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
June 27,2020

After admitting that the world may have a COVID-19 vaccine within one year or even a few months earlier, the World Health Organisation (WHO) on Friday said that UK-based AstraZeneca is leading the vaccine race while US-based pharmaceutical major Moderna is not far behind.

WHO Chief Scientist Soumya Swaminathan stated that the AstraZeneca's coronavirus vaccine candidate is the most advanced vaccine currently in terms of development.

"I think AstraZeneca certainly has a more global scope at the moment in terms of where they are doing and planning their vaccine trials," she told the media.

AstraZeneca's Covid-19 vaccine candidate developed by researchers from the Oxford University will likely provide protection against the disease for one year, the British drug maker's CEO told Belgian radio station Bel RTL this month.

The Oxford University last month announced the start of a Phase II/III UK trial of the vaccine, named AZD1222 (formerly known as ChAdOx1 nCoV-19), in about 10,000 adult volunteers. Other late-stage trials are due to begin in a number of countries.

Last week, Swaminathan had said that nearly 2 billion doses of the COVID-19 vaccine would be ready by the end of next year.

Addressing the media from Geneva, she said that "at the moment, we do not have a proven vaccine but if we are lucky, there will be one or two successful candidates before the end of this year" and 2 billion doses by the end of next year.

Scientists predict that the world may have a COVID-19 vaccine within one year or even a few months earlier, said the Director-General of the World Health Organization even as he underlined the importance of global cooperation to develop, manufacture and distribute the vaccines.

However, making the vaccine available and distributing it to all will be a challenge and will require political will, WHO chief Tedros Adhanom Ghebreyesus said on Thursday during a meeting with the European Parliament's Committee for Environment, Public Health and Food Safety.

One option would be to give the vaccine only to those who are most vulnerable to the virus.

There are currently over 100 COVID-19 vaccine candidates in various stages of development.

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Agencies
July 30,2020

New York, Jul 30: Can the coronavirus spread through the air? Yes, it's possible.

The World Health Organisation recently acknowledged the possibility that Covid-19 might be spread in the air under certain conditions.

Recent Covid-19 outbreaks in crowded indoor settings — restaurants, nightclubs and choir practices — suggest the virus can hang around in the air long enough to potentially infect others if social distancing measures are not strictly enforced.

Experts say the lack of ventilation in these situations is thought to have contributed to spread, and might have allowed the virus to linger in the air longer than normal.

In a report published in May, researchers found that talking produced respiratory droplets that could remain in the air in a closed environment for about eight to 14 minutes.

The WHO says those most at risk from airborne spread are doctors and nurses who perform specialized procedures such as inserting a breathing tube or putting patients on a ventilator.

Medical authorities recommend the use of protective masks and other equipment when doing such procedures.

Scientists maintain it's far less risky to be outside than indoors because virus droplets disperse in the fresh air, reducing the chances of Covid-19 transmission.

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News Network
May 13,2020

California, May 13: A fasting-mimicking diet could be more effective at treating some types of cancer when combined with vitamin C, suggests a new study conducted by the scientists from USC and the IFOM Cancer Institute in Milan.

In studies on mice, researchers found that the combination delayed tumour progression in multiple mouse models of colorectal cancer; in some mice, it caused disease regression. The results were published in the journal Nature Communications.

"For the first time, we have demonstrated how a completely non-toxic intervention can effectively treat an aggressive cancer," said Valter Longo, the study senior author and the director of the USC Longevity Institute at the USC Leonard Davis School of Gerontology and professor of biological sciences at the USC Dornsife College of Letters, Arts and Sciences.

"We have taken two treatments that are studied extensively as interventions to delay ageing-- a fasting-mimicking diet and vitamin C -- and combined them as a powerful treatment for cancer," added Longo.

The researchers said that while fasting remains a challenging option for cancer patients, a safer, more feasible option is a low-calorie, plant-based diet that causes cells to respond as if the body were fasting.

Their findings suggest that a low-toxicity treatment of fasting-mimicking diet plus vitamin C has the potential to replace more toxic treatments.

Results of prior research on the cancer-fighting potential of vitamin C have been mixed. Recent studies, though, are beginning to show some efficacy, especially in combination with chemotherapy.

In this new study, the research team wanted to find out whether a fasting-mimicking diet could enhance the high-dose vitamin C tumour-fighting action by creating an environment that would be unsustainable for cancer cells but still safe for normal cells.

"Our first in vitro experiment showed remarkable effects. When used alone, fasting-mimicking diet or vitamin C alone reduced cancer cell growth and caused a minor increase in cancer cell death. But when used together, they had a dramatic effect, killing almost all cancerous cells," said Longo.

Longo and his colleagues detected this strong effect only in cancer cells that had a mutation that is regarded as one of the most challenging targets in cancer research.

These mutations in the KRAS gene signal the body is resisting most cancer-fighting treatments, and they reduce a patient's survival rate. KRAS mutations occur in approximately a quarter of all human cancers and are estimated to occur in up to half of all colorectal cancers.

The study also provided clues about why previous studies of vitamin C as a potential anticancer therapy showed limited efficacy. By itself, a vitamin C treatment appears to trigger the KRAS-mutated cells to protect cancer cells by increasing levels of ferritin, a protein that binds iron.

But by reducing levels of ferritin, the scientists managed to increase vitamin C's toxicity for the cancer cells. Amid this finding, the scientists also discovered that colorectal cancer patients with high levels of the iron-binding protein have a lower chance of survival.

"In this study, we observed how fasting-mimicking diet cycles are able to increase the effect of pharmacological doses of vitamin C against KRAS-mutated cancers," said Maira Di Tano, a study co-author at the IFOM, FIRC Institute of Molecular Oncology in Milan, Italy.

"This occurs through the regulation of the levels of iron and of the molecular mechanisms involved in oxidative stress. The results particularly pointed to a gene that regulates iron levels: heme-oxygenase-1," added Tano.

The research team's prior studies showed that fasting and a fasting-mimicking diet slow cancer's progression and make chemotherapy more effective in tumour cells while protecting normal cells from chemotherapy-associated side effects. The combination enhances the immune system's anti-tumour response in breast cancer and melanoma mouse models.

The scientists believe cancer will eventually be treated with low-toxicity drugs in a manner similar to how antibiotics are used to treat infections that kill particular bacteria, but which can be substituted by other drugs if the first is not effective.

To move toward that goal, they say they needed to first test two hypotheses: that their non-toxic combination interventions would work in mice, and that it would look promising for human clinical trials.

In this new study, they said that they've demonstrated both. At least five clinical trials, including one at USC on breast cancer and prostate cancer patients, are now investigating the effects of the fasting-mimicking diets in combination with different cancer-fighting drugs.

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