Sue's Blog

Study: diet can cause insomnia in adults


About 30% of adults suffer from insomnia.

In a recent study, researchers examined data from more than 50,000 postmenopausal women who kept food diaries as part of the Women’s Health Initiative. Women who ate more sugars, starches and refined grains reported more insomnia -  those who ate more unprocessed food such as whole grains, fruits and vegetables had less sleeping problems.

The researchers concluded:

  "the dietary culprit triggering the women's insomnia was the highly processed foods"

They thought it might be the sugar. We don't agree.

Over 50 years ago, American allergist Dr Ben Feingold warned that certain food additives and dietary salicylates could cause sleeplessness in some children.

When we first started avoiding additives and some salicylates in our kids' food, I didn't realise I too could be affected. One evening, a restaurant served up icecream desserts each with a glace cherry on top, so I ate all 4 cherries - coloured with erythrosine E127, Red No 3 -  thinking I was being helpful. That night, my husband and kids slept peacefully, while I tossed and turned all night. No more artificial colours for me!

What our readers say

Our readers, often using the RPAH elimination diet, have found that additives and natural food chemicals - including colours, preservatives, flavours, MSG-type flavour enhancers, natural salicylates and/or amines - can trigger sleep problems at all ages. Everyone is different.

Some reader reports

"I have been an insomniac since I was 16 ... it has been a major issue in my life. I have lived on approximately four hours sleep a day. I have spent thousands of dollars in trying to find the answer. ...  I have only read probably one quarter of your book. But the next day I eliminated wheat, dairy and all preservatives/additives ... and I suddenly found myself able to fall asleep in ten minutes ... " - Ingrid from story [150]

"I didn't do the diet for insomnia but it has cured my insomnia which I had for over a decade" - Sharyn from facebook thread story [1464]

 "Diet has helped me with ... sleep issues including nightmares/insomnia/sleep walking ... " – Ruth from facebook thread story [1421]

"160b (annatto natural colour) has a terrible effect on me causing insomnia ..." - Peter from facebook thread story [1378]

"annatto ... keeps my husband and 3 children awake and feeling wired for hours if they have it at dinner time" – Jessica from facebook thread story [1378]

"... in recent years I have suffered with insomnia ...  after starting my low SAG (Salicylate-Amine-Glutamate) additive-free diet, the first miracle was being able to sleep again ..." - from story [1505]

"... not long after [eating a meat pie] I was feeling very thirsty and restless. In the middle of the night, I was waking ... from nightmares and spending long periods of time trying to fall asleep again, while feeling flushes of heat/itch all over my body. ... 5 months later: ... I have certainly tested MSG as the main culprit ... " - Carlos from story [1180]

"When my husband did the amine challenge [eg chocolate, cheese, banana] he couldn't fall asleep and when he finally did he woke up a couple of hours later and couldn't get back to sleep ... as long as he is careful about amines he hasn't had any more sleep issues" – Ruth from story [1437]  

Also see Sleepless babies and diet

“My baby was waking perhaps once a night … until I started her, at 10 months on bread. She immediately returned to night waking … I found that the bread had preservative 282 in it so we stopped feeding it to her. Within a couple of nights she again settled down to a peaceful nights' sleep! – from story [831]

... and check your toothpaste...

Most people think that additives in toothpaste won't affect them because they don't eat it. On the 14th day of a trek in Nepal, our guide who was an exceptionally fit, strong young man, admitted he was having terrible trouble sleeping at night. After looking at all the foods he was eating - which were the same as ours - I asked him to check his toothpaste. It contained 2 artificial red colours, one of which isn't even permitted in foods. He threw it away and immediately his severe chronic insomnia stopped, as described in story [1293] - we recommend plain unflavoured toothpaste.

What you can do

Everyone is different. For some people, simply cutting out one additive may be the answer. Or some people may need to try the RPAH elimination diet to find out exactly what is causing the problem,.

If cutting down on processed foods, be aware that this includes most wraps and breads due to the propionate bread preservative that can be misleadingly labelled, for example: "cultured (or fermented) wheat flour" even in a wholegrain and certified organic products claiming "no artificial colours or preservatives".   

See How to Start failsafe eating

If that doesn't work, we recommend a 2-3 week trial of the RPAH elimination diet with challenges for diagnosis of the problem - preferably supervised by one of the experienced dietitians on our list

See how manageable this elimination diet is with the free Failsafe booklet

The science

In 1994, Australian researchers Drs Katherine and Kenneth Rowe showed that sleep disturbance - both difficulty falling asleep and frequent night waking - could be caused by artificial colours in a dose-related response.  The study reported that younger children experienced:

“constant crying, tantrums, irritability, restlessness, and severe sleep disturbance … Their parents were exhausted through lack of sleep and the constant demands of their children, who were unable to be comforted or controlled.” 

Similarly, years of work from researchers at Sydney's Royal Prince Alfred Hospital Allergy Clinic has identified about 50 additives and 3 natural chemicals that can cause sleep problems.

Gangwisch JE1 et al, High glycemic index and glycemic load diets as risk factors for insomnia: analyses from the Women's Health Initiative.Am J Clin Nutr, 2019, Dec 11,pii: nqz275.

More in the factsheet Diet, sleep disturbance and insomnia with an attached story collection.