The Ultimate Guide to Senior Nutrition Part 1:
How the Five Senses Affect Healthy Aging
What was that? You haven’t heard that hearing affects your nutritional status? You haven’t seen how sight can affect it too? While these two statements are both true, they are just two of the senses that affect how we eat; in fact, all five senses play a role in healthy aging. Taste, vision, hearing, touch, and sense of smell altogether make up the stimuli that affect how our bodies react to food and to our relationship with food, which in turn, directly influence how we age (9). By knowing how our bodies can be used to physically relate with food, we can equip ourselves with the tools to best utilize the resources that these five senses give us.
TASTE
Taste is the sense that everyone most likely associates with food. What many people don’t know is that our ability to taste food well declines as we age. In fact, taste changes may occur starting as early as age 50 (3). The average human is born with about 9,000 taste buds, which serve to send taste signals to the brain by way of nerve cells. As we age, the number of taste buds decreases, and the taste buds remaining begin to shrink in size. After age 60, our ability to determine the difference between sweet, salty, sour, bitter and umami (savory) flavors begin to diminish as well (1)(7). Women retain their sense of taste better than men do (7). The reason that older populations tend to use larger amounts of spices and condiments is likely not because their affinity for these foods has increased, but because they need to use more in order to taste the ingredients as well as they did when they were younger and used less. This is important to know because as we get older, adding too much of some things, such as salt or butter, to flavor food can contribute to conditions such as hypertension and heart disease. Instead, flavor foods with herbs, spices, salt-free seasonings such as Mrs. Dash, hot sauce, garlic, onion, and acids such as lemon juice or balsamic vinegar in order to add great taste without the extra sodium or fat.
Just as our tastes change, our appetites do as well (1). Older people have a blunted appetite regulation compared to their younger counterparts (7). Because hunger and satiety cues are weaker in older adults, they should aim to be more mindful of their food intake; without feeling as much of a hunger or fullness sensation, it is easier to eat too much food in one sitting or to not eat at all. Both eating too much and not eating enough can contribute to weight gain. Setting timers to remember to eat can combat skipping, and keeping serving sizes to fit within the guidelines of MyPlate help with portion control. MyPlate is the updated version of the food pyramid that has been published by the USDA Center for Nutrition Policy and Promotion as the current guide for nutrition. It depicts a plate that is one quarter lean protein, one quarter whole grains, and one half fruits and vegetables, with a small serving of dairy on the side (6). Including all nutrients in our diet is essential, especially as we age and vitamin and mineral deficiencies become more common. Deficiencies of some vitamins and minerals, such as zinc, can cause changes in taste and appetite. It is important to get a full vitamin panel drawn at your primary care physician each year at your annual checkup in order to be sure you are maintaining normal vitamin and mineral levels. If you become low in any vitamins or minerals, a Registered Dietitian can recommend foods high in the vitamins and minerals that you need. For example, foods high in zinc include oysters, beef, pumpkin seeds and baked beans (5). You may also take a supplement that is recommended by a physician or Registered Dietitian in order to help replete any deficient vitamin or mineral levels.
Staying adequately hydrated is essential as an older adult, as dehydration is common in the elderly and can lead to diarrhea, vomiting, speech difficulty, chronic fatigue, dizziness, headaches and urinary tract infections (7) (10). Older adults actually need more fluid per pound or kilogram of body weight than younger people do, just to maintain adequate hydration status. This is important to note, because as we age, the thirst-regulating mechanism we have that allows us to know when we should drink something declines (7). To ward off dehydration, make sure you have a class of hydrating (caffeine-free) fluid on the table at every meal, and that you are sipping on hydrating fluid between snacks and meals. Keep a water bottle in your car, at your desk at work, and in your hand while you are running errands. Examples of hydrating fluids include water, decaf tea and coffee, sugar free juice, sugar free gelatin, sugar free popsicles, broth, flavored water, and water sweeteners such as Crystal Light or Mio drops. Be careful with sports drinks such as Powerade and Gatorade, as well as “health” drinks such as Vitamin Water, because these may be loaded with sugar. In order to help stay hydrated, you may also opt to eat foods with a high water content such as cucumbers, grapefruits, radishes, celery, tomatoes and bell peppers (11).
Another challenge that the aging population faces when it comes to eating is missing or poorly fitting teeth. Poor dietary choices are a modifiable habit that can contribute to poor dental health and even tooth loss. In fact, approximately 1 of 4 adults aged 60 and over have no natural teeth (7). If you fall within this category or have few natural teeth left, choose foods that are high in nutritive value but are also soft enough to chew with changing teeth and gums. Examples include eggs, berries, Greek yogurt, steamed vegetables and steel cut oatmeal. To prevent dental caries, cavities, and loss of teeth, utilize regular dental follow up and care, and be sure to brush and floss your teeth daily. Conditions that exacerbate periodontal disease are common in older age, so an oral health assessment is particularly important for aging adults (7).
Medication also may affect taste, cause an upset stomach, or change your appetite. Due to these symptoms, people on medications may have unwanted side effects by continuing to eat a certain way without knowing food may be the cause, and other people may avoid certain foods altogether (3). Discuss food/medication interactions with your doctor, and read your prescription labels for any special directions that discuss how to eat or drink while using those medications.
