Our Aging Digestion System

This is part one of a two part post on the issue of food and eating as we age; specifically written for those of us 50+ years of age. To start, I am here focused on our digestive system and how aging can change everything we understood and experienced about eating. That is, age related digestive changes that effect what we see, smell, taste, process, and expel.

Remember I am not a biologist, nutritionist, dietician, or a medically certified person. I am a cook trying to understand as much as I can about digestion as it is important to making the proper decisions when I cook for my own family or friends.

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Defining the Aging Process

What Is a Senior?

The acknowledged truth of human experience is that ever since our birth, all of us have been aging. At every step of the way, until dead, our ability to generate an appetite, eat, digest, and eliminate food changes. While there are external reasons for these changes such as: our environment, family and financial situation, etc., there are internal reasons too. My interest, for the next two posts, are in the normative digestive changes “elderly”, “geriatric”, or “old” people experience.

I do not like those particular terms, because another truth of human experience is that we do not hit a particular age and thereby achieve a state of “geriatric.” What we actually experience as aging, are a series of individualistic changes, that occur along a continuum. Therefore, I have a preference for calling myself a senior person, and have three specific qualifiers for that term that are not a measurement of years lived (and inversely how long we have yet to live), but reflects the state of our bodies.

• The first indicator of moving into the senior category is when our bodies initiate a major hormonal change named perimenopause for women, and a different type of hormonal change or andropause for men (1).
• A second indicator is the amount of prescriptions we taking to deal with aging-related complaints. The key is if we are taking 4+ pills/day, which induce chemical changes in our body (2).
• The third is when we start to feel the biological changes of aging in our digestive system, such as unusual gas, bloating, belching, heart burn, loss of appetite, etc., when eating foods we have never had a reaction to before (3).

When we start to meet these three conditions, we are a senior person, and most of us will start to experience some digestive problems.

The Digestion System

WebMD writes that nearly 40% of older adults have one or more age-related digestive symptoms each year. As part of the senior community, and a cook, it is important for me to understand how to deal with my own digestion problems, as well as for the family and friends I invite to dinner.

The start: Vision + Smell + Taste

I have always understood digestion as starting with our eyes, nose and mouth. We need our eyes to see the food and assess its attraction, along with our nose to sense the aroma of the food, and together they engage our brain to trigger our body to start creating hunger pangs and our mouths to produce saliva. In other words, our body is triggered to get ready to consume nourishment.

While cooking it is easy to tell when this happens. It is when all those people who were in the living room talking, start to meander into the kitchen lifting lids, wanting to taste the food, and saying things like, “oh that smells good”; clearly giving signs that their appetite is awakening and their digestive system is getting ready.

Scientific American wrote: To our brains, “taste” is actually a fusion of a food’s taste, smell and touch into a single sensation. But as we move into being a senior, the process of taste changes.

• Time affects our eyes and our sight becomes less sharp and color perception changes, which in-turn affects our appetite (4,5). To keep food looking delicious, a cook needs to consider how to brighten the distinct food on the plate, making sure there is contrast between the plate and the food. You do not want all whitish looking food on a white plate, nor a hodgepodge, messy plate where food combines.
• Also to help see better, the dining room light may need to be made a bit more bright to assure visual clarity for seniors. 
• Time changes our ability to smell, and 80% of our taste comes from smelling; so aging can result in dishes having a diminished flavor (6, 7). The result is aromas become far too subtle, leading to a sense of bland and unappetizing food. To help improve the flavor for seniors I add more brightly colored food to the plate, and add spices or seasonings (like mustard, vinegar, lemon, herbs, etc.) at the very end.
• Also, I consider adding one very flavorful cold dish, as sometimes temperature changes can help (8).
• The tongue, starts to lose the ability to sense salty and sweet tastes. This means food will tend to taste bland or even a little bitter. This can lead to seniors over-sweetening or salting food.

The older we are, the more careless some people seem to be about their mouths and gum disease or tooth decay can occur. Both of these can lead to other illnesses, but also affects our ability to properly chew and break down the food in our mouths. This breaking down food, along with saliva, are critical to being able to properly swallow food. If we cannot chew well, or generate saliva to start the digestive process, the food may not break down enough to swallow, or may not break down in the stomach as easily. It is important that as seniors, we continue to maintain our dental checkups to keep our mouths healthy.

Swallowing + Stomach

In general, seniors experience muscle mass loss and strength lessens all over the body; especially if physically inactive. Our swallowing mechanism, the upper esophageal sphincter, can loose it’s tension, and other related diseases can cause a multiplication of difficulties with swallowing. This makes it very important that we sit up straight when eating, so gravity can assist in swallowing. The statistics most relevant is that nearly 30% of folks aged 76+ have problems swallowing.

As we age, our stomachs’ lining loses some of its elasticity too, which means we cannot consume as much in one setting as we used to eat. But also the stomach’s resistance to the acid it contains starts to lessen. Which can result in us having to eat smaller amounts of food at one setting, but countering that change by eating more that 3x a day. Aging also increases the likelihood of ulcers if we do not adjust how we eat. This of course is complicated if we have been on antacid medications.

On top of that, the muscles in our GI tract, including our esophagus and bowel, start slowing down a bit more, which in turn can lead to acid reflux and/or constipation. Then of course there are all those medications to deal with constipation.

