The Siesta

The Siesta (or La Meridienne in French) is a famous painting by the artist Vincent Van Gogh. It depicts a siesta and symbolizes life in rural France in the late 1880’s. Siesta is a Spanish word meaning a short nap, usually taken in the afternoon, after lunch. In warm weather climates workers who do physical labor need to take a break to avoid the hottest part of the day. Siestas are common in Mediterranean countries, the Middle East, China, Latin America and the Philippines. Siestas are both practical and cultural. There are studies from Greece showing that naps are associated with a lower risk for heart attack. What is the data on siestas? How does day time napping affect cardiac health?

 

The health data on siestas is quite variable, showing some good and some bad effects. In a study from 2019, taking a daytime nap was associated with lower blood pressure. In those that nap, the blood pressure was 5 mmHg lower than in those that didn’t nap. Usually when something lowers blood pressure there is concomitant lowering of cardiac risk.  That doesn’t seem to be the case with napping. A comprehensive review of relevant studies showed that daytime napping over 60 minutes was associated with an increased risk for cardiac disease and mortality.  Another study followed 116, 000 people for 8 years and found that napping was associated with increased for major cardiac events and death in those that slept on average more than six hours per night. No increased risk was found in people who slept less than 6 hours per night. It was felt that naps compensated for lack of sleep for people who didn’t get enough sleep at night. The most recent study found some disturbing trends. The trial studied 476,000 people determining that 56% never or rarely took a nap, 38% sometimes napped and 5% usually took a daytime nap. Compared to people who never or rarely napped, frequent daytime napping increased the risk for atrial fibrillation and for dementia. This is the first time this association was made regarding the siesta. Why does napping lead to atrial fibrillation? One hypothesis is that napping indicates inadequate nighttime sleep from undiagnosed sleep apnea, a condition well known to cause atrial fibrillation. In addition, atrial fibrillation is a risk for dementia. 

 

It appears that frequent daytime napping can lead to dementia. What is the optimal amount of sleep to avoid dementia? The largest sleep study ever conducted just finished and concluded that 7 hours of sleep per night was the right amount for reasoning, verbal skills and overall cognitive thinking.  Sleeping more or less than that could lead to cognitive decline and dementia. What other new data has emerged regarding dementia? Eating processed red meat and sugar have been associated with dementia. Processed red meat (including bacon, hot dogs, sausages, salami, cold cuts) has been tied to an increased risk of cancer, heart disease and diabetes. A new study that tracked 100,000 people over four decades showed that eating two servings of red meat each week increased the risk for dementia by 14% and was associated with worse memory and thinking skills. The study also showed that replacing red meat with nuts, beans or tofu lowered the risk for cognitive decline by 23%. Processed red meat may affect the brain because of harmful chemicals such as nitrites and the increased sodium content can lead to high blood pressure. The study only found an association but did not prove cause and effect. So, we don’t know if red meat itself causes dementia or if people who avoid red meat are generally more health conscious. Unprocessed red meat, such as ground beef or steak, was not linked to dementia in the trial. In other news, on World Brain Day (July 22 2024), the German Society of Neurology warned that too much sugar can harm the brain.  High blood sugar levels can damage blood vessels, causing plaque, decreasing blood flow and causing vascular dementia. In addition, sugar directly affects the nerve cells, impairing cognition. What should be eaten instead? Try to eat whole fresh foods (fruits, vegetables, fish, nuts, beans) and the less processed, the better. Whole fresh foods bring protein, fiber, nutrients, minerals and vitamins the brain promoting a healthier body and longer lifespan.

 

Last month we found out that to decrease your risk for dementia you should take your blood pressure medications, go to the shore, plop down on a beach chair and watch the waves roll in. This month we learn that, to further lower your risk for dementia, try not to nap in that beach chair. In addition, skip the hot dog, ice cream and cotton candy on the boardwalk. It is hard to do, but it may be well worth it.