VISION
We use our eyes every waking second of every day, and this includes when we are shopping for, reading about, cooking and eating food. As we age, the structures of our eyes change, and the sharpness of our vision gradually declines. The most common vision changes occur around age 40, and visual acuity slowly continues to decrease thereafter (8). This may make it more difficult to read menus, cookbooks, or nutrition facts labels. If you notice that, over time, it is becoming more strenuous on your eyes to read fine print, your health can be compromised in conjunction with your vision because making healthy food choices can become a challenge by not being able to clearly see what you are looking at. Speaking with an eye doctor about options such as magnifying reading glasses or contact lenses is a relatively simple fix in order to contribute to better overall health. This way, you can have your bifocals ready at the store to compare two similar products by reading their ingredient lists, and you can read the menu in the dim lighting at the restaurant to select the more nutritious choice. You will also be able to see that your recipe calls for one teaspoon of chili powder versus one tablespoon, and save yourself an uncomfortably spicy dinner! The best part about being able to see clearly is to view the beautiful food presentation in front of you, and to fully enjoy your food before you even pick up your fork.
HEARING
As we age, humans develop a condition called presbycusis around age 60; as something that sounds very serious, it really just means a gradual loss of hearing (8). Although at first, it doesn’t seem like hearing and nutrition go hand and hand, hearing loss can in fact affect how we eat and our overall quality of life. If you are cooking at home, you want to make sure you can hear the stove timer going off in order to avoid burning your food or starting a fire. Invest in a handheld timer that you can take with you if you leave the kitchen, and cut down on background noise such as the radio or television that will make it harder to hear the timer when it goes off. Many cell phones now have a timer feature permanently installed on them, so having a timer essentially in your pocket at all times is pretty handy when multitasking!
Hearing is also the sense that most directly affects how we interact with others. Eating is a social gathering; it is rare that you go to a birthday party without cake or have a Thanksgiving gathering without turkey. Can you imagine what it would be like going to social events without being able to hear what others are saying, or without the ability to adequately communicate back? Many older adults struggle with being able to hear well or hear at all; therefore they choose to not go out with friends, or they avoid inviting their family over out of embarrassment. To allow socializing with others as a normal and enjoyable part of your life, choose restaurants that have lower ceilings with better acoustics, or with a quiet ambiance instead of a loud setting such as a sports bar. If poor hearing is impairing your ability to socialize and to eat, speak with a doctor. Options to help improve hearing include removing an impacted buildup of earwax, checking for fluid or perforation in the eardrum, or purchasing a hearing aid (1).
TOUCH
Although feeling your food may seem like an odd concept at first, think about how often we physically interact with our food. We pick produce up at the grocery store, we knead dough, we sprinkle in seasoning, and we swirl food around in our mouth before we swallow. The sense of touch is essential to food and nutrition. How do you know if an avocado is ripe? You pick it up, and if it is slightly impressionable and the stem is easily removed from the fruit, it is ready for use. Your hands are what helped you select this piece of food. In order to savor a perfectly cooked steak, we leave it on our tongue just a little bit longer; the tongue is used to fully feel the piece of meat before it is swallowed.
As we age, our ability to touch and feel things may be altered. Arthritis and joint pain, which are common as early as age 30, may make food preparation difficult (2). Using convenient, prepared meals may be easier, but could also be costing you your health depending on the choices you make, as many packaged foods are high in salt, sugar, and fat. Instead, look for convenient options that are also healthy, such as pre-chopped produce, steamable ready-to-go protein and vegetable blends, and pre-portioned snacks such as cheese sticks and 100 calorie bags of nuts.
Dysphagia, or difficulty swallowing, may also happen as we age (12). This can make eating certain textures of food or drinking certain textures of beverages dangerous, so if you notice that you are choking or allowing things to “go down the wrong pipe” when eating, consult a physician or Registered Dietitian about an eating plan that is safe.
Lastly, older people tend to make less saliva than younger people. This makes the oral cavity more sensitive to temperature extremes and course textures, which may result in pain while eating (7). If this begins to happen, you do not have to give up your favorite soup or iced beverage, but let them sit on the counter for a few minutes to moderate temperature so they are both safer and more enjoyable to consume. Because a dry mouth also makes it harder to swallow those courser textures, try taking sips of water between each bite of food, or cook your foods to be less tough by making more sauce-based, crockpot texture dishes.
SMELL
The final of the five senses, the sense of smell, is directly related to taste. Have you ever noticed how your stomach starts to grumble when the smell of your favorite food is wafting from the kitchen, even if you are rooms away and haven’t even tasted a bite? Your olfactory (smell) senses are kicking in, because both the sense of taste and the sense of smell use the same type of receptors in your body and are stimulated simultaneously. After age 60, it is natural to lose some sense of smell, and over 75% of people aged 80 and above have evidence of major olfactory impairment (4) (7).
Declining sense of smell unfortunately results in a lowered ability to smell that favorite recipe from far away, but more importantly, it also affects safety. If you’ve ever heard of people using the “smell test” when checking leftovers, it is one way to detect spoiled food. Without this extra measure, make sure that everything in your fridge is labeled clearly with expiration dates in order to avoid a stomach ache or food poisoning. A decreased sense of smell also makes it difficult to smell gas or smoke. Always set a timer when cooking, and make sure to double check your oven and stove when finished to ensure that they are turned off. Leaving notes taped to the display on your stove or the handle of your oven can help with this.
All in all, it is pretty amazing to see how well-equipped our bodies are to interact with food in ways that we can use to better enjoy our food and to optimize our health as we age. Leonardo da Vinci once said, “The five senses are the ministers of the soul.” If he was sitting down eating his favorite food, he may just have changed this statement to, “The five senses are the ministers of the stomach.” Go out into the world, equipped with the knowledge of how your senses can be harnessed for optimal health, and enjoy the delights of nutritious food along the way!
RD Nutrition Consultants LLC, is the industry leader in Registered Dietitian Consultant Services Nationwide. We specialize in providing contract Registered Dietitian services in a wide variety of healthcare and wellness organizations.
Resources
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