Pages

Thursday, April 18, 2019

Mediterranean diet may help counteract age-related declines in memory and thinking skills

The release of new guidelines on mammography never fails to renew the heated controversy over the potential benefits and harms of this procedure. The latest draft guidelines from the U.S. Preventive Services Task Force (USPSTF) are no exception. Various expert bodies have already taken conflicting positions on them. You can have your say, too, if you hurry — public comment on the draft closes today.

Screening mammography is done in healthy women to spot hidden breast cancer. Some expert groups say that women should begin having regular mammograms at age 40, others set the start age at 50. The age at which women should stop having mammograms is also disputed.

The USPSTF is an independent panel of experts in primary care and prevention. It is charged with making recommendations on the use of preventive services. Its last recommendations on mammography, made in 2009, said that women between the ages of 50 and 74 should have the test every other year.

The new draft recommendations are similar to those issued in 2009, though there are some differences. The starting and ending ages for screening mammograms are the same. The new draft says there isn’t enough evidence to recommend or discourage the use of a new technique called 3-D mammography for screening. The task force also says that there isn’t enough evidence to recommend that women with dense breasts, who are at higher risk of breast cancer, should have an ultrasound or MRI in addition to screening mammography.

The American Cancer Society and other medical organizations recommend that women begin getting regular mammograms at age 40. The USPSTF, in contrast, advises women between the ages of 40 and 49 to talk with their doctors to make their own decisions about screening depending on how they value the potential benefits and harms of mammography.

Many women, and their doctors, don’t think much about the possible downsides of screening mammography. A statistical model included in the USPSTF draft shows that annual mammograms among 1,000 women in their 40s would prevent one death compared to 1,000 women of the same ages who didn’t have mammograms (7 vs. 8). But screening in this age group would also trigger 576 false positive tests, 58 unnecessary breast biopsies, and two extra over-diagnosed tumors (20 vs. 18) that would not have affected health or longevity.

A study recently released in the journal Health Affairs estimates that false-positive mammograms and the over-diagnosis of breast tumors costs the U.S. health care system $4 billion per year. This figure is much larger than previous estimates and should be part of the national conversation on the use of screening mammography.

While annual mammograms save lives, there are many false positive scans and a small number of over-diagnosed tumors. Individual women may weigh these numbers differently and make different value judgments in deciding whether to start having mammograms at age 40.

For women ages 75 and older, the USPSTF panel continues to say that there isn’t enough evidence to recommend for or against routine mammograms. Other experts suggest that mammograms make sense for women in this age group who are expected to live 10 or more years, based on their good health.

Comments can be made on the USPSTF draft until 8:00 pm Eastern Time today. A final version of the recommendations is expected to be released in the fall of 2015. When appendicitis strikes, an operation to remove the appendix has long been the route to recovery. But a new strategy called “antibiotics first” could help some people avoid surgery for appendicitis.

In a clinical practice article in today’s New England Journal of Medicine, Dr. David Flum, a surgeon at the University of Washington in Seattle, explores the history of antibiotics first for appendicitis, how it is currently being used, who might benefit from this no-surgery approach, and its drawbacks.
Appendicitis 101

The appendix is a small, finger-like tube that hangs from the lower right side of the large intestine. Exactly what it does is something of a medical mystery.

In about 300,000 Americans a year, the appendix becomes inflamed, usually because of an infection or an obstruction in the digestive tract. This inflammation, called appendicitis, can cause pain, nausea, vomiting, and fever. If untreated, an inflamed appendix can burst and spill bacteria throughout the abdominal cavity and into the bloodstream, setting the stage for a life-threatening infection and requiring complicated emergency surgery.

Prompt removal of the appendix before it bursts helps avoid this dangerous scenario. Once a person is diagnosed with appendicitis, or even strongly suspected of having it, he or she usually has an operation to remove the organ, often within 24 hours.

This surgery, known as appendectomy, once required a large incision across the lower part of the abdomen. Today, however, it is done laparoscopically. This means the appendix is removed through several small incisions. Laparoscopic appendectomy has led to fewer complications and shorter recovery time.

Routine removal of the appendix is done largely because conventional (and medical) wisdom says that an inflamed appendix will burst if it is not removed, and the more time that passes after symptoms begin, the greater the risk that it will burst. Some evidence, however, is challenging that scenario.
Antibiotics first?

Everyone with appendicitis, even those on their way to surgery, gets antibiotics. These drugs treat the infection inside the appendix and reduce the risk of widespread infection if it bursts or has already burst.

Antibiotics first means giving antibiotics to someone with appendicitis and then watching to see what happens. If the drugs treat the infection and the appendicitis fades away, surgery isn’t needed. If a course of antibiotics doesn’t work, then an appendectomy will follow.

This idea was first tested unintentionally — and successfully — in Navy personnel who developed appendicitis while at sea, and out of reach of an operating room.

The idea of antibiotics-first has piqued interest because some evidence suggests that appendicitis doesn’t always lead to a burst appendix. And a 2014 study in JAMA Surgery showed no association between the amount of time adults with appendicitis spent in the hospital before having an appendectomy and the risk of the appendix bursting. So while appendicitis is still an urgent problem, it may not be quite as urgent as we thought.

