The kidneys are two bean-shaped organs, located below the rib cage, one on each side of the spine. Your kidneys have several important functions, and well-functioning kidneys are essential to your overall health. What you may not know about kidneys, however, is that there is a direct link between kidneys and blood pressure.
Healthy kidneys work to filter blood, removing waste and extra fluid to make urine. Your kidneys also maintain a balance of water, salt, and minerals in your body, and produce hormones that control your blood pressure. Not only do your kidneys play a role in regulating blood pressure, your blood pressure, in turn, can affect the health of your kidneys.
In this article, we share the surprising connection between kidneys and blood pressure and strategies for maintaining healthy blood pressure.
Blood Pressure Basics
Blood pressure is the force of blood pushing against your blood vessel walls as your heart pumps blood. According to the American Heart Association, blood pressure higher than 130/80 mmHg is considered hypertension, and lower than 120/80 mmHg is considered normal. The first number in a blood pressure reading is called systolic pressure. Systolic pressure represents the pressure your blood puts on your blood vessels when your heart beats. Diastolic pressure is the second number in your blood pressure reading. This number represents the amount of pressure on your blood vessels between heartbeats.
Your Kidneys and Blood Pressure
Hypertension can damage your kidneys over time by causing arteries that deliver blood to the kidneys to narrow, weaken or harden. Hardened arteries reduce the amount of blood delivered to the kidneys, which leads to damage. For these reasons, hypertension is the second leading cause of kidney failure. Years of uncontrolled hypertension can lead to serious health consequences. Some people call hypertension the “silent killer” because it generally does not have symptoms.
Diet and Lifestyle for Managing Your Blood Pressure
Keeping your blood pressure in check is a great way to keep your kidneys healthy. The best way to keep your blood pressure in the normal range is by making lifestyle changes such as eating a healthful diet, exercising regularly, reducing stress, and limiting alcohol and caffeine.
5 Diet Tips for Lower Blood Pressure
The DASH (Dietary Approaches to Stop Hypertension) Eating Plan is well known for its blood pressure lowering benefits. The DASH plan has also been shown to reduce the risk of heart disease, stroke, diabetes, kidney stones, and other chronic conditions.
A Mediterranean style diet has also been shown to lower blood pressure. Several studies have found that sticking to a Mediterranean style of eating may decrease the risk of heart disease, stroke, diabetes, and certain cancers, and it may even boost cognitive functioning in older adults.
The DASH and Mediterranean plans are quite similar. They both focus on plant-based whole foods such as vegetables, fruits, whole grains, and nuts, combined with lean meats, fish, and poultry, and heart-healthy fats. It’s no wonder that U.S. News and World Report chose Mediterranean and DASH as the best two overall diet plans for 2019, and there is now a plan called the DASH Diet Mediterranean Solution. Here are some tips for combining the best of these two plans to lower your blood pressure.
1. Focus on vegetables and fruits
Vegetables and fruits should be the base of any healthy diet. They are rich in fiber, phytonutrients, vitamins, and minerals, and have numerous health benefits. Studies have linked diets high in vegetables and fruits to a decreased risk of some cancers, heart disease, stroke, and other diseases. One nutrient that may be partially responsible for their blood pressure lowering effect is potassium. Higher intakes of potassium have been linked to lower blood pressure.
Aim to include vegetables and fruit at each meal. For example, add spinach or sliced tomatoes to eggs, or have fruit with your whole grain cereal or yogurt for breakfast. Have sliced vegetables and hummus or a salad with your sandwich at lunch.
2. Include heart-healthy fats
Focus on choosing the right types of fat, rather than the total amount of fat. The Mediterranean diet is rich in monounsaturated (think olive oil and avocados) and polyunsaturated (think salmon or other fatty fish, walnuts, flaxseeds) fats. Include a source of heart-healthy fats in each meal. For example, slice part of an avocado on whole grain toast for breakfast. Have a handful of nuts, or seeds, or some peanut butter with an apple for a snack. Eat fatty fish such as salmon, mackerel, herring, sardines, and albacore tuna at least twice a week. Add a side of vegetables sautéed or roasted with olive oil, garlic, and other herbs and spices.
3. Choose whole grains
Whole grains, as the name indicates, contain all three parts of the grain- the germ, bran, and endosperm. Refined grains such as white rice, bread, and pasta, include only the endosperm. Unlike refined grains, whole grains are rich in fiber and other nutrients and have been shown to lower blood pressure. Diets rich in whole grains may contribute to a reduced risk of heart disease, diabetes, and some cancers. Examples of whole grains include quinoa, oats, barley, brown rice, and whole wheat or other whole grain bread, cereal, and pasta.
4. Go easy on sodium (salt)
The relationship between sodium and blood pressure isn’t obvious. The American Heart Association estimates that just over half of all people with high blood pressure are “salt sensitive,” so eating less salt will help lower their blood pressure. For the other half, decreasing salt intake is not likely to impact their blood pressure.
Eat a diet rich in whole foods (like vegetables, fruits, and whole grains), and limit highly processed or pre-packaged foods to reduce sodium intake and manage blood pressure. These foods are rich in potassium, magnesium, and calcium, key minerals that help control blood pressure. When choosing packaged foods such as nuts, look for unsalted or reduced salt options.
5. Limit sugar-sweetened foods and drinks
When you think of excess sugar, you may think of weight gain or diabetes, not high blood pressure. It turns out, recent studies have shown that diets high in added sugars increase blood pressure. It seems that sugar-sweetened beverages such as soda are one of the main culprits. One study found that lowering sugary drinks by just one serving a day decreased blood pressure. The blood pressure raising effect seems to be specifically from sugar, not caffeine.
To lower your intake on added sugars, pass on soda and other sugary drinks, and limit cakes, cookies, or other sweets to special occasions. Pay attention to nutrition labels on packaged foods, many of which now list added sugars.
Add more vegetables, fruits, whole grains, and heart-healthy fats to your diet and reduce processed foods that are high in salt and sugar. These dietary practices will help you lower your blood pressure and keep your kidneys healthy. Combine these nutrition tips with daily physical activity and stress management techniques for best results.
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