The Superhighway to Better Health:

The vagus nerve is the superhighway that runs from the brain to the gut, exchanging information along the way. What happens in your gut affects your brain. Food and mental health are intertwined.

Studies have shown that people with irritable bowel syndrome have twice the rate of depression and anxiety. Stress less about food and understand why natural, unprocessed, high-fiber foods are so critical. Food plays a direct role in hormone and neurotransmitter synthesis, influencing mood-regulating chemicals such as serotonin, dopamine, and norepinephrine.

The gut is often called our second brain because of these interactions and the large number of nerve cells found in the intestines. In fact, the gut is the only organ in the human body with its own nervous system. So treat your gut well and focus on fiber.

Fiber is well known for its digestive benefits, and studies now show that its impact extends beyond the gut. It has been linked to improved cognitive health by reducing inflammation in the brain. Lower levels of inflammation may reduce the risk of memory loss and cognitive impairment over time. The prevalence of early-onset dementia (under age 65) has increased over time, due in part to environmental and nutritional factors.

One study demonstrated that for every 5-gram increase in daily fiber intake, the risk of depression dropped by 5 percent. Approximately 90 percent of the body’s serotonin—the “happy hormone”—is produced in the gut.

Fiber also acts as both a probiotic and a prebiotic. Probiotics are beneficial bacteria that produce short-chain fatty acids, communicate with the brain, aid digestion, protect the intestinal lining from inflammatory molecules, improve immunity, and help balance hormones and neurotransmitters. Prebiotics nourish and feed these beneficial bacteria, helping reduce inflammation and regulate mood.

Inflammation in the gut communicates through the vagus nervous system—the superhighway to the brain. And fiber is one of the key components in supporting that connection.

Why Fiber Matters
Not all fiber is created equal. Fiber is an indigestible carbohydrate, and in this age of carbohydrate restriction and heavily processed foods, the amount of fiber in the human diet has been significantly compromised.

Studies show that the average American consumes only 8–15 grams of fiber per day. USDA and FDA guidelines recommend between 22 and 34 grams daily, depending on age and sex. As a result, 90–95 percent of Americans do not consume the amount of fiber they need each day.

Common signs of insufficient fiber include constipation, hunger after meals, energy crashes, low mood, fatigue, and sugar cravings.

Types of Fiber
Carbohydrates are typically broken down into glucose, the body’s primary source of energy. Fiber, however, is a type of carbohydrate that cannot be digested and therefore passes through the digestive system relatively intact. In doing so, it helps prevent constipation and promotes regular bowel movements.

There are two types of fiber. Soluble fiber dissolves in water to form a gel, slowing digestion and helping manage blood sugar and cholesterol levels. Insoluble fiber does not dissolve in water and maintains its shape, acting as roughage that helps move material through the digestive tract.

Many foods in their natural form contain both types of fiber. However, much of that fiber is lost during the refining process. Processed foods are refined to remove the bran, or outer coating of the grain, reducing their overall fiber content.

Natural fiber is the intrinsic fiber found in foods such as fruits, vegetables, and whole grains. Added fiber, also called functional or isolated fiber, is added during manufacturing to increase a product’s fiber content. While some added fibers are derived from natural sources, many are produced synthetically in a laboratory.

Examples include beta-glucan soluble fiber, psyllium husk, cellulose, guar gum, pectin, bean gum, and hydroxypropyl methylcellulose. Nutrition labels listing total dietary fiber include both natural and approved added fibers, so it is important to read the ingredient list if you want to know the source of the fiber.

Although both natural and added fibers provide benefits, relying entirely on synthetic fibers may cause you to miss other important nutrients. Naturally occurring fiber works in synergy with phytonutrients and antioxidants found in whole foods, providing benefits that supplements alone cannot replicate.

Practical Sources of Fiber
Naturally high-fiber foods include whole grains, fruits, vegetables, legumes, lentils, nuts, and seeds. Fiber-rich fruits include berries and plums. Good vegetable sources include zucchini, cucumbers, leafy greens, and bell peppers.

Cooking with lentils and chickpeas and adding chia seeds and flaxseed to salads can significantly boost fiber intake. Eating the skins on apples, pears, and potatoes also helps maximize fiber consumption.

Avoid relying heavily on canned fruits and vegetables, white bread, non-whole-grain pasta, and white rice, as these are more heavily processed and contain less fiber.

Probiotic foods include yogurt, aged cheese, kefir, kimchi, sauerkraut, pickled vegetables, tempeh, vinegar, kombucha, and sourdough bread. Prebiotic foods that feed beneficial bacteria include artichokes, onions, garlic, shallots, leeks, bananas, berries, soybeans, eggplant, chia seeds, flaxseed, green tea, and raw honey. 

So let’s get on the superhighway toward better health and focus less on processed, packaged foods and more on natural whole foods. Shop the outer perimeter of the grocery store and avoid the middle aisles, where most boxed and packaged foods are found.

Drink more water, as high fiber intake without adequate hydration can lead to constipation. The superhighway to health can lead to a happier, healthier, and less complicated journey.

Start your travels now.