Key messages
° Nutritional therapy using oral energy and protein supplements may improve daily activities (very uncertain evidence).
° Nutritional therapy using oral energy and protein supplements may not reduce disability (uncertain evidence).
° We identified various types of nutritional interventions for disabilities and daily activities. More high-quality studies are needed to determine the effect of each type of nutritional therapy on disability and daily activities in people after stroke.
What is stroke?
A stroke occurs when the blood supply to part of your brain is interrupted or reduced. There are three main types of strokes: an ischaemic stroke, which happens when a blood clot blocks or narrows an artery leading to the brain; a haemorrhagic stroke, which occurs when a blood vessel in the brain bursts, causing bleeding in the brain; and a subarachnoid haemorrhage, which occurs when there is bleeding in the space between the brain and the surrounding membrane (subarachnoid space).
What is nutritional therapy?
Nutrition therapy is an intervention using nutrients such as protein, vitamins, and energy for daily meals and/or between meals, and includes nutrition care based on the condition of each patient. People with and after a disease often receive nutritional therapy.
Why is a specific focus needed on nutritional therapy in people after stroke?
Stroke patients easily get malnutrition because they do not receive enough energy and nutrients as a result of impairments. Stroke patients often experience physical and cognitive issues, and nutritional status may affect their improvement.
What did we want to find out?
We wanted to find out whether nutritional therapy reduces disability and improves daily activities in people after stroke.
What did we do?
We searched the medical literature for all randomised trials conducted on nutritional therapy in people after stroke. We also assessed whether nutritional therapy is safe in terms of unwanted effects. We compared and summarised the results of the studies and rated our confidence in the evidence, based on factors such as study methods and sizes.
What did we find?
We identified 52 studies that involved 11,926 participants. Thirty-six studies with acute stroke patients were conducted (within 14 days from stroke onset), 10 with subacute stroke patients (within 6 months, from 14 days after stroke onset), three with acute and subacute stroke patients, and three with chronic stroke patients (after 6 months from stroke onset). The stroke type investigated was ischaemic in 23 studies, haemorrhagic in three studies, subarachnoid haemorrhage (SAH) in three studies, and ischaemic or haemorrhagic stroke including SAH in 23 studies. We identified 25 types of nutritional intervention in this review. The number of studies that assessed disability and ADL as outcomes were 9 and 17, respectively.
For the primary intervention of using oral energy and protein supplements, we identified six studies.
We found that nutritional therapy using oral energy and protein supplements:
- may not reduce disability; however, the evidence is uncertain
- may improve daily activities; however, the evidence is very uncertain
For other outcomes, nutritional therapy using oral energy and protein supplements:
- may improve nutritional status in weight gain; however, the evidence is very uncertain
- may not decrease the risk of death from any cause; however, the evidence is uncertain
- were associated with an increased incidence of both diarrhoea and either hyperglycaemia (a condition where there is too much sugar (glucose) in the blood) or hypoglycaemia (a condition where there is too little sugar (glucose) in the blood); however, the evidence is uncertain
We did not find any studies with oral energy and protein supplements that reported walking speed and quality of life.
What were the limitations of the evidence?
We are not confident of the evidence for reducing disability and improving daily activities for the following reasons:
- Patients in most studies were aware of the intervention they were receiving.
- Healthcare providers and outcome assessors were aware of the interventions the patients were receiving.
- Most studies that assessed ADL(activities of daily living) did not describe their methods in sufficient detail.
- The effect may differ according to stroke type, time from stroke onset, and nutritional status at the start of nutritional therapy, but we could not assess those differences sufficiently due to the small number of studies.
How up-to-date is this evidence?
The evidence is current to 19 February 2024.
We are uncertain about the effect of nutritional therapy, including oral energy and protein supplements and other supplements identified in this review, on reducing disability and improving ADL in people after stroke. Various nutritional interventions were assessed for the outcomes in the included studies, and almost all studies had small sample sizes. This led to challenges in conducting meta-analyses and reduced the precision of the evidence. Moreover, most of the studies had issues with the risk of bias, especially in terms of the absence of blinding and unclear information. Regarding adverse events, the intervention with oral energy and protein supplements was associated with a higher number of adverse events, such as diarrhoea, hyperglycaemia, and hypoglycaemia, compared to usual care. However, the quality of the evidence was low. Given the low certainty of most of the evidence in our review, further research is needed. Future research should focus on targeted nutritional interventions to reduce disability and improve ADL based on a theoretical rationale in people after stroke and there is a need for improved methodology and reporting.
