Elsevier

Clinical Nutrition

Volume 26, Issue 5, October 2007, Pages 545-551
Clinical Nutrition

ORIGINAL ARTICLE
Effects of dietary supplements on depressive symptoms in older patients: A randomised double-blind placebo-controlled trial

https://doi.org/10.1016/j.clnu.2007.06.007Get rights and content

Summary

Background & aims

The effect of nutritional supplements on mental health in older patients has received little attention so far. The aims of this trial were therefore to test the effect of nutritional support on older patient's depressive symptoms and cognitive function.

Methods

In this prospective, double-blind, placebo-controlled study, we randomly assigned 225 hospitalised acutely ill older patients to receive either normal hospital diet plus 400 mL oral nutritional supplements (106 subjects) or normal hospital diet plus a placebo (119 subjects) daily for 6 weeks. The composition of the supplement was such as to provide 995 kcal for energy and 100% of the Reference Nutrient Intakes for a healthy old person for vitamins and minerals. Outcome measures were 6 weeks and 6 months changes in nutritional status, depressive symptoms and cognitive state.

Results

Randomisation to the supplement group led to a significant increase in red-cell folate and plasma vitamin B12 concentrations, in contrast to a decrease seen in the placebo group. There were significant differences in symptoms of depression scores in the supplement group compared with the placebo group at 6 months (p=0.021 for between groups difference). The effect of supplement was seen in all patient groups including those with no symptoms of depression, mild depression and those with severe depression (p=0.007). There was no evidence of a difference in cognitive function scores at 6 months.

Conclusion

Oral nutritional supplementation of hospitalised acutely ill older patients led to a statistically significant benefit on depressive symptoms.

Introduction

The number of older people is growing rapidly worldwide. Good nutrition contributes to the health and well-being of older people and to their ability to recover from illness.1 A recent National Diet and Nutrition Survey of older people in the UK identified low biochemical status of one or more micronutrients in 40% of the older population.2 Although nutritional deficiencies in older persons are common and the impact on their physical and mental well-being is likely to be high, research on the relationship between nutritional factors and psychological health is generally lacking.3, 4

A recent review of the literature on nutrition and older people psychiatry reported that although this issue has received little attention there has been recent research on the role of micronutrients in psychiatric disorders in older adults.4 For example, low folic acid/vitamin B12 has been found to be associated with depression in older persons whereas evidence for other micronutrients is still tentative.5 The Rotterdam study has also reported a relationship between hyperhomocyteinaemia, vitamin B12 and folate deficiency and depressive disorders.5 A recent meta-analysis of trials of protein and energy supplementation in older people reported that data were limited by the poor quality of most included trials and that future trials should have sufficient power, proper concealed allocation and blinding of treatment and should focus on outcome measures of relevance to patients such as improvement in function and well-being.6

The aim of this randomised double-blind placebo-controlled study was to test the effects of nutritional support on older patient's depressive symptoms and cognitive function.

Section snippets

Study population

Functional-enabling food (FED) is a randomised, double-blind, placebo-controlled single-centre trial in which we randomised hospitalised acutely ill elderly patients to normal hospital diet plus placebo versus normal hospital diet plus oral supplements daily for 6 weeks. Details of the trial have been published elsewhere.7 Briefly, patients were eligible for the study if they met the following criteria: age ⩾65 years; stable medical condition; able to swallow and able to sign an informed

Results

Details of the recruitment and intervention process were published before.7 Briefly 445 patients were recruited and 6-month follow up was 100% for the primary outcomes of disability, length of stay, readmission, morbidity and mortality. By six months, 225/445 (51%) patients responded to the follow-up nutritional status and depression assessments. Of the 220 non-responders 51 patients had died. There was no evidence of a difference in response rates between the groups (119/222 (54%) placebo vs.

Discussion

The results of this study indicate that nutritional supplementation confers significant clinical benefit to older people during acute illness and convalescence/rehabilitation period. Patients randomised to receive supplements did achieve significant increases in red blood cell folate and vitamin B12 concentrations compared to the placebo group and this was associated with improvement in depressive symptoms.

These clinical benefits were observed despite modest degree of compliance with the

Strengths and limitations

We believe this study to be the first randomised, double-blind, placebo controlled trial to compare the effect of a 6-week protein, energy and micronutrient supplementation on hospitalised older patients’ depressive symptoms. We cannot exclude the possibility that the decrease in depressive symptoms as a result of nutritional support is a chance finding, however, it is also possible that is a real one given the improvement in micronutrients status and that mild sub-clinical micronutrient

Acknowledgements

The International Standardised Randomised Controlled Trial Number for our trial is ISRCTN01133608. This study was funded by The Health Foundation project grant. There was no conflict of interest for the authors.

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Salah Gariballa was the lead investigator and prepared the first draft of the paper. Sarah Forster undertook subjects’ recruitment and assessments. All investigators were involved in the study design and writing of the manuscript.

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