Salt tied to elevated blood pressure, even with healthy diet, says study

Agencies
March 7, 2018

People who eat lots of fruits, veggies, and whole grains may still have an increased risk of elevated blood pressure if they consume a lot of salt, a new study suggests.

Eating high-sodium foods has long been associated with raised blood pressure readings, but some evidence suggests that body weight and other nutrients in the diet may modify or offset the effects of sodium on blood pressure.

To see how diet might influence the connection between salt and blood pressure, researchers examined data from food surveys completed by 4,680 middle-aged adults, and determined the amount of 80 nutrients in each person’s diet.

With the exception of potassium, none of these nutrients appeared to weaken the connection between eating a high-sodium diet and having higher average blood pressure readings over 24 hours than people who ate the least sodium, researchers report in Hypertension.

“This matters because it indicates that the problem of excess salt intake and its adverse effects on blood pressure cannot be solved by augmenting the diet with other nutrients,” said lead study author Dr. Jeremiah Stamler of the Feinberg School of Medicine at Northwestern University in Chicago.

“The solution is reduction in salt intake,” Stamler said. “This is difficult since, as a result of commercial food processing, salt is almost everywhere in the food supply.”

Chronic high blood pressure is tied to an increased risk of heart disease, heart attack, stroke and heart failure.

To lower the risk of heart disease, adults should reduce sodium intake to less than 2 grams a day, or the equivalent of about one teaspoon of table salt, according to the World Health Organization (WHO).

Sodium is found not only in salt, but also in a variety of foods such as bread, milk, eggs, meat and shellfish as well as processed items like soup, pretzels, popcorn, soy sauce and bouillon cubes.

Extra sodium in the bloodstream can pull water into the blood vessels and boost blood pressure by increasing the amount of fluid the heart needs to pump through the body. Potassium can help remove excess sodium from the body.

In the current study, researchers examined data on sodium and potassium levels in urine, as well as blood pressure, height, weight and eating habits from adults aged 40 to 59 in Japan, China, the UK and the US

Higher sodium levels were associated with elevated blood pressure for both men and women at all ages in the study, regardless of race and ethnicity or socioeconomic status.

The connection between sodium and blood pressure was similarly strong for both normal weight and obese people in the study, although the connection was weaker for overweight individuals who weren’t obese.

Potassium appeared to weaken the connection between dietary salt and elevated blood pressure only for people who had low sodium levels in their urine, the researchers also found.

The study wasn’t a controlled experiment designed to prove whether or how dietary salt or other things people eat might directly alter blood pressure. Another limitation is that surveys used to assess eating habits can be unreliable snapshots of what people actually consume.

Even so, the results add to evidence that managing blood pressure requires paying attention to salt, said Cheryl Anderson, a researcher at the University of California San Diego School of Medicine who wasn’t involved in the study.

“Even though potassium can help lessen the blood pressure-raising effects of sodium, eating more potassium isn’t a license to eat more sodium,” Anderson said.

The American Heart Association recommends the Dietary Approaches to Stop Hypertension (DASH) diet or a Mediterranean-style diet to help prevent cardiovascular disease. Both diets emphasize cooking with vegetable oils with unsaturated fats, eating nuts, fruits, vegetables, low-fat dairy products, whole grains, fish and poultry, and limiting red meat and added sugars and salt.

“There is data showing that when the DASH dietary pattern is combined with sodium reduction there are substantial effects on blood pressure,” Anderson said. “This can be as powerful as taking a drug prescription for high blood pressure.”

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Agencies
July 3,2020

Apart from the many benefits of doing exercise, new research has now found that exercise can slow down or prevent the development of macular degeneration and may benefit other common causes of vision loss, such as glaucoma and diabetic retinopathy.

The new study from the University of Virginia School of Medicine found that exercise reduced the harmful overgrowth of blood vessels in the eyes of lab mice by up to 45 per cent. This tangle of blood vessels is a key contributor to macular degeneration and several other eye diseases.

The study represents the first experimental evidence showing that exercise can reduce the severity of macular degeneration, a leading cause of vision loss, the scientists report. Ten million Americans are estimated to have the condition.

"There has long been a question about whether maintaining a healthy lifestyle can delay or prevent the development of macular degeneration. The way that question has historically been answered has been by taking surveys of people, asking them what they are eating and how much exercise they are performing," said researcher Bradley Gelfand, PhD, of UVA's Center for Advanced Vision Science.

"That is basically the most sophisticated study that has been done. The problem with that is that people are notoriously bad self-reporters ... and that can lead to conclusions that may or not be true. This [study] offers hard evidence from the lab for the very first time," Gelfand added.

Enticingly, the research found that the bar for receiving the benefits from exercise was relatively low - more exercise didn't mean more benefit.

"Mice are kind of like people in that they will do a spectrum of exercise. As long as they had a wheel and ran on it, there was a benefit. The benefit that they obtained is saturated at low levels of exercise," Gelfand said.

