Randomized trial of the effects of cholesterol-lowering dietary treatment on psychological function

doi:10.1016/S0002-9343(00)00330-2

The American Journal of Medicine

Volume 108, Issue 7, May 2000, Pages 547-553

https://doi.org/10.1016/S0002-9343(00)00330-2 Get rights and content

Abstract

PURPOSE: Epidemiological studies have suggested that cholesterol lowering could affect psychological functioning. This study was designed to test whether cholesterol-lowering diets adversely affect mood and cognitive function.

SUBJECTS AND METHODS: We randomly assigned 176 adults with elevated serum cholesterol levels (>5.2 mM [198 mg/dL]) to either a low-fat diet, a Mediterranean diet, or a waiting-list control. Cholesterol levels, psychological well-being (depression, anxiety, hostility), and cognitive function were assessed at baseline, 6 weeks, and 12 weeks.

RESULTS: Total serum cholesterol levels fell significantly more in the intervention groups (8.2% reduction) than in the control group (P <0.001). All three groups showed a modest improvement in psychological well-being during the 12-week treatment period, but there were no differences among the groups. There were no between-group differences on three measures of cognitive function, but for a fourth measure, which involved the task with the greatest processing load, the two intervention groups did significantly worse (P <0.001) than the control group. The change in performance was correlated with the change in total serum cholesterol level (r = 0.21, P = 0.01).

CONCLUSIONS: Two dietary interventions that successfully lowered serum cholesterol levels had no adverse effect on mood. There was some evidence for a relative impairment in cognitive function in the treated groups in one of four cognitive tests, but additional studies will be required to determine the relevance of this finding.

Section snippets

Participants and design

Adults with mildly or moderately raised serum cholesterol levels were referred by hospital dietetic clinics, hospital physicians, and general practitioners in London and Southeast England. Participants were required to have a serum cholesterol level >5.2 mM (198 mg/dL); no serious illness (except cardiovascular disease, for which cholesterol lowering was indicated); no current or previous (within 3 months) use of lipid-lowering medication; and physician’s permission to participate. In addition,

Results

Of the 176 participants who began treatment, 155 completed the posttreatment assessment and had attended at least four treatment sessions (Figure 1). Participants were generally middle-aged and somewhat overweight (Table 1). Nutrient analyses from the 7-day diaries showed that reported energy intakes were reasonable for adults of this age, as were levels of depression, anxiety, and aggression. There were no significant differences among the three treatment groups in any of the baseline

Discussion

The participants in this study were adults with at least mild hypercholesterolemia by UK criteria. As volunteers who agreed to participate in a relatively demanding study, participants were probably more highly motivated than the population at large, but that is true in most clinical trials. Many of the participants were already following a low-fat diet, and the recorded fat intake at baseline (32% of energy) was lower than the UK average of 39%. The dropout rate was low, partly because

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Cited by (86)

