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Thursday, April 25, 2019

Global cooperation needed to stop the spread of Ebola virus disease

People who want to follow a healthy diet sometimes need a little help knowing where a meal or snack falls on the healthfulness scale. Several apps let you snap a photo of what you’re about to eat and post it for all to see — and rate. And though many of the “raters” are regular folks without training in nutrition, a new study shows they do a pretty good job gauging whether foods are likely to make you fitter or fatter.

Researchers from South Carolina and Finland wanted to see how well the crowd stacked up against folks with trained to rate food. They turned to a mobile app called The Eatery. The researchers tallied up how 5,000 users of The Eatery ranked 450 photos of foods using predetermined nutrient labels such as saturated fat content, fruits, vegetables, and the like, as well as on a scale ranging from “fat” to “fit.” They also asked three trained reviewers to rank the foods using a scale based on the latest Dietary Guidelines for Americans.

The averages of the peer raters’ scores — the crowdsourcing — were closely in line with the averages of the experts’ scores. The report was published in the Journal of the American Medical Informatics Association.

Another positive sign: Foods and beverages that should be part of a healthy diet, like fruits, vegetables, whole grains, beans, and nuts were associated with higher crowdsourced ratings while those that should be limited, like fast foods, pastries, red meat, cheese, desserts, and sugar-sweetened beverages had lower ratings.

The results of this study don’t mean we should let the crowd stand in for trained nutrition professionals. After all, it was just one study and it used a limited rating system that doesn’t allow for a comprehensive evaluation of the food. And there wasn’t any follow-up to evaluate whether users of The Eatery stuck with this approach to choosing healthier foods or how well it worked.

But the results should give you confidence that, if you use an app like this, you can have confidence in the ratings you get back from your fellow app users.

This study also helps establish crowdsourcing as an inexpensive way to help people choose healthy foods, and shows the positive effect of mobile-based technology to facilitate “in-the-moment” dietary management. Fleetwood Mac’s hit song, “Don’t stop thinking about tomorrow,” got a second life as the anthem for then-candidate Bill Clinton’s first campaign for President. A new report in JAMA Neurology may trigger the return of that earworm. The report offers yet another reminder that tomorrow may not be better if you have uncontrolled high blood pressure.

Researchers with the long-term Atherosclerosis Risk in Communities (ARIC) Neurocognitive Study followed the health and mental function of nearly 13,500 men and women for more than 20 years. All of the participants were between the ages of 45 and 64 years when the study began; 76% were white and 24% were African-American. Between 1990 and 1992, the participants took three tests that measured memory and thinking skills. They took the same tests six years later, and again between 2011 and 2013. Their blood pressure was also measured, and researchers noted which participants were taking medicine to control high blood pressure (also known as hypertension).

There was a general decline over 20 years in memory and thinking skills (collectively called cognitive function). But high blood pressure in middle age was clearly linked with an increased risk of loss of memory and thinking skills:

    The decline among participants with high blood pressure was 6.5% greater than in those with normal blood pressure.
    The decline among those with high blood pressure was more pronounced in whites than in African-Americans. However, because African-Americans had a higher death rate before the last set of tests, the researchers believe that their proportionately small number remaining may have skewed the results.
    Among participants with high blood pressure in middle age, those who were taking medication to control it lost less cognitive ground over time than those with untreated high blood pressure.
    Those who had normal blood pressure in midlife and who developed high blood pressure in their late 60s, 70s, and 80s had similar test scores as those who had normal blood pressure throughout.

“This provides more evidence that hypertension contributes to lost memory and reasoning ability over the long term, ” says Melinda C. Power, ScD, an author of the study who just moved from the Harvard School of Public Health to Johns Hopkins University School of Medicine. The findings dovetail with an analysis that Power and her colleagues at the Harvard School of Public Health published last winter in the journal Epidemiology. It showed that the longer a person lives with high blood pressure, the more likely he or she is to develop memory loss and to have difficulty thinking.
High blood pressure and memory

An important strength of this study is its duration. It is the first study to track blood pressure and brain function over 20 years. But keep in mind that the ARIC study is an observational investigation. It can’t prove that high blood pressure causes declines in memory and thinking skills, and it definitely doesn’t prove that treating high blood pressure in middle age protects memory and thinking skills. Even so, Power says, observational studies can do things that clinical trials can’t, like track more people over a longer time.

