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 aswhen 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.
Our bodies need healthy levels of cholesterol to function. Cholesterol is a fatty substance made by the liver and distributed throughout the body. It allows our bodies to make vitamin D and hormones, and makes up bile acids. We also get less than 25 percent of our body’s cholesterol from the foods we eat, especially animal fats.
High cholesterol means you have a lot more cholesterol in your blood than you need. Most people who have high cholesterol don’t have any obvious symptoms. A simple blood test can tell you if you have high cholesterol. If you do have high cholesterol, dietary changes, exercise, and targeted medications can help lower it and reduce your risk of developing heart disease.
Circulatory System
Cholesterol moves through your bloodstream via lipoproteins. There are two kinds of lipoproteins, and we need them both. Low-density lipoproteins (LDL) transport cholesterol around to where it’s needed. If there’s too much cholesterol, it may be deposited into the arteries. LDL is commonly referred to as “bad cholesterol.” High-density lipoproteins (HDL) take the extra cholesterol from your tissues and cells and return it to your liver for repurposing. That’s why HDL is called “good cholesterol.”
The job of the arteries is to move blood from your heart to other parts of your body. Too much LDL and not enough HDL makes it more likely that your arteries will develop plaque, a hardened mixture of cholesterol, fat, and other elements.
As coronary arteries narrow, it’s harder for blood to make it through to your heart. If an area of plaque breaks open, it can result in a blood clot, which can block blood flow altogether. This puts you at great risk of having a heart attack. Symptoms of reduced blood supply to the heart include chest discomfort, pressure, and pain (angina). You may also have pain in your jaw, neck, shoulders, arms, or back. Angina can be mistaken for indigestion.
If blood flow to one section of heart muscle is blocked, the result is a heart attack. That means the heart muscle is dying. Blood flow has to be restored fast, or there’s a risk of permanent heart damage or death.
When plaque builds up in the arteries that carry blood to your brain, your brain is deprived of oxygen. Brain cells quickly become damaged and start to die (stroke). Symptoms include sudden weakness and numbness. Depending on the area of the brain involved, you may have trouble speaking, seeing, or moving your limbs. A stroke can cause brain damage, disability, or death.
Plaque can also build up and interfere with blood flow to your arms and legs (peripheral arterial disease). If the blood supply to your limbs is blocked, you may feel numbness or pain. There’s an increased risk of infection in those limbs. Lack of blood can cause tissue death (gangrene).
Digestive System
High cholesterol can create a bile imbalance, leading to gallstones. According to the National Digestive Disease Information Clearinghouse, more than 80 percent of gallstones are cholesterol stones.
A buildup of plaque in your arteries can also block blood flow to your kidneys and stomach. Intestinal ischemic syndrome is when there’s a blockage in arteries leading to the intestines or bowel. Symptoms include abdominal pain, nausea, vomiting, and bloody stools.
There are some facts about cholesterol that the majority of the public does not know and even some doctors seem to have forgotten because it has been so long since they learned about them in the early years of medical school.
a) cholesterol is an animal product from the catabolism of heamoglobin. As plants do not have blood, they produce phytosterols which inhibit cholesterol absorption in the guts. The claim "no cholesterol" on labels of plant-base food is non-sense, a commercial trick.
b) Human body needs quite a lot of cholesterol and manufactures about 1g daily (with a total body amount of 35g), and mother Nature gives us the ability to recycle most of the cholesterol from the guts.
c) cholesterol is produced by the liver and secreted into the gallbladder, stored there under the form of bile salts. When the stomach content moves down to the upper portion of the small intestine, it triggers a contraction of the gallbladder which forces the bile into the guts. The bile salts (with their cholesterol component) are water soluble and can be easily absorbed through the blood vessels in the intestine wall, then into the blood.
d) on the other hand, the cholesterol in the food are under the esterified forms, not water soluble and not easily absorbed through the intestine wall. Most of them ends up to be food for the gut bacteria.
d) consequently, most of the cholesterol in our blood comes from ourselves, less than 20% come from food.
e) go ahead and enjoy egg, butter, crustaceans (crab, shrimp, lobster ...) because the recommendations about them the last 50 years concerning cholesterol have been wrong on biochemical and physiological basis.
*** for people who want to lower cholesterol but don't know what to believe, these are other tidbits:
a) as the largest source of cholesterol comes from bile. the most logical way to reduce cholesterol is to prevent the bile salts from being absorbed.
b) soluble fiber in grains and fruits is the most effective and SAFE weapon to do that because the bile salts adsorb (with a d, not b) onto the fiber, cannot be released to be absorbed (with a b) and will be eaten by the bacteria or .... pooped out.
c) this is the caveat: as bile is not secreted into the guts all day long but only in spurts (especially during meals high in lipid), eating high fiber in the form of oat meal or high fiber cereal once a day in breakfast is non-sense, mainly because that breakfast is fat-free, that is without egg, bacon, butter!
So, the best way to lower cholesterol inexpensively, without a doctor visit or a prescription is to go to the pharmacy, ask for one of the fiber caplet or pill available OTC and take one of them three times daily WITH EACH MEAL.
If your blood cholesterol does not drop in few weeks, you can think about asking your doctor for extended-released niacin or a statin. 50% of my patients did not need anything beyond a high fiber diet and only 30% more needed a fiber supplement.
Daily egg consumption in hyperlipidemic adults - Effects on endothelial function and cardiovascular risk. Valentine Njike, Zubaida Faridi, and David L Katz
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