow-up, adjusting for race, height, activity, television/video time, energy intake, and other dietary factors.

    Exposures: Mean dietary sodium and potassium intakes and the mean potassium to sodium ratio in individuals aged 9 to 17 years. To eliminate potential confounding by energy intake, energy-adjusted sodium and potassium residuals were estimated.

    Main Outcomes and Measures: Mean systolic and diastolic blood pressures throughout adolescence and at the end of follow-up (individuals aged 17-21 years).

    Results: Sodium intakes were classified as less than 2500 mg/d (19.4% of participants), 2500 mg/d to less than 3000 mg/d (29.5%), 3000 mg/d to less than 4000 mg/d (41.4%), and 4000 mg/d or more (9.7%). Potassium intakes ranged from less than 1800 mg/d (36.0% of participants) to 1800 mg/d to less than 2100 mg/d (26.2%), 2100 mg/d to less than 2400 mg/d (18.8%), and 2400 mg/d or more (19.0%). There was no evidence that higher sodium intakes (3000 to <4000 mg/d and ≥4000 mg/d vs <2500 mg/d) had an adverse effect on adolescent blood pressure and longitudinal mixed models showed that those consuming 3500 mg/d or more had generally lower diastolic blood pressures compared with individuals consuming less than 2500 mg/d (P = .18). However, higher potassium intakes were inversely associated with blood pressure change throughout adolescence (P < .001 for systolic and diastolic) and at the end of follow-up (P = .02 and P = .05 for systolic and diastolic, respectively). While the potassium to sodium ratio was also inversely associated with systolic blood pressure (P = .04), these effects were generally weaker compared with effects for potassium alone. Conclusions and Relevance: In this study of adolescent girls, consumption of 3500 mg/d of sodium or more had no adverse effect on blood pressure. The beneficial effects of dietary potassium on both systolic and diastolic blood pressures suggest that consuming more potassium-rich foods during childhood may help suppress the adolescent increase in blood pressure. Be well! JP

  11. JP Says:

    Updated 09/10/15:

    http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9945134&fileId=S0007114515002986

    Br J Nutr. 2015 Sep 7:1-8.

    Effects of sodium and potassium supplementation on endothelial function: a fully controlled dietary intervention study.

    High Na and low K intakes have adverse effects on blood pressure, which increases the risk for CVD. The role of endothelial dysfunction and inflammation in this pathophysiological process is not yet clear. In a randomised placebo-controlled cross-over study in untreated (pre)hypertensives, we examined the effects of Na and K supplementation on endothelial function and inflammation. During the study period, subjects were provided with a diet that contained 2·4 g/d of Na and 2·3 g/d of K for a 10 460 kJ (2500 kcal) intake. After 1-week run-in, subjects received capsules with supplemental Na (3·0 g/d), supplemental K (2·8 g/d) or placebo, for 4 weeks each, in random order. After each intervention, circulating biomarkers of endothelial function and inflammation were measured. Brachial artery flow-mediated dilation (FMD) and skin microvascular vasomotion were assessed in sub-groups of twenty-two to twenty-four subjects. Of thirty-seven randomised subjects, thirty-six completed the study. Following Na supplementation, serum endothelin-1 was increased by 0·24 pg/ml (95 % CI 0·03, 0·45), but no change was seen in other endothelial or inflammatory biomarkers. FMD and microvascular vasomotion were unaffected by Na supplementation. K supplementation reduced IL-8 levels by 0·28 pg/ml (95 % CI 0·03, 0·53), without affecting other circulating biomarkers. FMD was 1·16 % (95 % CI 0·37, 1·96) higher after K supplementation than after placebo. Microvascular vasomotion was unaffected. In conclusion, a 4-week increase in Na intake increased endothelin-1, but had no effect on other endothelial or inflammatory markers. Increased K intake had a beneficial effect on FMD and possibly IL-8, without affecting other circulating endothelial or inflammatory biomarkers.

    Be well!

    JP

  12. JP Says:

    Updated 08/12/16:

    http://www.ncbi.nlm.nih.gov/pubmed/27509520

    Nutrients. 2016 Aug 6;8(8).

    The Effect of the Sodium to Potassium Ratio on Hypertension Prevalence: A Propensity Score Matching Approach.

