Factors Affecting Adherence, Intake, and Perceived Palatability of Oral Nutritional Supplements: A Literature Review.

Oral nutritional supplements (ONS) are a clinically effective and relatively inexpensive way to supplement the diet of patients with, or at risk of, undernutrition. Good adherence is a primary determinant of the effectiveness of ONS. However adherence can be problematic for those with the greatest clinical need, such as undernourished older adults. This review aimed to appraise the available literature for the factors (contextual, personal and product related) affecting patient adherence and perceived palatability of ONS, identify areas requiring improvement and uncover gaps in the evidence to guide the focus of future research. Contextual factors identified were healthcare staff and the timing of administration. Personal factors included sensory changes and motivation which alter experience of and desire to consume ONS. The product's sensory characteristics determined palatability and intake, but undesirable attributes, such as off-flavours, can stem from nutritional ingredients. The contribution made by aroma to older adults' experience of ONS was a comparatively under-researched area. Further research should address this evidence gap to optimise the flavour, aroma profile and palatability for undernourished older consumers, thereby optimising intake. A combined multidisciplinary effort involving strategic expansion of research, industry development and clinical practice should simultaneously address the factors identified, to provide the best approach to improve adherence.

The relation between stimulated salivary flow and the temporal consumption experience of a liquid oral nutritional supplement.

Use of oral nutritional supplements (ONS) in undernourished patients has proven clinical benefits, but this can be hampered by low adherence due to poor experience of palatability. Many patients, particularly older patients, experience hyposalivation which can cause taste changes and reduce the enjoyment of foods. The aim of this study was to investigate differences in the temporal consumption experience (comprising sensory perception, in-mouth aroma release and subjective appetite) of a clinically relevant portion of ONS, for groups differing in saliva flow rates (SFR). The SFR (mL/min) of thirty healthy individuals was measured on three occasions. This data was used to categorise individuals into three groups using quartile analysis: low flow (LF) (0.3-0.6 mL/min, n = 5), medium flow (MF) (0.7-1.2 mL/min, n = 16) and high flow (HF) (1.3-1.8 mL/min, n = 9). Over the consumption of eight 15 mL sips of ONS, individuals rated their sensory perception and subjective appetite perception using line scales. Additionally, in-mouth aroma release was measured for each sip, using atmospheric pressure chemical ionisation (APCI). Compared with the MF and HF group, the LF group reported a significantly greater increase of mouth-drying over increased sips (p = 0.02). The LF group also experienced significantly higher aftertaste perception (p < 0.001), and more intense in-mouth aroma release (p = 0.015), compared with the HF group. These findings occurred concurrently with relatively lower hunger sensations in the LF and MF group. Many patients who are prescribed ONS likely experience reduced salivary flow rates. The unique sensory experiences of these individuals should be considered in order to optimise palatability and nutritional intake.

Intake of dietary phytoestrogens is low in postmenopausal women in the United States: the Framingham study(1-4).

Many plants that are consumed contain phytoestrogens. Only a few published studies have examined the dietary intake of phytoestrogens in the general Western population. The potentially positive health effects of phytoestrogens might be of relevance to postmenopausal women. The aim of the present study was to estimate the intake of dietary isoflavones, coumestans and lignans by healthy Western postmenopausal women. For this purpose, we studied 964 postmenopausal, Caucasian women who participated in the Framingham Offspring Study and completed the Willett food-frequency questionnaire (FFQ). By searching the medical and agricultural literature and contacting experts, we identified food sources of phytoestrogens. The concentrations of the different isoflavones, coumestrol and lignans in each food in the FFQ were scored in seven categories and multiplied by the serving size of the food and the frequency of its consumption. The estimated daily median intake of the isoflavone daidzein was 39 microg (24-57 microg); of genistein, 70 microg (28-120 microg); of formononetin, 31 microg (13-44 microg); and of biochanin A, 6 microg (2-11 microg). Median total intake of isoflavones was 154 microg (99-235 microg). The main sources of isoflavones were beans and peas. The estimated daily intake of coumestans was 0.6 microg (0.2-1.7 microg), with broccoli as the main source. The estimated daily median intake of matairesinol was 19 microg (12-28 microg) and of secoisolariciresinol 560 microg (399-778 microg). The median total intake of lignans was 578 microg (416-796 microg). The main source of the lignans was fruits. The daily dietary intake of phytoestrogens in healthy postmenopausal Caucasian women in the United States is <1 mg.

Phyto-oestrogens and cardiovascular disease risk.

AIM: To present the currently available evidence on the cardiovascular benefits and risks associated with phyto-oestrogens. DATA-SYNTHESIS: Medline search from 1966-1999 updated with cross-check of references of papers with keywords such as phyto-oestrogens, isoflavones, lignans, genistein, daidzein, enterolactone, enterodiol, cardiovascular disease, cardiovascular disease risk factors. CONCLUSIONS: Phyto-oestrogens are plant chemicals divided into three main classes: isoflavones, coumestans, and lignans that display oestrogen-like activity due to their ability to bind to the oestrogen receptor. They are found in grains, beans, green vegetables, fruits, nuts, and grasses. Isoflavones are primarily found in soybeans and soy foods. For epidemiological studies of the relation between phyto-oestrogen intake and disease parameters, intake is estimated with several measures, such as biomarkers (concentrations in urine or blood) or dietary questionnaires, though the optimal method is not yet clear. Phyto-oestrogens are considered to act as selective oestrogen receptor modulators (SERM), exerting both oestrogen agonist and antagonist action. Supplementation with isolated soy protein containing the isoflavones genistein and daidzein reduces serum total and LDL-cholesterol and triglycerides in animals and in humans. Vascular reactivity might be improved by supplementation with isolated soy protein or isoflavones isolated from red clover. Studies on atherosclerosis in animals indicate a potential for risk reduction. Evidence in humans is still scanty. The little we know of the effects of regular dietary phyto-oestrogen intake comes from studies in which phyto-oestrogens were added to the usual diet. Most supplementation studies have been conducted with soy isoflavones, whereas the importance of lignans has not been determined, though they could be more important sources than isoflavones in Western populations. Research has been focused on risk factors. Studies of clinically manifest endpoints are urgently needed.