Efficacy of an adjuvant non-face-to-face multimodal lifestyle modification program for patients with treatment-resistant major depression: A randomized controlled trial
2023, Psychiatry Research
The high prevalence of depression is partly attributable to the poor response of patients to first-line antidepressants. Multimodal programs that promote a healthy lifestyle are successful in treating depression when used as a complementary therapy, but their medium- and long-term benefits have not been demonstrated for patients with treatment-resistant depression (TRD). The main aim of this study was to compare the effectiveness of a lifestyle modification program (LMP) with mindfulness-based cognitive therapy (MBCT) and a placebo-control (written suggestions for lifestyle changes) in Spanish patients with TRD.
This controlled clinical trial randomized 94 patients with TRD into 3 arms. The primary outcome was the Beck Depression Inventory-II (BDI-II) score at baseline, 2, 6 and 12 months. The secondary outcomes were changes in scores that evaluated quality-of-life, adherence to the Mediterranean diet, physical activity, and social support.
Relative to the placebo group, the LMP and MBCT groups had significantly better quality of life (p = 0.017; p = 0.027), and the LMP group had significantly better adherence to the Mediterranean diet (p<0.001) and reduced use of antidepressants (p = 0.036). However, the three groups showed no significant differences in BDI-II score.
Only about half of the planned 180 patients were recruited, in part due to the COVID-19 pandemic.
There was no evidence that the LMP treatment significantly reduced symptoms of depression relative to the other groups during the COVID-19 lockdown.
The Effect of Adherence to the Mediterranean Diet on Late-Life Cognitive Disorders: A Systematic Review
2020, Journal of the American Medical Directors Association
Citation Excerpt :
The main characteristics of the RCTs are outlined in Supplementary Material S2 and those of the longitudinal studies in Supplementary Material S3. Seven of the 45 studies included were RCTs18–24 and 38 were longitudinal.25–62 Twenty-two were carried out in the United States,25–27,29–32,34–37,39,41,46–50,54,55,58,61 16 in Europe,18–22,24,28,38,40,43,44,51–53,57,60 4 in Australia,23,33,42,56 2 in China,45,59 and 1 in Israel.62
Although some results are conflicting, numerous investigations have demonstrated that the Mediterranean Diet (MedDiet) has positive effects on brain health. This review intends to provide an update on the scientific evidence regarding the effects of adherence to the MedDiet on late-life cognitive disorders.
A systematic review was performed. The PubMed and Scopus databases were searched for longitudinal studies and randomized controlled trials (RCTs) published between the databases’ inceptions and May 4, 2020. PRISMA guidelines were followed; the quality of the studies was assessed using version 2 of the Cochrane risk-of-bias tool for the RCTs and the Newcastle-Ottawa Scale for the longitudinal studies. The results are reported descriptively.
Middle-aged and older adults.
The review's principal outcomes were cognitive decline, cognitive performance and function, Mild Cognitive Impairment (MCI), Alzheimer's disease (AD), and dementia.
Forty-five of the 995 articles retrieved from the databases met our criteria. Seven were RCTs and 38 were longitudinal studies. Overall the studies showed that the MedDiet has some protective effects on cognitive decline. As far as cognition domains were concerned, the MedDiet was associated only with improved global cognition. The results were mixed for MCI and AD. There was no evidence that it has a beneficial effect on dementia.
The review's analysis confirmed that adherence to the MedDiet is associated with some improvement in cognitive health. The heterogeneity of the scoring systems assessing adherence to the MedDiet and of the modalities evaluating the cognitive outcomes has played no small role in the differences emerging in the results and has hindered efforts to interpret them. Although other interventional studies are warranted to confirm the efficacy of the MedDiet in preventing cognitive disorders, the results show that it can be considered part of a multifactorial approach to improve late-life cognitive function.
The Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) Diets Are Associated with Less Cognitive Decline and a Lower Risk of Alzheimer's Disease-A Review
2019, Advances in Nutrition
As there is currently no cure for dementia, there is an urgent need for preventive strategies. The current review provides an overview of the existing evidence examining the associations of the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diets and their dietary components with cognitive decline, dementia, and Alzheimer's disease (AD). A systematic search was conducted within Ovid Medline for studies published up to 27 March 2019 and reference lists from existing reviews and select articles were examined to supplement the electronic search results. In total, 56 articles were included. Higher adherence to the Mediterranean diet was associated with better cognitive scores in 9 of 12 cross-sectional studies, 17 of 25 longitudinal studies, and 1 of 3 trials. Higher adherence to the DASH diet was associated with better cognitive function in 1 cross-sectional study, 2 of 5 longitudinal studies, and 1 trial. Higher adherence to the MIND diet was associated with better cognitive scores in 1 cross-sectional study and 2 of 3 longitudinal studies. Evidence on the association of these dietary patterns with dementia in general was limited. However, higher adherence to the Mediterranean diet was associated with a lower risk of AD in 1 case-control study and 6 of 8 longitudinal studies. Moreover, higher adherence to the DASH or MIND diets was associated with a lower AD risk in 1 longitudinal study. With respect to the components of these dietary patterns, olive oil may be associated with less cognitive decline. In conclusion, current scientific evidence suggests that higher adherence to the Mediterranean, DASH, or MIND diets is associated with less cognitive decline and a lower risk of AD, where the strongest associations are observed for the MIND diet.
