Cardiovascular disease (CVD), a general term for conditions affecting the heart or blood vessels, is the leading cause of death globally. The disease leads to an estimated 18 million deaths each year, of which nearly 80 percent are due to heart attacks and stroke. While the exact cause of CVD is not clear, there are several factors that increase the risk of developing the disease, and, the more risk factors you have the greater the chance of developing CVD.
Behavioral risk factors of CVD, including unhealthy diet, lack of physical activity, smoking and alcohol abuse, raise blood pressure, blood glucose and blood lipid levels, as well as promote overweight and obesity, all of which individually or together raise the risk of CVDs. Unhealthy diets in particular have long been identified as a major risk factor for CVDs, accounting for an estimated 8 million deaths each year.
A new study by researchers at multiple universities and institutes in Spain and France adds to the list of risk factors for developing CVD, by showing that not only unhealthy diets but also the time we consume our foods have a bearing on raising the risk of CVDs. The accelerated pace of our modern lifestyles lead to an increase in unhealthy diets and mistimed nutritional behaviors, such as skipping breakfast, gorging on fast foods during the day, and having late night meals.
The new study found that mistimed meals, in particular having later times for the first and last meals of the day, was linked to a higher overall risk of cardiovascular diseases. The study builds on the growing body of literature that shows eating earlier in the morning and in the evening — earlier breakfast times and earlier dinner times — is beneficial in terms of metabolism.
Data from observational and interventional studies have also indicated that breakfast consumption is an important habit for cardio-metabolic health, while its omission has been associated in meta-analyses with overweight and obesity, both of which are risk factors for CVD and diabetes. Similarly, late-night eating has been linked in prospective studies to cardiovascular risk factors such as arterial stiffness, obesity, imbalance of lipoproteins and triglycerides,and to a higher risk of coronary heart disease.
In their study, researchers looked at the link between when people ate their meals throughout the day and their risk of cardiovascular disease.
The cohort study included 103,389 adults participating in the NutriNet-Santé study, an ongoing web-based study in France that began in 2009 and looks at the link between nutrition and health. The mean age of participants was around 42 years old, and almost 8 out of 10 were women. Researchers used dietary records submitted online by participants to estimate when and how often people ate during the day. They followed participants for an average of around 7 years.
The researchers found that each additional hour in delaying the time of the first meal of the day in the morning was associated with a higher risk of overall cardiovascular disease.And, that each additional hour in delaying the time of the last meal in the evening was associated with an 8 percent increased risk of cerebrovascular disease. People eating their last meal after 9pm were also shown to have a 28 percent higher risk of cerebrovascular disease compared to people who ate their last meal before 8pm.
Additionally the study showed that the number of times the participants ate during the day did not appear to have an effect on overall risk of cardiovascular disease or coronary heart disease. The study results suggest a potential benefit of adopting earlier eating timing patterns, and coupling a longer nighttime fasting period with an early last meal, rather than breakfast skipping, in preventing cardiovascular disease.
The researchers noted that while their study had several strengths, such as the large number of participants, the extended follow-up, and that they took into account other variables that could affect cardiovascular risk, more research was needed on an individual person’s preferences, lifestyles, and health characteristics
before affirmative conclusions could be drawn on the link between eating times and cardiovascular health.
One potential explanation for the lower cardiovascular risk with earlier meal times is the effects of meal timing on circadian rhythms in the organs. Research shows that the daily eating and fasting cycle helps synchronize circadian rhythms in organs such as the liver, heart, kidney, and pancreas. Circadian rhythms are the roughly 24-hour cycles that form the body’s internal clock. One of the best-known circadian rhythms is the sleep-wake cycle, which is tied to the cycle of day and night. Other environmental cues can also affect the circadian rhythms.
