Hypertension Dietary Guide: Hidden Sodium, FDA Label Changes, and the Salt You Don't See

Blood pressure is recorded as two numbers: systolic (pressure when the heart beats) over diastolic (pressure between beats). The American Heart Association and the 2017 ACC/AHA guidelines define:

• Normal: less than 120/80 mmHg
• Elevated: 120-129 systolic, less than 80 diastolic
• Stage 1 Hypertension: 130-139/80-89 mmHg
• Stage 2 Hypertension: 140/90 mmHg or higher
• Hypertensive Crisis: above 180/120 mmHg

Sodium drives blood pressure through osmotic pressure. Higher blood sodium concentration pulls water into the bloodstream, increasing blood volume. The heart must work harder to pump that volume, and arterial walls experience greater pressure. Over time, this damages artery walls, accelerating atherosclerosis, and straining the heart muscle.

About 60 percent of people with hypertension are "salt-sensitive," meaning their blood pressure responds directly to sodium intake. The remaining 40 percent are "salt-resistant" and show minimal blood pressure response to sodium changes, but they represent a minority, and clinical guidelines apply population-wide targets rather than attempting to identify individual responders.

The Dietary Approaches to Stop Hypertension (DASH) trial, published in the New England Journal of Medicine, found that a diet rich in fruits, vegetables, low-fat dairy, and reduced saturated and total fat lowered systolic blood pressure by an average of 5.5 mmHg and diastolic by 3.0 mmHg compared to the control diet in participants with normal blood pressure. In participants with hypertension, the DASH diet reduced systolic blood pressure by 11.4 mmHg, comparable to the effect of a single antihypertensive medication.

The follow-up DASH-Sodium trial specifically tested the interaction of diet pattern and sodium level. At the lowest sodium level tested (1,500 mg/day), the combination of the DASH diet and low sodium produced a systolic reduction of up to 8.9 mmHg compared to the high-sodium control diet among participants without hypertension, and over 11 mmHg in those with hypertension.

The DASH diet prioritizes:

• 4 to 5 servings of vegetables per day
• 4 to 5 servings of fruit per day
• 2 to 3 servings of low-fat dairy per day
• 6 to 8 servings of whole grains per day
• 6 or fewer servings of lean meat, poultry, or fish per day
• 4 to 5 servings of nuts, seeds, or legumes per week
• Limited sweets, added sugars, and sodium

The diet is potassium-rich by design. Potassium counters sodium's blood pressure effects by increasing urinary sodium excretion and relaxing blood vessel walls. The FDA Daily Value for potassium is 4,700 mg, but most Americans consume only about 2,600 mg per day.

FDA regulates sodium claims under 21 CFR 101.61. The official thresholds are:

Sodium-Free / Zero Sodium: less than 5 mg per serving

Very Low Sodium: 35 mg or less per serving

Low Sodium: 140 mg or less per serving

Reduced Sodium / Less Sodium: at least 25 percent less sodium per serving than the regular reference food

Light in Sodium / Lightly Salted: at least 50 percent less sodium than the regular version

No Added Salt / Unsalted: no salt (sodium chloride) added during processing. This does not mean the product is sodium-free, natural ingredients like dairy, vegetables, and grains all contain inherent sodium.

The key practical insight: a "low sodium" product can still contain 140 mg per serving, and if you eat three servings, you have consumed 420 mg of sodium, nearly 30 percent of most adults' recommended daily limit from one food.

In 2021, FDA issued its Phase I voluntary sodium reduction goals targeting a 2.5-year average, seeking to bring the US average sodium intake from approximately 3,400 mg/day down to 3,000 mg/day. These targets were category-specific, covering over 160 categories of packaged and restaurant food. They were voluntary: manufacturers and food service operators were asked but not required to comply.

In 2024, FDA published Draft Guidance for Phase II, which proposes reducing average intake to 2,750 mg/day over an additional 2.5 years. Both targets remain well above the American Heart Association's recommended limit of 1,500 mg/day for adults with hypertension.