The association between diet and mood: A systematic review of current literature
2019, Psychiatry Research
Citation Excerpt :
Among interventional studies, two categorized as high (Wardle et al., 2000; Fontani et al., 2005) and the others as low quality (Hyyppä et al., 2003; McClernon et al., 2007; Torres et al., 2008; Cheatham et al., 2009; McMillan et al., 2011; Beezhold and Johnston, 2012; Torres and Nowson, 2012; Lee et al., 2015; Olabi et al., 2015; Breymeyer et al., 2016; IJff et al., 2016; Lee et al., 2017). Finally, eleven studies recruited healthy (Fontani et al., 2005; McClernon et al., 2007; Cheatham et al., 2009; Beezhold et al., 2010; McMillan et al., 2011; Beezhold and Johnston, 2012; Beezhold et al., 2015; Lee et al., 2015; Olabi et al., 2015; Breymeyer et al., 2016; Valipour et al., 2017), two epileptic (Lambrechts et al., 2012; IJff et al., 2016), two hypercholesterolemic (Wardle et al., 2000; Hyyppä et al., 2003) and the others were hypertensive (Torres et al., 2008), postmenopausal (Torres and Nowson, 2012) and multiple sclerosis subjects (Lee et al., 2017). In the first study, Torres et al. recruited 95 post-menopausal healthy women (59.3 ± 5.1, years old) which were assigned to either DASH-type or healthy diet for 14 weeks.
A number of studies have examined the association between diet and mood state, but the findings have been inconclusive. Herein, we conducted a systematic review to assess the association between different diet and mood state. PubMed, Cochrane's library, Science direct, Scopus, Google scholar and ISI web of science databases were searched for all available literature until December 2017 for studies assessing the association between diet and mood state. The Newcastle-Ottawa Scale and Jadad scale for reporting randomized clinical trials were used to assess study quality. A total of 18 studies out of 2857 met our inclusion criteria and included in our systematic review. Although there are not consistent findings between studies, it seems that DASH, vegetable-based, glycemic load-based, ketogenic and Paleo diets could improve mood more than the others. Further studies are needed to assess such relationship in a longer period to draw a firm link between diet and mood.
Effect of the Mediterranean diet on cognition and brain morphology and function: A systematic review of randomized controlled trials
2018, American Journal of Clinical Nutrition
Observational studies of the Mediterranean diet suggest cognitive benefits, potentially reducing dementia risk.
We performed the first published review to our knowledge of randomized controlled trials (RCTs) investigating Mediterranean diet effects on cognition or brain morphology and function, with an additional focus on intervention diet quality and its relation to “traditional” Mediterranean dietary patterns.
We searched 9 databases from inception (final update December 2017) for RCTs testing a Mediterranean compared with alternate diet for cognitive or brain morphology and function outcomes.
Analyses were based on 66 cognitive tests and 1 brain function outcome from 5 included studies (n = 1888 participants). The prescribed Mediterranean diets varied considerably between studies, particularly with regards to quantitative food advice. Only 8/66 (12.1%) of individual cognitive outcomes at trial level significantly favored a Mediterranean diet for cognitive performance, with effect sizes (ESs) ranging from small (0.32) to large (1.66), whereas 2 outcomes favored controls. Data limitations precluded a meta-analysis. Of 8 domain composite cognitive scores from 2 studies, the 3 (Memory, Frontal, and Global function) from PREDIMED (PREvención con DIeta MEDiterránea) were significant, with ESs ranging from 0.39 to 1.29. A posttest comparison at a second PREDIMED site found that the Mediterranean diet modulates the effect of several genotypes associated with dementia risk for some cognitive outcomes, with mixed results. Finally, the risk of low-plasma brain-derived neurotrophic factor was reduced by 78% (OR = 0.22; 95% CI: 0.05, 0.90) in those who consumed a Mediterranean diet compared to control diet at 3 y in this trial. There was no benefit of the Mediterranean diet for incident cognitive impairment or dementia.
Five RCTs of the Mediterranean diet and cognition have been published to date. The data are mostly nonsignificant, with small ESs. However, the significant improvements in cognitive domain composites in the most robustly designed study warrant additional research.
Effects of Changing the Amount and Source of Dietary Carbohydrates on Symptoms and Dietary Satisfaction Over a 1-Year Period in Subjects with Type 2 Diabetes: Canadian Trial of Carbohydrates in Diabetes (CCD)
