Sunday, 24 December 2023
Eat Carrots and Prevent Cancer: Unveiling the Superfood's Hidden Powers
Thursday, 6 April 2023
Some Diets Better Than Others for Heart Protection
Five other popular diets appeared to have little or no benefit with regard to these outcomes.
"These findings with data presentations are extremely important for patients who are skeptical about the desirability of diet change," write the authors, led by Giorgio Karam, with University of Manitoba, Winnipeg, Canada.
The results were published online March 29 in The BMJ.
Dietary guidelines recommend various diets along with physical activity or other cointerventions for adults at increased CVD risk, but they are often based on low-certainty evidence from nonrandomized studies and on surrogate outcomes.
Several meta-analyses of randomized controlled trials with mortality and major CV outcomes have reported benefits of some dietary programs, but those studies did not use network meta-analysis to give absolute estimates and certainty of estimates for adults at intermediate and high risk, the authors note.
For this study, Karam and colleagues conducted a comprehensive systematic review and network meta-analysis in which they compared the effects of seven popular structured diets on mortality and CVD events for adults with CVD or CVD risk factors.
The seven diet plans were the Mediterranean, low fat, very low fat, modified fat, combined low fat and low sodium, Ornish, and Pritikin diets. Data for the analysis came from 40 randomized controlled trials that involved 35,548 participants who were followed for an average of 3 years.
There was evidence of "moderate" certainty that the Mediterranean diet was superior to minimal intervention for all-cause mortality (odds ratio [OR], 0.72), CV mortality (OR, 0.55), stroke (OR, 0.65), and nonfatal MI (OR, 0.48).
On an absolute basis (per 1000 over 5 years), the Mediterranean diet let to 17 fewer deaths from any cause, 13 fewer CV deaths, seven fewer strokes, and 17 fewer nonfatal MIs.
There was evidence of moderate certainty that a low-fat diet was superior to minimal intervention for prevention of all-cause mortality (OR, 0.84; nine fewer deaths per 1000) and nonfatal MI (OR, 0.77; seven fewer deaths per 1000). The low-fat diet had little to no benefit with regard to stroke reduction.
The Mediterranean diet was not "convincingly" superior to a low-fat diet for mortality or nonfatal MI, the authors note.
The absolute effects for the Mediterranean and low-fat diets were more pronounced in adults at high CVD risk. With the Mediterranean diet, there were 36 fewer all-cause deaths and 39 fewer CV deaths per 1000 over 5 years.
The five other dietary programs generally had "little or no benefit" compared with minimal intervention. The evidence was of low to moderate certainty.
The studies did not provide enough data to gauge the impact of the diets on angina, heart failure, peripheral vascular events, and atrial fibrillation.
The researchers say that strengths of their analysis include a comprehensive review and thorough literature search and a rigorous assessment of study bias. In addition, the researchers adhered to recognized GRADE methods for assessing the certainty of estimates.
Limitations of their work include not being able to measure adherence to dietary programs and the possibility that some of the benefits may have been due to other factors, such as drug treatment and support for quitting smoking.
The study had no specific funding. The authors have disclosed no relevant financial relationships.
BMJ. Published online March 29, 2023. Full text
Tuesday, 21 March 2023
Intermittent fasting may change how your DNA is expressed
Mice who only ate at specific times of the day experienced “profound” changes in genetic expression, leading to health benefits like reduced risk of obesity and inflammation, new research found.
To an extent, it’s not about what you eat as much as when you eat it — so says recent research that sheds new light on the benefits of intermittent fasting.
The study, published Tuesday in journal Cell Metabolism, found that mice fed only during certain blocks of time experienced “profound” changes in gene expression. Nearly 80 per cent of all genes were impacted in some way, the paper reads.
The changes resulted in a plethora of health benefits, the authors wrote, including: improved blood sugar regulation, decreased risk of obesity and even a reversal of certain hallmarks of ageing.
You can think of a gene as the blueprint for a specific protein, written in DNA. When a gene is expressed, the blueprint is converted into its protein product by cellular machinery. Because proteins are responsible for most cellular functions from fat metabolism to immune response, even slight changes in gene expression could leave a massive impact.
According to the research, restricting when mice could eat reshaped when and to what extent certain genes were expressed — for example, some organs learned to switch on the genes for regulating blood sugar when it came feeding time, and to repress them when it was time to fast.
The researchers say their findings opened the door for further research into how dietary interventions might impact our genes and what this means for those suffering from issues like diabetes, heart disease and cancer.
What is time-restricted eating?
