Salt And High Blood Pressure: What You Need To Know

Salt makes for tasty food, but it's not always good for our health. It is one of the leading causes of hypertension,¹ affecting almost a third of the US population. This post explores the relationship between salt and high blood pressure and offers recommendations on reducing salt intake. 

How does salt impact blood pressure?

Salt contains 40% sodium and 60% chloride. The body needs sodium to balance water and minerals, conduct nerve impulses, and contract and relax muscles. When you consume excess salt, the body has to hold on to more water to balance the sodium concentration in the blood. The increased amount of water in the body increases blood volume. 

With more blood flowing through the arteries, your blood pressure elevates. Over time, the continued pressure on the arteries causes them to narrow and harden. The buildup of plaque can block the blood vessels, while the extra water causes bloating and imbalance in body fluid homeostasis. 

The impact of excess salt intake on blood pressure is more dramatic in people sensitive to salt. Certain factors like age, ethnicity, weight and underlying medical conditions can influence the effects of salt on your blood pressure.

The harm caused by salt also occurs quickly. Salt impairs the blood vessels' ability to dilate within half an hour² of consumption.

 Moreover, salt doesn't strain just the heart – it's a problem for the whole body. In people with high blood pressure, the kidneys hold on to excess salt instead of eliminating it. This creates new health issues, including swollen ankles and fluid buildup around the heart and lungs. 

Excess salt also threatens the brain by damaging arteries, elevating blood pressure, and increasing the risk of stroke and dementia. It may impact the brain stem, which is responsible for regulating blood pressure and salt balance in the body.

A recent study³ has shown that salt could affect the immune system. It causes inflammation, which may play a role in heart disease and other health issues. This same study suggests that salt induces inflammation and high blood pressure through its detrimental effects on gut bacteria. 

Much about the impact of salt on the human body remains a mystery. However, we do know that it affects people differently. Some people can eat salt without seeing an increase in blood pressure, and for others, a moderate salt intake triggers a spike in blood pressure. The consensus is that, for most people, cutting salt intake is good for overall wellness. 

Where does a lot of the salt in our diets come from?

The Food and Drug Administration (FDA) estimates that 70% of the sodium⁴ in our diets comes from processed, packaged, and prepared foods. America's food supply contains too much sodium, mainly because the mineral adds flavor and helps with preservation. Frozen dinners; smoked and cured meats; pickled, jarred, or canned sauces; salad dressings; and canned soups, beans, fruits, and vegetables are high in sodium.

Restaurants and manufacturers use varying sodium levels in different versions of the same foods. Always check the labels before you buy and choose products with the lowest amount of sodium. Additionally, making more meals at home rather than purchasing processed foods can help control the amount of salt in your diet. 

The rest of the salt in our diet occurs naturally or is added when cooking or eating. Dairy products, shellfish, meats, and even some vegetables contain the highest natural salt amounts. 

Some foods that naturally contain salt include:

• Meats and seafood: Ham ranks highly, with an estimated 1,203mg of sodium per 100g. A 3oz serving of ground beef can provide 60–70mg of natural sodium, while two pork sausage links may contain more than 200mg of sodium.

• Vegetables: While generally a healthy food choice, some vegetables contain elevated amounts of sodium. A single stalk of celery can provide over 30mg of sodium and adds up to 100mg per cup of the veggie. Artichokes have a sodium content of 160mg per cup.

• Eggs and dairy products: The sodium amount found in eggs and dairy products is only rivaled by meats. One egg can contain up to 170mg of sodium, mainly in the yolk. One cup of whole, reduced-fat, or non-fat milk may contain up to 100mg of sodium, while a serving of yogurt has 100–175mg.

Even with foods naturally low in sodium, last-minute salt additions account for 11% of the sodium in our diets. This may lead to excessive sodium intake if you aren't careful. Prescription and over-the-counter drugs may also contribute to sodium intake.

Guidelines and recommendations on salt amounts in our diet

According to the Dietary Guidelines for Americans, a maximum daily sodium intake of 2,300mg⁵ is sufficient for people between 14 and 50 years. The guidelines advise that individuals over 50 years old, African Americans, or people with diabetes, kidney disease, or hypertension should limit their sodium intake to 1,500mg per day. 

Other organizations make different recommendations. The American Heart Association (AHA) suggests a maximum of 1,500mg of sodium per day to reduce the risk of hypertension, heart disease, or stroke. The World Health Organization advises a higher minimum daily sodium intake of 2,000mg or 5g of salt. 

These recommendations may not apply to highly active people, for example, workers exposed to heat and competitive athletes. Such people lose more sodium due to increased sweating. Additionally, restricting sodium intake may not benefit people with normal blood pressure levels. 

Moderating daily sodium intake: What the data says

A recent review study⁶ involving 133,000 people without hypertension from 49 countries across six continents examined the impact of sodium intake on the risk of heart disease and early death. 

The review found that regardless of blood pressure, there was an increased risk of heart disease and early death among individuals who consumed less than 3,000mg of sodium each day compared to those who consumed more than 4,000mg. There were also worse health outcomes for those who consumed less than 3,000mg of sodium daily than those who consumed 7,000mg. Still, there was a greater risk of heart disease and death among those who consumed 7,000mg than those with a daily sodium intake of 4,000–5,000mg. 