2017, Canadian Journal of Diabetes
Citation Excerpt :
We found that gloomy thoughts tended to be more severe in those on the low-carbohydrate than the low-GI diet, and inner tension was more severe on the low-carbohydrate than on the high-GI diet, but the changes in the severity of these symptoms was not related to changes in total fat intake or diet GI. Although these symptoms are not precise measures of depression, this finding is consistent with some (33–35) but not all (36) studies, suggesting that diets higher in total fat are associated with symptoms or diagnoses of depression. The effect may be related to the tendency for high-fat diets to increase insulin resistance, because depression is associated with insulin resistance (37), and there is some evidence that increasing insulin sensitivity using pioglitazone reduces depression scores in patients with schizophrenia (38).
To determine the long-term effects of changing the amount or source of dietary carbohydrate on quality of life (QOL), symptoms and dietary satisfaction in people with type 2 diabetes.
Subjects with diabetes treated by diet alone (n=162) were randomly assigned to high-carbohydrate/high-glycemic-index (HGI) diets; high-carbohydrate/low-glycemic-index (LGI) diets; or lower-carbohydrate/high-monounsaturated-fat (LC) diets for 1 year. We measured QOL at baseline and at study's end, and we measured symptoms and dietary satisfaction quarterly.
The HGI, LGI and LC diets contained, respectively, 47±1, 52±1 and 40±1% energy carbohydrate; 30±1, 27±1 and 40±1% fat with GI 64±0.4, 55±0.4 and 59±0.4. Significantly more participants reported increased flatulence on LGI than on LC and HGI diets at 3 months (41%, 19%, 14%; p<0.05), but not at 12 months (29%, 17%, 17%; ns). Abdominal distension was more severe (46% vs. 14%, 19%; p<0.05), and headache less severe (8% vs. 22%, 23%; p<0.05) on LGI than on both other diets. Increased appetite was more severe on LC (33%) than on HGI diets (14%, p<0.05). Joint/limb pains were less severe on LGI (16%) than HGI (28%) diets. LC elicited more severe gloomy thoughts (23%) than LGI (4%; p<0.05) but greater dietary-satisfaction (70%; p<0.05) than LGI (40%) and HGI (48%) diets. For all diets, glycated hemoglobin (A1C) levels increased less in those who gained less weight, had less increased appetite and were more satisfied with the enjoyment obtained from eating.
Each diet elicited increased severity of 1 or more symptoms than the other diets. Although overall dietary satisfaction was greater on the 40% carbohydrate diet than on the 50% carbohydrate diet, the LGI diet was no less satisfying than the HGI diet. Changes in appetite and dietary satisfaction may influence body weight and glycemic control, or vice-versa.
Déterminer les effets à long terme de la modification de la quantité ou de la source des glucides alimentaires sur la qualité de vie (QdV), les symptômes et la satisfaction alimentaire chez les personnes atteintes du diabète de type 2.
Les sujets diabétiques traités par le régime alimentaire seul (n=162) ont été répartis de manière aléatoire entre les régimes à haute teneur en glucides/à indice glycémique élevé (IGÉ), les régimes à haute teneur en glucides/à indice glycémique faible (IGF) ou les régimes à plus faible teneur en glucides/à forte teneur en gras mono-insaturés (FTG) durant 1 année. Nous avons mesuré la QdV au début et à la fin de l'étude, et mesuré les symptômes et la satisfaction alimentaire tous les 3 mois.
Les régimes alimentaires à IGÉ, à IGF et à FTG contenaient respectivement 47±1%, 52±1% et 40±1% d'énergie en glucides; 30±1%, 27±1% et 40±1% d'énergie en gras et un IG de 64±0,4%, de 55±0,4% et de 59±0,4%. Beaucoup plus de patients rapportaient une augmentation de la flatulence avec les régimes à IGF qu'avec les régimes à FTG et à IGÉ après 3 mois (41%, 19%, 14%; p<0,05), mais non après 12 mois (29%, 17%, 17%; ns). La distension abdominale était plus importante (46% vs 14%, 19%; p<0,05) et les céphalées, moins importantes (8% vs 22%, 23%; p<0,05) avec les régimes alimentaires à IGF qu'avec les deux autres régimes alimentaires. L'augmentation de l'appétit était plus importante avec les régimes à FTG (33%) qu'avec les régimes alimentaires à IGÉ (14%, p<0,05). Les douleurs aux articulations et aux membres étaient moins importantes avec les régimes alimentaires à IGF (16%) qu'avec les régimes alimentaires à IGÉ (28%). Les régimes alimentaires à FTG suscitaient plus d'idées pessimistes importantes (23%) que les régimes alimentaires à IGF (4%; p<0,05), mais une plus grande satisfaction alimentaire (70%; p<0,05) que les régimes alimentaires à IGF (40%) et à IGÉ (48%). Dans tous les régimes alimentaires, les concentrations d'hémoglobine glyquée (A1c) augmentaient moins chez ceux qui prenaient moins de poids, avaient une augmentation moindre de l'appétit et étaient plus satisfaits du plaisir obtenu par l'alimentation.
Chaque régime alimentaire provoquait 1 ou plusieurs symptômes de plus grande importance que les autres régimes. Bien que les régimes alimentaires contenant 40% de glucides aient apporté une plus grande satisfaction alimentaire globale que les régimes alimentaires contenant 50% de glucides, le régime alimentaire à IGF n'était pas moins satisfaisant que le régime à IGÉ. Les modifications de l'appétit et de la satisfaction alimentaire peuvent influencer le poids corporel et la régulation de la glycémie, ou vice-versa.

