I know the feeling of tossing and turning while trying to get to sleep all too well.
Years ago, it used to regularly take me hours to get to sleep.
Now, I can pass out within about 20 minutes on average.
It turns out that falling asleep in between 10 to 20 minutes is “normal” when it comes to sleep studies (1). If it takes less, you’re likely sleep deprived. If it takes longer, there’s something going wrong.
Ready to learn how to sleep better? Let’s dive in…
Sleep Science: 12 Common Causes of Sleep Issues
While many things can affect your sleep onset latency (how long it takes to fall asleep), we’re going to focus on the lifestyle and dietary factors that can make a big difference.
If your problems only started after going vegan, pay close attention to the dietary factors.
Lifestyle Factors That Affect Sleep
Sleep is largely controlled by your circadian rhythm, which is an internal timing system that all humans have. It controls when you’re alert, and when you’re sleepy.
This rhythm has been fine-tuned over our many years of evolution.
It’s not surprising that if you’re doing things that affect your circadian rhythm, it’s going to affect your sleep.
The lifestyle factors we’ll look at can have a big impact on your rhythm.
Melatonin and Sleep Time
Melatonin is the main hormone that regulates your sleep-wake cycle (2).
As the image above shows, melatonin secretion starts at around 9 pm, after the sun has set and the temperature has gone down.
Your deepest sleep, and highest melatonin secretion is around 2 am, and you’ll continue producing melatonin until around sunrise (7:30 am or so).
The takeaway: Aim to go to sleep as soon after 9 pm as possible. The more you delay it, the more you mess with your circadian rhythm.
Going to sleep a bit later isn’t a deal breaker, but blue light is.
Light contains many different wavelengths of light, which all impact us differently.
Blue light is found in certain light sources like the sun and almost all screens (televisions, laptops, phones, etc.).
The problem is that blue light exposure suppresses melatonin production (3).
In the past, people would wake up with the sun (which has blue light) and become more alert. When the sun went down, there wasn’t much for us to do except maybe sit by a campfire (which has no blue light), and go to sleep. It makes sense that our melatonin levels would reflect that.
Now there’s blue light everywhere, and those hours of watching TV or browsing on your computer after sunset is wreaking havoc on your circadian rhythm.
So how do you fix it? Ideally, you stop using anything with a screen after sunset. But, that’s not very realistic.
The alternative is to block that specific band of blue light from your vision. You can buy blue light glasses that filter it out. Or, use an app like Flux (Windows and Macs have a built-in filter you can activate as well) to stop emitting blue light.
The takeaway: Blue light is good during the day, it’s what keeps us alert and energetic. However, it prevents melatonin production at night, which you need to get to sleep. So either stop using screens or take action to block the blue portion of the light spectrum.
Activity Before Bed
It’s hard to work or study and then go right to bed.
Your brain is still very active and alert, which is a recipe for lying in bed awake.
That’s why most sleep experts recommend a relaxation period before sleeping as a part of sleep hygiene (4). You’ll find varying recommendations, but Nick Littlehales (who’s worked with many professional athletes) recommends 90 minutes of winding down time before going to sleep.
The takeaway: Don’t go from playing that stressful game or planning finances straight to bed. Give yourself a period to wind down and prepare to sleep.
Anxiety and Overthinking
In the Great British Sleep Survey of 2012, over 20,000 people from the UK were surveyed (5).
One of the biggest insights was that most people are frequently kept awake by certain types of thoughts:
- 82% think about what happened during the day, and what will happen the next day
- 79% of respondents think about how long they’ve been awake
- 76% think about trivial things of no importance
- 71% think of things that happened in the past
Anxiety is all too common in modern society, and unfortunately I don’t have an easy answer to give you to fix it.
If thoughts are keeping you awake at night, developing habits such as meditation, and even getting therapy may help you learn to quiet them.
The takeaway: Being kept awake by thoughts is incredibly common, you’re not alone. Unfortunately, it’s not an easy problem to solve, and there are many different causes that may need to be addressed.
Temperature and Discomfort
The Great British Sleep Survey also found that there were common physical factors that made it harder to sleep:
- Bodily discomfort (67%)
- Noise (36%)
- Partner (34%)
- Room temperature (34%)
- Light levels (19%)
Creating a better sleep environment can alleviate most issues, even if there are a few you can’t control (like noisy neighbors):
- Get a larger bed if you have a partner
- Use earplugs or a static noise machine
- Lower the temperature well in advance of sleeping (most sleep experts recommend between 60 and 67 degrees Fahrenheit, or about 17 to 19 degrees Celsius) (6). It’s typically better to be on the cold side as long as you’re not freezing (7).
- Get blackout curtains to reduce light pollution
Exercise is of course important for good health, and it can affect your sleep as well.
What’s really interesting is that the type of exercise matters.
One study split subjects into different exercise groups and examined the effect it had on sleep (8). The results were surprising:
- High-intensity aerobic exercise – No significant effect on sleep.
- Moderate-intensity resistance exercise – No significant effect on sleep.
- Moderate-intensity aerobic exercise – Significant reduction in pre-sleep anxiety and improved sleep in patients suffering from chronic insomnia.
Basically, sprinting and relatively heavy weight lifting won’t help you get to sleep. However, running at a moderate intensity will help you sleep better.
The other big aspect of exercise is when should you do it?
You might guess that it’s bad to do it right before bed because it raises your body temperature. However, studies have found inconsistent results about this, with some saying it does affect sleep, and others finding no effect. The only consistent finding is that people with insomnia shouldn’t exercise vigorously within a few hours of trying to sleep (9).
The takeaway: If sleep is your main concern, regularly incorporate medium-intensity aerobic exercise (e.g. swimming, running, etc.) into your day. While it might be better to do it early in the day, the science is inconclusive on the best time to do it.
