Mendelian randomization study on the causal relationship between dietary factors and insomnia symptoms

doi:10.3969/j.issn.1674-8115.2026.06.010

Abstract

Abstract:

Objective ·To investigate the causal relationships between multiple dietary factors and insomnia symptoms by using a two-sample Mendelian randomization (MR) approach. Methods ·Single nucleotide polymorphisms (SNPs) associated with various dietary factors and insomnia symptoms were extracted from publicly available Genome-Wide Association Studies (GWAS) databases and used as instrumental variables. The inverse variance weighted (IVW) method was applied as the primary analysis, complemented by the weighted median, MR-Egger regression, weighted mode, and simple mode methods. Heterogeneity was assessed by using Cochran's Q test, while horizontal pleiotropy was evaluated by using the MR-Egger intercept test. Leave-one-out analyses were conducted to examine the influence of individual SNPs on the overall results. Results ·Six dietary factors were identified as having potential causal associations with insomnia symptoms. Alcohol intake (OR=1.07, 95%CI 1.01‒1.12, P=0.018) and poultry intake (OR=1.12, 95%CI 1.00‒1.24, P=0.041) were positively associated with insomnia symptoms.. In contrast, oily fish (OR=0.91, 95%CI 0.84‒1.00, P=0.047), cereals (OR=0.92, 95%CI 0.87‒0.99, P=0.017), fresh fruit (OR=0.84, 95%CI 0.72‒0.98, P=0.022), and dried fruit (OR=0.77, 95%CI 0.69‒0.85, P=5.256×10^-7) intake were negatively associated with insomnia symptoms. After Bonferroni correction, the causal relationship between dried fruit intake and insomnia symptoms remained statistically significant. Conclusion ·The findings support potential causal associations between different dietary factors and insomnia symptoms, providing genetic evidence for further investigation into the role of dietary factors in sleep health and potential intervention strategies.

Key words: insomnia, dietary factor, Mendelian randomization study

CLC Number:

R749

Cui Guoyu, Wang Qiuyun, Tan Haozhou, Yang Qianzi, Luo Yan. Mendelian randomization study on the causal relationship between dietary factors and insomnia symptoms[J]. Journal of Shanghai Jiao Tong University (Medical Science), 2026, 46(6): 778-785.

Figures/Tables 4

TrendMD

References 30

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Category	Trait	Population	Sample size/n	SNP number/n	Open GWAS ID
Liquids	Alcoholic drinks per week	European	335 394	11 887 865	ieu-b-73
	Water consumption	European	445 799	5 733 790	ebi-a-GCST90096929
	Tea consumption	European	434 171	5 733 790	ebi-a-GCST90096926
	Milk intake	European	64 943	9 851 867	ukb-b-2966
	Yogurt intake	European	64 949	9 851 867	ukb-b-7753
	Coffee intake	European	428 860	9 851 867	ukb-b-5237
Meat	Pork consumption	European	187 202	5 733 790	ebi-a-GCST90096919
	Beef consumption	European	241 092	5 733 790	ebi-a-GCST90096901
	Lamb consumption	European	189 984	5 733 790	ebi-a-GCST90096915
	Poultry intake	European	461 900	9 851 867	ukb-b-8006
	Oily fish consumption	European	297 881	5 733 790	ebi-a-GCST90096918
	Non-oily fish consumption	European	318 136	5 733 790	ebi-a-GCST90096917
Staple foods	White rice intake	European	64 949	9 851 867	ukb-b-14690
Grains	Cereal intake	European	441 640	9 851 867	ukb-b-15926
Fruit	Fresh fruit consumption	European	433 186	5 733 790	ebi-a-GCST90096912
Fruit	Dried fruit consumption	European	409 125	5 733 790	ebi-a-GCST90096909
Vegetable	Cooked vegetable intake	European	448 651	9 851 867	ukb-b-8089
Vegetable	Salad/raw vegetable intake	European	435 435	9 851 867	ukb-b-1996
Nuts	Salted nuts intake	European	64 949	9 851 867	ukb-b-15960
Nuts	Unsalted nuts intake	European	64 949	9 851 867	ukb-b-12217
Outcome	Insomnia	European	462 341	9 851 867	ukb-b-3957

