Introduction
Older family caregivers (FCs) and their care recipients (CRs) are threatened with poor nutritional status [
1‐
4] and insufficient dietary intake [
3]. FCs are also more vulnerable to the risk of malnutrition than other community-dwelling older people without a CR [
5]. Insufficient dietary intake is common among older FCs [
6,
7], although sufficient dietary intake has many benefits for older people. For example, optimal intake of nutrients can prevent frailty [
8], and optimal protein intake can prevent the decline of physical performance [
9] and improve lean body mass [
10‐
13]. Because of the negative effects of poor nutritional status on many health outcomes, such as physical function [
7,
14‐
16], cognitive status [
15,
17], hospitalization [
17], morbidity [
7], and mortality [
16], it is important to prevent deterioration of the nutritional status of older FCs, contributing their ability to serve as FCs. In addition to malnutrition, obesity is common in older community-dwelling people [
18,
19]. Despite obesity, older people may have functional disability [
18]. Obesity has many detrimental effects on health, such as risk of frailty [
19], increased risk of falls [
20], and declined cognition [
21].
There has been only one earlier study with nutritional guidance and its impact on the dietary intake of older FCs [
22]. In that earlier study, older FCs, especially male FCs, increased their energy and protein intake. Most earlier nutritional guidance or education trials with FCs and CRs have concentrated on studying changes in health outcomes and dietary intake of CRs [
23‐
25]. These studies have shown that nutritional guidance can improve dietary intake and/or reduce the nutritional risk of CRs [
23‐
25]. It has been found that malnourished and/or frail older people benefit from protein supplementation [
12,
13]. However, there is also some evidence that non-frail community-dwelling older people did not benefit from protein supplementation [
26].
To our knowledge, there are no randomized controlled trials about individually tailored nutritional guidance targeted to older FCs and its impact on the nutritional status of older FCs. The aim of this study was to assess the impact of individually tailored nutritional guidance on the dietary intake and nutritional status of older FCs and their CRs’ nutritional status.
Discussion
Individually tailored nutritional guidance improved the intake of protein, riboflavin, iodine, and phosphorus of the FCs during the 6-month intervention. Significant differences between the intervention and control groups were observed in the intake levels of protein, riboflavin, calcium, potassium, phosphorus, and iodine during the 6-month intervention. In addition, the intake of vitamin D supplementation improved in the intervention group for both the FCs and the CRs. The MNA scores of the FCs and the CRs did not change during the 6-month intervention in either of the groups. However, there were an increase during the 12-month period, i.e. the 6-month intervention and the 6-month follow-up, in the MNA scores of the CRs in the intervention group, but there was also an increase in the CRs in the control group when 12-month results were compared with 0- and 6-month time points.
The main result of this study is the increased protein intake of the FCs in the intervention group compared with the control group. Previous studies with older people have shown that the consumption of dairy products, eggs, and fish can increase due to nutritional intervention [
41,
42]. When reflecting on what kind of changes the FCs of this study made to improve their protein intake, it seems that the improved protein intake of the FCs in the intervention group was mainly due to increased consumption of dairy products. The increased intakes of riboflavin, iodine, and phosphorus in the intervention group, and the increased difference between groups in the intakes of calcium and potassium supports an increased use of dairy products. The facility, familiarity, and likability of dairy products can be important reasons why FCs increased their use. In addition, there are many protein-rich dairy products available in Finland, which are easy to add to the diet. Despite the increased protein intake, the mean protein intake (1.05 ± 3.7 g/kg BW/day) of the FCs in the intervention group did not reach the recommended intake (1.2–1.4 g/kg BW/day) according to the Nordic Nutrition Recommendations [
30]. Similar findings showed Kunvik et al. [
22] with older FCs when protein intake increased + 0.1 g/kg BW/day to 0.96 g/kg BW/day in the intervention group. Lower than recommended protein intake may be due to the inability of FCs to improve the quality or number of their main meals. More attention to cooking can be experienced burdensome and they have chosen easier ways (dairy products) to improve their protein intake. However, this has not been sufficient for all FCs. The burden of care may have affected unaccomplished changes in nutrition. Nutritional guidance can prevent insufficient protein intake in older people and consequently protects against weight loss [
43], prevents frailty [
44], predicts better physical performance [
45], and prevents mobility limitations [
46]. In most of the earlier intervention studies with positive effects of higher protein intake or protein supplementation on lean body mass, an increase in physical activity was also included, so it is difficult to draw specific conclusions regarding protein intake alone [
10,
11]. Caregivers have limited time to have physical activity because of hours of care [
6], and synergy of optimal nutrition and physical activity can be missing.