For context: the Dietary Guidelines for Americans 2020-2025 recommend less than 2,300 mg of sodium per day for adults. WHO recommends less than 2,000 mg/day. Most adults in the US consume 3,400 mg/day.

About 70 percent of Americans' dietary sodium comes from processed and restaurant foods, not the salt shaker. Many of these sources are invisible on casual label review:

Bread and baked goods: A single slice of commercial bread can contain 100 to 200 mg of sodium, and bread is the leading source of sodium in the American diet by sheer volume consumed. A sandwich using two slices and deli meat can easily deliver 1,000 to 1,200 mg of sodium.

Cottage cheese: 400 to 500 mg per half-cup serving, more than many processed snack foods.

Canned tomato products: Canned diced tomatoes contain 300 to 400 mg per half-cup. Tomato sauce: 400 to 500 mg. Tomato juice: up to 700 mg per 8 ounces.

Soy sauce and tamari: Standard soy sauce contains approximately 900 to 1,000 mg per tablespoon. "Reduced sodium" soy sauce still contains approximately 600 mg.

Monosodium glutamate (MSG): Contains about 12 percent sodium by weight, compared to table salt at 39 percent sodium. FDA requires MSG to be listed by name in ingredients.

Sodium in unexpected forms on ingredient lists:

• Sodium benzoate (preservative)
• Sodium bicarbonate (baking soda, leavening)
• Sodium citrate (pH control)
• Sodium nitrate / nitrite (curing agent in processed meats)
• Sodium phosphate (stabilizer, common in processed cheese)
• Disodium inosinate (flavor enhancer, often combined with MSG)
• Disodium guanylate (flavor enhancer)
• Sodium alginate (thickener in dairy analogs)
• Sodium lauryl sulfate (in some baked goods)

These forms of sodium do not appear in the overall "Sodium" line on the Nutrition Facts panel alongside table salt, they are all included in that total. But consumers who scan labels for the word "salt" miss them.

Restaurant food: A single restaurant meal frequently contains 2,000 to 3,000 mg of sodium. Menu labeling rules (effective 2018) require large restaurant chains to post calorie counts, but sodium is not required to be disclosed to customers unless specifically requested.

The United Kingdom uses "salt" rather than "sodium" as the standard unit on food labels. Salt is sodium chloride, and the conversion is: salt = sodium x 2.5.

The Food Standards Agency in the UK uses a traffic light system on the front of pack for salt content:

• Green (low): less than 0.3g salt per 100g
• Amber (medium): 0.3g to 1.5g salt per 100g
• Red (high): more than 1.5g salt per 100g

This front-of-pack system is voluntary in the UK but widely adopted by major retailers and manufacturers. When comparing UK and US labels for the same product, you must convert: to convert a UK salt figure to sodium, divide by 2.5.

An Australian or Canadian product listing "sodium 400 mg" and a British equivalent listing "salt 1.0g" represent the same sodium content (400 mg sodium × 2.5 = 1,000 mg salt = 1.0g salt). Both systems describe the same food; understanding the conversion prevents double-counting.

FDA updated the Nutrition Facts panel in 2016 to make potassium a mandatory declaration, reflecting its established role in blood pressure regulation. The current Daily Value is 4,700 mg.

Potassium is found in high concentrations in bananas (422 mg per medium banana), white beans (829 mg per half cup), spinach (839 mg per cup cooked), sweet potato (542 mg per medium), and avocado (708 mg per medium). These are naturally occurring potassium sources that require no label checking.

For processed foods, the Nutrition Facts panel lists potassium content in milligrams and as a percentage of Daily Value. A food with 15 percent or more of the potassium Daily Value (705 mg) can be labeled a "good source of potassium."

One critical warning: individuals with chronic kidney disease should NOT increase potassium intake without medical supervision. Impaired kidneys cannot excrete excess potassium, and hyperkalemia (high blood potassium) can cause fatal cardiac arrhythmias. The dietary guidance for hypertension and kidney disease directly conflicts in this respect.

Potassium chloride is the most common sodium chloride substitute in "reduced sodium" and "no salt added" products. It delivers the same salty taste mechanism with less cardiovascular risk for most people.