    This study investigated the effect of the sodium to potassium ratio on hypertension prevalence and blood pressure. The study population was constructed by pooling the Korean National Health and Nutrition Examination Surveys between 2010 and 2014. The study population was divided into quartiles based on the sodium to potassium ratio, and the effect was inferred by the difference in hypertension prevalence across quartiles by six pairwise comparisons using a propensity score matching technique. The quartiles with the higher sodium to potassium ratio had higher hypertension prevalence rates based on the following pairwise comparisons: the first vs. third quartile, the first vs. fourth quartile, the second vs. third quartile, and the second vs. fourth quartile. The prevalence differences were 2.74% point (p < 0.05), 3.44% point (p < 0.01), 2.47% point (p < 0.05), and 2.95% point (p < 0.01), respectively. In addition, statistically significant higher systolic (p < 0.05) and diastolic blood pressure (p < 0.01) was observed in the second quartiles compared to the first quartiles. Because a strong association was also detected between the sodium to potassium ratio and blood pressure even at a low level of sodium to potassium ratio, a lower sodium to potassium ratio diet than a usual diet is recommended to control high blood pressure in Korea. Be well! JP

  13. JP Says:

    Updated 11/22/16:

    https://www.jstage.jst.go.jp/article/circj/advpub/0/advpub_CJ-16-0756/_html

    Circ J. 2016 Nov 19.

    Effects of Salt Loading on Plasma Osteoprotegerin Levels and Protective Role of Potassium Supplement in Normotensive Subjects.

    BACKGROUND: Excess dietary salt is strongly correlated with cardiovascular disease, morbidity, and mortality. Conversely, potassium likely elicits favorable effects on cardiovascular disorders. In epidemiological studies, increased plasma osteoprotegerin (OPG) concentrations are associated with atherosclerosis and vascular deaths. Our study was designed to examine the effects of salt intake and potassium supplementation on plasma OPG levels in normotensive subjects.

    Methods and Results: The 18 normotensive subjects were selected from a rural community in China. They were sequentially maintained on low-salt diet for 7 days (3 g/day, NaCl), high-salt diet for 7 days (18 g/day), and high-salt diet with potassium supplementation for 7 days (18 g/day of NaCl+4.5 g/day of KCl). High-salt intake enhanced plasma OPG levels (252.7±13.9 vs. 293.4±16.1 pg/mL). This phenomenon was abolished through potassium supplementation (293.4±16.1 vs. 235.1±11.3 pg/mL). Further analyses revealed that the OPG concentration positively correlated with 24-h urinary sodium excretion (r=0.497, P<0.01). By contrast, OPG concentration negatively correlated with 24-h urinary potassium excretion (r=0.594, P<0.01).

    CONCLUSIONS: Salt loading can enhance the production of circulating OPG. Potassium supplementation can reverse the effects of excessive OPG. Our study results may improve our understanding of the roles of salt and potassium in the risk of cardiovascular disorders.

    Be well!

    JP

  14. JP Says:

    Updated 05/27/17:

    http://onlinelibrary.wiley.com/doi/10.1111/jch.13014/full

    J Clin Hypertens (Greenwich). 2017 May 8.

    Dietary sodium, dietary potassium, and systolic blood pressure in US adolescents.

    Both high sodium and low potassium diets are associated with hypertension, but whether these risk factors are distinct or overlapping has not been thoroughly investigated. The authors evaluated the relationship between dietary sodium, potassium, and high systolic blood pressure among 4716 adolescents aged 12 to 14 years who participated in the National Health and Nutrition Examination Survey from 1999 to 2012. There was no association with blood pressure across most values of sodium or potassium intake. However, participants who reported sodium intake ≥7500 mg/d, potassium <700 mg/d, or sodium-potassium ratio ≥2.5 had increased odds for high systolic blood pressure (≥95th percentile for age, sex, and height). Although the high sodium and low potassium groups did not overlap, 49.2% of these adolescents also had a sodium-potassium ratio ≥2.5. In young adolescents, both excessive sodium and limited potassium are associated with high systolic blood pressure, but the balance between sodium and potassium intake may be more useful in explaining blood pressure in this population.

    Be well!

    JP

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