07 | Diet: How to Eat for Effective Blood Pressure Reduction?

Hello, welcome back to the "Hypertension Medical Course." I am Jessica.

From this lesson, we enter the realm of lifestyle interventions for hypertension: diet, exercise, and stress reduction. Among these, dietary strategies are the most effective and show the fastest results. When you hear "dietary therapy," what comes to mind? Celery juice? Vinegar-soaked peanuts? Raw eggplant? Lotus seed tea? If you search online, you’ll find hundreds of so-called antihypertensive teas. These are mostly harmless, but the real danger lies in expensive health products that promise "money-back if not effective"—many are unregulated and may secretly contain unknown doses of antihypertensive drugs. Currently, there is no medical evidence supporting the effectiveness of these single foods.

The Effect of Dietary Adjustment

But that doesn’t mean dietary strategies are ineffective. Most evidence-based lifestyle interventions for hypertension are related to diet. According to the 2017 American Hypertension Guidelines, for overweight individuals, every 1 kg of weight loss lowers blood pressure by 1 mmHg; 2 kg means 2 mmHg, and this effect can accumulate up to 5–10 mmHg. Similarly, reducing heavy drinking to light drinking can lower blood pressure by 4 mmHg. These effects are additive. Tempting, right? In this lesson, I’ll share the two most effective dietary strategies: salt reduction and the DASH diet. Strategy 1: Salt Reduction Salt reduction simply means eating less salt. Global research shows that salt intake drives hypertension. In populations consuming less than 3g of salt per day, primary hypertension and age-related blood pressure increases are rare. At 3–6g per day, blood pressure rises but not enough to cause primary hypertension. Above 6g per day, hypertension is very common. In northern China, average daily salt intake exceeds 15g. What does this mean? A landmark study showed that giving chimpanzees an extra 15g of salt daily for six months raised their systolic pressure by 33 mmHg and diastolic by 10 mmHg; stopping the extra salt reversed the effect. So, how much salt should you eat? First, reduce daily salt intake to 3.5–6g. If you have hypertension without complications like coronary heart disease, heart failure, or stroke, keep it under 6g per day. But less is not always better—below 3.5g, your body may not get enough, leading to fatigue. Second, eat more potassium-rich foods. Sodium and potassium are a balancing pair for blood pressure. Increasing potassium intake counteracts sodium’s effects. Studies show potassium-rich diets can lower blood pressure by 4 mmHg. Sources include fresh vegetables, fruits, nuts, and legumes. For example, two oranges contain 0.5g of potassium and no sodium. Sounds easy—just use less salt and eat more potassium-rich foods, right? Not quite. The hardest part isn’t using less salt when cooking, but avoiding hidden salt in your diet. I divide these into three categories: First, condiments. Soy sauce, chicken essence, MSG, oyster sauce, ketchup, bean paste, sweet sauce, chive flower sauce, fermented tofu—all contain lots of salt. You can’t avoid them all, but be sure to count them in your daily salt total. Second, processed foods. Pickles, sausages, cured meats, smoked meats, dried tofu, and some fast foods (burgers, sandwiches, fried chicken, hot dogs, fries, instant noodles) are all high in salt. Even noodles—100g of dried noodles can contain 0.6g of salt, and some "springy" noodles have up to 1.2g due to added baking soda. Third, sweets. "To make it sweet, add some salt." Ice cream, cakes, puddings, milk tea, egg tarts, sweet-and-salty dishes, nuts, and preserved plums are all surprisingly salty. These are the pitfalls of salt reduction. But if you want both taste and health, here are some tips: First, gradually use smaller salt spoons and know how many grams each holds. Chinese cooking rarely measures salt by grams, but by spoonfuls. Using smaller spoons naturally reduces intake. A large-scale study in Shandong found that this simple change lowered systolic pressure by 5.3–10.9 mmHg. Second, use strong-flavored seasonings to enhance taste. Add more vinegar, chili, Sichuan pepper, star anise, or pepper to enrich flavor. I especially recommend chili—not only does it mask reduced saltiness, but capsaicin also has cardiovascular benefits. Add more tomatoes, cilantro, scallions, ginger, and garlic. Third, always check food labels on processed and sweet foods. If sodium exceeds 0.4g per 100g, avoid it; choose foods with less than 0.12g per 100g. Finally, choose fresh ingredients whenever possible. The fresher the food, the less salt you need. Over time, your taste buds will adjust, and you’ll be satisfied with less salt. If you stick to a low-salt diet, your blood pressure will likely drop by 4–6 mmHg after four weeks.

Strategy 2: The DASH Diet

The DASH diet (Dietary Approaches to Stop Hypertension) is the best dietary pattern for lowering blood pressure. On its own, it can lower systolic pressure by an average of 11 mmHg—equivalent to a dose of antihypertensive medication. It also helps with weight loss, diabetes, and cardiovascular disease. It’s been ranked the best diet in the U.S. for ten consecutive years. I recommend it especially because it suits Chinese eating habits. The DASH diet is based on staple foods, making it easy to follow. The salt reduction requirements are the same as above; the core is balanced proportions. For example, if you need 2,000 kcal per day, divide it as follows: - Whole grains: 6–8 servings (half a bowl of rice or one slice of bread per serving) - Vegetables: 4–5 servings (half a bowl per serving) - Fruits: 4–5 servings (one medium fruit per serving—apple, pear, orange, banana, etc.; don’t juice them) - Meat: 5–6 servings (30g per serving, preferably fish or shrimp; for other meats, remove skin and fat; one serving can be replaced by an egg) - Dairy: 2–3 servings (one cup, 250ml per serving, preferably low-fat or skim) - Oil: 2–3 servings (one tablespoon per serving) - Nuts: 3–5 servings per week (unsalted, unsweetened, not fried; two tablespoons per serving) Adjust according to your calorie needs. This approach naturally results in low sodium, low fat, high potassium, calcium, magnesium, fiber, and unsaturated fatty acids—all beneficial. But what if you eat out or order takeout? You can follow the DASH proportions, but what about salt? My suggestion: buy a salt meter. It measures the salt content of dishes. If it shows "low salt," eat freely; "medium salt," eat less; "high salt," avoid it. This isn’t precise, but it helps those who don’t cook.

Preview of the Next Lesson

Having covered dietary prescriptions, next time we’ll discuss exercise prescriptions for hypertension. I am Jessica. See you next time.

Key Points

Among all hypertension treatments, dietary prescriptions are the most effective and fastest-acting. Two recommended approaches: - Salt reduction: keep daily salt intake below 6g and increase potassium-rich foods. - DASH diet: base meals on whole grains, with balanced portions of vegetables, meat, dairy, and nuts.