I was shocked and surprised to see headlines this week suggesting that intermittent fasting – particularly a type known as time-restricted eating (TRE) – could be bad for your heart, increasing your risk of fatal heart attack.
After the news broke, my phone was filled with calls asking me to comment – because, like many others, I have been incorporating different elements of intermittent fasting into my daily routine for years, to help me manage my weight and keep my blood sugar levels low. . In fact, intermittent fasting is a central part of my successful Fast 800 diet.
Over the past decade, I’ve spoken to many experts, read lots of research, and participated in studies that have all shown how beneficial intermittent fasting can be. But will this new study change my mind?
There are many different forms of intermittent fasting, including the 5:2 diet (in which you reduce calories two days a week) to time-restricted eating (TRE), in which you simply reduce the number hours during which you eat.
Essentially, it’s a way to give your body a break from digesting food, to help trigger “autophagy”, a form of cellular “spring cleaning”, where old cells are broken down and recycled.
Dr Michael Mosley was perplexed by research suggesting that following a time-restricted 16:8 diet is linked to a 91 per cent higher risk of death from cardiovascular disease.
A review of all the best research, published in the New England Journal of Medicine in 2019, concluded that “intermittent fasting has broad-spectrum benefits for many health conditions, such as obesity, diabetes mellitus (diabetes type 2), cardiovascular diseases, cancers. , and neurological disorders (such as dementia).”
So I was very perplexed by this new research which suggests that following a time-restricted 16:8 diet (fasting for 16 hours and eating during an eight-hour window) is linked to a 91 percent higher risk of death from cardiovascular disease. disease.
Could I and so many others have gone spectacularly wrong? I’ve read the abstract of the study — that’s all that’s currently available and it’s basically the abstract — and I’m convinced there’s nothing to worry about.
The previously unpublished study, by researchers at Shanghai Jiao Tong University School of Medicine, examined data from the U.S. National Health and Nutrition Examination Surveys, collected between 2003 and 2018.
In these surveys, Americans were asked about their eating habits. The Chinese researchers selected those who checked a box indicating that for two days they had limited their food intake to a window of eight hours or less. The researchers then cross-referenced these people with the US National Death Index database to see what happened to them.
It turned out that these intermittent fasters were almost twice as likely to die from heart disease as people who didn’t check these boxes.
There are many problems in making sense of this study, not least because we don’t know how old the participants were, what their health was, whether their memories were accurate, and, most importantly, whether those two days were representative of what they had experienced. they did it the rest of the week.
As Kevin McConway, Emeritus Professor of Applied Statistics at the Open University, pointed out: “We don’t know whether their eating times during these two 24-hour periods were typical of the times they usually ate. So linking these patterns to a deliberate, long-term, time-limited dietary intervention seems to go well beyond the data.
Sir David Spiegelhalter, emeritus professor of statistics at the University of Cambridge, agrees, adding somewhat scathingly: “This summary should not have been the subject of a press release.”
Other experts pointed out that people who reported only eating during an eight-hour window might have done so because they had previous heart problems or ate that way because they were carrying out shift work, which itself is linked to an increased risk of heart disease and type 2 diabetes.
Ultimately, we have no idea what these people were consuming. Was it a healthy Mediterranean diet or processed junk food? So no, my belief in the benefits of intermittent fasting was not shaken by this summary.
If you’re happy with your TRE diet, the latest research suggests it’s best to eat more calories earlier, avoiding a large meal in the evening.
A study published in the journal Nature Communications of 100,000 adults found that eating breakfast before 8 a.m. and stopping eating 12 to 13 hours later led to the greatest improvements in heart disease and diabetes risk. type 2. Eating after 9 p.m. was associated with a 13% increased risk of heart disease.
(This is probably because it works better with the rhythms of your body clock and the production of hormones such as insulin.)
So I recommend avoiding late-night eating (try stopping two to three hours before bed), aiming for a 12-14 hour “fasting” window, and sticking to a nutritious Mediterranean diet .
Analysis could detect different types of bowel cancer more quickly
The good news is that thanks to screening and new treatments, survival rates for most cancers have skyrocketed.
Unfortunately, rates of some cancers continue to rise, particularly in younger age groups. One of the most striking examples is bowel cancer. A recent article in the journal Annals of Oncology predicts that bowel cancer deaths among young people in the UK this year will be 26% higher among men and almost 39% higher among women than in 2018.
Researchers at the University of Milan blame rising obesity rates, as well as excessive alcohol consumption and low physical activity. But sometimes, of course, it’s just bad luck. The best way to protect yourself is to catch it early, so if the NHS has sent you a home test (in England it is offered to people aged 60 and over, although soon everyone over 50 will be eligible), then use it.
The test involves collecting a small sample of poop and sending it to a laboratory where they check for the presence of tiny amounts of blood. If it shows signs of blood, you will be referred for a colonoscopy to look inside your intestine (and possibly a biopsy). I did this and although it was a significant test, I can’t say I enjoyed the process.
So I was delighted to see new research from the University of Glasgow showing that in the future it might be possible to use a PET scan instead of taking a biopsy. This showed that PET can accurately diagnose different types of bowel cancer more quickly, which could help patients find the treatment best suited to their needs.
More good news is that researchers at the Massachusetts Institute of Technology have discovered how early colon cancers manage to evade our immune system.
To do this, they make a protein, SOX17, which is normally produced by the fetus to protect itself from attacks by its mother’s immune system. Due to a mutation, intestinal cells also start producing them – if scientists can find a way to block SOX17, it could offer a new way to treat early-stage cancers.
For ethical and environmental reasons, I’m trying to reduce the amount of meat I eat, which means that along with tofu and lentils, I’m exploring meat substitutes, like insects, which are packed with protein and fiber .
I tried crickets, grasshoppers and mealworms, which were all OK. But what about eating snakes?
A recent study from Macquarie University in Australia concluded that snakes are an excellent source of protein and are more environmentally friendly than eating beef or lamb.
In fact, cold-blooded reptiles are more efficient than warm-blooded animals at converting the food they eat into protein.
During my last trip to China, I was offered snake cooked in a stew. It made me feel a little gross, but it was tasty, kind of like chicken.