How aging affects what you can eat and drink, even if you’re in your 20s

As a kid, I could eat everything without consequence. My only consideration was whether or not it tasted good. This bliss lasted until I hit my early 20s, when my body began to reject my “anything goes” diet. Not only did my stomach change, but so did my palette. I started craving new foods and disliking old favorites, all the while wondering why these changes had happened.

Our bodies evolve every single year and our digestive system isn’t exempt from this depressing reality. Digestive conditions like acid reflux, constipation, and lactose intolerance can become much more common as we go through adulthood. Some differences naturally happen as we leave our teenage years behind while others happen not directly because of aging, but because of lifestyle and environmental changes we inevitably experience.

So, what are the actual medical and biological reasons I can’t enjoy certain foods I had no issue with just a few years ago? I reached out to some health professionals to get a little clarity on my gastro-existential crisis.

Our tolerance to certain foods change

When we get older, the biochemical processes inside of us change how we process food. We have digestive enzymes, which are tiny proteins that break down the food we eat into the nutrients that our bodies absorb. The loss and degradation of these enzymes is a big catalyst for digestive change.

“As people age, we tend to lose the lactase enzyme in our gut and many people develop lactose intolerance,” says Dr. Rabia De Latour, a NYC-based professor of gastroenterology at NYU Langone School of Medicine. “Many people start losing lactase by age five and by their 20s, are lactose intolerant.” Lactose intolerance happens when individuals face gastrointestinal discomfort after the consumption of milk products — this means cheese, ice cream, and several other joy-inducing foods. The cost of consuming these things if you’ve got a dairy intolerance can be awful. We’re talking diarrhea, bloating, and all types of discomfort, Dr. De Latour tells Mic.

One thing to keep in mind is that you’re not doomed if you develop a food intolerance. They’re treatable, for many, with over-the-counter meds. Also, while food intolerances can appear spontaneously as we age, they can disappear that way as well. “Food allergies or intolerances that we had when we’re younger may actually go away as we age,” says Dr. Loren Brook, gastroenterologist and an assistant professor in the University of Cincinnati College of Medicine’s division of digestive diseases. If you had an allergy as a kid and want to know if it's still present, consult with a doctor to find out — DIY “tests” are not the best move.

We lose stomach acid secretion

Another chemical-related reason you might not be able to down nachos and rum like champ anymore might be a reduction in stomach acid secretion, says Amanda Archibald, a Wisconsin-based registered dietitian and founder of Genomic Kitchen, a nutritional coaching company. “When there’s less acid in the stomach, food is more prone to be incompletely digested,” she says. Stomach acid secretion can begin to slowly decline in individuals as early as their 20s.

When food that is not completely digested ends up in the gut for absorption, the immune system recognizes it as a foreign substance and has an immune response. “This response injures not only the gut wall but the individual too,” Archibald tells Mic. The injuries caused by incompletely digested foods “can manifest as allergies, food intolerances, bloating, gas and more critical health issues such as Crohn's disease and other auto-immune diseases.” The loss of gastric acid leads to problems absorbing some essential vitamins such as B12, adds Dr. Brook.

Our organs lose some of its power

Similar to how skin can sag and knees can weaken, our digestive organs can also lose their power. According to Dr. Jason Reich, a Massachusetts-based gastroenterologist, “the muscle between the stomach and esophagus, the lower esophageal sphincter, weakens. This allows acid reflux to occur.” Brook adds that the weakening of esophagus muscles can also “give us the sensation of difficulty swallowing or food getting stuck.”

This one doesn’t generally happen to very young people, but does naturally happen as early as 40 for some, adds Reich. Copious consumptions of foods such as coffee, chocolate, soda, and alcohol can also diminish the esophagus faster. Changes in the stomach also occur because the stomach loses some of its elasticity, so it can’t hold as much. It also empties more slowly, says Los Angeles-based registered dietitian, Susan Bowerman. When we get older our gut immunity becomes less effective, adds Dr. Latour.

We make less-than-responsible lifestyle choices

Remember those environmental and lifestyle factors I mentioned? One of them is stress, which experts assert increase with age. I can attest, since the carefree bliss of my younger years are now a distant memory. Stress, of all types, has an especially negative effect on digestion functions. “It induces the release of the corticotropin-releasing hormone which can directly impact the gut, causing discomfort and diarrhea, and further aggravate gut-related auto-immune issues,” Archibald says.

Another lifestyle factor that affects our digestion is the decrease in exercise and physical activity that often occurs in adults. The majority of American adults are not getting enough exercise. Most adults get less physical activity than kids do and adults also comparatively get more sedentary as they get older. Working out stimulates the smooth muscles of the digestive tract, Bowerman says, so a lack of sweating it out regularly greatly diminishes digestive function.

Yet another factor in this equation is dehydration, which is a life-long issue that affects many of us, but as we get older, the effects are much more pronounced. “Adequate fluids are critically important for the digestive process as well as for the transport of nutrients to the cells,” Archibald says. According to a study conducted by the CDC, many adult Americans are not getting enough hydration each day and that can lead to constipation and acid reflux. Consider this reminder #367,400 to drink more water.

Some people also take more medications as they get older, which impacts digestive function. My experts tell me that some medications can be constipating and some can even contribute to gastrointestinal ulcers, says Dr. Inna Lukyanovsky, a pharmacist and functional medicine practitioner in Marlboro, New Jersey. For people experiencing digestive problems, Dr. Brook suggests that they talk with their “physician about limiting the number of unnecessary medications [to] help improve regularity.”

Our taste changes

As we age, we not only digest foods differently but also appreciate foods differently. We like to think our palettes change simply because of age and refinement, but there’s a biological component to the evolution of our taste buds as well. “We lose taste buds as we age and, with a small number of active taste buds, foods tend to taste more bland,” says Bowerman. We actually start losing taste buds pretty much as soon as we start taking our first steps (infants have more tastebuds than the average adult). By the time we hit our 20s, we have roughly half the taste buds we were born with. When the foods appear more bland, people often pour on more condiments or seek more naturally flavorful foods.

Know that your digestive system isn’t doomed the day you hit 25. We can take initiatives to slow down — and even prevent — some of these uncomfortable changes from happening. Dr. Brook recommends eating a balanced diet, getting adequate amounts of fiber, and exercising several times a week. Dr. Reich agrees, and believes it's okay to “splurge once in a while, but to just be aware that the body's capacity to digest food wanes with age.”