Retinoids or carotenoids: is there another choice?

Area of Science:

• Nutritional Science
• Oncology
• Preventive Medicine

Background:

• Retinoids and carotenoids demonstrate anticancer properties in animal models.
• Retinoids exhibit potent activity against various tumors but have dose-limiting toxicities.
• Carotenoids appear safer for general populations, but human cancer prevention data relies heavily on epidemiological studies.

Purpose of the Study:

• To evaluate the comparative efficacy and safety of retinoids and carotenoids in cancer prevention.
• To explore the role of specific nutrients versus dietary patterns in reducing cancer risk.
• To inform recommendations for cancer prevention strategies in the general population.

Main Methods:

• Review of animal models of carcinogenesis for retinoid and carotenoid activity.
• Analysis of epidemiological studies on diet, serum nutrient levels, and cancer occurrence.
• Consideration of clinical trial designs for nutrient-specific and diet-based interventions.

Main Results:

• Retinoids show broader and more potent anticancer effects in animals but are limited by toxicity.
• Carotenoids exhibit a favorable safety profile, making them potentially suitable for widespread use.
• Epidemiological evidence for carotenoid cancer prevention in humans is inconclusive and may be confounded by other dietary factors.

Conclusions:

• A diet high in fruits, vegetables, and grains is the most prudent approach for cancer prevention currently.
• Supplemental retinoids and antioxidants are not recommended for general use due to insufficient evidence of effectiveness and safety.
• Further research, including well-designed clinical trials, is needed to establish the definitive role of specific nutrients and dietary patterns in human cancer prevention.