An initial test comparing mice that voluntarily exercised versus those that did not found that exercise reduced the blood vessel overgrowth by 45%. A second test, to confirm the findings, found a reduction of 32 per cent.

The scientists aren't certain exactly how exercise is preventing the blood vessel overgrowth. There could be a variety of factors at play, they say, including increased blood flow to the eyes.

Gelfand, of UVA's Department of Ophthalmology and Department of Biomedical Engineering, noted that the onset of vision loss is often associated with a decrease in exercise.

"It is fairly well known that as people's eyes and vision deteriorate, their tendency to engage in physical activity also goes down. It can be a challenging thing to study with older people. ... How much of that is one causing the other?" he said.
The researchers already have submitted grant proposals in hopes of obtaining funding to pursue their findings further.

"The next step is to look at how and why this happens, and to see if we can develop a pill or method that will give you the benefits of exercise without having to exercise," Gelfand said.

He explained, "We're talking about a fairly elderly population [of people with macular degeneration], many of whom may not be capable of conducting the type of exercise regimen that may be required to see some kind of benefit." (He urged people to consult their doctors before beginning any aggressive exercise program.)
Gelfand, a self-described couch potato, disclosed a secret motivation for the research: "One reason I wanted to do this study was sort of selfish. I was hoping to find some reason not to exercise," he joked. "It turned out exercise really is good for you."

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Agencies
March 16,2020

New Delhi, Mar 16: A recent survey across 140 districts of the country shows that about 54 per cent of Indians are finding travelling to be unsafe as the deadly coronavirus (COVID-19) pandemic sweeps globally.

The big worry that people have is community transmission, something that researchers from around the world have approximated at 10 per cent of total infections and more common in places like Wuhan in China, South Korea, Iran and Italy.

The months of March to June have historically been high travel season for most Indians, largely due to the summer vacations in schools. "But it seems that Indians do not want to take a chance with this rather scary virus and are either cancelling or postponing their travel plans," concluded the survey by LocalCircles.

The survey gathered more than 22,000 responses from participants in tier one, two and three cities. It said 48 per cent Indians plan to cancel their international business travel for the next four months.

Besides, nearly 38 per cent of respondents said they had to pay cancellation fee to the website, travel agent, airline or railways.

"These are testing times for the entire travel and tourism industry -- airlines, hotels, travel agents as well as small tour and taxi operators. The best solution at this point is to adjust cost structures, stay flexible and work with a collective approach to minimise the period of impact to both citizens and business," said LocalCircles.

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News Network
June 20,2020

Washington, Jun 20: Pregnant and postpartum women are usually at a high risk of depression and anxiety - one in seven women struggle with symptoms in the perinatal period and the coronavirus pandemic is exacerbating those struggles according to a recent study.

The study was published in Frontiers in Global Women's Health, which found that the likelihood of maternal depression and anxiety has substantially increased during the health crisis.

"The social and physical isolation measures that are critically needed to reduce the spread of the virus are taking a toll on the physical and mental health of many of us," said Dr. Margie Davenport of the University of Alberta, Canada, who co-authored the study.

For new moms, those stresses come with side effects.

"We know that experiencing depression and anxiety during pregnancy and the postpartum period can have detrimental effects on the mental and physical health of both mother and baby that can persist for years," said Davenport.

Such effects can include premature delivery, reduced mother-infant bonding, and developmental delays in infants.

The study surveyed 900 women - 520 of whom were pregnant and 380 of whom had given birth in the past year - and asked about their depression and anxiety symptoms before and during the pandemic.

Before the pandemic began, 29 percent of those women experienced moderate to high anxiety symptoms, and 15 percent experienced depressive symptoms. During the pandemic, those numbers increased - 72 percent experienced anxiety and 41percent experienced depression.

Because lockdown measures have affected daily routines and access to gyms, researchers also asked women whether their exercise habits had changed. Of the women surveyed, 64 percent reduced their physical activity since the pandemic began, while 15 percent increased and 21 percent experienced no change.

Exercise is a known way to ease depression symptoms, so limited physical activity may result in an uptick in depressive symptoms. Indeed, the study found that women who engaged in at least 150 minutes of moderate physical activity a week had significantly lower symptoms of depression and anxiety.

The findings are somewhat limited given the fact that researchers could not survey women before the pandemic began (since they could not know a pandemic would occur). The women surveyed could only offer their pre-pandemic symptoms in hindsight.

Also, while the researchers asked women about their symptoms using validated measures, only mental health care professionals can validly diagnose an individual with depression or anxiety.

The study was specifically interested in the impact of COVID-19 on new moms, but Davenport says maternal mental health is a critical issue no matter the time.

"Even when we are not in a global pandemic, many pregnant and postpartum women frequently feel isolated whether due to being hospitalized, not having family or friends around or other reasons," she said.

"It is critical to increase awareness of the impact of social (and physical) isolation on the mental health of pregnant and postpartum women," Davenport added.

Increased awareness makes diagnosis and treatment - the ultimate goal - more likely.

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