7 Foods to Avoid Before Bed

Sleep disorders are a common problem that affects more and more people. They lead to reduced quality of life and decreased mental performance. They are also a risk factor for chronic conditions, including hypertension, heart disease and type 2 diabetes. The etiology of sleep disorders is not fully examined. They can be caused by psychological factors, such as excessive stress, or even bad eating habits. It has been proven that what we eat has a significant impact on the quality and quantity of sleep. In the following article I will focus on types of food and drinks we should avoid before bedtime in order to enjoy a good night’s sleep.

1. Caffeine

Caffeine is found in coffee, energy drinks, black tea or cocoa. It’s no surprise that its excessive consumption can disrupt sleep. Caffeine is structurally similar to adenosine, a molecule that reduces the release of excitatory neurotransmitters in the central nervous system. Adenosine promotes sleep and suppresses arousal, leading to daytime sleepiness, fatigue and decreased motivation. Caffeine acts as a competitive inhibitor of adenosine receptors by attaching to these receptors and preventing their activation by adenosine. It results in increased energy level, arousal and alertness. Besides that, caffeine is considered a psychostimulant – it dilates blood vessels, which improves blood flow in the body and stimulates the central nervous system. Its consumption increases and prolongs the secretion of adrenaline, the main excitatory neurotransmitter. And this is why we often reach for coffee or energy drinks. Unfortunately, the same mechanisms can disrupt sleep patterns. Drinking caffeinated beverages before bedtime makes it difficult to fall asleep and maintain good sleep quality. It extends the duration of light sleep while reducing time spent in deep sleep. Keep in mind that caffeine reaches its maximum plasma concentration 30-60 minutes after consumption, however, it remains in the body for another 4-6 hours. Because of that, coffee in the afternoon or evening can worsen the quality of our sleep, so it is crucial to maintain adequate intervals between caffeine intake and bedtime.

2. Nightshades

Plants in the nightshades family, such as potatoes, tomatoes, eggplant, peppers and goji berries, produce natural pesticides called glycoalkaloids. Their function is to protect plants from adverse factors, such as mechanical damage or overexposure to light. However, in the human body, they affect the nervous system by blocking the enzyme acetylcholinesterase. This leads to an increase in acetylcholine, which is an excitatory neurotransmitter. The subsequent overstimulation and anxiety can disrupt sleep.

3. Alcohol

Some people believe that drinking alcohol makes it easier to fall asleep. While alcohol can indeed make you feel drowsy and help you fall asleep faster, it will significantly disrupt the second half of sleep. Studies have shown that older adults are particularly vulnerable to this. After drinking the same amount of alcohol as younger people, their blood and brain alcohol concentrations were higher. Alcohol affects the central nervous system and alters neurotransmission. Initially, it inhibits the release of acetylcholine, which leads to an increase in slow-wave sleep, reduces the amount of REM sleep and increases the amount of NREM sleep. After a few hours, alcohol is rapidly metabolized and its blood concentration decreases. In the second half of the night, the symptoms of withdrawal syndrome begin to appear. That is why a person is more likely to have shallower, lower-quality sleep with more awakenings and nightmares during the night. 

4. Foods rich in biogenic amines 

Sleep problems can result from eating foods rich in biogenic amines, such as histamine and tyramine. Biogenic amines are nitrogenous compounds that are essential for maintaining cell viability and proper cellular processes in many organisms. They accumulate as the food ages. Histamine is found in dry aged meat such as salami, aged cheese, pickled herring or seafood, wine and champagne. It is involved in regulating immune response and acts as a mediator of inflammatory as well as allergic reactions. In addition, it controls the state of wakefulness by modulating the secretion of catecholamines such as adrenaline and dopamine. Excess histamine causes overstimulation of the sympathetic nervous system, but also an increase in blood pressure and the heart rate, making it difficult to fall asleep. Tyramine has similar properties. It is present in aged cheese and meat, soybean products and sauerkraut.

5. Simple carbohydrates

Physiologically, insulin secretion from pancreatic beta cells usually remains low. It rises after meals and its concentration varies throughout the day, with higher levels in the early morning and evening. Simple carbohydrates, which can be found in white bread, white rice, pastries or pasta, lead to a sharp rise in insulin and glucose levels after a meal. In response, there is a release of stress hormones such as cortisol and adrenaline. It leads to an increase in blood pressure and heart rate which may negatively impact sleep quality.

6. Processed foods

Processed foods, such as fast food of all kinds, are high in salt, saturated fat, trans fatty acids and sugar. All these ingredients take a long time to digest which makes it challenging to fall asleep. Processed foods especially impair our deep sleep, which is considered the most restorative. In addition, fatty meals before bed can trigger acid reflux, leading to disrupted sleep.

7. Spicy food

Spicy food is risky in regards to sleeping as it can cause acid reflux, heartburn and chest pain, which may be related to discomfort and trouble falling asleep. Spicy food also contains high levels of capsaicin – a substance that increases metabolism and thermogenesis which should be lowered during the night. In addition, this type of food can give you nightmares. And most of us wouldn’t really like that because, after all, bad dreams don’t necessarily support sleeping comfort.

So what should we eat to sleep well?

As you can tell, eating certain foods before bedtime can cause sleep problems and poor recovery. That’s why it’s crucial to know which products to avoid in order to improve the quality of your sleep and overall well-being. So what should we eat for a good night’s sleep? We will tell you about it soon. Stand by for part 2 of our guide on food and sleeping to learn what can make your night more comfortable and refreshing.