Recommendations for cancer prevention from the WCRF / AICR:
- Be as lean as possible without becoming underweight.
- Be physically active for at least 30 minutes every day. Limit sedentary habits.
- Avoid sugary drinks. Limit consumption of energy-dense foods.
- Eat more of a variety of vegetables, fruits, whole grains and legumes such as beans.
- Limit consumption of red meats (such as beef, pork and lamb) and avoid processed meats.
- If consumed at all, limit alcoholic drinks to 2 for men and 1 for women a day.
- Limit consumption of salty foods and foods processed with salt (sodium).
- Don't use supplements to protect against cancer.
American Institute for Cancer Research (AICR) and the World Cancer Research Fund (WCRF) published Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective, the most comprehensive report on diet and cancer ever completed.
The Report took six years to produce, and the process was transparent, objective and comprehensive. First, the global scientific literature was searched for relevant studies. Initial searches found some half a million studies, which were soon culled to 22,000. Ultimately, over 7,000 scientific studies were deemed relevant and met the report’s rigorous criteria.
These studies were independently reviewed, compiled and presented to an Expert Panelexternal site of 21 world-renowned scientists, who judged the accumulated evidence and developed 10 Recommendations for Cancer Prevention.
Vitamin C, or L-ascorbic acid, or ascorbate, is an essential nutrient for humans, a water-soluble vitamin. Humans, unlike most animals, are unable to synthesize vitamin C, so it is an essential dietary component.
- Vitamin C is required for the biosynthesis of collagen (an essential component of connective tissue), L-carnitine, and certain neurotransmitters, it is also involved in protein metabolism.
- Vitamin C is also an important physiological antioxidant and has been shown to regenerate other antioxidants within the body, including alpha-tocopherol (vitamin E). Vitamin C regenerates vitamin E by reducing vitamin E radicals formed when vitamin E scavenges the oxygen radicals.
- Vitamin C plays an important role in immune function and improves the absorption of nonheme iron, the form of iron present in plant-based foods.
Approximately 70%–90% of vitamin C is absorbed at moderate intakes of 30–180 mg a day. At doses above 1 g a day, absorption falls to less than 50% and absorbed, unmetabolized ascorbic acid is excreted in the urine.
Insufficient vitamin C intake causes scurvy, which is characterized by fatigue or lassitude, connective tissue weakness, and capillary fragility.
Cells accumulate vitamin C. The total body content of vitamin C ranges from 300 mg (at near scurvy) to about 2 g.
- High levels of vitamin C are maintained in cells and tissues, and are highest in leukocytes (white blood cells), eyes, adrenal glands, pituitary gland, and brain.
- Relatively low levels of vitamin C are found in extracellular fluids, such as plasma, red blood cells, and saliva.