This post stems from my personal quest to improve the quality of my own sleep. When not confined to a 9-5 job, I tend to indulge my night owl tendencies and stay up late working, at the expense of a decent night’s sleep. I’d also been waking up anywhere from 6am (and feeling rubbish) to midday (and still feeling rubbish). Ah, the freedom of the self-employed.
Anyway, I’ve successfully cleaned up my sleeping act and am happy to report that for the past couple of months I’ve consistently gotten out of bed at 6:30am feeling refreshed and with a clear head. Hurrah! Now I can be one of those insufferable people who go on and on about how beautiful the dawn light is and how great they feel. (But seriously, there is some spectacular light going on and I DO feel much better).
In my practice as dietitian, I always ask people about their sleeping patterns because the quality of your sleep has such an impact on your health and the food choices you make. Chronic sleep deprivation is associated with a range of metabolic derangements, such as decreased glucose (blood sugar) tolerance and insulin sensitivity, and increased hunger and appetite (1). One study showed that after just one night of sleep-restriction (4 hours sleep), subjects ate significantly more calories (22% more) when compared to their well-rested counterparts (2).
The most common sleep-related problems I hear are:
- Not getting enough sleep and waking up unrefreshed and feeling tired through the day
- Being forced into an irregular sleeping pattern due to working shifts or partying on the weekends
- Taking a long time to fall asleep
The following is a list of food and nutrition-related ways to improve the quality of your sleep. Let me know if you've already tried any of the following strategies and had any success by leaving a comment below.
1. Reduce or eliminate caffeine from your diet
Caffeine is a potent central nervous system stimulant found in coffee, black tea, diet Coke, energy drinks and cacao (chocolate). Caffeine has a long half-life - around 5 hours - which means that if you drink coffee throughout the afternoon, there can still be a significant amount of caffeine floating round in your bloodstream when it comes time to go to sleep.
If you find it hard to fall asleep at night and think that caffeine may be a factor, I'd recommend avoiding caffeine after midday or cutting it out of your diet altogether. The amount of caffeine in a cup of coffee is highly variable - instant coffee generally contains less caffeine than espresso-style coffee (approximately 70mg compared to anywhere from 100-200mg per cup), and a cup of tea can also contain anywhere from 25 to 110mg of caffeine per cup, depending on how strongly it is brewed.
To kick the caffeine habit:
- Try a coffee replacement: if you're a hardcore coffee addict, switch to roasted dandelion root (often blended with chicory and marketed as a coffee alternative, such as this one), which has a very similar taste to coffee, and makes a top-notch latte.
- Go green: if you get your kicks from multiple cups of black tea throughout the day, try switching to green tea, which has slightly less caffeine (at around 30-50mg per cup) but has the same beneficial effects on the brainwaves as black tea, as they come from the same plant (Camelia sinesis).
- Go herbal: rooibos is another good option as it's still mentally-stimulating like black tea, yet totally caffeine-free. You could also try any number of the vast array of herbal teas available. I'm currently hooked on cold-steeped hibiscus - it's packed with antioxidants.
2. Try herbal remedies
Herbal teas are a great option to try if you find it difficult to fall asleep at night. Chamomile, lemon balm and passionflower tea have all been shown to help reduce stress and anxiety and promote sleep. Stick to a small (150mL) cup about an hour before you go to bed, as you don't want to be getting up through the night to use the bathroom. Nighttime trips to the bathroom interfere with sleep cycles and affect sleep quality in a big way, so go easy on the fluids before bed!
If you'd like to try a supplemental herbal extract such as valerian, chat to a Naturopath or Herbalist first to make sure it's the right choice for you. Always let your practitioner know if you're taking any medications or other supplements as many herbs can interact with one another and with drugs. Always check with your GP or Obstetrician if you're pregnant or breastfeeding before commencing any herbal therapies - even herbs that are readily accessible to the public may not be safe in pregnancy.
3. Boost the levels of serotonin in your brain with whole plant foods (not supplements!)
Serotonin is a neurotransmitter which can affect our mood, appetite and sleep. Serotonin is converted to melatonin in the brain by the pineal gland, which is a hormone which induces sleep at night. Unfortunately we can't just take a serotonin supplement or eat foods which contain serotonin (such as bananas), as it can't get cross the blood-brain barrier and get into the brain. However, the precursor to serotonin - the amino acid tryptophan - can get into the brain (3). Tryptophan supplements are available, but I always recommend choosing food sources of nutrients rather than relying on supplements.
Tryptophan is found in in high levels in protein-rich foods such as legumes, soy foods, nuts and seeds. Whether the tryptophan in the blood actually gets into the brain depends on a two main factors: the ratio of tryptophan to total protein in the food, and whether carbohydrate is consumed with the protein (4).
