Carrots, green vegetables and lung cancer: a case-control study

Area of Science:

• Epidemiology
• Nutritional Science
• Oncology

Background:

• Lung cancer remains a leading cause of cancer mortality worldwide.
• Dietary factors, including carotenoid intake, are being investigated for their role in cancer prevention.
• Understanding the interplay between diet, smoking, and lung cancer risk is crucial for public health.

Purpose of the Study:

• To investigate the association between the consumption of specific foods rich in retinol or carotene and lung cancer risk.
• To assess the impact of carrot and leafy green vegetable intake on lung cancer risk, considering smoking status.
• To determine if dietary factors modify lung cancer risk independently of smoking.

Main Methods:

• A hospital-based case-control study involving 417 lung cancer cases and 849 controls.
• Data collected through interviews on lifelong tobacco usage and dietary intake of liver, cheese, carrots, and leafy green vegetables.
• Statistical analysis using odds ratios (OR) adjusted for tobacco use, residence, and birthplace.

Main Results:

• Current smokers consuming carrots less than once a week had a three-fold increased lung cancer risk compared to those eating carrots more than weekly (OR = 2.9).
• A significant linear trend (p < 0.01) indicated a reduced risk with higher carrot consumption among smokers.
• Low intake of green vegetables was associated with a non-significant excess risk, primarily in epidermoid carcinomas.

Conclusions:

• Carrot consumption appears to be associated with a reduced risk of lung cancer, particularly among current smokers.
• The protective effect of carrots against lung cancer is independent of histological type.
• Dietary interventions focusing on carotene-rich foods like carrots may offer a complementary strategy for lung cancer prevention in smokers.