This all leads to another senior truth, as we age we can often wake up from a great night’s sleep with a new, unexpected, and more surprising list of aches and pains. In the west we self medicate to treat these symptoms, such as taking pills for joint pain, acid reflux, heartburn, constipation, etc.; all those chemicals can affect our ability to swallow, our sensitive stomachs, and our ability to properly digest food.

Organs + Biome

Organs like the liver, pancreas, and gallbladder also change with time. Cells die, and it is not always the case that they are automatically replaced, thus some organs wind up shrinking. Sometimes blood flow to certain organs lessens, which reduces their ability to function well. This means, we may not be able to handle changes, illness, or stresses as well as we could have once and our digestion is effected.

• The pancreas’ secretions of major digestive enzymes can be interrupted.
• Our liver shrinks with age, and its rate of protein synthesis lowers, affecting our metabolism; also the liver’s ability to detoxify many substances from our bodies lessons.
• The gallbladder squirts the bile into the intestines to emulsify fat. But with age, and diminished abilities, women find the effect is higher blood cholesterol.

As we age, we may have already experienced illnesses or diseases which have adversely affected these organs. For instance, I had my gallbladder removed when younger. HealthLine writes, without a gallbladder, there’s no place for bile to collect. Instead, your liver releases bile straight into the small intestine. This allows you to still digest most foods. However, large amounts of fatty, greasy, or high-fiber food become harder to digest. So for many without a gallbladder the result can be diarrhea or constipation as the liver cannot regulate the bile production as well as the gall bladder would have.

Similar to how we use bile from the gall bladder to help digest food, our microbial environment is critical to our digestive ability, crucial to our nourishment, and can effect our whole body. Millions of “bugs” enter our body with our food each time we eat. So clearly our digestive tract is full of passengers.

• Our mouth has 100-200 species right now.
• Our esophagus and stomach do not have many bugs.
• But the small and large intestines do!
• The digestive tract overall contains ~100 trillion bacteria.

To give a sense of how important these bugs are to our overall health. One type of microbiome, according to AMNH: modulates the immune system to reduce the risk of allergies and asthma, prevents esophageal cancer and gastric reflux disease, and even helps regulate appetite, with experiments showing that the removal of this bacterium is associated with weight gain.

The NursingTimes writes: The aging process mimics the intestinal microbe profile that accompanies inflammatory bowel diseases and obesity (Neish, 2009). Which means as we age, our gut bacteria can change and may participate in creating our digestive issues.

Intestines + Anus

The easy way to distinguish between the small and large intestines is: the smaller is meant to absorb most of the nutrients from the teeth-saliva-stomach process, while the larger intestine is meant to absorb the final bits of water and electrolytes, produce vitamins, and create waste.

The small intestine, is meant to continue to digest food through the mixing of chemicals to reduce the sloshy, broken down food into absorbable nutrients. The organs squirt chemicals like digestive enzymes into the small intestines to help produce more and more nutrition from that food.

As far as I can tell, the main negative aging-related issue for the small intestines is that the lactose enzyme levels may decrease over time, so that we may start to show signs of dairy, or lactose intolerance. Additionally, certain bacteria can overgrow, which we can experience as pain, bloating, reduction in vitamin absorption, and even weight loss.

Then we come to the large intestine and anus, the final stop of our digestive systems. The large intestine is meant to reduce the water content of the waste, and then push that waste material to the anus for elimination. The main issue related to this organ is constipation, and with the anus is hemorrhoids.

Constipation

There are age-related changes to our bowel movements, and seniors are prone to constipation for the reasons listed above. As our muscles lose strength, food and waste move slower through our systems, which reduces the liquid in the waste even more, and in-turn makes it harder to eliminate. The steps that lead toward constipation include (9):

• Medication for high blood pressure
• Narcotic pain reducers (like with my recent knee replacement)
• Nonsteroidal anti-inflammatory drugs (NSAIDs) to control pain, say from arthritis
• Changes in our exercise level, if we become more stationary
• Not drinking enough water or getting enough fiber
• Diverticular Disease
• Polyps
• GERD

Hemorrhoids

Constipation, and even diarrhea, can cause hemorrhoids, which are internal, swollen veins inside the rectum or right under the skin around the external part of the anus. The reasons to be concered about hemorrhoids include the list below, most of which can be treated with medication and changing bathroom habits (1).

• Anemia due to constant hemorrhoid bleeding.
• Having a strangulated hemorrhoid, where the sphincter muscle cuts off the blood flow to an internal hemorrhoid (which I hear is very painful).
• Giving off a blood clot causing thrombosis hemorrhoids (also a painful situation).

But mostly hemorrhoids are uncomfortable and painful, which makes using the toilet a chore that one just has to get through. There are many other causes that I am not going to discuss (e.g., pregnancy and anal sex).

• Aging: the older you get, the higher your chances are because the tissues that support the veins within your anus and rectum become weak and stretch out over time (10).
• Straining or sitting for a long time on the toilet stresses the veins around the anus.
• A diet low in fiber.
• A side effect of medication already mentioned in this post.

Summary + Next Post

This first post on seniors provides a background on our digestive system from a normative aging perspective. I tried to not make this too scientific or too detailed, but we need to know enough to understand the changes we are, or will be, experiencing at some time in our life. The next post looks at other changes that affect our eating and processing of various foods, as well as what we can do to help our situations.

—Patty

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