KATHMANDU — Putting just a bit less on your dinner plate each day reducing caloric intake might be key to a longer life, a preliminary research has suggested.
According to a small clinical trial, people who reduced their caloric intake by just 15 percent over two years experienced a significant decrease in their metabolism.
These people also saw improvements in biomarkers associated with slower aging and longer life span, said lead researcher Leanne Redman, an associate professor of clinical sciences at Pennington Biomedical Research in Baton Rouge, La.
For the study published March 22 in the journal Cell Metabolism, Redman’s team recruited 34 healthy people with an average age of 40 to follow a calorie-restricted diet for two years.
The researchers found that the participants developed a lower core body temperature, lower blood sugar and insulin levels, and significant drops in hormones that moderate metabolism.
“We know these things are lower in people who live longer lives,” Redman said.
Researchers taught the study participants how to cut 25 percent of their daily caloric intake using three different models of a healthy diet, Redman said.
The participants then were free to follow their diet by any means they chose.
“On their own, they achieved a 15 percent reduction in calorie intake that was sustained for the two years, which is pretty remarkable,” Redman said.
On average, the group lost about 20 pounds, mostly in the first year, even though half entered the study at normal weight and the rest were only modestly overweight, Redman said.
Aging studies in animals have tied lower calorie intake to longer lives, but this is the first clinical trial to bridge the gap between animals and humans, said Rozalyn Anderson, an expert with the American Federation for Aging Research who reviewed the findings.
“So much of what they’re reporting is entirely consistent with what we’ve seen in our monkey studies,” said Anderson, an associate professor who studies aging and calorie restriction at the University of Wisconsin School of Medicine and Public Health.
“We’ve got a match between the monkeys and the humans, and that’s absolutely brilliant. This is a really neat gap to have closed in terms of aging biology,” she said.
The researchers said this offers support to controversial theories linking high metabolism and increased oxidative stress to faster aging.
“When we make energy, we have byproducts of metabolism, and these byproducts called oxygen radicals accumulate in the body and cause damage to cells and tissues,” Redman said. Such damage can cause cells to age faster and contribute to diseases like cancer.
Anderson isn’t so sure that’s the best explanation. She noted that lab studies in mice have shown that damage done by oxidative stress has no effect on overall life span.
Anderson thinks lower calorie intake prompts the body to use energy more efficiently, and that somehow results in benefits for aging.
“We know, for example, there’s a really tight connection that we don’t understand between fasting and resilience — the ability to stand up against distress,” Anderson said.
People who want to try to eat less in an attempt to live longer should focus on portion size while following a healthy and well-balanced diet, Redman said.
They should aim for lowering calorie intake by 25 percent, with the understanding that they will probably fall short of the goal, Redman said. They shouldn’t be discouraged if they don’t keep losing weight long-term.
“The goal is not to lose weight. The goal is to have this sustained lower intake,” Redman said.
Drinking 3 cups of coffee or tea daily may keep stroke risk at bay
KATHMANDU — There have been several conflicting studies on the health benefits of drinking coffee and tea and their various varieties. But drinking up to three cups of coffee or tea in a day is safe because it reduces irregular heartbeat and stroke risk, according to a new study published in the journal JACC: Clinical Electrophysiology.
Coffee has previously been believed to worsen abnormal heart rhythms, as doctors generally discourage patients suffering from the condition. However, the results of this particular study say that a daily consumption of upto 300 mg of caffeine may be safe for arrhythmic patients.
This is because the caffeine acts as a stimulant to the central nervous system and blocks the effect of adenosine. Adenosine is a chemical which causes Atrial Fibrillation (AFib).
A single cup of coffee contains about 95 mg of caffeine. It acts as a stimulant to the central nervous system and works to block the effects of adenosine — a chemical that causes AFib.
AFib is the most common heart rhythm disorder, causes the heart to beat rapidly and skip beats, and if left untreated, can cause strokes.
“There is a public perception, often based on anecdotal experience, that caffeine is a common acute trigger for heart rhythm problems,” said lead author Peter Kistler, Director at Melbourne’s Alfred Hospital.
But, “caffeinated beverages such as coffee and tea have long-term anti-arrhythmic properties mediated by antioxidant effects and antagonism of adenosine,” he added.
A meta-analysis of 228,465 participants showed that AFib frequency decreasing by 6 per cent in regular coffee drinkers, and an analysis of 115,993 patients showed a 13 per cent reduced risk.
Another study of 103 post-heart attack patients who received an average of 353 mg of caffeine a day showed improvement in heart rate and no significant arrhythmias — or abnormal heart rhythms, that cause the heart to beat too fast, slow or unevenly.
However, in two studies, where patients drank at least 10 cups and nine cups of coffee per day, showed an increased risk for ventricular arrhythmias (VAs) – a condition in which the lower chambers of the heart (ventricles) beat very quickly.
On the other hand, patients with pre-existing heart conditions who consumed two or more energy drinks — that contains concentrated caffeine — per day reported palpitations within 24 hours.
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