What is potassium and why do we need it?
Potassium is a micronutrient needed for optimal health. It’s an integral part of your nervous system and the brother of sodium. Your nervous system sends signals using a variety of chemicals. One major pathway of that is called the sodium-potassium pump. Eating a balanced intake of sodium and potassium optimizes your bodies functions. Some of the benefits of increased potassium intake include lowering blood pressure and reducing risk of cardiovascular disease and stroke.
Check out this quick intro video on potassium and why you need to eat so much of it.
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What happens if you have a low potassium level?
Most people have enough potassium to function. Extremely low levels are diagnosed by doctors hypokalemia. Low levels of potassium have been related to higher risk of cardiovascular disease (1).
Approximately 49% of those with coronary heart disease and 62% of strokes are related to high blood pressure (systolic greater than 115 mmHg) (2). There is a strong correlation between higher potassium levels and lower blood pressure (2)
The problem is that the base potassium levels most people are at are not high enough to get all the benefits potassium has to offer.
Potassium Blood Test
Your potassium levels are analyzed during your yearly physical. During the physical you’ll have blood drawn and analyzed for electrolyte levels. Monitoring potassium is one of the ways of evaluating other potential issues such as kidney disease or risk for high blood pressure.
What is a safe level of potassium in my blood?
Ideal blood levels for potassium range from 3.5 millimole per liter (mmol/L) to 5 mmol/L (3). Below 3.5 and you are in danger of hypokalemia (low potassium). Above 5 and you are in danger of having hyperkalemia (high potassium levels).
What are the benefits of potassium?
Keeping potassium at ideal levels comes with many benefits, the strongest of which keep your heart healthy.
Blood pressure and cardiovascular health
The most numerous benefits of eating more potassium include:
- The World Health Organization reviewed dozens of studies on potassium. After the study the recommended intake was 4,700 milligrams (mg) of potassium per day for the average sized adult. Adults over age 15 eating ideal levels of potassium had significantly lower blood pressure and lower risks of cardiovascular disease (CVD), stroke, and coronary heart disease (4)
- Children eating optimal potassium levels had lower blood pressure (5). High blood pressure in children strongly correlates to having high blood pressure as adults along with its associated problems such as CVD (6, 7).
- Higher potassium leads to less stroke and less CVD (8).
- Lowers blood pressure – (9, 10)
- Even if you eat have a lot of sodium in your food, increasing potassium can help lower blood pressure (11, 12). Beware of that sodium because higher sodium relates to higher total mortality (13).
- Potassium reduces the need for hypertension medication by up to 75% (14).
- Higher sodium to potassium ratios shows increased CVD (15, 16).
- Randomized controlled trials showed that increasing potassium relative to sodium reduces medical expenses, blood pressure, and CVD death (17, 18).
- Eating more potassium may reduce bone loss (19)
- Reduces Risk of Developing Kidney Stones (19)
- Increases sodium excretion (20)
- Longer life – Veterans given potassium salt had increased lifespans -(21)
- Lowers medical expenses – Veterans given potassium salt had lower medical expenses (21)
Sources of potassium
To get more potassium you need to eat more potassium. You can get it in foods or you can get it in supplements like potassium salt. Switching to potassium salt instead of table salt is easy and reduces blood pressure and lowers sodium levels (22).
Food sources to get potassium naturally
It’s easy to eat more potassium. The simplest way is to eat more potatoes, fish, beans, leafy greens, and dried fruits. The standard healthy eating advice we hear over and over.
Personally I was surprised how much potassium is in fish. Fish generally ties with beans when it comes to potassium content. Nothing beats dried fruits like dried apricots and peaches. Eating dishes that use tomato paste work wonders as well. It seems concentrating foods goes a long way to increasing potassium levels. Time for pasta with lots of sauce and fruit cake. Though who likes fruit cake?
See the list below for some of the highest foods in potassium. We didn’t start at 200 mg per 100 grams of food. We set the bar at 400 to get you the most potassium for your buck. Remember, the ideal amount is 4,700 mg per day. After this list we’ll offer a few meal plans to easily reach that number.
15 Foods That Are High In Potassium
- Adzuki beans 532 mg/100g
- Black beans 433 mg/100g
- Soybeans – 515 mg/100g
- Salmon – 628 mg/100g
- Mackerel 521 mg/100g
- Dried peaches – 996 mg/100g
- Dried apricots – 1162 mg/100g
- Spinach cooked 346 mg/100g
- Chard 549 mg/100g
- Beet greens 904 mg/100 g
- Yams 670 mg/100g
- Potato 544 mg/100g
Other Vegetables and Fruits
- Avocado 485 mg/100g
- Banana 358 mg/100g
- Acorn squash cooked 437 mg/100g
- Tomato Paste 1014 mg/100g
- Almonds 705 mg/100g
- Mixed nuts 632 mg/100g
- Cashews 660 mg/100g
Potassium Content Source (23)
Example Meal Plan to Hit 4,700 mg of Potassium Per Day
Breakfast – Oatmeal
- Oatmeal – 1 cup cooked (234 g, 158 calories, 143 mg K)
- Dried peaches – 3 servings (100 g, 300 calories, 996 mg K)
- Banana – 1 medium (100 g, 100 calories, 358 mg K)
- Calories: 558
- Potassium: 1,497 mg
Lunch – Salad
- Spinach – 3 cups (100g, 30 calories, 346 mg K)
- Apricots, dried – 5 pieces (17.5 g, 40 calories, 203 mg K)
- Almonds – ¼ cup (30 g, 163 calories, 200 mg K)
- Feta – 2 ounces (60 g, 150 calories, 36 mg K)
- Dressing – 1 ounce (100 calories)
- Calories: 483
- Potassium: 885 mg
Dinner – Meat and Potatoes
- Salmon – ½ fillet (200 g, 412 calories, 1260 mg K)
- Potato – 1 medium (200 g, 300 calories, 1080 mg K)
- Calories: 712
- Potassium: 2,340 mg
Total for Day
- Potassium: 4,722 mg
Potassium deficiency happens when your bloods levels of potassium are lower than 3.5 mmol/L (Below 3.5 mmol/L)(24). This is a doctor diagnosed condition called hypokalemia. Even though you can check it with a home blood test, you still need to discuss what to do about it with your doctor.
