atherosclerosis

Posted on Diabetes, Obesity, Weight Loss

Time-restricted eating reshapes gene expression throughout the body.

Science image


Time-restricted eating reshapes gene expression throughout the body. In this illustration, the Ferris wheel displays the interconnected organ systems working smoothly during time-restricted eating, represented by the clock in the middle CREDIT Salk Institute

Numerous studies have shown the health benefits of time-restricted eating, including an increase in life span in laboratory studies, and practices like intermittent fasting, a hot topic in the wellness industry. However, how it affects the body on the molecular level and how those changes interact across multiple organ systems has not been well understood. Now, Salk scientists show in mice how time-restricted eating influences gene expression across more than 22 regions of the body and brain. Gene expression is the process through which genes are activated and responds to their environment by creating proteins.

The findings, published in Cell Metabolism on January 3, 2023, have implications for many health conditions where time-restricted eating has shown potential benefits, including diabetes, heart disease, hypertension, and cancer.

“We found that there is a system-wide, molecular impact of time-restricted eating in mice,” says Professor Satchidananda Panda, senior author and holder of the Rita and Richard Atkinson Chair at Salk. “Our results open the door for looking more closely at how this nutritional intervention activates genes involved in specific diseases, such as cancer.”

For the study, two groups of mice were fed the same high-calorie diet. One group was given free access to food. The other group was restricted to eating within a feeding window of nine hours each day. After seven weeks, tissue samples were collected from 22 organ groups and the brain at different times of the day or night and analyzed for genetic changes. Samples included tissues from the liver, stomach, lungs, heart, adrenal gland, hypothalamus, different parts of the kidney and intestine, and different areas of the brain.

The authors found that 70 per cent of mouse genes respond to time-restricted eating.

“By changing the timing of food, we were able to change the gene expression not just in the gut or in the liver, but also in thousands of genes in the brain,” says Panda. 

Nearly 40 per cent of genes in the adrenal gland, hypothalamus, and pancreas were affected by time-restricted eating. These organs are essential for hormonal regulation. Hormones coordinate functions in different body and brain parts, and hormonal imbalance is implicated in many diseases, from diabetes to stress disorders. The results offer guidance on how time-restricted eating may help manage these diseases.

Interestingly, not all sections of the digestive tract were affected equally. While genes involved in the upper two portions of the small intestine—the duodenum and jejunum—were activated by time-restricted eating, the ileum, at the lower end of the small intestine, was not. This finding could open a new line of research to study how jobs with shiftwork, which disrupt our 24-hour biological clock (called the circadian rhythm) impact digestive diseases and cancers. Previous research by Panda’s team showed that time-restricted eating improved the health of firefighters, who are typically shifting workers.

The researchers also found that time-restricted eating aligned the circadian rhythms of multiple body organs.

“Circadian rhythms are everywhere in every cell,” says Panda. “We found that time-restricted eating synchronized the circadian rhythms to have two major waves: one during fasting and another just after eating. We suspect this allows the body to coordinate different processes.”

Next, Panda’s team will take a closer look at the effects of time-restricted eating on specific conditions or systems implicated in the study, such as atherosclerosis, which is a hardening of the arteries that is often a precursor to heart disease and stroke, as well as chronic kidney disease.

Posted on Cardiovascular disease, Rheumatoid arthritis

Physical activity reduces cardiovascular risk in rheumatic patients

People with diseases such as rheumatoid arthritis and lupus are more likely to have heart attacks, angina, and strokes. Regular exercise improves vascular function CREDIT Diego Rezende

The risk of developing atherosclerosis – a narrowing of the arteries as cholesterol plaque builds up, leading to obstruction of blood flow – is higher for people with autoimmune rheumatic diseases than for the general population. As a result, they are more likely to have heart attacks and other cardiovascular disorders. 

The good news, according to a new study published in Rheumatology, is that regular exercise is a powerful weapon against vascular dysfunction in these patients.

In the article, researchers working in Brazil and the United Kingdom report the results of a systematic review of the scientific literature on the subject. The review, which was supported by FAPESP, covered ten studies involving 355 volunteers with various diseases, such as rheumatoid arthritis, lupus, and spondyloarthritis (inflammation of the spine). The subjects took exercise programs such as walking in a park or on a treadmill, stationary cycling, high-intensity interval training, and muscle building. Most of the programs lasted 12 weeks.

“Our analysis of the results showed that exercise improved small and large vessel endothelial function to a clinically significant extent. Accordingly, we suggested that exercise can be considered ‘medication’ for these patients because of its potential to reduce the incidence of cardiovascular events,” said Tiago Peçanha, first author of the article. Peçanha is a postdoctoral fellow at the University of São Paulo’s Medical School (FM-USP) in Brazil.

