Dear Doctor: Our dad is a meat-and-potatoes guy who always skips the vegetables. But he’s crazy about his grandkids and wants to see them grow up. I just read about a study where people who ate vegetables live longer. Can you tell us about it? It might help persuade our dad.

Dear Reader: The links between improved health and a diet rich in fresh vegetables, leafy greens and fruit are quite strong. Numerous studies over the course of decades continue to reveal an array of health benefits. These include improved blood pressure and blood lipid levels; lower risk of heart disease and certain cancers; better blood glucose control; and improved gut health. Now, a team of researchers from the Harvard School of Public Health in Boston has added longevity to that impressive list.

The new study you’re asking about appeared in March in the journal Circulation. It took the veggies-are-good health claims a step further by getting specific about how many daily servings give you a better shot at a longer life. The authors found a connection between eating five servings of vegetables and fruits per day and a longer life span.

To reach that conclusion, researchers analyzed health and behavioral data from two different decadeslong health studies. They selected 66,719 women from the Nurses’ Health Study, which is a collection of 30 years of information about lifestyle factors, behaviors and personal characteristics, and the incidence of more than 30 diseases during the course of the research. They also used 28 years of data from the all-male Health Professionals Follow-up Study, from which they selected 42,016 men. To be included in this new research, each participant had to have been free from diabetes, cardiovascular disease and cancer at the start of their respective studies. They also had to have been diligent in reporting their dietary intake. Any significant gaps in that reporting disqualified them from being included in the new study.

Once the researchers crunched the numbers, they found the optimal consumption to be three servings of vegetables and two servings of fruit per day. The groups who reported eating those amounts had a reduced risk of death from any cause -- 13% less -- than those who ate two or fewer servings. The reduced risk of death from heart disease was 10%, and the risk of death from a respiratory illness was 35% lower. While eating more than those five servings was fine, it wasn’t associated with additional longevity. And apologies to you potato and fruit juice lovers, but these foods were not associated with the same health benefits.

So how do you measure servings? A small to medium-sized fruit -- such as an apple, peach or a pear -- is considered a single serving. If you’re eating berries or melon, it’s 1 cup. A serving of cooked vegetables is 1/2 cup, and for fresh leafy greens, it’s 1 cup.

We hope that this newest addition to the veggies-are-good canon of research helps you in your quest to get more fresh foods on your dad’s plate.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I’m a 52-year-old man, and I find that lately I have to urinate more often. My doctor says that it’s overactive bladder. I thought that’s something that happens to women. Why am I getting it? My doctor says it’s not because of my prostate.

Dear Reader: It’s true that many types of bladder issues, including overactive bladder, tend to be more common in women than in men. This is attributed to life events that are unique to women, including pregnancy and childbirth, and the hormonal changes that accompany menopause.

But, as you have now experienced, bladder problems occur in men as well. A gender-specific cause of overactive bladder in men does include an enlarged prostate. This can occur because the prostate sits just below the connection point of the bladder and the urethra, which is the tube through which urine exits the body. If the prostate presses against the urethra and impedes the flow of urine, it can lead to irritation that causes the bladder to contract. This can create the need to go, even when only small amounts of urine are present.

Overactive bladder, also referred to as OAB, isn’t a disease in and of itself. Rather, it’s a collection of symptoms related to urinary control. One of the more common signs of overactive bladder is the increased frequency that you have developed. Most people empty their bladders somewhere in the neighborhood of eight times every 24 hours. Another in the group of symptoms is something known as urinary urgency. That’s when, once your body signals the need to urinate, you pretty much have to go right away. When the signal to urinate is accompanied by leakage, that’s known as urge incontinence. And if you’re heading to the bathroom multiple times a night, it’s called nocturia. Someone with one or more of these symptoms is considered to have an overactive bladder.

In both women and men, being overweight, which increases abdominal pressure, can play a role in developing an overactive bladder. So can weak pelvic muscles, which can be caused by pregnancy and childbirth, as well as chronic constipation, coughing, prolonged sitting and aging. Certain medications can contribute to the condition, as can caffeine and alcohol. In some cases, an overactive bladder can be an indication of an underlying problem, such as a urinary tract infection. Neuromuscular diseases, such as multiple sclerosis or Parkinson’s disease, often have an effect on bladder control. Due to nerve placement, a herniated disc or the effects of pelvic of back surgery can also contribute to OAB.

Treatment usually begins with lifestyle changes. This includes reaching and maintaining a healthy weight and doing regular exercises to strengthen the pelvic floor. Your doctor may also discuss bladder training, which is a series of techniques designed to help you learn to delay urination. In more severe cases, nerve stimulation, a range of medications and surgery may be an option. Because the condition can be a sign of bladder stones, nerve damage and even bladder cancer, it’s wise to check with a health care professional if symptoms develop.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I’ve had both doses of the Moderna vaccine, and my husband just got the Johnson & Johnson shot. Does this mean we can stop wearing masks? What does being vaccinated mean in terms of what we are safe to do now?

Dear Readers: With vaccinations taking place nationwide, we’ve entered a new stage of the pandemic. And just as when the coronavirus first began to spread throughout the world, we’re learning the answers to important questions about health, behavior and risk in real time.

You’ve asked one of the biggest questions we’re hearing lately, which is what fully vaccinated people can safely do. The fact is, until enough reliable data has been acquired and analyzed, we have only a broad picture of the do’s and don’ts of post-vaccine behavior. As time passes and we continue to learn and understand more, information about safe behaviors will continue to be fine-tuned.

When you get the vaccine, it takes two weeks after your final dose for immunity to kick in. Even then, though, you’re not home free. None of the three vaccines is 100% effective, which means that although the risk of infection and illness are greatly reduced, they have not been completely eliminated.

Another unknown is if people who have been vaccinated can still spread the virus. On that front, there’s encouraging news: Analysis of health data from 4,000 health care professionals, first responders and other front-line workers suggests that when people are fully inoculated, they are unlikely to spread the virus. To be certain, though, more research is needed. We’ll share updates as they become available.

To answer your question about what it is safe to do, the Centers for Disease Control and Prevention (CDC) has put together some general guidelines. The federal agency says that when out in public, everyone, including those who have been fully vaccinated, should continue to wear a mask and to practice social distancing. You should also continue to steer clear of crowded and poorly ventilated spaces. When it comes to private gatherings, the restrictions we’re familiar with have been somewhat relaxed.

Someone who has been fully vaccinated can attend small indoor gatherings with other vaccinated individuals without wearing a mask or staying 6 feet apart. The CDC says that these small groups may include unvaccinated individuals as long as they are from a single household and are not at high risk of severe COVID-19. “High risk” refers to someone who is 65 and older or has a health condition such heart disease, autoimmune disease, diabetes or cancer. It is recommended that you not gather indoors with unvaccinated individuals from multiple households. If a fully vaccinated individual comes into contact with someone who has COVID-19, they do not need to isolate or get tested, unless they develop symptoms.

When it comes to things like dining out, travel or going to the movies or a concert, we each have to do our own risk assessment. We know it’s been a long, hard year. But as you reenter the wider world, we urge you to be conservative in your choices, and err on the side of caution.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)