Dealing with a potassium deficiency is discussed in in the hypokalemia section below.
The body is very good at excreting potassium through urine if consumption is too high. Even elevated potassium consumption over a year didn’t have negative effects (25, 26).
High potassium from supplements can be dangerous, but intake from food was not (27). High levels of potassium were defined as 5 to 7 g per day (27)
Up to 3 g per day of supplement potassium beyond that found naturally in food was not harmful (27).
Are there any interactions with potassium that I should know about?
Yes, there are medications used to treat high blood pressure. Some, such benazepril and losartan reduce potassium lost in urine which can create high levels in the blood. Others such as furosemide, bumetanide, chlorothiazide, and metolazone cause you to lose more potassium in urine creating lower levels in your blood (28).
If you plan to change your potassium intake and you’re taking medication, discuss it with your doctor first.
Treating imbalanced potassium
Hypokalemia is defined as having blood concentrations of potassium below 3.5 mmol/L (3). This is assessed using an electrolyte blood test. Causes can include use of diuretics or other gastrointestinal losses. Treatment must be conducted with your doctor and includes a review of your history, current medications, and special circumstances.
This is a common condition found in 21% of hospitalized patients (29). It can be treated by various means of increasing potassium intake via food, supplements, or intravenously.
Hyperkalemia (high potassium) is defined as blood potassium concentrations above 5.1 to 6 mmol/L (3). It’s most commonly caused by some medications, hyperglycemia, or kidney disease.
Again, it’s diagnosis and treatment must be discussed with your doctor.
For blood levels between 5 to 6 mmol/L, treatment includes reducing dietary potassium (29). Blood levels above 6 mmol/L could be life threatening. Your doctor will conduct other tests such as an electrocardiogram.
Based on those tests your doctor may use intravenous calcium, insulin, or even dialysis to reduce potassium levels (29).
How do I get some of the potassium out of my favorite high-potassium vegetables?
It’s possible to boil vegetables in water to leach out some of the potassium; however, this should only be done with foods already low in potassium and under the guidance of your doctor.
Basic leaching involves boiling vegetables in 10 times the volume of water compared to the volume of vegetables (3). As an example you’d boil 3 cups of broccoli in 30 cups of water.
Clearly leaching requires some monster sized pots that you might not want to deal with.
You can do this with smaller pans but it may require a few boiling and draining cycles.
See the cookbooks for low potassium cooking in the “Where Can I Find Out More” section below.
Foods that are low in potassium
- White bread
- White pasta
- White rice
- Some fruits – apples, blueberries, grapes, pears
- Don’t eat dried fruit or fruit baked into pastries – see high potassium food products above. Dried fruits like dried apricots or condensed tomato paste are some of the highest potassium containing foods and are easy to eat.
Potassium Concentrations Source (30)
How much potassium should you take?
Less than 5% of men get the recommended 4700 mg per day and less than 2% of adults overall get it (31).
21 countries studied and intake of potassium was less than recommended. Intake ranged from 1.7 g/day in China to 3.7 g per day in Poland, Netherlands, and Finland (32).
Sodium and potassium go hand in hand. The WHO recommends a 1:1 intake of sodium to potassium but at 3510 mg/day of potassium, that would be too much sodium. The FDA found that the average intake of sodium for US adults is already at 3400 mg/day (33). While increasing potassium to 3400 mg/day is ideal, lowering sodium to 2300 mg/day is recommended (33).
What is a normal amount of potassium intake per day for the average healthy individual?
The World Health Organization (WHO) recommends 3510 mg/day for adults (4)
WHO – children should reduce from 3510 mg/day based on their size and and energy requirements. [add formula] (4).
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What kinds of potassium dietary supplements are available?
Your first step for increasing potassium should always be through your diet. See the common high potassium foods listed above.
Some of the highest potassium foods include beans, root vegetables, leafy greens, fish, and dried fruit.
If you still want to increase potassium levels with supplement, make sure to consult with your doctor first, especially if you are already taking blood pressure medications. Some medications reduce potassium in your blood while others increase it (34). You don’t want to induce hyperkalemia by taking supplements.
Due to the danger, most supplements in pill form have very limited potassium amounts. While the daily recommended dose varies is 4,700 mg per day, most supplements have only 100 mg of potassium (34). Taking supplements regulated by the FDA shouldn’t pose a great danger.
Potassium salt (a salt substitute), found at most grocery stores is where you can get into trouble.
You could easily ingest hundreds of mg of potassium using potassium salt as there’s nothing stopping you from using as much as you want.
The cost effective solution is to use potassium salt, just be careful to measure what you use and keep your daily intake at 100 mg or less. For that we recommend this brand.
It contains 690 mg of potassium per ¼ teaspoon. Use very sparingly! If you are already eating high potassium foods listed in the section above you should use table salt instead.
The FDA controlled solution is to use potassium supplements and follow the directions on the label. For that we recommend this brand.
Again, potassium supplement is not as ideal as eating higher potassium foods. You’ll get greater benefits for your health if you eat more leafy greens, beans, and fruit for potassium than if you just take supplements.
Where can I find out more about potassium?
Read the WHO guide on potassium here.