These rheumatic diseases, he explained, are the result of an imbalance in the immune system that leads to the production of antibodies against the subject’s own organism, especially joints, muscles, ligaments and tendons. While there is no definitive cure for these diseases, they can be controlled by treatment with anti-inflammatory drugs, immunosuppressants, and biologics (drugs from living sources).

“Treatment doesn’t prevent patients from developing certain co-morbidities. Cardiovascular disease is the most worrisome,” Peçanha said. “The risk of heart attack is twice as high for people with rheumatoid arthritis as for healthy people. For people with lupus or psoriatic arthritis, the incidence of ischemic events [heart attack, angina and stroke] is between twice and five times as high.” 

Atherosclerosis develops rapidly in these patients owing to the chronic inflammation associated with rheumatic disease and continuous use of anti-inflammatory drugs. “It all begins with changes in blood vessel structure and function,” Peçanha said. “The arteries gradually harden and stop being able to dilate when necessary. Changes occur above all in the endothelium [the layer of cells lining the interior surface of blood vessels]. Alterations in vascular function, especially endothelial function, are considered initial markers of atherosclerosis for this reason.”

The systematic review showed that exercise improved small and large vessel vascular function in patients with autoimmune rheumatic diseases. However, the authors note that given the small number of studies reviewed the evidence is not sufficient to state categorically that exercise also promotes a structural recovery of damaged arteries.

“This area [physical activity in rheumatology] is still new, so more research is needed to identify the best exercise protocols and investigate such aspects as safety and adherence,” Peçanha said. “In any event, the data in our study underlines the importance of regular exercise to prevent and treat cardiovascular disease in these patients.”

For people with rheumatic disease, as indeed for everyone else, Peçanha recommends at least 150 minutes of moderate to vigorous exercise per week. Aerobic exercise should predominate and be complemented by activities that foster strength and balance.

Leave a comment Posted on Cardiovascular disease

Regularly skipping breakfast linked to hardening of the arteries




Breakfast and your arteries

Breakfast and your arteries




“Skipping breakfast may be linked to poor heart health,” The Guardian reports. Researchers from Spain found that people who regularly skipped breakfast were more likely to have atherosclerosis – hardening and thickening of the arteries due to a build-up of fatty deposits known as plaques.

Atherosclerosis doesn’t usually cause any noticeable symptoms at first but can eventually lead to life-threatening problems, such as heart attacks and strokes, if it gets worse.

The researchers looked at the breakfast habits and artery health of around 4,000 middle-aged bank workers who were not known to have heart disease. They found those who skipped breakfast were more likely to have plaques than those who ate a breakfast containing at least a fifth of their daily calories – this would be 500kcal or more for a man whose daily intake was the recommended 2,500kcal.

The study is planning to follow up the participants to see what happens to their arteries over time.




This study can’t say for certain whether skipping breakfast was affecting artery health directly, as both were assessed at the same time. However, skipping breakfast did seem to be a habit shared by people who also tended to be unhealthy in other ways, such as being more likely to be a smoker or to have a higher body mass index (BMI).

While skipping breakfast may seem a tempting option if you’re trying to lose weight, it’s counterproductive if you find yourself having unhealthy snacks and overeating during the rest of the day.

 

Where did the story come from?

The study was carried out by researchers from the Centro Nacional de Investigaciones Cardiovasculares Carlos III, Santander Bank, and other hospitals and research centres in Spain and the US. It was funded by the Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Santander, the Instituto de Salud Carlos III and the European Regional Development Fund.

The study was published in the peer-reviewed Journal of the American College of Cardiology.

The research was covered well by The Guardian, which pointed out limitations and explained that skipping breakfast was not likely to be affecting heart health directly; instead, it was likely to be a marker for other unhealthy behaviours.

The Mail Online suggested that skipping breakfast “triggered the same emergency response in the body as starvation”, but the study itself didn’t assess this. Also, its headline stated that skipping breakfast to lose weight was the problem, but not all of the participants who skipped breakfast did so to lose weight.

The Daily Telegraph took a more cautious approach, explaining there may be a potential link between skipping breakfast and heart attacks but that additional research with long-term follow-up is probably required to confirm or disprove it.

 

What kind of research was this?

People who skip breakfast are thought to be at greater risk of heart disease. However, no studies have so far looked at whether breakfast habits are linked to the early build-up of fatty tissue in the arteries (atherosclerosis) before a person starts to experience symptoms. Atherosclerosis is an early sign of heart disease.