These results show that sodium is not all bad; there are dangers to consuming too little sodium.  In moderation, sodium helps maintain healthy blood pressure levels and aids communication between nerve cells. A balanced diet is key to maintaining healthy sodium levels.

While future investigations may confirm the optimum sodium amount that offers the lowest cardiovascular risk, avoid ingesting less than the daily recommendation of 1,500–2,300mg daily for optimal health benefits. You should also consult a doctor for more precise dietary recommendations.

Sodium and potassium: A delicate balancing act

Sodium and potassium are closely connected and have both been linked to chronic conditions like cardiovascular disease. They also play a vital role in maintaining physiological balance. Excess salt intake can elevate blood pressure and increase the risk of heart disease. On the other hand, high potassium intake relaxes blood vessels and helps with sodium excretion, normalizing blood pressure.

The body needs more potassium than sodium. Unfortunately, the typical American diet is just the opposite. The average American gets 3,000mg of sodium and 2,900mg of potassium each day. 

Such a high sodium-to-potassium ratio can increase the risk of hypertension,⁷ heart attack, and early death.

How to reduce sodium intake and manage blood pressure

Prevention is better than cure, and limiting sodium intake is essential for managing blood pressure. But what can you do? 

Track your sodium intake

A sodium tracker is an easy tool to keep tabs on how much you consume. Simply note down what you eat and the amount of sodium it contains. Tally the total at the end of each day, and make better food choices if necessary. Keep in mind that sodium levels may vary in the same foods depending on the brand, so check labels carefully.

Understand food labels

The nutrition label lists the ingredients and tells you exactly what the food product contains. Manufacturers list ingredients in descending order. You want to avoid products with salt or sodium high on the list.

Remember that sodium comes in many forms, including salt, soda, and sodium. Some manufacturers may use terms you may not recognize, for example:

• Himalayan pink salt

• Sea salt

• Disodium inosinate (IMP)

• Disodium guanylate (GMP)

• Kosher salt

• Monosodium glutamate (MSG)

• Trisodium phosphate

Keep an eye out for claims about sodium levels on food and beverage nutrition labels, and make an informed decision. The most common sodium-related claims and their meaning are as follows:

• Salt-free or sodium-free: Contains less than 5mg per serving

• Very low sodium: Contains 35mg of sodium or less per serving

• Low sodium: Has 140mg of sodium or less per serving

• Reduced sodium: Contains at least 25% less sodium than the regular product

• Lightly salted or light in sodium: Has at least 50% less sodium than the standard product

• Unsalted or no salt added: No salt has been added during manufacturing

Some nutrition labels list ingredients and nutrients in terms of the % Daily Value (DV) or the daily recommended amount. If you're looking to reduce sodium intake, look for products with less than 5% DV of sodium. 

Aim for the foods with the lowest sodium content. If purchasing fresh fruits and vegetables, choose those without added sauces. 

Cook with less salt

Making meals at home allows you to control the amount of salt in your food. That said, some people end up adding too much salt while cooking and at the table. An easy way to avoid this is to reduce the salt amount you use to cook. Try experimenting with other seasonings like garlic, fresh or dried herbs, and lemon juice. 

Black pepper is an excellent substitute for salt when cooking pasta, fish, scrambled eggs, and soup. Try spices and fresh herbs in meat, vegetables, and pasta dishes. Baking or roasting tomatoes, courgettes, parsnips, squash, and red tomatoes will bring out their flavor while reducing the need for salt. 

Salt tips for eating out

Contrary to popular opinion, reducing salt intake when eating out or ordering a takeaway is possible. Here are a few tips to get you started:

• Order pizza with chicken or vegetable toppings rather than pepperoni, extra cheese, or bacon

• Choose pasta dishes whose tomato sauce contains chicken or vegetables instead of cheese, bacon, or sausage

• Go for plain rice when ordering Chinese or Indian food as it has less salt than egg-fried rice or pilau rice

• Avoid burger toppings with barbeque sauce, bacon, or cheese

• When ordering sandwiches, go for fillings like chicken, vegetables, egg, roasted peppers, or avocado. Replace pickle and mustard with salad or reduced-fat mayonnaise.

• Order salad dressings and sauces on the side so that you can add just what you need

• Instead of a full English breakfast, try poached eggs with grilled tomatoes and mushrooms. You can add bacon or sausage, but not both. 

More tips for reducing salt intake

• Cut down on processed and pre-prepared foods

• Reduce the portion size

• Rinse canned foods containing sodium before eating them

• Choose unsalted or low-sodium snack products, nuts, and seeds or switch to healthy snacks like carrot sticks

• Be careful with condiments and use oil or vinegar instead of bottled salad dressings

The lowdown

According to the World Health Organization,⁸ reducing salt intake to the recommended levels can prevent 2.5 million deaths worldwide each year. 

And while breaking the one-sided affair with salt may seem impossible, small dietary changes can make a huge impact. 

Start by ditching the table salt and preparing more meals at home. It's a journey like any other, and gradually implementing the above recommendations will help normalize your blood pressure.