A Mediterranean-style dietary intervention supplemented with fish oil improves diet quality and mental health in people with depression: A randomized controlled trial (HELFIMED)

Figures & data

Figure 1 Consort flow chart of participants through the study. LTF = lost to follow-up; DSQ = dietary screening tool.

Table 1 Participant demographics and health status by treatment group (n = 152)

	Treatment n = 75	Control n = 77	P
Age (M ± SD)	43.8 ± 12.8	44.6 ± 13.3	0.698
Gender	28% male	34% male	0.277
Race	93% Caucasian	90% Caucasian	0.412
Education			0.132
– completed years 8–12 (n)	12	20
– completed post school qualifications (n)	63	57
Household income per annum			0.862
– $20 000–$60 000 (n)	42	39
– more than $60 000 (n)	23	20
SEIFA index (M ± SD)	6.11	6.25	0.737
Marital status			0.670
– married or defacto (n)	33	34
– separated/divorced/single (n)	18	22
Depression diagnosis (n)^b	24	33	0.167
Taking antidepressant medication (n)	24	30	0.338
DASS Depression score (M ± SD)	22.5 ± 10.6	21.3 ± 9.0	0.508
Sleep problems (n)	74	75	0.575

T-tests were used to compare continuous variables and Chi-square tests for categorical variables.

^aSEIFA, a ranking of Australian neighbourhood disadvantage and advantage, based on census data for variables such as education, income and occupation status.

^bNote that participants who did not have a diagnosis of depression were excluded if they reported symptoms in the normal-mild categories.

Figure 2 Mediterranean diet scores in each group at baseline and 3 months (P < 0.001). Bars represent standard error of the mean.

Table 2 Mediterranean diet and food group scores in Mediterranean diet (MedDiet) and Social groups at baseline, 3 and 6 months, and test of differences between groups using linear mixed modelling, n = 152 (MedDiet n = 75; social group n = 77)

	Baseline M ± SD	3 months M ± SD	6 months M ± SD	Baseline to 3 months					3 months to 6 months
				Estimate	SE	t-score	P	95% CI	Estimate	SE	t-score	P	95% CI
Mediterranean diet score^a
MedDiet	4.57 ± 0.24	7.08 ± 0.28	7.44 ± 0.32
Social group	4.55 ± 0.24	5.20 ± 0.32	5.72 ± 0.36	0.95	0.24	3.95	<0.001**	0.47, 1.42	−0.22	0.42	−0.53	0.597	−1.06, 0.61
Vegetables
MedDiet	1.73 ± 0.13	2.93 ± 0.15	3.07 ± 0.20
Social group	1.74 ± 0.13	1.99 ± 0.17	2.27 ± 0.22	0.95	0.24	3.95	<0.001**	0.47, 1.42	−0.20	0.26	−0.75	0.454	−0.71, 0.32
Fruit
MedDiet	1.35 ± 0.12	1.85 ± 0.14	2.02 ± 0.17
Social group	1.38 ± 0.12	1.45 ± 0.15	1.42 ± 0.19	0.43	0.20	2.10	0.038*	0.02, 0.83	0.12	0.21	0.55	0.581	−0.30, 0.53
Wholegrain
MedDiet	3.81 ± 0.47	5.49 ± 0.53	4.49 ± .56
Social group	4.33 ± 0.47	3.92 ± 0.59	4.29 ± .62	2.09	0.80	2.63	0.010*	0.51, 3.67	−1.40	.84	−1.68	0.098	−3.07, 0.26
Takeaway food
MedDiet	1.01 ± 0.18	0.73 ± 0.21	0.47 ± .21
Social group	0.84 ± 0.18	0.87 ± 0.23	0.78 ± .23	−0.32	0.29	−1.07	0.29	−0.90, 0.27	−0.19	0.37	−0.51	0.61	−0.92, 0.54
Unhealthy snacks
MedDiet	4.98 ± 0.56	2.70 ± 0.63	3.10 ± 0.55
Social group	3.62 ± 0.55	3.30 ± 0.70	3.00 ± 0.61	−1.95	0.93	−2.10	0.038*	−3.79, −0.11	0.78	0.64	1.22	0.226	−0.49, 2.04
Sweetened drinks
MedDiet	2.06 ± 0.38	1.24 ± 0.43	1.38 ± 0.38
Social group	2.63 ± 0.38	1.62 ± 0.47	1.98 ± 0.42	0.19	0.59	0.32	0.752	−0.99, 1.37	−0.10	0.49	−0.20	0.841	−1.08, 0.88
Nuts
MedDiet	2.13 ± 0.36	4.05 ± 0.41	4.10 ± 0.50
Social group	1.40 ± 0.35	1.82 ± 0.46	1.58 ± 0.56	1.49	0.65	2.29	0.024*	0.20, 2.78	0.29	0.66	0.44	0.659	−1.03, 1.62
Legumes
MedDiet	0.93 ± 0.18	2.35 ± 0.21	1.99 ± 0.27
Social group	0.72 ± 0.18	1.25 ± 0.24	0.98 ± 0.30	0.90	0.37	2.41	0.017*	0.16, 1.64	−0.12	0.38	−0.31	0.759	−0.86, 0.63
Fish
Intervention	0.79 ± 0.16	1.50 ± 0.19	1.32 ± 0.23
Control	1.07 ± 0.16	1.43 ± 0.21	1.46 ± 0.26	0.34	0.33	1.03	0.307	−0.32, 0.99	−0.23	0.26	−0.89	0.376	−0.75, 0.29
Meat/chicken
MedDiet	4.84 ± 0.38	3.23 ± 0.43	3.57 ± 0.34
Social group	4.79 ± 0.37	4.46 ± 0.47	4.19 ± 0.48	−1.28	0.60	−2.13	0.035*	−2.48, −0.89	0.44	0.65	0.69	0.495	−0.84, 1.73
Vegetable diversity
MedDiet	12.19 ± 0.66	16.90 ± 0.74	15.64 ± 0.83
Social group	11.17 ± 0.66	12.57 ± 0.83	13.26 ± 0.94	3.31	1.01	3.27	<0.001**	1.30, 5.32	−2.18	0.96	−2.26	0.026*	−4.10, −0.26
Fruit diversity
MedDiet	5.35 ± 0.41	7.20 ± 0.46	8.38 ± 0.59
Social group	4.71 ± 0.40	5.37 ± 0.51	6.41 ± 0.67	1.19	0.66	1.81	0.073	−0.11, 2.49	0.03	0.66	0.04	0.967	−1.28, 1.34

