Research links intermittent fasting to death from heart disease; Is he really bad?

Not always associated with healthy diets, intermittent fasting is a fad that nutrition experts validate, on the one hand, but condemn, on the other. Now, more evidence adds to the arguments about the practice: a study shows that people who eat only during an eight-hour interval (and spend the remaining 16 hours fasting) have a 91% higher risk of death from cardiovascular diseases in compared to those who eat at regular intervals.

The research analyzed data from around 20,000 adults in the US, comparing dietary pattern data from participants in the National Health and Nutrition Examination Surveys (NHANES) from 2003 to 2018 with information from the CDC’s (National Center for Health and Disease Prevention) from 2003 to 2019.

The researchers themselves highlight, however, that the analysis implies a relationship between the two factors, but not necessarily a cause — that is, it is not possible to say that intermittent fasting caused cardiovascular problems.

Nutritionist Cristiane Alecrim highlights other caveats that need to be taken into account in this type of study: “the database does not consider the population’s diet and the composition of the diet. Therefore, we only analyzed whether the person was fasting intermittently or not and the cause of death. Therefore, it is not necessary to consider that fasting is the root cause of deaths. The patient could be obese and have an unbalanced diet, posing a risk to cardiovascular health, which was cited as the cause of death.” She recommends paying attention to the conclusion of other studies that present sometimes positive and sometimes negative evidence about this type of diet — some extrapolate discoveries made in animals to human health, for example.

In the midst of so much disparate information, when is it recommended to adhere to the practice? Nutritionists do not categorically condemn it, however they emphasize that it should only be followed with a healthy diet and, of course, professional supervision. “This study is important because, in a way, it is in line with what the past told us: it is better to eat fractionally, with small meals, than to go eight hours or more without eating. It is an important study, but it needs to be replicated. There is a need for new studies on this”, introduces nutritionist, endocrinologist and professor of nutrition at Centro Universitário Padre Albino (Unifipa) in São Paulo Durval Ribas Filho.

“Intermittent fasting is nothing more than a low-calorie, low-calorie diet. In the 70s, there was a diet called five for two, in which, for five days, people ate 1,500 to 2,000 calories and, for two, only 500. In total, this popular diet was hypocaloric”, he continues. He assesses that, with medical supervision, types of low-calorie diets can benefit weight loss in obese people, for example.

Nutritionist and partner of the Be Light clinic Thiago Cunha recalls that intermittent fasting gained more traction after the Nobel Prize in Physiology and Medicine was awarded, in 2016, to Japanese biologist Yoshinori Ohsumi. He researched autophagy, a natural cell regeneration process, in yeast, a type of fungus. Based on this, research on mice demonstrated an increase in the longevity of those who were subjected to fasting. But studies on humans still need to be in-depth, reinforces Cunha.

What can be said for now, he says, is that any fast needs to be combined with a balanced diet. “Only individuals with a good training and nutrition routine will really benefit from this practice. There is no point in fasting and not eating well. Just as important as the strategy adopted, such as intermittent fasting, is how you eat during these windows of opportunity. Some patients without comorbidity, who seek a more dynamic routine and already have a good eating practice, can benefit positively from intermittent fasting”, he concludes.