Randomized clinical trials comparing antibiotics first to appendectomy first haven’t made the case for delaying surgery. On the plus side, antibiotics first does not appear to increase complications, including burst appendix, compared to immediate appendectomy. On the negative side, up to one-third of people assigned to antibiotics first still end up having an appendectomy, either within 48 hours or within the next year.

“It’s fair to say that antibiotics may simply postpone the inevitable for some patients,” says Dr. Joshua Kosowsky, clinical director of emergency medicine at Harvard-affiliated Brigham and Women’s Hospital.
Stay the course

The antibiotics first approach has the potential to help some people with appendicitis avoid surgery. But it also has downsides. Keeping the appendix in place leaves open the possibility of repeat bouts of appendicitis, with an appendectomy still down the road. It could also lead to lingering symptoms and a sense of uncertainty that could affect quality of life.

Appendectomy, on the other hand, when done laparoscopically, is safe, has a short recovery time, takes care of appendicitis, and prevents it from recurring.

Doctors don’t yet have a good way to tell who might benefit most from antibiotics first versus prompt surgery.

In the NEJM article, Dr. Flum concludes that appendectomy should remain the first choice of treatment for most people with appendicitis, at least until larger trials directly comparing surgery and antibiotics first have been done. The American College of Surgeons, the World Society of Emergency Surgery, and other professional groups agree.

However, antibiotics-first could be appropriate now for individuals who

    prefer not to have surgery
    aren’t healthy enough for surgery
    aren’t near a medical center that routinely does laparoscopic appendectomy.

Diagnosing appendicitis isn’t always easy. Conditions like inflammatory bowel disease can look like appendicitis. And young children often can’t describe their symptoms accurately enough to rule out other causes for their stomach pain. “Giving antibiotics to a patient with an uncertain diagnosis and then watching them carefully is a reasonable course of action in some cases,” says Dr. Kosowsky. “But appendectomy is still the standard of care for appendicitis.” When I make a salad, I drizzle olive oil onto it and toss in a handful of toasted walnuts. Could this simple, tasty habit help me stay mentally sharp in the coming years? Maybe so. A new study in this week’s JAMA Internal Medicine suggests that eating a Mediterranean-style diet enhanced with extra-virgin olive oil or nuts is good for your mind as well as your heart.

These findings, which come from a long-term clinical trial of different diets, are the first ever to show possible brain-related benefits of one eating pattern over another.

The participants were part of a large Spanish trial known as PREDIMED, short for Prevención con Dieta Mediterránea (which means “prevention with Mediterranean diet”). The plant-based Mediterranean diet focuses mainly on fruits, vegetables, whole grains, beans and other legumes, nuts, seeds, and olive oil. It also features moderate amounts of seafood, poultry, eggs, and dairy, but includes only scant helpings of red meat and sweets.

The participants were mostly in their 60s and 70s and were at risk for developing heart disease. Most were overweight and many had high blood pressure or high cholesterol. They were divided into three groups: one followed a Mediterranean-type diet and also ate an extra ounce of mixed nuts (walnuts, hazelnuts, and almonds) a day; another followed a Mediterranean-type diet and also ate an extra five tablespoons of extra-virgin olive oil a day; the third group, which served as the control, followed a low-fat diet.

All 447 participants in this part of the PREDIMED trial took six different tests of cognitive function — a combination of memory and thinking skills — at the start of the trial. Three-quarters of them completed the same tests again about four years later.

In the control group, average scores on both types of tests — memory and thinking skills — fell during those four years. By comparison, average scores on the memory tests improved among those following the Mediterranean-type diet with extra servings of nuts, while scores on the tests of thinking skills improved among those following the Mediterranean diet with extra servings of olive oil.

Although the results of this study are promising, it’s important to keep a few caveats in mind: This study included only a small fraction (6%) of all the PREDIMED participants. The trial wasn’t designed to look at connections between diet and brain health. And one-quarter of the participants never took the second round of tests. All of this means the results need to be taken with a grain of salt.
How might olive oil and nuts help?

Extra-virgin olive oil and nuts contain compounds called polyphenols. These substances help quell oxidation and inflammation, which are harmful to blood vessels and the brain. This may explain why diets rich in polyphenols seem to prevent both heart disease and age-related cognitive problems, says Dr. Olivia Okereke, an assistant professor of psychiatry at Harvard Medical School. Her research focuses on lifestyle factors that contribute to late-life cognitive decline.

Researchers have long appreciated links between the circulatory system and the mind. “It makes sense because the brain is an oxygen-hungry organ. You need healthy blood vessels for a healthy brain,” says Dr. Okereke.

The new findings are consistent with earlier studies showing that people who closely follow a Mediterranean diet are more likely to maintain their memory and thinking skills over time. Still, the authors and other experts concur that further research is warranted. Dr. Okereke is curious about what seem to be the different effects of olive oil and nuts. “It would be great if future studies of this type could link to neuroimaging to see how and where these different foods create the specific cognitive performance changes seen in the study,” she says.

To date, there’s no evidence of any downside to eating olive oil, nuts, or a full Mediterranean diet, unless you end up taking in more calories than you need and gain weight. So I’ll keep enjoying my salads and look forward to learning about — and remembering — new research on the Mediterranean diet in the future.

No comments:

Leave a comment