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^☆: Supported by a grant from the Biotechnology and Biological Sciences Research Council.

^∗: Access the “Journal Club” discussion of this paper at http://www.elsevier.com/locate/ajmselect/

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Clinical studiesRandomized trial of the effects of cholesterol-lowering dietary treatment on psychological function∗☆,

Abstract

Section snippets

Participants and design

Results

Discussion

Lancet

J Psychosom Res

Lancet

Am J Med Sci

Lancet

Am J Clin Nutr

Am J Clin Nutr

Guide to primary prevention of cardiovascular diseases

Circulation

Cholesterol, violent death, and mental disorder

BMJ

Health through cholesterol reductionare there unforeseen risks?

Ann Behav Med

Lowering cholesterol concentrations and mortalitya quantitative review of primary prevention trials

BMJ

Report of the conference on low blood cholesterolmortality associations

Circulation

Serum cholesterol concentrations in parasuicide

BMJ

Low serum cholesterol and suicide

Lancet

Serum lipids and depression

Lancet

Low cholesterol concentrations and severe depressive symptoms in elderly people

BMJ

Serum cholesterol in antisocial personality

Neuropsychobiology

Plasma lipid levels and psychologic characteristics in men

Am J Epidemiol

Clinical studies
Randomized trial of the effects of cholesterol-lowering dietary treatment on psychological function∗☆,