*P < 0.05.

**P < 0.01.

^aMediterranean diet score out of 14. Food groups are derived from the SDQ; for each food group, frequency of intake was reported using six to nine-item response scales ranging from never/don’t eat to consume seven or more serves per day. Vegetable and fruit diversity were calculated as the total number of different types vegetables and fruits consumed during the previous 2 weeks. CI = confidence interval (95%).

Figure 3 DASS depression scores in each group at baseline and 3 months (P = 0.027). Bars represent standard error of the mean. Dotted line represents cut-off for ‘extremely severe depression’.

Figure 4 DASS depression scores at baseline, 3 and 6 months.

Table 3 Mental health and quality of life in Mediterranean diet (MedDiet) versus social groups at baseline, 3 and 6 months, and test of differences between groups using linear mixed modelling n = 152 (MedDiet n = 75; social group n = 77)

	Baseline M ± SD	3 months M ± SD	6 months M ± SD	Baseline to 3 months					3 months to 6 months
				Estimate	SE	t-score	P	95% CI	Estimate	SE	t-score	P	95% CI
Depression^a
MedDiet	23.00 ± 1.10	12.63 ± 1.26	12.50 ± 1.45
Social group	21.79 ± 1.08	15.94 ± 1.45	15.28 ± 1.66	−4.52	2.02	−2.24	0.027*	−8.53, −0.52	−0.17	2.15	−0.08	0.936	−4.44, 4.09
Anxiety^a
MedDiet	14.08 ± 0.94	7.04 ± 1.05	6.17 ± 1.12
Social group	14.49 ± 0.93	10.01 ± 1.18	8.68 ± 1.29	−2.56	1.43	−1.79	0.077	−5.40, 0.28	−0.64	1.35	−0.48	0.636	−3.33, 2.05
Stress^a
MedDiet	23.47 ± 0.97	13.96 ± 1.11	13.77 ± 1.31
Social group	22.44 ± 0.96	15.98 ± 1.27	16.33 ± 1.50	−3.04	1.74	−1.75	0.082	−6.48, 0.39	−1.85	1.76	−1.05	0.297	−5.36, 1.66
Positive affect^b
MedDiet	23.31 ± 0.92	28.64 ± 1.06	28.31 ± 1.32
Social group	22.55 ± 0.91	27.02 ± 1.23	27.63 ± 1.51	1.41	1.67	0.85	0.399	−1.89, 4.72	−0.76	1.73	−0.44	0.660	−4.19, 2.67
Negative affect^b
MedDiet	26.03 ± 0.85	19.67 ± 0.97	18.30 ± 1.08
Social group	26.44 ± 0.84	21.62 ± 1.11	21.35 ± 1.23	−1.53	1.48	−1.04	0.302	−4.47, 1.40	−2.07	1.50	−1.39	0.170	−5.05, 0.90
AQoL Independent living^c
MedDiet	0.77 ± 0.02	0.87 ± 0.02	0.84 ± 0.02
