European Journal of Cardiovascular Medicine

Colorectal cancer (CRC) is one of the leading causes of cancer-related morbidity and mortality worldwide¹. It ranks among the most commonly diagnosed malignancies, with an increasing global burden due to changing lifestyle patterns, urbanization, and aging populations². According to the Global Cancer Statistics (GLOBOCAN 2020), CRC accounts for approximately 10% of all cancer cases and is the second leading cause of cancer-related deaths³. Despite advances in early detection and treatment, the disease remains a major public health concern, particularly in developing countries where screening programs are limited⁴.

The development of CRC is influenced by a complex interplay of genetic, environmental, and lifestyle factors. Several modifiable risk factors, including high red meat consumption, low fiber intake, physical inactivity, smoking, alcohol consumption, and obesity, have been strongly associated with increased CRC risk^5,6. Additionally, individuals with a family history of CRC or metabolic disorders such as diabetes and hypertension may have a higher predisposition to developing the disease. Despite strong epidemiological evidence linking these factors to CRC, understanding their combined impact remains crucial for prevention strategies.

Preventive measures such as dietary modifications, increased physical activity, smoking cessation, and routine screening (e.g., colonoscopy) have been shown to reduce CRC incidence⁷. However, disparities in adherence to these recommendations persist across different populations. Identifying the most significant lifestyle factors contributing to CRC risk in specific populations is essential for targeted public health interventions.

This study aims to evaluate the association between lifestyle factors and the risk of CRC by analyzing dietary patterns, physical activity, smoking, alcohol consumption, family history, and comorbid conditions. Understanding these relationships will help develop effective prevention strategies and guide early detection efforts to reduce CRC burden.  

Study Design and Setting

A case-control study was conducted at CMR Institute of Medical Sciences, Hyderabad, to assess the impact of lifestyle factors on colorectal cancer (CRC) risk. The study was carried out from December 2024 to February 2025.

Study Population

A total of 100 participants were included in the study, consisting of 50 histologically confirmed CRC cases and 50 age- and gender-matched controls.

Cases: Patients diagnosed with CRC at Raja Medical College during the study period.

Controls: Healthy individuals without a history of CRC or other malignancies, selected from the general population and hospital outpatient department.

Inclusion and Exclusion Criteria

Inclusion Criteria:

Cases: Patients aged 40–75 years with a confirmed diagnosis of colorectal adenocarcinoma, irrespective of disease stage.

Controls: Individuals with no prior diagnosis of CRC, matched for age and gender.

Exclusion Criteria:

Patients with hereditary colorectal cancer syndromes (e.g., Lynch syndrome, familial adenomatous polyposis).

Individuals with a history of inflammatory bowel disease (IBD).

Those who had undergone a colectomy or other gastrointestinal surgery.

Patients on long-term immunosuppressive therapy or chemotherapy.

Data Collection and Variables

Data were collected using a structured questionnaire and medical record review. The questionnaire included sections on demographics, dietary habits, physical activity levels, smoking and alcohol consumption, family history of CRC, and comorbid conditions.
The following variables were assessed:

• Demographic factors: Age, gender, body mass index (BMI).
• Dietary factors: Frequency of red meat consumption, fiber intake.
• Physical activity: Categorized as sedentary (≤150 min/week) or active (>150 min/week).
• Smoking and alcohol consumption: Current/ former/ non-smoker; regular/ occasional/ non-drinker.
• Family history of CRC: Presence of CRC in first-degree relatives.
• Colonoscopy screening history: Whether participants had undergone a colonoscopy in the past five years.
• Comorbidities: Diabetes and hypertension, confirmed through medical records.

Statistical Analysis

Data were analyzed using SPSS version 25.0. Descriptive statistics were presented as means, standard deviations, and percentages. Chi-square tests were used to assess associations between categorical variables, and an independent t-test was used for continuous variables. A p-value <0.05 was considered statistically significant.

Ethical Considerations

The study was approved by the Institutional Ethics Committee of CMR Institute of Medical Sciences, Hyderabad. Written informed consent was obtained from all participants before data collection. Confidentiality of participant information was ensured throughout the study.

A total of 100 participants were included in the study, with 50 cases of colorectal cancer and 50 controls. The analysis focused on demographic characteristics, dietary factors, physical activity, lifestyle habits, family history, colonoscopy screening, and comorbidities.

Demographic Characteristics

The mean age of cases was 55.4 ± 9.2 years, compared to 54.8 ± 8.7 years in controls, with no significant difference (p = 0.62). The gender distribution was similar between cases and controls (p > 0.05). However, the mean BMI was significantly higher in cases (27.1 ± 3.4 kg/m²) compared to controls (24.5 ± 2.8 kg/m², p < 0.05) (Table 1).

Table 1: Demographic Characteristics of Cases and Controls

Dietary Factors

A higher frequency of red meat consumption was significantly associated with colorectal cancer risk. Among cases, 68% reported consuming red meat more than three times per week, compared to 34% in controls (p = 0.01). Conversely, a low red meat intake (<1 time per week) was more common in controls (30% vs. 8%, p = 0.003). Additionally, low fiber intake was more prevalent in cases (72% vs. 40%, p = 0.003) (Table 2).

Table 2: Dietary Factors between Cases and Controls

Figure No: 1.Dietary Factors Between Cases and Controls

Physical Activity and Sedentary Lifestyle

A sedentary lifestyle (≤150 min/week of physical activity) was observed in 66% of cases compared to 38% of controls (p = 0.02). In contrast, moderate to high physical activity (>150 min/week) was significantly more common in controls (62% vs. 34%, p = 0.02) (Table 3).

