Colorectal cancer is no longer a disease of the elderly. Rates are rising in younger adults across the world, and this shift is forcing researchers to look beyond genetics because our genes are not fundamentally different than they were 50 years ago.
The colon is one of the most metabolically active tissues in the body. Its cells require a constant supply of energy to maintain structure, regulate inflammation, and renew the intestinal lining. When energy production is impaired, tissue repair becomes less efficient, inflammation increases, and normal growth regulation is disrupted.
Modern environments disrupt our ability to make energy properly. They are inherently stressful, so our cells are pushed into compensatory metabolic states that prioritize survival over repair.
- Diets dominated by ultra-processed foods and industrial seed oils interfere with mitochondrial respiration and increase oxidative stress.
- Polyunsaturated fats, which readily accumulate in tissues and cells are especially prone to oxidation, producing reactive byproducts that damage proteins and suppress normal metabolism. Over time, the colon becomes a tissue under constant metabolic strain.
- Excess estrogen relative to protective hormones like progesterone promotes water retention, inflammation, and disrupted cell function in intestinal tissue.
- Impaired thyroid function slows intestinal movement and cellular turnover. Waste products and toxins remain in contact with the gut lining longer, increasing irritation, inflammation, and exposure to harmful byproducts.
Serotonin plays a particularly important role in the gut and in cancer. While serotonin is often discussed as a “feel-good” neurotransmitter, when elevated, smooth muscle activity in the intestine is inhibited, slowing transit time and altering normal digestive function.
At the cellular level, serotonin suppresses mitochondrial respiration and shifts cells away from efficient oxidative metabolism. This reduces carbon dioxide production, promotes vasoconstriction, and limits oxygen delivery to tissues, a central feature of cancer.
Over time, these changes create a low-energy, inflammatory environment that favors tumor growth.
Chronic stress compounds this problem. Cortisol is a stress hormone designed for short-term survival. When it stays elevated, it pushes the body to rely less on efficient, oxygen-based energy production and more on emergency fuel pathways. It does this by suppressing thyroid signaling, reducing glucose oxidation, and increasing reliance on fatty acids and amino acids for energy—processes that produce less usable energy and more metabolic byproducts.
In the gut, cortisol also slows tissue renewal and weakens the intestinal barrier. Blood flow is redistributed away from digestion toward muscles and the brain, intestinal movement slows, and repair processes are deprioritized. This creates an environment where inflammation and irritation are more likely to persist.
One line of investigation has focused on the gut microbiome.
A growing body of evidence suggests that specific bacterial toxins, such as colibactin produced by certain strains of E. coli, may damage DNA very early in life, even within the first nine months.
This kind of early genetic insult could create a vulnerability that plays out decades later in the form of cancer. If confirmed in larger studies, this would fundamentally shift how we think about cancer risk across the lifespan.
Researchers also emphasize that how we start life, including mode of delivery at birth, breastfeeding versus formula feeding, and early microbial exposures, can shape the developing immune system and microbiome in ways that may influence long-term disease risk.
Babies born by cesarean section or given formula rather than breastmilk tend to acquire different microbial communities, which may change how their immune systems learn to regulate inflammation and repair tissue over time.
The rise of colorectal cancer in younger adults is a warning sign. It suggests that modern life is pushing the gut, and the body as a whole, into a state of metabolic exhaustion much earlier than it should.
Restoring metabolism and reducing chronic stress may be among the most powerful tools we have for changing that trajectory.
Screening is important, but it cannot fully address the metabolic conditions that allow disease to develop. Supporting mitochondrial function, maintaining stable blood sugar, reducing inflammatory fats, supporting thyroid and hormonal balance, and lowering chronic stress signals such as excess serotonin may all help restore the energetic conditions that protect intestinal tissue.
Factors that reduce risk:
Adequate vitamin E plays an important protective role by limiting lipid peroxidation, particularly from polyunsaturated fats that accumulate in tissues. Vitamin E helps stabilize cell membranes, reduce oxidative stress, and protect mitochondrial function. This is especially relevant in modern diets where exposure to oxidizable fats is high.
Maintaining sufficient vitamin D supports immune regulation, cellular differentiation, and normal growth control. Vitamin D deficiency has been associated with higher cancer risk and poorer outcomes, likely due to impaired immune surveillance and increased inflammatory signaling. Sensible sun exposure and supplementation when needed can help maintain adequate levels.
Calcium intake is another key factor, particularly for colorectal health. Calcium supports cellular stability, helps regulate growth signals, and may bind irritating or toxic compounds in the gut. Adequate dietary calcium has consistently been associated with lower colorectal cancer risk, especially when balanced with sufficient vitamin D.
Supporting thyroid function is central to cancer prevention in a bioenergetic model. Thyroid hormone drives mitochondrial respiration, maintains tissue oxygen utilization, and supports normal cell turnover. Low thyroid function slows metabolism, impairs intestinal motility, and increases vulnerability to inflammation and abnormal growth.
Reducing chronic exposure to polyunsaturated fats and seed oils helps lower oxidative stress and metabolic burden. Replacing them with more stable fats, such as saturated and monounsaturated fats, may reduce lipid peroxidation and support healthier cellular respiration over time.
Maintaining stable blood sugar is critical. Repeated spikes and crashes increase stress hormones like cortisol and adrenaline, which suppress oxidative metabolism and promote inflammatory signaling. Regular meals with adequate protein, carbohydrates, and minerals help reduce metabolic stress and support consistent energy production.
Lowering excess serotonin in the gut is another protective strategy. Supporting regular bowel movements, adequate protein intake, sufficient sunlight, and balanced carbohydrate intake can help reduce excessive serotonin signaling.
Adequate protein intake, especially from easily digested sources, provides the amino acids needed for tissue repair, detoxification, and immune defense. Protein deficiency impairs regeneration and shifts the body toward stress metabolism, increasing long-term cancer risk. Make sure to prioritize anti-inflammatory amino acids such as glycine.
Carbon dioxide production, a marker of healthy oxidative metabolism, is often overlooked. Efficient metabolism naturally increases carbon dioxide, which helps regulate blood flow, stabilize proteins, reduce inflammation, and improve oxygen utilization.
Chronic stress reduction matters at the cellular level. Psychological stress translates into biochemical stress, raising cortisol, serotonin, and inflammatory mediators that suppress energy production. Regular sleep, daylight exposure, gentle movement, and emotional regulation all support metabolic resilience.