Dear Doctors: I love walking and do at least 2 miles per day. I have followed the endless debate about how many steps per day is best with great interest. Apparently, there's a new study that says the goal should be stamina and not steps? I'm not sure I understand, and I would like to know more.

Dear Reader: First, congratulations on having such a healthy habit in your daily life. Walking burns calories, supports cardiovascular health and helps with balance, flexibility and range of motion. It aids in blood sugar control and helps you maintain a healthy weight. It releases endorphins, improves mood and has been shown to play a role in improving cognition. It's free. You need only a pair of supportive shoes and weather-appropriate clothing, and you can do it almost anywhere at any time.

Walking seems an unlikely exercise to generate debate. But as you point out, that’s exactly what happened with the near-mythic 10,000 steps. This number was interpreted as the ideal amount of walking per day. That number actually comes from a Japanese advertising campaign that, in 1965, promoted a brand of pedometer. More recent studies have challenged the 10,000 steps, coming in both lower and higher. Now, new research suggests it’s not total steps that matter most to heart health. It’s the length of time spent walking at a steady pace that is most important.

Researchers in the United Kingdom looked at two years of health data collected from 33,560 healthy adults who walked at least 8,000 steps per day. The participants, with an average age of 62, were among the more than half-million volunteers in a long-term health study called U.K. Biobank. The walkers were asked to wear fitness trackers for between three and seven days. Rather than analyzing the resulting tracking and health data solely in terms of the number of steps each person took, the researchers also created categories for the duration of each walk.

They found that individuals whose walks lasted about 15 minutes had a lower risk of developing cardiovascular disease than those who got their 8,000 steps through shorter walks. There was also a lower rate of death from any cause in the longer walkers. Because they all walked at least 8,000 steps per day, the researchers concluded that the disparity in health outcomes came down to the main difference between the groups, which was walk duration.

Why would duration matter? It takes time for the body to shift into exercise mode. As it makes the switch, heart rate rises, blood vessels dilate and blood flow increases. Muscles make the transition from sedentary to engaged, which means they begin to use fuel. As all of this happens, the metabolic and anti-inflammatory effects that help protect the heart and circulatory system begin to kick in.

The bottom line: Steps do matter, but duration may be even more important. By giving the body’s finely tuned systems time to warm up, the study suggests that the ordinary motion of walking has the potential to become a heart-protective habit.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

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Dear Doctors: I just had my yearly physical, and my blood pressure has moved into the upper range of normal. The idea that it may be increasing is worrying me. I prefer not to take medications, so I want to get ahead of this. What can I do to lower my blood pressure naturally?

Dear Reader: Your instinct to take this change seriously is well-founded. Blood pressure is an important metric of good health, and an upward trend, even within guidelines, can be concerning. High blood pressure, also known as hypertension, makes your heart work harder. It also stresses blood vessels. Over time, uncontrolled hypertension can increase the risk of heart disease, heart attack and stroke. It also increases risk for kidney disease, plaque build-up in the arteries, sexual dysfunction and vision loss. More recently, research has found that chronic high blood pressure can play a role in cognitive decline.

The good news is that a range of lifestyle choices can help bring blood pressure into a normal range. These include regular physical activity, a healthier diet, getting enough good-quality sleep and managing stress. No doubt these guidelines sound familiar, which can make them easy to acknowledge and then set aside. But the key to successfully lowering blood pressure is making them into daily habits. Incorporating even a few can lead to meaningful improvements in your health. And -- more good news -- it can happen faster than you might think. Many people begin to see a positive trend in blood pressure within weeks of adopting more healthy habits.

When it comes to diet, limit salt. Dietary guidelines recommend that adults not exceed 2,300 mg of sodium per day. That's close to only a teaspoon. To stick to this limit, pay close attention to added salt in prepared foods. Cutting back on highly processed foods, which are high in salt and low in nutrients, is also key. Replace them with whole, fresh foods, including leafy greens, vegetables, fruit, beans, legumes, grains, healthy oils, seafood and lean proteins. Limit alcohol and quit tobacco.

Although sodium gets headlines when it comes to improving blood pressure, potassium is equally important. This mineral helps the body excrete sodium. It’s part of a biochemical process that relaxes blood vessel walls. For best results, potassium intake should at least match sodium intake and ideally exceed it. Following the DASH diet, the fresh food eating plan we wrote about quite recently, is an excellent way to lower sodium and increase potassium.

It is also important to get moving with a mix of aerobic exercise, resistance training and stretching. The goal is 150 minutes per week in sessions of at least 10 minutes each. Exercise improves sleep, which also helps with healthy blood pressure. Regular exercise has also been shown to help manage stress. Yoga, tai chi, deep breathing and meditation can be useful. And remember, you don't have to do this all at once. Start small, build gradually and give your body time to adjust and to respond.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Hello, dear readers! Welcome to the monthly letters column. We hope the new year is treating you well, and that those who made resolutions are having a few victories. Forming new habits continues to be a popular topic, and we'll explore new research in an upcoming column. And now, on to your mail.

-- A column about the use of Botox to help manage migraines continues to generate interest. We heard from a reader in Virginia who suffers from this debilitating form of headache. “I get vicious migraines at least eight times per month. They start at the nape of my neck, and the pain moves forward to behind my right eye,” she wrote. “Do either the symptoms or how often this happens mean I can be referred for Botox therapy?”

According to current U.S. Food and Drug Administration guidelines, Botox is reserved for chronic migraine. This is defined as 15 or more headache days per month, with at least eight of those days meeting criteria for migraine. If you were to experience seven more headache days per month on top of the migraine days you described, you would meet the criteria to be eligible for treatment with Botox.

-- The phantom ringing, buzzing and chiming sounds of tinnitus are a challenge for many older adults. A reader from upstate New York wrote to say he had good results from a popular dietary supplement that combines vitamin C, B vitamins and naturally occurring plant compounds known as bioflavonoids. “I got a few friends who have tinnitus to try it, but it didn’t work for them at all,” he wrote. “It did work for me. Any idea why that would be?”

While there are various claims regarding the use of dietary supplements to lessen the sounds of tinnitus, studies have produced inconclusive results. Tinnitus often fluctuates over time, which can create the perception that a particular treatment is helping. We should also consider the placebo effect, a powerful response by the body. Centuries after it was first identified, we still don’t fully understand it. In your case, what matters is that the supplement you are using is not harmful to health, and that the outcome is an improvement to a challenging condition.

-- A column about the benefits of walking prompted a reader to ask for a definition. “I am 80 years old and walk twice a day for 20 to 30 minutes. The advice I always see says to walk briskly,” he wrote. “Just how fast is brisk?” While the term “brisk walk” suggests a certain speed, what you’re really after is a specific effect on the body. The goal is to modestly raise your heart rate without strain or pain. You should feel a bit of exertion but still be able to carry on a conversation. Also, some good news. Your 20-minute time frame aligns with newer research showing cardiovascular benefits from sustained walking.

Thank you, as always, for taking the time to write. We love hearing from you. Our email address is askthedoctors@mednet.ucla.edu. We read all your letters and look forward to hearing from more of you.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)