Category	Trait	Population	Sample size/n	SNP number/n	Open GWAS ID
Liquids	Alcoholic drinks per week	European	335 394	11 887 865	ieu-b-73
	Water consumption	European	445 799	5 733 790	ebi-a-GCST90096929
	Tea consumption	European	434 171	5 733 790	ebi-a-GCST90096926
	Milk intake	European	64 943	9 851 867	ukb-b-2966
	Yogurt intake	European	64 949	9 851 867	ukb-b-7753
	Coffee intake	European	428 860	9 851 867	ukb-b-5237
Meat	Pork consumption	European	187 202	5 733 790	ebi-a-GCST90096919
	Beef consumption	European	241 092	5 733 790	ebi-a-GCST90096901
	Lamb consumption	European	189 984	5 733 790	ebi-a-GCST90096915
	Poultry intake	European	461 900	9 851 867	ukb-b-8006
	Oily fish consumption	European	297 881	5 733 790	ebi-a-GCST90096918
	Non-oily fish consumption	European	318 136	5 733 790	ebi-a-GCST90096917
Staple foods	White rice intake	European	64 949	9 851 867	ukb-b-14690
Grains	Cereal intake	European	441 640	9 851 867	ukb-b-15926
Fruit	Fresh fruit consumption	European	433 186	5 733 790	ebi-a-GCST90096912
Fruit	Dried fruit consumption	European	409 125	5 733 790	ebi-a-GCST90096909
Vegetable	Cooked vegetable intake	European	448 651	9 851 867	ukb-b-8089
Vegetable	Salad/raw vegetable intake	European	435 435	9 851 867	ukb-b-1996
Nuts	Salted nuts intake	European	64 949	9 851 867	ukb-b-15960
Nuts	Unsalted nuts intake	European	64 949	9 851 867	ukb-b-12217
Outcome	Insomnia	European	462 341	9 851 867	ukb-b-3957

Category	Exposure	IV number/n	β	SE	P value	OR (95%CI)
Liquids	Alcoholic drinks per week	34	0.064	0.027	0.018	1.07 (1.01‒1.12)
	Water consumption	56	-0.004	0.015	0.770	1.00 (0.97‒1.02)
	Tea consumption	26	-0.042	0.066	0.520	0.96 (0.84‒1.09)
	Milk intake	6	-0.019	0.049	0.690	0.98 (0.89‒1.08)
	Yogurt intake	3	0.019	0.048	0.699	1.02 (0.93‒1.12)
	Coffee intake	39	0.004	0.029	0.905	1.00 (0.95‒1.06)
Meat	Pork consumption	5	0.348	0.418	0.405	1.42 (0.62‒3.21)
	Beef consumption	6	-0.214	0.409	0.601	0.81 (0.36‒1.80)
	Lamb consumption	20	0.155	0.229	0.501	1.17 (0.74‒1.83)
	Poultry intake	7	0.112	0.055	0.041	1.12 (1.00‒1.24)
	Oily fish consumption	42	-0.090	0.045	0.047	0.91 (0.84‒1.00)
	Non-oily fish consumption	5	-0.239	0.186	0.198	0.79 (0.55‒1.13)
Staple foods	White rice intake	3	0.005	0.137	0.972	1.00 (0.77‒1.32)
Grains	Cereal intake	39	-0.078	0.033	0.017	0.92 (0.87‒0.99)
Fruits	Fresh fruit consumption	47	-0.178	0.078	0.022	0.84 (0.72‒0.98)
Fruits	Dried fruit consumption	41	-0.267	0.053	5.256×10^-7	0.77 (0.69‒0.85)
Vegetables	Cooked vegetable intake	17	-0.052	0.089	0.559	0.95 (0.80‒1.13)
Vegetables	Salad/raw vegetable intake	18	0.064	0.066	0.332	1.07 (0.94‒1.21)
Nuts	Salted nuts intake	7	-0.012	0.067	0.855	0.99 (0.87‒1.13)

Category	Exposure	IV number/n	β	SE	P value	OR (95%CI)
Liquids	Alcoholic drinks per week	34	0.064	0.027	0.018	1.07 (1.01‒1.12)
	Water consumption	56	-0.004	0.015	0.770	1.00 (0.97‒1.02)
	Tea consumption	26	-0.042	0.066	0.520	0.96 (0.84‒1.09)
	Milk intake	6	-0.019	0.049	0.690	0.98 (0.89‒1.08)
	Yogurt intake	3	0.019	0.048	0.699	1.02 (0.93‒1.12)
	Coffee intake	39	0.004	0.029	0.905	1.00 (0.95‒1.06)
Meat	Pork consumption	5	0.348	0.418	0.405	1.42 (0.62‒3.21)
	Beef consumption	6	-0.214	0.409	0.601	0.81 (0.36‒1.80)
	Lamb consumption	20	0.155	0.229	0.501	1.17 (0.74‒1.83)
	Poultry intake	7	0.112	0.055	0.041	1.12 (1.00‒1.24)
	Oily fish consumption	42	-0.090	0.045	0.047	0.91 (0.84‒1.00)
	Non-oily fish consumption	5	-0.239	0.186	0.198	0.79 (0.55‒1.13)
Staple foods	White rice intake	3	0.005	0.137	0.972	1.00 (0.77‒1.32)
Grains	Cereal intake	39	-0.078	0.033	0.017	0.92 (0.87‒0.99)
Fruits	Fresh fruit consumption	47	-0.178	0.078	0.022	0.84 (0.72‒0.98)
Fruits	Dried fruit consumption	41	-0.267	0.053	5.256×10^-7	0.77 (0.69‒0.85)
Vegetables	Cooked vegetable intake	17	-0.052	0.089	0.559	0.95 (0.80‒1.13)
Vegetables	Salad/raw vegetable intake	18	0.064	0.066	0.332	1.07 (0.94‒1.21)
Nuts	Salted nuts intake	7	-0.012	0.067	0.855	0.99 (0.87‒1.13)