Omega-3s: Do they help you sleep?

This is the first in a short series exploring the evidence behind popular sleep-promoting ingredients, starting with omega-3 fatty acids.

Sleep Supplements

Omega-3s: What ARE THEY?

Omega-3 refers to a group of essential fatty acids, meaning that the body cannot make them itself, so we need to get them from our diet.

They are polyunsaturated fats that play key roles in your brain, heart, and overall health, as components of cell membranes.

The three main types are: 

• EPA (eicosapentaenoic acid): This is an active molecule essential for cardiovascular health, reducing triglycerides and inflammation.

• DHA (docosahexaenoic acid): This is a major building block of your brain, eyes, and nervous system. In fact, a large portion of the fat in your brain is DHA, which is why it’s so important for brain development, cognitive function, and vision.

• ALA (alpha-linolenic acid): This is found in plants; your body converts a very small amount into EPA/DHA, but only 5-10%.

Omega-3 fatty acids are found in oily fish like salmon and sardines, as well as plant sources such as flaxseed and chia.

How might omega-3s affect sleep?

Omega-3, especially DHA, may affect sleep through a few biological mechanisms:

• Melatonin support: low DHA levels have been linked to lower melatonin production

• Brain function: DHA helps stabilise the neurons and neurotransmitters involved in sleep

• Inflammation: EPA has anti-inflammatory effects, which may support sleep quality

DO we geT enough OMEGA-3s IN OUR DIET?

The Omega-3 Index reflects the percentage of EPA and DHA (the most beneficial omega-3 fats) in your blood. This provides a much clearer picture than only tracking what you eat and gives a useful insight as to who may be deficient:

• Optimal: ≥8%

• Typical in Western populations: 5%

• Some vegans and military personnel: 3.5%

An index below 4% is considered low, and thought to negatively impact health, while around 8% or higher is viewed as optimal for supporting heart and brain health (Harris, 2010).

An estimated 90–95% of people fall below this optimal range, meaning that most of us are operating with suboptimal levels without realising it. Rather than a dramatic deficiency with obvious symptoms, this tends to be a “silent gap” that may subtly impact long-term health, which is why increasing omega-3 intake, through diet or supplementation, could be positive over time.

Do we NEED omega-3 supplements?

We do not necessarily need supplements. The richest sources are often summarised as the SMASH fish:

S- Salmon

M- Mackerel

A- Anchovies

S- Sardines

H- Herring

Two to three portions of oily fish per week can be enough to significantly improve omega-3 status for many people. However many people dislike or choose not to eat fish, and may not get sufficient plant sources of omega-3s, making supplementation a sensible step.

What does the research say About omega-3 Supplements to help sleep?

The evidence in adults is mixed - it's possible that supplementation may support sleep in those with a deficiency, but trials do not typically report on omega 3 intake prior to the start of the study.

• A systematic review of studies in postmenopausal women found no clear improvement in sleep quality or vasomotor symptoms - so omega-3s may not be helpful for hormone-related sleep problems (Iqbal et al. 2023).

  
  

• In normal sleepers, actigraphy results from one randomised placebo controlled trial showed potential benefits for falling asleep faster and sleep efficiency with DHA-rich oil, but the participants also reported feeling less rested and energetic. EPA-rich oil was associated with a reduction in time in bed (Patan et al. 2021).

However, a recent systematic review  (Conti 2025) suggested that there could be benefits in specific groups:

• Maternal omega-3 levels during pregnancy were found to affect neonatal sleep–wake patterns. Omega-3s may be particularly important for developing brains and early sleep patterns.

• Omega-3 supplementation has been found to reduce symptoms of sleep disturbances throughout childhood, especially in the presence of clinically-diagnosed sleep problems.

• Higher DHA levels have been linked to less severe sleep apnea.

  
  

So… Should You Take Omega-3

supplements to help you sleep?

Omega-3 are generally considered safe supplements for most people to take.

But:

• Evidence for sleep-specific benefits in adults is limited

• Effects tend to be modest and inconsistent

However, omega-3s do have compelling benefits beyond sleep. Omega-3s (especially EPA & DHA) are strongly linked to better health, particularly:

• Brain health (cognition, mood, dementia risk) (DiNicolantonio & O’Keefe, 2020)

• Heart health (stroke, heart disease, mortality) (Calder, 2010)

We recommend listening to the Zoe podcast, 25^th July 2025, on omega-3s and brain health for more insights. If you are feeling the benefits from omega-3 supplements, there is certainly no reason to stop.

The Bigger Picture when it comes to supplements for sleep...

Supplements can support sleep but they are not a substitute for healthy sleep habits such as:

• Regular sleep and wake times

• Daily morning daylight exposure

• Physical activity

• Winding down without screens

A consistent routine always wins!