The ARIC report serves as a reminder to keep an eye on your blood pressure. A healthy blood pressure is under 120/80. Although the guidelines from various expert groups aren’t in complete accord on when to begin treating high blood pressure, how to do it, and what target to aim for, most agree that otherwise healthy people under age 60 with high blood pressure should aim for a goal of under 140/90. That said, individual recommendations should be based on age, medication use, and general state of health. The appropriate goal for you, and the way to reach it, is best decided in a discussion with your doctor.

Preventing blood pressure from creeping into the unhealthy range is even better than treating high blood pressure. These lifestyle strategies are excellent ways to do this:

    Keep your weight in the healthy range
    Eat a heart-healthy diet with plenty of fruits and vegetables
    Watch your salt intake, most of which comes from processed foods
    Exercise daily, or at least five times a week
    Limit the alcohol—no more than one drink a day for women, no more than two a day for men
    Don’t smoke or use other tobacco products

The main take-home lesson from this study and others like it, says Power, is this: The longer you live with normal blood pressure, the less likely you are to have memory and reasoning problems when you’re older. The news and images out of West Africa, the center of an outbreak of deadly Ebola virus, are a bit scary. In the three countries affected by the outbreak —Liberia, Sierra Leone, and Guinea — more than 1,300 people have been sickened by the virus and more than 700 have died. Liberia closed its borders in an effort to prevent the infection from spreading. Images of health workers in protective gear ministering to patients and disinfecting the dead flash across screens. The Peace Corps has pulled all of its volunteers out of the three countries, and U.S. health officials have issued a warning not to travel to this area.

The Ebola virus (its name comes from the Ebola River in Zaire, site of the first known outbreak) causes an illness known as hemorrhagic fever. It is characterized by aches, fever, abdominal pain, organ failure, and uncontrolled bleeding. A person who has Ebola is contagious for up to 21 days. Spread of the infection occurs by direct contact with body fluids. There is no known cure, and half or more of those who develop Ebola virus disease die from it. Dr. Tom Frieden, director of the federal Centers for Disease Control and Prevention, called the Ebola virus “a dreadful and merciless virus.”

We live in an interconnected world in which air travel can spread contagious infection thousands of miles away in a few hours. As a physician, I am bracing myself for the possibility that Ebola may spread away from West Africa to other nations — like the United States. This morning, the director-general of the World Health Organization warned that “this outbreak is moving faster than our efforts to control it,” and it comes with a “high risk of spread to other countries.”
Preventing the spread of Ebola

This epidemic of Ebola virus disease has accelerated in the past couple of weeks. Experts from the World Health Organization and Centers for Disease Control continue to reassure us that its spread can be contained with appropriate care. This is true. But appropriate care is difficult—it requires a long stretch of quarantine for anyone who contracts Ebola virus disease and those who come into contact with them.

Work is being done to control the spread of the disease. There is a “level 3” travel advisory for the involved countries, which warns against nonessential travel to them. Surveillance methods are being put in place at airports to check individuals leaving the affected countries, so that no one travels while having symptoms that might turn out to be Ebola virus disease. A person without symptoms is not contagious, even if they have been exposed to the virus.

Here are some strategies that will help contain the disease:

    Identify new cases early. This means that health systems grappling with the epidemic need financial support so they can do appropriate lab testing, and they need the trust of their communities. Trust requires collaboration with local traditional healers.
    Isolate (quarantine) patients during the 21 days they are known to be potentially contagious.
    Identify people who have been in contact with individuals with Ebola virus disease and watch them carefully for the appearance of symptoms.
    Meticulous use of safe burial practices and protective clothing. Medical providers should use hoods, goggles, gloves, boots, and multiple layers of gowns when caring for Ebola virus disease patients.
    Research the non-human source (“reservoir”) of Ebola virus. So far, experts aren’t 100% sure how epidemics of Ebola begin. Spread from a mammal, possibly a fruit bat, is suspected but not proven.
    Develop a treatment and vaccine.

Looking ahead

The United States government has said it will work with other countries to try to end the Ebola epidemic. The CDC announced yesterday that it will send 50 more disease-control specialists into the three countries in the next 30 days. And President Obama’s budget proposal for fiscal year 2015 asks for $45 million to fund a “Global Health Security Agenda.” Work on Ebola would fall within this request.

I hope that Ebola can be contained before it spreads to other countries. But if it does spread, containing the epidemic will take a level of cooperation on the part of the global public that we’ve never before needed.

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