I don't understand why the potassium sodium ratio is so important. My doctor tells me to reduce my salt and to eat more fruits and vegetables. Isn't that enough? Depends. What else do you eat? How do you prepare it? How much sodium does it really contain?
This website has emphasized the potassium sodium ratio in many of its posts. Medical guidelines discuss reducing sodium and talk about eating more fruits and vegetables as a way to reduce hypertension and cardiovascular disease. However the guidelines don't explain why to eat the fruits and vegetables or what is important about them.
Why Fruits And Vegetables Are Important
Although fruits and vegetables have many admirable qualities, such as fiber, antioxidants, phytochemicals, and polyunsaturated fats, their most important quality is that they have a high potassium to sodium ratio. This has been shown indirectly in many studies. Many studies show that decreasing sodium improves blood pressure. Almost as many studies show that increasing potassium improves blood pressure. But there have been only a few that have directly studied the ratio.
It's The Ratio
The report (1) that we will be discussing today directly studied the potassium to sodium ratio. It found that the ratio had the strongest fit to cardiovascular disease. The ratio was stronger than sodium by itself or potassium by itself. It found that there was an effect on cardiovascular disease even after statistical adjustments for blood pressure.
How To Go Wrong Eating Fruits And Vegetables
It is important to understand the potassium sodium ratio because just eating vegetables and fruits is not the key to reducing cardiovascular disease. Increasing the potassium to sodium ratio is the key. The last 2 posts showed some societies that eat more fruits and vegetables than the average Western society. Yet these societies have just as much hypertension as a Western society.
The reason is that they add sodium in the form of salt to the vegetables. Kimchi is a pickled vegetable that is the national food of Korea. Korea has just as much hypertension as Western societies. India is composed of 30 to 50% vegetarians and even non-vegetarians eat very little animal food. However their hypertension is the same as any Western society and they have pockets with a much higher percentage of hypertensive people than the average Western society.
I'm Vegan. Why Are My Blood Tests Bad?
I have vegan friends who do not understand why their cardiovascular biomarkers are so poor. They avoid all animal food. However they eat a great deal of processed food made from plants. Many of the processed foods, such as the veggie burgers, cocoa and sugar products, and the vegan pasta, have a poor ratio. Eating too many of the processed veggie foods and not enough vegetables and fruits as they come from the ground will be counterproductive to being a vegan, if being vegan is done for health reasons.
There have been a great many studies of reduced sodium in the diet. There also have been a great many studies of fruits and vegetables, especially vegans versus omnivores. Most of the studies are done with food frequency questionnaires, which are a good first start.
More Rigor Is Needed
However a more rigorous study would involve measuring urinary sodium and potassium and this is rarely done. Usually when it is done, it is only done once. Because of the variability of what people eat, the amount of sodium and potassium on any given day will be highly variable.
The study we are discussing today did multiple measurements over several years. This gives a much better idea of the average sodium and potassium that someone consumes than a single measurement.
This study (1) actually included participants and data from 2 studies. The first one was 18 months and the second was 3 years in duration. The average number of sodium measurements and of potassium measurements over these periods was 4.8 each. The study included over 2200 participants.
The researchers did a follow-up at approximately 15 years after the first study and 10 years after the second. They examined the number of deaths that were due to cardiovascular disease and the number of nonfatal cardiovascular events.
The result was that there were fewer and fewer cardiovascular deaths and events in participants as the ratio of potassium to sodium got larger and larger. The ratio provided a better fit to the data than did sodium alone or potassium alone. This was even true when they adjusted results for blood pressure.
The Potassium Sodium Ratio Is Basic
Hypertension is a sign of a basic cellular disease. It is very similar to the sign of fever indicating an infection. Fever is not the disease. Hypertension is not the disease. This basic cellular disease is an imbalance of potassium to sodium. It affects every cell in the body, including the heart and blood vessels. The more rigorous the study, the more likely it is to demonstrate the importance of the ratio.
1. Joint effects of sodium and potassium intake on subsequent cardiovascular disease: the Trials of Hypertension Prevention follow-up study. Cook NR, Obarzanek E, Cutler JA, Buring JE, Rexrode KM, Kumanyika SK, Appel LJ, Whelton PK; Trials of Hypertension Prevention Collaborative Research Group. Arch Intern Med. 2009 Jan 12;169(1):32-40. doi: 10.1001/archinternmed.2008.523.