Table 3: Physical Activity and Sedentary Lifestyle among Cases and Controls

Figure No: 2. Physical Activity and Sedentary Lifestyle among Cases and Controls

Smoking and Alcohol Consumption

A significant association was observed between smoking and colorectal cancer risk. Among cases, 44% were current smokers, compared to 22% of controls (p = 0.04). Non-smoking status was more common in controls (64% vs. 38%, p = 0.03). Similarly, regular alcohol consumption was reported by 52% of cases, compared to 30% of controls (p = 0.03) (Table 4).

 Table 4: Smoking and Alcohol Consumption in Cases and Controls

Figure No: 3. Smoking and Alcohol Consumption in Cases and Controls

Family History of Colorectal Cancer

A positive family history of colorectal cancer was significantly associated with disease risk, reported by 28% of cases, compared to 10% of controls (p = 0.02) (Table 5).

Table 5: Family History of Colorectal Cancer in Cases and Controls

Colonoscopy Screening and Preventive Health Check-Ups

Preventive screening was notably different between groups. Only 18% of cases had undergone a colonoscopy in the past five years, compared to 42% of controls (p = 0.01) (Table 6). This suggests that regular screening may play a protective role in colorectal cancer prevention.

Table 6: Colonoscopy Screening and Preventive Health Check-Ups in Cases and Controls

Comorbidities

Comorbid conditions such as diabetes and hypertension were more prevalent among cases. Diabetes was present in 34% of cases, compared to 18% of controls (p = 0.04), while hypertension was reported in 40% of cases and 26% of controls (p = 0.05) (Table 7).

Table 7: Prevalence of Comorbidities in Cases and Controls

The study findings highlight significant associations between dietary habits, physical activity, smoking, alcohol consumption, family history, and comorbidities with CRC risk.

Diet and Colorectal Cancer Risk

Our results indicate that high red meat consumption (>3 times/week) significantly increases CRC risk (p = 0.01), whereas a high-fiber diet appeared protective. These findings align with previous studies that suggest processed and red meats promote carcinogenesis through heterocyclic amines and N-nitroso compounds, which contribute to colonic inflammation and DNA damage^8,9. In contrast, fiber-rich diets reduce CRC risk by enhancing gut microbiota diversity and improving bowel motility, thereby reducing contact time between carcinogens and colonic mucosa (Song et al¹⁰., 2021).

Physical Activity and Sedentary Lifestyle

A sedentary lifestyle was significantly associated with CRC risk (p = 0.02), with 66% of cases reporting low physical activity levels. This supports existing evidence that physical inactivity promotes obesity, insulin resistance, and chronic inflammation, all of which contribute to colorectal tumorigenesis (Moore et al¹¹., 2019). Increasing physical activity to >150 minutes per week was observed in 62% of controls, reinforcing its role in CRC prevention through modulation of inflammatory and metabolic pathways¹².

Smoking and Alcohol Consumption

This study found that smoking (p = 0.04) and alcohol consumption (p = 0.03) significantly increased CRC risk. Smoking has been implicated in colonic epithelial DNA damage and mutations in tumor suppressor genes, particularly KRAS and APC, which are frequently mutated in CRC. Similarly, chronic alcohol intake leads to the production of acetaldehyde, a known carcinogen, which enhances colonic oxidative stress and inflammation, contributing to CRC development (Rehm et al¹³., 2021).

Family History and Genetic Predisposition

A positive family history of CRC was reported in 28% of cases compared to 10% of controls (p = 0.02), suggesting a strong genetic predisposition. Previous studies have shown that first-degree relatives of CRC patients have a 2- to 3-fold increased risk due to inherited mutations in DNA mismatch repair genes (MLH1, MSH2, PMS2), which predispose individuals to early-onset colorectal malignancies (Lynch & de la Chapelle¹⁴, 2020).

Colonoscopy Screening and Prevention

A significant difference in colonoscopy screening rates was observed between cases and controls (p = 0.01), with only 18% of cases having undergone a colonoscopy in the past five years compared to 42% of controls. This finding emphasizes the role of early screening in CRC prevention, as regular colonoscopic surveillance allows for early detection and removal of precancerous adenomas, reducing CRC incidence by up to 60% (Zauber¹⁵, 2020). Low screening uptake among cases suggests the need for increased awareness and accessibility of CRC screening programs in India.

Comorbidities and CRC Risk

Comorbidities such as diabetes (p = 0.04) and hypertension (p = 0.05) were more prevalent among CRC cases. Studies suggest that hyperinsulinemia, chronic inflammation, and oxidative stress associated with diabetes and hypertension contribute to colorectal carcinogenesis (Ma et al¹⁶., 2021). The findings reinforce the need for early CRC screening among high-risk populations with metabolic disorders.

Strengths and Limitations

This study provides valuable insights into modifiable risk factors for CRC in an Indian population. The case-control design allowed for a direct comparison of lifestyle factors between affected and unaffected individuals. However, the study has some limitations. Small sample size (n=100) may limit generalizability to larger populations. Self-reported dietary and lifestyle habits may introduce recall bias. Confounding factors such as socioeconomic status, genetic mutations, and gut micro biome composition were not analyzed.

This study identifies high red meat consumption, low fiber intake, sedentary lifestyle, smoking, alcohol consumption, positive family history, and comorbidities (diabetes and hypertension) as significant risk factors for colorectal cancer (CRC). Regular physical activity (>150 min/week) and routine colonoscopy screening were associated with reduced CRC risk. A lack of preventive screening was observed in cases, highlighting the need for increased awareness and accessibility of CRC screening programs. Based on these findings, lifestyle modifications, smoking cessation, dietary improvements, and enhanced screening uptake should be prioritized in public health interventions. Future research should explore genetic and molecular biomarkers for early CRC detection and risk stratification, particularly among high-risk populations.

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