Cancer Prevention:
Lifestyle

1. Introduction: The Myth of Genetic "Bad Luck"

Cancer is often perceived as a random or purely genetic event. However, the World Cancer Research Fund (WCRF) estimates that about 40% to 50% of all cancer cases could be prevented solely through lifestyle changes and avoiding exposure to known carcinogens.

Although hereditary mutations (such as BRCA1/2) play a crucial role in specific cases, the vast majority of neoplasms are "sporadic," resulting from the accumulation of DNA damage over a lifetime due to modifiable external factors. Primary prevention is not only possible; it is oncology's most powerful weapon.

2. Pathophysiology: How Cancer Starts

The transformation of a normal cell into a malignant one is a multi-step process:

1. Initiation: Irreversible DNA damage (mutation) caused by a carcinogen (e.g., tobacco, UV radiation, viruses). The cell becomes "initiated."
2. Promotion: Continuous exposure to promoting agents (e.g., chronic inflammation, hormones like estrogen or insulin) stimulates the proliferation of the initiated cell. This phase is long, reversible, and the main target of lifestyle prevention.
3. Progression: The tumor acquires genetic instability, becomes invasive, and capable of metastasis (spreading).

3. Obesity: A State of Chronic Inflammation

Obesity has surpassed smoking as the leading preventable risk factor for cancer in non-smokers. Adipose tissue is not just an energy depot; it is an active endocrine organ that secretes inflammatory cytokines (TNF-α, IL-6).

The obesity-cancer relationship is mediated by:

• Chronic Inflammation: Generates free radicals that damage DNA.
• Hyperinsulinemia: Insulin resistance raises levels of Insulin and IGF-1 (Insulin-like Growth Factor 1), which are potent mitogens (stimulators of cell division) and inhibitors of apoptosis (programmed cell death).
• Aromatase: Excess fat increases the conversion of androgens into estrogen, raising the risk of hormone-dependent cancers (breast, endometrium).

4. Diet: Protective Nutrients and Villains

There is no single "superfood" that cure cancer, but global dietary patterns have a profound impact.

4.1 The Villains (Dietary Carcinogens)

• Processed Meats: Sausages, bacon, ham, and pepperoni are classified by IARC (WHO) as Group 1 Carcinogens (proven cause of cancer in humans), mainly colorectal, due to nitrates/nitrites and heme iron.
• Sugar and Refined Carbs: Indirectly carcinogenic by promoting obesity and insulin/IGF-1 spikes.
• Acrylamide: Formed in starchy foods cooked at high temperatures (frying, potato chips), it is a probable carcinogen.

4.2 The Protectors (Natural Chemoprevention)

• Cruciferous Vegetables: Broccoli, kale, and cauliflower contain sulforaphane and indole-3-carbinol, which aid in the hepatic detoxification of carcinogens.
• Fiber: Accelerates intestinal transit, reducing the contact time of toxins with the colon mucosa and binding to secondary bile acids.
• Antioxidantes (Polyphenols): Green tea (EGCG), turmeric (curcumin), and berries combat oxidative stress.

5. Alcohol: The Socially Accepted Carcinogen

Alcohol is a Group 1 carcinogen. There is no safe level of consumption regarding cancer risk. Ethanol is metabolized into Acetaldehyde, a toxin that directly damages DNA and prevents its repair.

Alcohol consumption is causally linked to seven types of cancer: mouth, pharynx, larynx, esophagus, liver, colorectal, and breast (women). The risk is dose-dependent and synergistic with tobacco (smoking and drinking multiplies the risk exponentially).

6. Exercise: The Immunological Shield

Physical activity acts on multiple fronts in oncological prevention:

• Hormonal Control: Reduces circulating insulin, IGF-1, and estrogen.
• Immunological Surveillance: During exercise, the release of adrenaline and muscle IL-6 (myokine) mobilizes Natural Killer (NK) cells into circulation. NK cells are the first line of defense, identifying and destroying nascent tumor cells.
• Intestinal Motility: Reduces mucosal exposure time to fecal carcinogens.

7. Sun Exposure and Vitamin D

The relationship with the sun is paradoxical. Excessive UV radiation is the primary cause of skin cancer (melanoma and non-melanoma). However, sun-dependent Vitamin D synthesis is crucial for regulating cell proliferation.

Adequate Vitamin D levels are associated with a lower risk of colorectal and breast cancer. The ideal strategy involves moderate and safe sun exposure, avoiding burns, and supplementation when necessary to maintain optimal serum levels (40-60 ng/mL).

8. Conclusion

Cancer prevention is not about fear, but about empowerment. While we cannot control our genetic inheritance, we have significant control over the cellular environment in which our genes operate. Adopting a plant-based diet, maintaining a healthy weight, limiting alcohol, and moving your body daily are the most effective "preventive chemotherapies" available, with no adverse side effects.