Bananas For Insomnia: Do They Actually Help?

I’ve read claims about bananas improving insomnia symptoms.

Some people are convinced about this, but there isn’t much research that specifically looks at the impact of bananas on sleep.

However, some sleep studies do exclude bananas, along with other foods like milk, tomatoes, or caffeine-containing drinks, because of their potential to alter a person’s circadian rhythm (1).

I’ll walk you through the possible ways that bananas may affect insomnia, and we’ll summarize everything at the end.

Bananas Can Increase Melatonin Levels

Melatonin is one of the most important hormones involved in sleep. In short, your melatonin levels control how sleepy you feel.

Your body starts to produce more melatonin in the dark, but certain things (like blue light from screens) can inhibit melatonin production and worsen sleep quality.

While it’s most effective to remove those things, another approach is to take melatonin supplements, or eat foods that encourage melatonin production.

One study found that consuming bananas raised blood melatonin levels significantly (along with a few other fruits like pineapples and oranges) (2).

While it varied among subjects, melatonin levels peaked at the 120 minute mark, and ranged from about 2-4 times baseline.

SummaryMelatonin levels returned to baseline within the next 60 minutes, so the optimal time to eat a banana before sleeping would likely be around 2 hours before going to sleep.

Why Do Bananas Raise Melatonin Levels?

Bananas aren’t the only food to raise melatonin levels.

In general, carbohydrates increase tryptophan production, which is a precursor of melatonin and serotonin (3).

As mentioned above, both pineapples and oranges also had similar effects on melatonin. So this specific result is less of a “bananas are a magical food for sleep,” and more of a “carbohydrates in reasonable amounts can improve sleep” thing.

Glycemic Index Can Affect Insomnia

Just because eating some carbohydrates can improve melatonin production, doesn’t mean you should eat a bag of sugary candy before going to sleep.

There’s more to the story...

The glycemic index is a scale from 0 to 100 that indicates how much blood sugar rises after eating a certain amount of a food. It’s not a perfect measure, but is often used in research.

One study looked at the effect of the most popular fruits and other carbohydrates in the United States and their effect on sleep (4). For reference, here are the categories that the fruits fell into

• Low GI (<55) - Apples, strawberries, oranges, peaches.
• Intermediate GI (56-69) - Ripe bananas, grapes.
• High GI (>70) - Watermelon. 

The study found::

The results suggest that high-GI diets could be a risk factor for insomnia...Substitution of high-GI foods with minimally processed, whole, fiber-rich carbohydrates should be evaluated as potential treatments of, and primary preventive measures for insomnia...

Note that this study was on postmenopausal women (who are at high risk for insomnia), but you’d reasonably expect the results to apply to the general population.

SummaryBananas have a low-medium glycemic index, which puts them among the “good” carbohydrates to eat to help reduce insomnia symptoms.

Could Nutrients in Bananas Help Insomnia?

One other aspect of bananas that you might wonder about affecting sleep is their nutritional value.

Bananas are relatively high in 2 major nutrients: potassium and vitamin C.

There’s very little evidence linking potassium to affecting sleep quality.

However, there is some weak evidence that suggests that vitamin C may improve cancer-related symptoms that include insomnia (as well as fatigue, nausea, pain, etc.) (5).

SummaryAt best there is weak evidence that the high amount of vitamin C in bananas may improve insomnia symptoms, but there doesn’t appear to be anything special about a banana’s nutrition.

Summary: Do Bananas Improve Insomnia?

As I said from the start, there’s little specific research on bananas and insomnia, so we have to piece together what we can.

We have seen that there is some evidence that bananas can improve sleep quality.

Like other “healthy” carbohydrates, bananas upregulate melatonin production, one of the most important hormones for inducing sleep. It's a good thing to eat at night if you're hungry before sleeping.

However, I didn’t come across anything particularly special about bananas aside from that, and other foods (particularly vegetables and some fruits) can have a similar effect.

More melatonin can help sleep issues in many cases (particularly with shift work or jet lag), but it’s also not likely to be a complete cure for insomnia (although it’s unlikely that eating a banana a few hours before sleeping would hurt either).

To learn more about where this would fit into a treatment plan, see our post on what doctors prescribe for insomnia.

References

1. Insomnia in Shift Work Disorder Relates to Occupational and Neurophysiological Impairment
2. Serum melatonin levels and antioxidant capacities after consumption of pineapple, orange, or banana by healthy male volunteers
3. Amino acid assignment to one of three blood-brain barrier amino acid carriers
4. High glycemic index and glycemic load diets as risk factors for insomnia: analyses from the Women's Health Initiative
5. The effect of intravenous vitamin C on cancer- and chemotherapy-related fatigue and quality of life