However, potassium chloride is not universally safe:

• Kidney disease patients cannot safely use potassium chloride salt substitutes, as their kidneys cannot excrete the excess potassium
• Patients on ACE inhibitors or ARBs (first-line hypertension medications) are already at elevated potassium levels; additional dietary potassium from salt substitutes can push them into hyperkalemia
• Potassium-sparing diuretics (spironolactone, amiloride) similarly increase hyperkalemia risk when combined with potassium chloride

On ingredient lists, potassium chloride may appear as potassium chloride, KCl, or "potassium salt." It is increasingly common in commercial bread, soups, and snack foods as manufacturers reduce sodium to meet FDA voluntary targets.

This section is designed to work as a standalone reference when reading food labels for sodium management.

Ingredients and Additives to Avoid

The following ingredients contribute sodium or raise blood pressure and should be flagged when managing hypertension:

Direct sodium contributors (limit strictly; cumulative mg matters)

• Salt / sodium chloride (NaCl)
• Monosodium glutamate (MSG / E621)
• Sodium benzoate (E211; preservative)
• Sodium bicarbonate / baking soda (E500)
• Sodium citrate (E331)
• Sodium nitrate (E251) / sodium nitrite (E250), cured and processed meats
• Sodium phosphate / disodium phosphate / trisodium phosphate (E339)
• Sodium alginate (E401)
• Sodium ascorbate (E301)
• Sodium propionate (E281; bread preservative)
• Sodium sulfite (E221) / sodium metabisulfite (E223)
• Disodium inosinate (E631) + disodium guanylate (E627), flavor enhancers, often paired with MSG
• Sodium stearoyl lactylate (E481; common in baked goods)
• Sodium caseinate (dairy protein derivative in non-dairy creamers)

High-sodium processed food categories (read labels carefully; avoid high-sodium versions)

• Canned soups and broths (target under 400 mg per serving)
• Processed and deli meats (salami, bologna, ham, hot dogs)
• Pickled and fermented foods (pickles, sauerkraut, olives, kimchi)
• Soy sauce, teriyaki sauce, fish sauce, oyster sauce
• Seasoning packets and bouillon cubes
• Instant noodles and ramen
• Commercial bread and rolls (100-200 mg per slice)
• Cottage cheese and processed cheese (300-500 mg per serving)

Misleading label claims to scrutinize

• "No added salt" / "unsalted" (natural sodium from ingredients still present)
• "Reduced sodium" (only 25% less than the regular version, still potentially high)
• "Lightly salted" (unregulated; no defined sodium threshold)
• "Healthy" (FDA definition does not require low sodium for all product categories)

Step-by-step checklist:

1. Check the serving size first. The sodium figure on the panel is per serving. A can of soup that shows 800 mg per serving may contain 1.5 or 2 servings. Always multiply by how much you will actually eat.

1. Read the Sodium line in milligrams, not percent. The Daily Value for sodium is 2,300 mg. For hypertension management, use the absolute milligram figure, your personal target (1,500 to 2,000 mg/day) may be lower than the reference DV.

1. Scan the ingredient list for all sodium forms. Every chemical form in the avoid list above contributes to the total sodium declared on the panel. Products using multiple sodium forms are often higher in sodium than products using only salt.

1. Prioritize potassium-rich foods. Potassium directly counters sodium's blood pressure effects. The Daily Value is 4,700 mg. Target foods showing 15% DV or more for potassium.

1. Convert UK/EU "salt" figures to sodium. British and European labels report "salt" in grams. Divide by 2.5 (or multiply by 0.4) to get the equivalent sodium in mg.

IngrediCheck can identify the cumulative sodium load across all chemical forms in an ingredient list, flag high-sodium categories, and alert you when "reduced sodium" or "no added salt" claims may not meet your personal daily target.

If you have both hypertension and chronic kidney disease, a frequent combination, be aware that kidney patients face an additional hazard: the Kidney Disease Dietary Guide explains why potassium chloride salt substitutes, often recommended for high blood pressure, can be dangerous when kidney function is reduced.

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