A recent study in Nature Communications explored how eating and fasting fluctuations affect the incidence of heart problems (CVD).
Human bodies have physiological cycles that span roughly 24 hours, termed circadian cycles.
These include fasting/eating cycles that set peripheral clocks in various tissues, and the latter, in turn, help regulate the working of the guts and blood vessels. A brand new study seeks to throw more light on this topic by exploring how alterations within the timing of eating and fasting affect the incidence of CVD.
CVD is the leading reason for disease and death worldwide. Dietary patterns contribute significantly to cardiovascular risk, with almost 8 million deaths from CVD being linked to faulty food plan. In recent times, many parts of society have turn into less focused on traditional meal times, and diets have turn into commonplace, meaning that meal timings are sometimes irregular.
Nonetheless, the link between cardiovascular health and the eating/fasting cycle is a component of the vital recent field of chrononutrition that seeks to elucidate the network of connections between meal timings and health.
Research has shown that breakfast is crucial to maintaining normal metabolism and cardiovascular health, while late-night meals promote arteriosclerosis, obesity, and abnormal lipid profiles. In women, it also results in metabolic syndrome. Nonetheless, there may be considerable confusion over what timing identifies each meal and what defines late-night eating.
Time-restricted eating (TRE) could possibly be a way of improving cardiometabolic health. It refers to extending nighttime fasting to over 12 hours, and in humans, it has shown corresponding reductions in body weight, blood pressure, and inflammation.
The relative paucity of information on how CVD risk is impacted directly by nighttime fasting duration and specific meal timings motivated the present study. The study, published in Nature Communications, used data from the NutriNet-Sante study involving over 100,000 adults. Their dietary records were used to construct a database on eating frequency and meal timing.
What did the study show?
Individuals who were younger, single, with no family history of CVD, smoked repeatedly, were more energetic, higher educated, had lower monthly incomes, and were more more likely to eat later breakfasts and late-night meals.
Individuals eating later meals were also at higher risk of getting more variable meal timings, binge drinking, and better mean alcohol consumption, in addition to later bedtimes.
The median follow-up period was 7 years. This covered almost 700,000 person-years. During this era, there have been just over 2,000 recent cases of CVD, almost equally distributed between cerebrovascular diseases, including strokes and transient ischemic attacks, and coronary heart diseases (CHD), including heart attacks, angioplasty, acute coronary syndrome, and angina.
The later the primary meal, the upper the chance of CVD was, but no such trend was observed with the timing of the last meal. Nonetheless, when it was eaten after 9 pm, there was a 13% increase in risk in comparison with before 8 pm. The chance of cerebrovascular disease rose by 8% with each hour of delay of the last meal, and on the inflection point (after 9 pm vs. before 8 pm), it was 28% higher.
Increased nighttime fasting was linked to a discount of cerebrovascular disease risk by 7%, but no similar decrease was observed for either CVD overall or CHD.
Thus, if the primary meal was eaten after 9 am as in comparison with before 8 am, and if the last meal was taken after 9 pm vs. before 8 pm, the chance of cardiovascular outcomes was increased, more so amongst women in comparison with men. The advantages of increased nighttime fasting interval were also more outstanding amongst women.
The utmost advantages would look like when nighttime fasting periods were prolonged by advancing the time of the evening meal reasonably than delaying or skipping the primary meal of the day. This might be because persons are most sensitive to insulin and better glucose levels early within the morning, becoming less so because the day progresses.
In actual fact, animal studies show the onset of weight gain, increased fat mass, fat deposition within the liver, and a delay within the rhythmic expression of lipid metabolism genes when breakfast was routinely delayed by 4 hours.
Human studies indicate that aberrations in glucose regulation and insulin sensitivity, dyslipidemia, and weight gain beyond normal limits occur when evening meals are delayed.
This will be linked to food intake through the body’s rest phase, when melatonin secretion is at its peak, causing prolonged elevations of glucose within the blood after the meal.
What are the implications?
It seems that cardiometabolic health is best served by early TRE, with early first and last meals, and that is supported by an earlier finding from the identical cohort that individuals who ate breakfast before 8 am and fasted for >13 hours overnight had a lower risk of type 2 diabetes mellitus.
The findings that later first and last meal timing are each individually linked to a better risk of overall CVD corroborate earlier studies showing improved cardiometabolic risk aspects with earlier breakfasts and last meals. Timely meals promote the metabolism of food, as food has been established to set peripheral circadian rhythms that regulate blood pressure.
While these findings are suggestive, due to large sample size and the possible design, confounding aspects should be considered, reminiscent of the potential for night shift work amongst those that eat later within the night.
That is an independent correlate of cerebrovascular disease and impaired sleep. Nonetheless, no participant on this study ate meals exceptionally early or late in an try to rule out such shift work.
Other aspects reminiscent of light exposure at night, nighttime awakenings, timing of exercise or other activity, drinking, and substance abuse could all potentially cause disturbances of the circadian rhythms and weren’t controlled on this study.
These findings suggest that, beyond the dietary quality of the food plan itself, recommendations related to meal timing for patients and residents may help promoting a greater cardiometabolic health.
Palomar-Cros et al. (2023)
Further studies are needed to validate these findings.