Social group	0.77 ± 0.18	0.83 ± 0.02	0.85 ± 0.03	0.04	0.02	1.46	0.148	−0.01, 0.08	−0.03	0.03	−1.21	0.231	−0.09, 0.02
AQoL Pain^c
MedDiet	0.68 ± 0.03	0.74 ± 0.03	0.74 ± 0.04
Social group	0.71 ± 0.03	0.73 ± 0.39	0.72 ± 0.04	0.04	0.05	0.72	0.475	−0.06, 0.13	0.03	0.05	0.57	0.570	−0.07, 0.12
AQoL Senses^c
MedDiet	0.78 ± 0.02	0.88 ± 0.19	0.88 ± 0.02
Social group	0.82 ± 0.02	0.85 ± 0.02	0.83 ± 0.02	0.06	0.03	1.93	0.056	−0.00, 0.11	0.02	0.03	0.77	0.444	−0.04, 0.09
AQoL Physical health^c
MedDiet	0.58 ± 0.03	0.70 ± 0.03	0.69 ± 0.03
Social group	0.60 ± 0.03	0.67 ± 0.03	0.65 ± 0.04	0.06	0.04	1.53	0.129	−0.02, 0.13	0.02	0.04	0.43	0.668	−0.06, 0.09
AQoL Mental health^c
MedDiet	0.47 ± 0.01	0.61 ± 0.02	0.61 ± 0.02
Social group	0.46 ± 0.01	0.55 ± 0.02	0.55 ± 0.03	0.06	0.03	2.10	0.037*	0.00, 0.11	0.01	0.03	0.09	0.930	−0.06, 0.06
AQoL Happiness^c
MedDiet	0.54 ± 0.02	0.67 ± 0.02	0.69 ± 0.03
Social group	0.51 ± 0.02	0.63 ± 0.02	0.63 ± 0.03	0.01	0.03	0.18	0.856	−0.06, .07	0.02	0.03	0.76	0.449	−0.04, 0.09
AQoL Coping^c
MedDiet	0.53 ± 0.02	0.68 ± 0.02	0.69 ± 0.03
Social group	0.53 ± 0.02	0.66 ± 0.02	0.64 ± 0.03	0.02	0.03	0.58	0.563	−0.05, 0.08	0.04	0.03	1.12	0.266	−0.03, 0.11
AQoL Relationships^c
MedDiet	0.55 ± 0.01	0.65 ± 0.02	0.67 ± 0.02
Social group	0.54 ± 0.01	0.63 ± 0.02	0.63 ± 0.03	0.01	0.02	0.32	0.751	−0.04, 0.06	0.03	0.03	1.07	0.286	−0.02, 0.08
AQoL Self worth^c
MedDiet	0.58 ± 0.02	0.75 ± 0.02	0.75 ± 0.03
Social group	0.58 ± 0.02	0.69 ± 0.02	0.71 ± 0.03	0.05	0.03	1.68	0.095	−0.01, 0.12	0.01	0.03	0.33	0.745	−0.06, 0.08
AQoL Psychosocial super dimension^c
MedDiet	0.16 ± 0.02	0.31 ± 0.02	0.34 ± 0.03
Social group	0.14 ± 0.02	0.27 ± 0.02	0.26 ± 0.03	0.03	0.03	1.03	0.307	−0.03, 0.10	0.03	0.03	1.04	0.301	−0.03, 0.10
AQoL Utility Score^c
MedDiet	0.44 ± 0.02	0.63 ± 0.02	0.65 ± 0.03
Social group	0.43 ± 0.02	0.58 ± 0.03	0.58 ± 0.04	0.05	0.03	1.48	0.143	−0.02, 0.12	0.02	0.04	0.63	0.533	−0.05, 0.10

*P < 0.05.

**P < 0.01.

^aDASS.

^bPANAS.

^cAssessment of Quality of Life (AQoL)-8d.

Table 4 Pearson correlations between changes in mental health and diet over 3 months (n = 95)