Considering of the intakes of vegetables, fruits, or berries, it seems that FCs could not considerably improve their intake of vegetables, fruits, or berries. This is supported by the results that there were no significant changes in e.g. vitamin C, folate or fiber. Previously, Berendsen et al. [
41] and Bernstein et al. [
47] showed that older people can improve their fruit and vegetable intake due to nutritional guidance. However, both these earlier studies evaluated home-dwelling older people [
41,
47], and counseling was given nine times during a 12-month intervention [
41] or through eight home visits, biweekly phone contacts, and monthly letters during a 6-month intervention [
47]. The present study consists of older FCs who are more vulnerable to the risk of malnutrition than home-dwelling older people [
5], and they had nutritional guidance only twice during the 6-month intervention. Moreover, some of the participants ended the 6-month intervention during the first wave of the COVID-19 pandemic. Voluntary isolation was recommended for older people at that time by the Finnish government. This could have affected the shopping behaviors of older people, i.e., they might have visited grocery stores less often or not at all, relatives or friends may have taken care of their food purchases, or FCs have made grocery shopping online. All these factors could have decreased the consumption of fresh products, such as vegetables, fruits, and fresh fish, at the 6-month time point, which was observed earlier in one study with adults [
48].
Our study confirms an earlier finding that nutritional guidance improves the use of vitamin D supplementation in older people [
41]. Vitamin D deficiency is associated with many health outcomes, such as bone density [
49], sarcopenia [
50], and poor physical performance [
51,
52] in older people. Therefore, it is important and efficient to take sufficient vitamin D supplementation with nutritional guidance.
Although nutrient intake of the FCs improved in the intervention group, it was not seen as an improvement in the MNA scores. However, it had a positive impact on blood hemoglobin concentration in the intervention group. There were significant differences between the groups in the MAC and CC of the FCs, and the MAC of the CRs. However, these changes were minor and no conclusions about the effect of nutritional guidance to the MAC and CC cannot be drawn. The study sample consisted mainly of FCs with normal nutritional status (79.6%), partly explaining the lack of improvement in the MNA scores. FCs also have a demanding duty to take care of their CRs. This can be seen as increases in stress [
53], caregiver burden [
54], and sleeping disturbances, mostly because of care performed at night [
55]. All these factors have a negative effect on nutritional status [
56‐
58].
Earlier evidence of the effectiveness of nutritional guidance targeted to FCs on the nutritional status of CRs is not clear. Fernández-Barrés et al. [
23] showed that it has a positive impact on the nutritional status of CRs, while Shatenstein et al. [
24] did not find any effect. In the present study, there was some evidence of positive effects of nutritional guidance on CRs’ MNA scores in the intervention group. However, there were parallel changes in the MNA scores of the control group. Even two-thirds of the CRs in the control group were malnourished or at risk of malnutrition at baseline, and almost all of them were guided to the health care or received nutritional guidance from the clinical nutritionist if necessary because of the ethical approval. This could have protected CRs in the control group from declined nutritional status during the 6-month intervention and may explain the increase in the MNA scores at the 12-month time point.
It seems that FCs can easily adopt improvements by simple means in their dietary intake and use of supplementations, but because of daily tasks and care routines, some more time-consuming changes are more difficult to adopt [
55]. This can prevent more substantial improvements and positive impacts on the nutritional status of FCs and CRs. They can also need more frequent support and monitoring. For example, in a Spanish study, CRs’ nutritional status increased during the intervention, which included monthly support and dietary advice about optimal nutrition by nurses [
23]. There was also more frequent support and guidance in the two other previous studies [
41,
47]. In addition, van den Helder et al. [
42] reported higher protein intakes after one group session, monthly face-to-face sessions, and weekly/monthly video sessions with a dietician.
The intervention increased protein intake, although it did not reach recommendations [
30]. It is important to be able to prevent decrease in dietary intake, not only to improve it, because decreased dietary intake can accelerate the deterioration of health. ESPEN guidelines recommend that protein intake of older people should be at least 1 g/kg BW/day until more evidence is available [
59]. This recommendation was achieved in the present study, so this could protect FCs of negative health effects of protein intake being too low (< 1 g/kg BW/day). Nutritional guidance should be part of the services to FCs, preventing early deterioration of nutritional status and promoting the ability to serve as FCs. However, further studies are warranted to optimize the support for FCs’ nutritional status.
The strengths of this study are the randomized, population-based design and the validated methods used and suitable in older people. The data on MNA and food records were collected/checked by a clinical nutritionist, which improves the reliability of these tools. However, under- or over-reporting assessing dietary intake with the food record or 24-h recall is possible. Our study was carried out during home visits and phone calls, which improved FCs’ ability to participate. The COVID-19 pandemic could have changed the behavior of older people or increased their anxiety during this intervention, and some benefits of the intervention could have been diluted.