The current study was a cross-sectional analysis looking at whether people who skipped breakfast were more likely than those who ate breakfast to have atherosclerosis that was not yet causing any symptoms of heart disease.

The analysis was part of the ongoing Progression of Early Subclinical Atherosclerosis (PESA) study, which will follow the participants to see whose atherosclerosis progresses. This initial analysis cannot tell us whether breakfast habits directly caused the atherosclerosis seen, as both the people’s habits and their fatty tissue build-up were measured at the same time.

 

What did the research involve?

Researchers recruited 4,082 adults aged 40 to 54 who worked at the headquarters of Santander Bank in Madrid. To be eligible, participants could not have heart or kidney disease, could not be morbidly obese (BMI of 40 or more) and could not have a serious disease that could lead to death in the next six years.

They reported their breakfast habits over 15 days by filling out a detailed computerised questionnaire about what and when they ate and drank, and the researchers looked at their arteries to see if they showed signs of fatty tissue build-up. The results were then analysed to see whether breakfast habits were linked to artery health.

The researchers used the questionnaire information to calculate what percentage of their daily energy intake the participants consumed at breakfast. Anything eaten before 10am was considered to be breakfast, and they were grouped into those who consumed:

more than 20% of their daily energy intake at breakfast (“high-energy breakfast”)

5-20% of their daily energy intake at breakfast (“low-energy breakfast”)

less than 5% of their total energy intake at breakfast (“skipped breakfast”)

The energy level for skipping breakfast was equivalent to just having an orange juice or coffee.

The researchers used ultrasound to assess whether people had fatty build-ups in major arteries in the neck (carotid arteries), the major artery leading from the heart through the abdomen (infrarenal abdominal aorta) and major arteries in the groin (iliofemoral arteries). They also assessed the level of calcium in the walls of the arteries supplying the heart, as this is a sign of fatty deposits.

This identified people who had signs of atherosclerosis either in any of the arteries, in the arteries supplying the heart or in multiple (four or more) sites.

They then looked at whether people with different breakfast habits were more or less likely to have atherosclerosis or other unhealthy outcomes, such as being overweight or having high blood pressure. In their analyses, they accounted for potential confounders such as:

age

education level

physical activity level

smoking status

dietary characteristics (such as whether

they were dieting to lose weight)

What were the basic results?

Only 3% of the participants skipped breakfast. Most (69%) had a low-energy breakfast, and 28% had a high-energy breakfast. Those who skipped breakfast were more likely to:

be male

be smokers

have changed their diet to try to lose weight in the past year

consume most of their calories at lunch

have a more unhealthy diet (higher in calories, animal protein and cholesterol; and lower in fibre and carbohydrates)

Overall, about 63% of participants showed some signs of atherosclerosis, and it was more common among people who skipped breakfast than those who did not.

Once the researchers took into account other factors that could have affected the results, people who skipped breakfast were more likely to have atherosclerosis at multiple sites or in the arteries not feeding the heart.

 

How did the researchers interpret the results?

They concluded that skipping breakfast was associated with an increased likelihood of having fatty tissue build-up in multiple arteries or in arteries not feeding the heart. This increase was found to be independent of other risk factors for heart disease.

 

Conclusion

This study found a link between skipping breakfast and fatty tissue build-up in the arteries – an early sign of heart disease.

However, because it assessed people’s diets and artery health at the same point in time, and fatty deposits build up gradually in arteries, we can’t say their breakfast habits directly influenced their artery health. Also, as breakfast habits were only assessed over 15 days, we can’t be sure they were representative of lifelong patterns.

It looks like people who skip breakfast tend to have other unhealthy habits, such as smoking and eating more. While the researchers did try to account for the impact of these other factors, it’s possible they still affected the results.

But overall, it looks like skipping breakfast tends to be a sign of someone whose habits may put them at risk of heart disease.

In general, while this study can’t prove that eating breakfast will reduce the risk of heart disease, eating a healthy breakfast is in line with current UK guidance from the National Institute for Health and Care Excellence (NICE). The advice is part of its guidance about preventing excessive weight gain.

NICE recommends eating breakfast, without increasing overall daily calorie intake, as one way to help prevent excess weight gain. This means you shouldn’t just eat breakfast without considering your overall calorie consumption – cut down elsewhere if you need to.

What you eat at breakfast is also likely to be important. NICE recommends that breakfast should reflect existing healthy eating advice. So for example, opt for unsweetened wholegrain cereals or bread, lower-fat milk and a portion of fruit, rather than a fry-up.