Dietary Factors That Affect Sleep
In addition to lifestyle factors, sleep researchers have found that certain foods and nutritional deficiencies can have a significant impact on sleep quality.
We’re going to look at them in the context of a vegan diet when relevant.
Caffeine can be a useful stimulant, as it improves alertness, concentration, reaction time, and more (10).
However, it can negatively affect your sleep if it’s still in your system.
That’s why the recommended amount is 400 mg per day for the average person (11). Ideally, if you have to consume caffeine, do it early in the day.
Because it’s a habit-forming chemical, you can build up a tolerance to caffeine, which can be dangerous. You may find that you continually need more to get a “hit” of alertness (12).
If you’re having trouble reducing your coffee intake, try going with decaf coffee instead.
Sugar and Processed Foods
Researchers have found that diets low in fiber, and high in saturated fat and sugar intake correlates with lower sleep quality (13).
Even though a vegan diet typically contains fewer processed foods than an omnivorous diet, there are still plenty of sources of sugar. Try limiting your processed sugar intake for a few weeks and see if it makes a difference.
Vitamin D is incredibly important to your health in multiple ways. A deficiency can lead to weak bones, impaired sleep, and depression, among other conditions (14).
The scary thing is that vitamin D deficiencies are very common. An estimated 1 billion people worldwide have a deficiency (15)
Many studies have shown that a vitamin D deficiency impacts sleep quality:
- It results in shorter sleep duration (16)
- It’s associated with worse sleep apnea symptoms (17, 18)
- Low vitamin D levels lead to longer time to fall asleep (19)
This shouldn’t be that surprising considering we synthesize vitamin D from sunlight, and we already saw the impact of the sun on our circadian rhythm.
Vitamin B12, also known as the bane of a modern vegan’s existence.
Okay, that’s a little dramatic, but it’s an important vitamin for overall health and sleep that vegans need to be careful about getting enough of.
Research shows that vitamin B12 helps regulate the circadian rhythm, and there’s a correlation between insomnia and low B12 levels (20).
Research has shown that after controlling for variables like anxiety and depression, iron deficiency anemia has a detrimental impact on sleep quality (22).
Magnesium deficiency can also contribute to RLS.
In addition, a small clinical trial found that a magnesium supplement helped subjects fall asleep faster (23).
There isn’t too much research specifically on magnesium deficiencies and sleep quality, but it does look like there could be a link.
How to Optimize a Vegan Diet to Sleep Faster and Deeper
What did those vitamins and minerals that we looked at above have in common?
They only impact sleep quality if you have a deficiency.
If you’re already getting lots of vitamin D, getting more isn’t going to help you fall asleep faster (24).
Don’t just pop a multivitamin assuming that it will cover any issues you have. Research has shown that the use of a multivitamin is actually associated with poorer sleep maintenance (25).
So, the first step you should take to see if your vegan diet is affecting your sleep quality is to check for deficiencies.
Ideally, go get a blood panel to test if you have any. If that’s not an option for some reason, track your diet using a free tool like Cronometer to see if you’re regularly not getting enough of any of these key nutrients.
If you do have a deficiency, refer to the sections below for ways to correct it.
You’re not going to find vitamin D in many plant foods.
Really, the only good plant source of it is lichen, which is a marine plant that basically no one eats. That’s what vegan vitamin D supplements are made from.
So either take a vitamin D supplement if you have a deficiency, or find a way to get more sun. Keep in mind that sunlight needs to be absorbed by the skin in order to stimulate vitamin D production in the body.
Much like vitamin D, you won’t find vitamin B12 naturally in a standard vegan diet.
That’s why somewhere around 50-70% of vegans have a vitamin B12 deficiency around the world (26).
You have 2 options to get vitamin B12.
The best option is to get a vegan vitamin B12 supplement. They’re cheap and convenient.
Alternatively, some vegan foods are fortified with B12. While it varies by brand, this typically includes:
- Nutritional yeast
- Non-dairy yogurts
- Seaweed snacks
Iron is a tough mineral for vegans to get.
Not only is there less iron in plant sources, but plants also only have nonheme iron. Non-heme iron is less absorbable than heme iron (found in meat).
It’s even harder for women, as they require more iron in their diet because it’s lost through menstruation.
Again, you can either get iron through your diet or through supplementation. Be aware that an iron deficiency can take a long time to fix. Here’s a list of the best vegan iron supplements if interested.
For example, one study treated patients with oral iron for 4-5 months to treat a deficiency. The subjects average sleep latency went from 143 minutes to 23 minutes (27); It can have a huge impact.
If you’d like to get it from food sources, the best vegan sources of iron are:
- Vegetables (spinach, brussel sprouts, kale, mushrooms)
- Seeds and nuts (sesame seeds, cashews, flaxseed)
- Beans (all varieties are great)
Note that you can increase the absorption of nonheme iron by 3-6 times by eating it alongside vitamin C (28).
Magnesium is readily available in a wide variety of plants, so you should be able to get enough without much issue.
The best types of vegan foods for magnesium include:
- Swiss chard
- Buckwheat groats
- Sesame seeds
- Brazil nuts
- Sunflower seeds
- Hemp seeds
If you’re paying close attention, you’ll have noticed that spinach, oats, and sesame seeds are also great sources of iron.
If for some reason you can’t get as much magnesium as you’d like, there are vegan magnesium supplements, and they can be useful.
Research indicates that oral magnesium taken regularly in the evening can be a useful therapy in certain patients with RLS (29).
If you’ve made it this far, you’re probably having a hard time getting to sleep.
Hopefully this will be a starting point to identifying the root cause(s) of your problems. Going to see a sleep specialist would be the ideal next step.