Turkey is often thought to be sleep-inducing thanks to its tryptophan content, but this is actually a myth. Turkey actually contains about the same amount of tryptophan as other meats such as chicken (250mg compared to 230mg per 100g meat), and the tryptophan doesn't actually get into the brain as animal protein contains high levels of other amino acids which compete for transport across the blood-brain barrier (4).
The best way to raise your brain levels of serotonin is to eat plant-based, protein-rich foods such as lentils and legumes, which have a high ratio of tryptophan to total protein and contain carbohydrate, which stimulates insulin release. Insulin causes the uptake of the competing amino acids into the muscle, which allows the tryptophan to get into the brain and convert to serotonin.
Seeds are particularly high in tryptophan - so get into the habit of sprinkling them on your dinner meal (I love pepitas on just about everything) or snacking on them with some fruit after dinner.
4. Ensure you're getting the micronutrients your body needs
Supplemental magnesium is often recommended as a sleep aid, as magnesium acts as a cofactor for an enzyme involved in the synthesis of melatonin in the brain. If you have a magnesium deficiency (because of an inadequate diet), supplemental magnesium may be of use, but I believe in preventing deficiencies in the first place through dietary adequacy rather than recommending supplements.
The best dietary sources of magnesium are pepitas (just 30g provides 50% of the RDI for magnesium for a woman), oat bran, rolled oats, tofu, brown rice, chia seeds, soy milk and bananas.
If you do choose to take a magnesium supplement, don't exceed 350mg elemental magnesium per day.
Vitamin B12 is involved in the secretion of melatonin in the brain from the pineal gland, and as such, low levels of vitamin B12 can interfere with sleep. Vitamin B12 is only found in animal products and if you follow a plant-based diet, supplementation with vitamin B12 is essential. You can read more about vitamin B12 in my post here.
Niacin (vitamin B3):
Niacin is also important in maintaining levels of tryptophan in the body, as if the dietary intake is inadequate, the body will convert tryptophan to niacin. Good sources are whole grain pasta, potatoes and sweet potatoes, almonds, cashews, tahini and tofu.
Vitamin B6 (pyridoxine) is required for the conversion of tryptophan to serotonin in the brain (5). Good sources of B6 are sunflower seeds, pistachio nuts, bok choy, bananas, sweet potatoes and potatoes.
Omega-3 fats are required to convert serotonin to melatonin in the brain, and are another nutrient you need to pay special attention to if you’re on a plant-based diet.
Good sources of plant-based omega-3 are ground flaxseeds, chia, walnuts, hemp seeds and green leafy vegetables. These foods provide the omega-3 ALA, which is converted to the longer chain forms of omega-3 (DHA and EPA) in the body. As the conversion of ALA to DHA and EPA is known to be quite inefficient in the body, supplemental EPA and DHA in the form of algal DHA supplements are available.
And one more bonus (not nutrition-related) strategy:
No screens before bed!
TV, computer, laptop and phone screens emit short-wave blue light which can suppress the production of melatonin (the hormone released at night which induces sleep).
To minimise the effect of blue light at night:
- Download the program f.lux on your laptop and computer - it blocks blue wavelengths and gives your screen a weird (yet kind of fun) sunset-orange glow.
- Ban iPhones from the bedroom. It's particularly detrimental to lie in bed staring at a phone close to your face, as the short distance between the light source and your eyes means you're exposed to a lot of blue light
- Get outside when the sun is up to expose your eyes to these blue wavelengths that are found naturally in sunlight - they boost attention, wakefulness and mood, which is what we want through the day (but not at night!)
Happy sleeping! x
1. Spiegel K. Sleep loss: a novel risk factor for insulin resistance and Type 2 diabetes. Journal of Applied Physiology. 2005 Nov 1;99(5):2008–19.
2. Brondel L, Romer MA, Nougues PM, Touyarou P, Davenne D. Acute partial sleep deprivation increases food intake in healthy men. American Journal of Clinical Nutrition. 2010 Jun 1;91(6):1550–9.
3. Young SN. How to increase serotonin in the human brain without drugs. Journal of psychiatry & neuroscience: JPN. 2007;32(6):394.
4. Wurtman RJ, Wurtman JJ, Regan MM, McDermott JM, Tsay RH, Breu JJ. Effects of normal meals rich in carbohydrates or proteins on plasma tryptophan and tyrosine ratios. The American journal of clinical nutrition. 2003;77(1):128–32.
5. Peuhkuri K, Sihvola N, Korpela R. Diet promotes sleep duration and quality. Nutrition Research. 2012 May;32(5):309–19.