Shaunak Deota, first author of the study and a post-doctoral fellow at the Salk Institute for Biological Studies in San Diego, explained time-restricted eating as “eating consistently in a narrow window of 8 to 10 hours” when one is most active and fasting the remainder of the day. Intermittent fasting is a form of this practice, he said.
By feeding and fasting at the same time every day, we are reinforcing a biological rhythm in our bodies, Deota said: “Our body is getting the food at the same time every day, so all our organ systems know when the food is going to come and they’re prepared for it.”
Previous studies have shown that time-restricted eating may reduce the risk of obesity and diabetes, help to improve cardiovascular health, provide benefits for gut function and cardiovascular health and more.
Deota’s research now contributes, to his knowledge, the first “holistic” look at how time-restricted eating impacts the body as a system.
To achieve their results, the researchers put two groups of mice on the same high-calorie diet. One group was only allowed to eat during a nine-hour window when they were most active. The other could feed whenever they wanted.
After seven weeks, the mice on a time-restricted diet gained less weight than their counterparts, despite eating the same amount of food.
The researchers then killed 48 of the mice — 24 from each group — to investigate the diet’s impact on the body. They sacrificed two mice from each group every two hours over a 24-hour period, noting how their organ systems changed over time.
How time-restricted eating changes the body
After studying the mouse organs, Deota and his team made a “pretty surprising” discovery; mice on the time-restricted diet had synchronized their gene expression with their feeding schedules.
“That is important because these genes will get translated into proteins,” Deota said. “Those proteins are helping our body to anticipate that there is food coming.”
According to their paper, roughly 70 per cent of all mouse genes fell into rhythm with the feeding schedule. Come mealtime, individual organs could promote genes in charge of nutrient metabolism while suppressing those responsible for inflammatory signalling and immune activation.
Moreover, the scientists found the diet reversed several hallmarks of aging, leading to reduced inflammation, increased cellular housekeeping, improved RNA and protein balance and more.
“Molecularly speaking, we saw a lot of pathways which are activated by (the time-restricted diet) in multiple organ systems. And a lot of these pathways actually have been implicated in improving health and leading to a longer, healthy life,” Deota said.
The limitations
All that being said, we need to remember these results were seen in mice, not humans — we’re still a long way off from demonstrating the same phenomenon happens in people, said Dani Renouf, a registered dietitian at St. Paul’s Hospital in Vancouver. For now, these results represent a “wonderful start to a conversation.”
“We’re just prototyping at this point because we’re using animal models and looking at things on a cellular level,” she said. “In order to now make conclusions in human beings, we need to take several steps before we can definitively do that with time restricted-eating.”
Renouf also noted the experiments took place in a tightly controlled environment. Real life is messy and chaotic, she said, and will likely influence results.
On the flip side, Deota believes “most of these benefits can be translated to humans” because his lab’s findings line up with what clinical studies into time-restricted eating have discovered.
You can think of a gene as the blueprint for a specific protein, written in DNA. When a gene is expressed, the blueprint is converted into its protein product by cellular machinery. Because proteins are responsible for most cellular functions from fat metabolism to immune response, even slight changes in gene expression could leave a massive impact.
Sunday, 17 February 2019
Lose Your Weight and Stomach Fat Fast With These 10 Diet Life Hacks
- LISS (Low Intensity Steady State): Going for a long walk or light jog would be considered low intensity cardio. The benefits of this kind of exercise are that you’ll burn calories without taxing your body too badly and driving up your appetite. The downside? It can be kind of boring and lengthy, therefore difficult to incorporate on a consistent basis as a result.
- HISS (High Intensity Steady State): Think going for a long run. The plus side of HISS is that you’ll burn more calories a lot faster when compared to LISS, however these workouts are more draining and difficult to recover from. You may find yourself extremely hungry as a result of the exertion.
- HIIT (High Intensity Interval Training): HIIT refers to short bursts of intense exercise followed by stretches of rest or long intensity work. Imagine walking on a treadmill and occasionally working in high-speed sprints, or doing a circuit of pushups, air squats, lunges, etc. with rest intervals worked in. These workouts burn a ton of calories quickly and dramatically improve your conditioning, but they can also be difficult for your body to recover from and can drive up your appetite.
J Strength Cond Res.: The effect of abdominal exercise on abdominal fat | ||
Science Direct: Calories do count | ||
Science Direct: Slower eating rate reduces the food intake of men, but not women | ||
The American Journal of Clinical Nutrition: A high-protein diet induces sustained reductions in appetite … | ||
Trusty Spotter: I tried my first 24 hour fast. Here’s what happened. | ||
Science Daily: Taking a break from dieting may improve weight loss | ||
WebMD: Sleep and Weight Gain |