Caloric restriction and cancer.

Area of Science:

• Oncology
• Nutritional Science
• Molecular Biology

Background:

• Early observations in 1909 by Moreschi indicated that underfeeding inhibited tumor growth in mice.
• Subsequent research confirmed that caloric restriction negatively impacts both transplanted and spontaneous tumor growth.
• Methodological limitations initially hindered research, with significant advancements occurring in the 1940s and resurgence in the 1980s.

Purpose of the Study:

• To review the historical and contemporary understanding of the relationship between caloric restriction and cancer.
• To explore the underlying physiological and molecular mechanisms through which energy restriction influences tumor development.
• To highlight recent findings regarding energy restriction's effects on DNA repair, oxidative damage, gene expression, and hormonal pathways.

Main Methods:

• Historical review of research on caloric restriction and tumor growth, from early observations to modern molecular studies.
• Analysis of studies utilizing defined diets to isolate the effects of caloric content.
• Examination of contemporary research investigating molecular mechanisms, including DNA repair, oxidative stress, oncogene expression, and hormonal influences.

Main Results:

• Caloric restriction consistently demonstrates an inhibitory effect on tumor growth across various models.
• Energy restriction enhances DNA repair mechanisms and reduces oxidative DNA damage.
• Caloric restriction impacts oncogene expression, insulin metabolism, and hormonal pathways (e.g., adrenal and pituitary function), potentially through a 'pseudohypophysectomy' effect.

Conclusions:

• Caloric restriction is a significant factor in modulating cancer development and progression.
• Mechanisms involve enhanced DNA repair, reduced oxidative stress, altered oncogene expression, and hormonal pathway modulation.
• Understanding these mechanisms provides a basis for developing novel cancer prevention and therapeutic strategies.