Glutamate can make a helpful contribution to nutrition for the elderly by making many foods more appetizing and appealing.

As we grow older, most of us lose some of our sense of taste and smell. This process normally begins at about the age of sixty, and becomes more noticeable in our seventies. As a result, elderly people’s food choices can change, and sometimes these changes lead to a poorer quality diet or to an inadequate level of food intake.

Under-nutrition in older individuals due to decreased food intake is a serious and growing problem. A study investigating nutrition for the elderly, conducted by researchers at Queen’s University Belfast, found that adding seasonings and sauces to the meals of elderly people, resulted in a significant increase of energy, protein and fat intake, with no differences between meals with seasoning and meals with sauce.

Many of the sauces and seasonings used in this study contained either monosodium glutamate or glutamate-rich ingredients such as sundried tomatoes or mushrooms and were added to a meal consisting of chicken, vegetables and mashed potatoes.

The results demonstrate that the addition of seasonings and sauces may be beneficial in increasing the food intake of older people as well as promoting overall improvements in nutrition for the elderly. They are also consistent with a previous study by Susan Schiffman, which showed that the use of the flavour enhancer monosodium glutamate (MSG) in meals for hospital patients resulted in consumption of 10% more calories compared to non-enhanced meals.

Comparable increases in energy, protein and fat intakes following the addition of seasonings and sauces to an older person’s meal

Rachael L. Best and Katherine M. Appleton
doi:10.1016/j.appet2010.10.11

Under-nutrition in older individuals is a serious and growing problem, as a result, amongst other factors, of decreased intake. Research has shown some support for the use of flavour enhancers or flavoursome foods as a tool for increasing nutritional intake in older individuals. In this study, seasonings and sauces were added to an older person’s meal to investigate and compare effects on food consumption. Participants’ were 18 free-living older individuals from Belfast. They consumed three meals on three separate occasions: one with seasoning, one with sauce, and one without seasoning or sauce, and intakes of energy, protein, carbohydrate and fat were compared. Other measures included pre and post-meal hunger and desire to eat, and pleasantness, familiarity, and flavour intensity of the meal. Significantly greater amounts of energy, protein and fat were consumed in the meals with seasoning and meals with sauce compared to meals served plain (smallest t(17)=2.11, p=0.05), with no differences between seasoning and sauce conditions (largest t=0.51, p=0.62). Flavour intensity ratings were also significantly higher for meals with sauce and meals with seasonings compared to meals served plain (smallest t(17)=2.78, p=0.01). These findings suggest that the addition of both seasoning and sauce to an older person’s meal can result in comparable increases in energy, protein and fat intake. Effects support a role for flavour in increasing food intake in older individuals. These effects, however, need to be demonstrated repeatedly over a longer time period before their true value can be established.

Supplement
Intensification of Sensory Properties of Foods for the Elderly

Susan S. Schiffman
Journal of Nutrition. 2000;130:927S-930S.
Department of Psychiatry, Duke University Medical Center, Durham, NC 27710

Taste and smell losses in the elderly can reduce appetite and lead to inadequate dietary intake. Although these chemosensory deficits are generally not reversible, sensory interventions including intensification of taste and odor can compensate for perceptual losses. One method for “treatment” of chemosensory losses involves sensory enhancement of foods with flavors and monosodium glutamate (MSG). Amplification of flavor and taste can improve food palatability and acceptance, increase salivary flow and immunity, and reduce oral complaints in both sick and healthy elderly.

The ability to taste umami in food (the fifth taste) could be beneficial for overall health, particularly in older people, Japanese researchers suggest.

The important role of umami taste in oral and overall health
Takashi Sasano, Shizuko Satoh-Kuriwada and Noriaki Shoji
Flavour 2015, 4:10

There is a close relationship between an individual’s perception of umami taste and that individual’s physical condition. Our newly developed umami taste sensitivity test revealed the loss of only the umami taste sensation with preservation of the other four basic taste sensations (sweet, salty, sour, and bitter) in some elderly patients. All such patients complained of appetite and weight loss, resulting in poor overall health. We also found that treatment of hyposalivation diminishes hypogeusia, indicating that salivation is essential to the maintenance of normal taste function. Based on these findings, we consider that improvement in salivary flow may serve as a treatment for patients with taste disorders. Umami taste stimulation increases the salivary flow rate because of the gustatory-salivary reflex. We used Japanese Kobucha (kelp tea: tea made of powdered tangle seaweed) to stimulate umami taste and promote reflexive salivation. Improvements were noted in salivation, taste function, appetite, weight, and overall health. Maintenance of umami taste function contributes not only to the preservation of good oral health but also to the general overall health in elderly people.

Access the Published Study