Intermittent fasting has grown in popularity in recent years as a dietary method that offers potential health benefits. So you may have been surprised to see a headline last week suggesting that this habit could increase your risk of death from heart disease.

This news article is based on a recent study that found a link between time-restricted eating, a type of intermittent fasting, and an increased risk of death from cardiovascular disease or heart disease.

So what do these findings tell us? And how do they fit with other information we know about intermittent fasting and heart disease?

study of the problem

The study was presented as a scientific poster at an American Heart Association meeting last week. The full study has not yet been published in a peer-reviewed journal.

The researchers used data from the National Health and Nutrition Exam Survey (NHANES), a long-term study that collects information from a large number of people in the United States.

This type of research, known as observational research, involves analyzing large groups of people to identify relationships between lifestyle factors and disease. This research was conducted over his 15 years.

They found that people who ate within eight hours had a 91% increased risk of dying from heart disease compared to those who ate over 12 to 16 hours. A closer look at the data shows that during the study, 7.5% of those who ate within 8 hours died from heart disease, compared to 3.6% of those who ate over 12 to 16 hours. It is suggested.

We do not know whether the authors controlled for other factors that may influence health, such as weight, medication use, and diet quality. Perhaps some of these questions will be answered once the full details of the study are made public.

Also note that participants may have been eating in short time frames for a variety of reasons. It’s not necessarily because I was intentionally on a time-restricted diet. For example, the patient may have had a decreased appetite due to illness, which may have also affected the results.

Other research

Although this study may have a number of limitations, its results are not completely unique. These are consistent with several other published studies using the NHANES dataset.

For example, one study showed that in patients with heart failure, dieting over a long period of time reduced the risk of death from heart disease by 64%.

Another study of diabetics showed that those who ate more frequently had a lower risk of dying from heart disease.

A recent study found that overnight fasting of less than 10 hours and more than 14 hours increased the risk of death from heart disease. This suggests that fasting too short can also be a problem.

But did you think intermittent fasting was healthy?

The scientific literature has conflicting results regarding intermittent fasting, in part due to different types of intermittent fasting.

This research focuses on time-restricted eating, which restricts eating to a certain time each day. There are also different patterns for fasting and feeding days. For example, in the well-known 5:2 diet, about 25% of the energy needed is typically expended on fasting days, but there is no restriction on food intake on feeding days.

Despite this variety of fasting patterns, systematic reviews of randomized controlled trials (RCTs) consistently show the benefits of intermittent fasting in terms of weight loss and heart disease risk factors (such as blood pressure and cholesterol levels). It has been proven.

RCTs have shown that intermittent fasting produces comparable improvements in these areas compared to other dietary interventions such as moderate daily energy restriction.

So why are we getting such different results?

RCTs directly compare two conditions, such as intermittent fasting and daily energy restriction, and control for a variety of factors that can influence the results. Therefore, it provides insight into causal relationships that observational studies alone cannot provide.

However, they often focus on specific groups or short-term outcomes. These studies followed participants for about 12 months on average, and long-term effects remain unknown.

Observational studies provide valuable insight into population-level trends over long periods of time, but they rely on self-reports and cannot prove cause and effect.

Relying on someone to accurately report your eating habits can be difficult because you may not remember what you ate or when. This is a long-standing problem in observational research, and it is difficult to rely solely on this type of research to understand the relationship between diet and disease.

The relationship between meal timing and health may be more complex than simply eating more or less regularly. Our bodies are controlled by a set of internal clocks (circadian rhythms), and when our actions don’t align with these clocks, such as eating at different times, our bodies have a harder time managing this. It might be.

So is intermittent fasting safe?

There is no easy answer to this question. RCTs show that it appears to be a safe option for short-term weight loss.

However, people in the NHANES dataset appear to be at higher risk of dying from heart disease if they eat during limited hours of the day. Of course, many other factors can cause such a diet and influence the results.

When faced with conflicting data, there is general agreement among scientists that RCTs provide a higher level of evidence. There are too many unknowns to accept the conclusions of such epidemiological studies without question. Naturally, it has been the subject of criticism.

That said, to better understand the long-term safety of intermittent fasting, we need to be able to follow participants in these RCTs for 5 or 10 years.

In the meantime, if you are interested in intermittent fasting, you should first consult a medical professional.

Caitlin Day, Lecturer in Human Nutrition; RMIT University Sharaya Carter, Lecturer in Nutrition and Dietetics; RMIT University

This article is republished from The Conversation under a Creative Commons license. Read the original article.