Stroke patients often face disabilities that significantly interfere with their daily lives. Poor nutritional status is a common issue amongst these patients, and malnutrition can severely impact their functional recovery post-stroke. Therefore, nutritional therapy is crucial in managing stroke outcomes. However, its effects on disability, activities of daily living (ADL), and other critical outcomes have not been fully explored.
To evaluate the effects of nutritional therapy on reducing disability and improving ADL in patients after stroke.
We searched the trial registers of the Cochrane Stroke Group, CENTRAL, MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1982), and AMED (from 1985) to 19 February 2024. We also searched trials and research registries (ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform) and reference lists of articles.
We included randomised controlled trials (RCTs) that compared nutritional therapy with placebo, usual care, or one type of nutritional therapy in people after stroke. Nutritional therapy was defined as the administration of supplemental nutrients, including energy, protein, amino acids, fatty acids, vitamins, and minerals, through oral, enteral, or parenteral methods. As a comparator, one type of nutritional therapy refers to all forms of nutritional therapies, excluding the specific nutritional therapy defined for use in the intervention group.
We used Cochrane’s Screen4Me workflow to assess the initial search results. Two review authors independently screened references that met the inclusion criteria, extracted data, and assessed the risk of bias and the certainty of the evidence using the GRADE approach. We calculated the mean difference (MD) or standardised mean difference (SMD) for continuous data and the odds ratio (OR) for dichotomous data, with 95% confidence intervals (CIs). We assessed heterogeneity using the I2 statistic. The primary outcomes were disability and ADL. We also assessed gait, nutritional status, all-cause mortality, quality of life, hand and leg muscle strength, cognitive function, physical performance, stroke recurrence, swallowing function, neurological impairment, and the development of complications (adverse events) as secondary outcomes.
We identified 52 eligible RCTs involving 11,926 participants. Thirty-six studies were conducted in the acute phase, 10 in the subacute phase, three in the acute and subacute phases, and three in the chronic phase. Twenty-three studies included patients with ischaemic stroke, three included patients with haemorrhagic stroke, three included patients with subarachnoid haemorrhage (SAH), and 23 included patients with ischaemic or haemorrhagic stroke including SAH. There were 25 types of nutritional supplements used as an intervention. The number of studies that assessed disability and ADL as outcomes were nine and 17, respectively.
For the intervention using oral energy and protein supplements, which was a primary intervention in this review, six studies were included. The results for the seven outcomes focused on (disability, ADL, body weight change, all-cause mortality, gait speed, quality of life, and incidence of complications (adverse events)) were as follows: There was no evidence of a difference in reducing disability when 'good status' was defined as an mRS score of 0 to 2 (for 'good status': OR 0.97, 95% CI 0.86 to 1.10; 1 RCT, 4023 participants; low‐certainty evidence). Oral energy and protein supplements may improve ADL as indicated by an increase in the FIM motor score, but the evidence is very uncertain (MD 8.74, 95% CI 5.93 to 11.54; 2 RCTs, 165 participants; very low‐certainty evidence). Oral energy and protein supplements may increase body weight, but the evidence is very uncertain (MD 0.90, 95% CI 0.23 to 1.58; 3 RCTs, 205 participants; very low-certainty evidence). There was no evidence of a difference in reducing all-cause mortality (OR 0.57, 95% CI 0.14 to 2.28; 2 RCTs, 4065 participants; low-certainty evidence). For gait speed and quality of life, no study was identified. With regard to incidence of complications (adverse events), there was no evidence of a difference in the incidence of infections, including pneumonia, urinary tract infections, and septicaemia (OR 0.68, 95% CI 0.20 to 2.30; 1 RCT, 42 participants; very low-certainty evidence). The intervention was associated with an increased incidence of diarrhoea compared to usual care (OR 4.29, 95% CI 1.98 to 9.28; 1 RCT, 4023 participants; low-certainty evidence) and the occurrence of hyperglycaemia or hypoglycaemia (OR 15.6, 95% CI 4.84 to 50.23; 1 RCT, 4023 participants; low-certainty evidence).