	Med	Veg	Fruit	Grains	T/away	Snacks	Drinks	Nuts	Legumes	Fish	Meat	Vegdiv	Fruitdiv
DASS depression	−.298**	−.137	−.191	−.049	−.040	.138	−.003	−.264*	−.196	−.124	.037	−.303**	−.148
DASS anxiety	−.238*	−.186	−.255*	−.198	−.013	.195	−.103	−.207*	−.253*	.024	.172	−.292**	.204
DASS stress	−.177	−.281**	−.151	−.011	−.017	.088	−.207*	−.280*	−.242*	−.033	.127	−.204	−.151
PANAS positive	.172	.224*	.228*	−.025	.035	−.039	−.064	.139	.203	.128	.115	.218*	−.159
PANAS negative	−.218*	−.155	−.151	−.092	.100	.121	−.025	−.155	−.273**	−.193	.081	−.231*	−.159
AQoL independent	.124	.025	.117	.110	−.046	−.165	−.190	.056	.060	.134	−.098	.327**	.271**
AQoL pain	.160	.092	.129	−.001	−.275**	.091	.037	.124	.105	.150	−.252*	.146	.056
AQoL physical health	.169	.092	.133	.031	−.248*	−.031	−.083	.096	.147	.151	−.177	.186	.185
AQoL mental health	.195	.176	.175	.049	−.073	−.232*	−.055	.221*	.257*	.170	−.091	.302**	.309**
AQoL happiness	.195	.253*	.152	.082	−.028	−.171	−.060	.155	.186	.074	.010	.295**	.304**
AQoL coping	.211*	.203	.174	.003	−.094	−.212*	−.148	.191	.277**	.108	.019	.195	.174
AQoL relationships	.109	.129	.216*	.011	−.053	−.184	−.160	−.001	.135	.071	.040	.270*	.208*
AQoL self-worth	.175	.139	.146	.083	−.160	−.156	−.099	.221*	.146	.030	−.092	.196	.170
AQoL psychosocial	.194	.179	.189	.042	−.079	−.297**	−.102	.150	.225*	.168	−.035	.297**	.303**
AQoL Utility score	.251*	.203	.165	.061	−.204	−.195	−.140	.183	.236*	.193	−.099	.323**	.276**

*P < 0.05.

**P < 0.01.

Note that all change scores are calculated as 3 months minus baseline. Med = Mediterranean diet score; Veg = vegetables; Grains = wholegrains; T/away = take away food; Snacks = unhealthy snacks; Drinks = sweetened drinks; Vegdiv = vegetable diversity; Fruitdiv = fruit diversity. AQoL = Assessment of quality of life. AQoL independent = independent living. A higher AQoL score = better quality of life on that scale.

Table 5 Pearson correlations between changes in mental health and erythrocyte PUFAs over 3 and 6 months

	3 months (n = 95)							6 months (n = 85)
	AA	EPA	DHA	Total n-6	Total n-3	n-6/n-3	AA/EPA	AA	EPA	DHA	Total n-6	Total n-3	n-6/n-3	AA/EPA
DASS
Depression	−.143	.213	.119	.027	.184	−.125	−.295**	.152	−.144	−.112	−.018	−.110	.065	−.041
Anxiety	.207	−.242*	.012	−.049	−.061	.045	.157	.201	−.241*	−.120	−.057	−.139	.081	.214
Stress	.267**	−.227*	−.158	−.123	−.207*	.097	.158	.259*	−.245*	−.226*	−.108	−.200	.098	.168
PANAS
Positive	−.014	.049	−.066	.031	.065	−.066	.008	−.065	.051	.033	.099	.009	.056	.052
Negative	.114	−.087	−.057	−.174	−.034	−.051	−.030	.177	−.136	−.302**	−.037	−.210	.194	.043
AQoL-8D
Independent^a	−.132	.029	−.002	.084	.144	−.123	−.077	.062	.228*	−.001	−.040	.054	−.036	−.189
Pain	−.070	.040	−.005	.008	.075	−.068	−.077	−.070	.124	.137	−.033	.093	−.107	−.225*
Senses	−.167	.099	.015	−.049	.054	−.119	−.041	−.161	.274*	.163	.136	.059	.051	−.240*
Physical^b	−.143	.213	.119	.027	.184	−.125	−.295**	−.098	.267*	.204	.001	.152	−.107	−.316**
Mental health	−.243*	.080	.138	.070	.143	−.039	−.054	−.245*	.122	.148	.043	.124	−.049	−.069
Happiness	−.139	.023	−.005	.079	−.027	.032	.060	−.203	.005	.065	.046	−.024	−.001	.002
Coping	−.188	−.010	−.047	.026	−.053	.082	.043	−.280*	.006	.054	−.030	−.010	.032	−.030
Relationships	−.108	−.030	.033	.020	.022	−.017	.066	−.185	−.029	.118	−.019	.052	−.064	.014
Self-worth	−.165	.097	.074	−.032	.154	−.147	−.061	−.044	.133	.112	.061	.015	.014	−.074
Psychosocial	−.222*	.081	.079	.126	.148	−.058	−.025	−.265*	.042	.132	.053	.083	−.012	−.054
Utility score	−.226*	.048	.016	.056	.126	−.104	−.028	−.240*	.123	.168	.062	.090	−.015	−.143

*P < 0.05.

**P < 0.01.

AA = arachidonic acid (omega-6); EPA = eicosapentaenoic acid (omega-3); DHA = docosahexaenoic acid (omega-3); n-6 = omega-6; n-3 = omega-3. Note that all change scores are calculated as 3 months minus baseline. Higher DASS scores = worse symptoms. ^aIndependent = independent living. Physical^b = physical health. A higher AQoL score = better quality of life on that scale.