Cancer Prevention Strategies: DNA Repair

By: Elizabeth J. Hall

Approximately one in three Americans will develop cancer sometime during their lives. In this article we outline a lifestyle program which reduces the risk for cancer through DNA repair.

Cancer originates in genes which are encoded in DNA. Genes tell a cell what to do, when to divide, and even when to die! The start of cancer begins with the sabotage of DNA. Because of faulty genes and other factors, cancer cells react more aggressively than normal to growth factors. Consequently, cancer cells whose DNA has been irreversibly damaged divide out of control. Cancer cells also develop their own blood supply by creating new blood vessels to feed the tumor, and mechanisms which allow them to invade tissues.

DNA Repair to the Rescue

The DNA in every cell in your body is under constant environmental and lifestyle assaults from various directions. Your body’s DNA repair genes produce many different proteins whose job is to recognize and repair damaged DNA. Some of these enzymes remove the damaged DNA while others sew up the microscopic holes caused by epinephrine, free radicals, and other factors.  The DNA repair ability of a cell is essential to the integrity of its DNA and chromosomes, and thus it is vital not only for the normal functioning of the cell but also of the whole organism.  Many genes that influence longevity have actually been involved in DNA repair and protection.  As of today, 130 genes have been identified as being involved in DNA repair. Please note: superior DNA repair would not only help to prevent cancer but many other diseases as well. Failure to correct these molecular lesions in the DNA leads to the introduction of mutations, and most mutations are not beneficial. Of course, DNA repair mechanisms must perform constantly and effectually to insure optimal protection.

Strategies that Improve DNA Repair

  1. Skip caffeine and smoking.Not only does caffeine usually interfere with DNA repair(1) leaving it more vulnerable to cancer-producing agents and/or viruses, it also decreases the production of melatonin, a hormone produced in the pineal gland. Melatonin not only induces refreshing sleep but also exerts an antioxidant effect in the cells and DNA.
  2. Treasure temperance. Alcohol drinking and cigarette smoking also inhibit DNA repair.  Wise calorie restriction increases DNA repair while obesity inhibits it, especially in the liver and skeletal muscles. It’s not just the quality of the food we eat, but also the quantity that plays a key role in effective DNA repair.  Wise caloric restriction helps the DNA work more effectively by inhibiting damage to it and proteins, and improving DNA repair.(2)
    Generally speaking, wise caloric restriction for most people consists of eating 15% less than a person would normally eat.  To be the most effective, this restriction should also be combined with moderate exercise.  These two habits can activate genes which prolong life.  Note that individuals with anorexia or those who are underweight would certainly not need to implement the caloric restrictions mentioned above.  Malnutrition has a terrible impact on the brain and body.  On the other hand, those who are morbidly obese would need to restrict their calorie intake by more than just 15% to get the combined effect of weight loss and reduced DNA damage.
  3. Get sufficient sleep.Just one week of inadequate sleep disrupts over 700 genes that regulate the immune system, metabolism, and stress responses. Sleep deficiency reduces DNA repair in the brain.(3)
  4. Engage in regular moderate exercise.Mild exercise training also activates a number of protective genes in the heart muscle.  Animal studies show that regular exercise improves DNA repair in skeletal muscles(4) and liver cells(5) and reduces oxidative damage done to the DNA in the liver.  Exercise also seems to enhance selective enzymes involved in detoxification of certain cancer-producing agents. Exercise can alter other biological processes that contribute to the beginning stage of cancer and its progression.(6) Interestingly, studies show that strenuous, exhaustive exercise causes oxidative damage to the DNA in the heart muscle and in white blood cells (lymphocytes, to be precise).
  5. Have your vitamin D level checked.Vitamin D and its receptors play an important role in DNA repair.(7) As many as 50% of North Americans and Western Europeans have insufficient amounts of vitamin D levels. Obesity decreases its bioavailability.

Good Foods Aid DNA Repair

  1. Enjoy cruciferous veggies.Broccoli, cabbage, cauliflower, and Brussels sprouts boost DNA repair. Don’t like broccoli? Try adding broccoli florets to potato soup. Or put chopped kale into your lentil soup. Cabbage and bok choy add more health benefits to a delightful vegan stir fry dish. Cruciferous vegetables also help the liver to detoxify cancer-producing agents.
  2. Eat orange fruits and vegetables.Carotenoids (8), (9) from orange fruits and vegetables and leafy greens also improve DNA repair.
  3. Eat an ounce of Brazil nuts several times a week.Their selenium helps to maintain DNA repair. Sunflower seeds, whole wheat and rye also provide selenium. Whole grains, leafy greens, and sprouted legumes also provide zinc. A deficiency in zinc impairs DNA repair. Phytic acid found in whole grains promotes DNA repair.(10), (11)
  4. Enjoy citrus fruit and cooked tomatoes.Kiwis are one fruit that is also known to significantly increase the rate of DNA repair when three are eaten daily. Citrus fruits and cooked tomatoes contain naringenin which stimulates DNA repair in prostate cancer cells.(12)

While this lifestyle program helps improves your DNA repair, cancer is serious business. Get regular preventive checkups. Judicious surgery and medical treatments may be essential in conquering cancer.

This is copyrighted 2017 by 

Works cited:
1.  Selby, C.P., and  Sancar, A., Molecular Mechanisms of DNA Repair Inhibition by Caffeine. Proceedings of the National Academy of Sciences, 87:3522-3525, 1990.
2.  Heydari, A.R., et al, Caloric restriction and genomic stability. Nucleic Acids Research, 35(22):7485-7496, 2007.
3.  Siddique, Ashik, One Week of Sleep Deprivation Disrupts DNA Expression; A Third of Americans at Risk. Feb 26, 2013 12:33 AM EDT
4.  Radak, Z, et al, Exercise improves import of 8-oxoguanine DNA glycosylase into the mitochondrial matrix of skeletal muscle and enhances the relative activity. Free Radic Biol Med, 46(2):238-43, 2009.
5.  Nakamoto, H., et al, Regular exercise reduces 8-oxodG in the nuclear and mitochondrial DNA and modulates the DNA repair activity in the liver of old rats. Exp Gerontol, 42(4):287-95, 2007.
6.  Rogers, C.J., et al, Physical activity and cancer prevention: pathways and targets for intervention. Sports Med, 38(4):271-96, 2008, review.
7.  Holick, M., Influence of vitamin D status and vitamin D3 supplementation on genome wide expression of white blood cells: a randomized double-blind clinical trial. PLoS One. 2013;8(3):e58725.
8.  Astley, B.S., et al, Evidence that dietary supplementation with carotenoids and carotenoid-rich foods modulates the DNA damage: repair balance in human lymphocytes. Br J Nutr, 91(1):63-72, 2004.
9.  Lorenzo, Y., et al, The carotenoid beta-cryptoxanthin stimulates the repair of DNA oxidation damage in addition to acting as an antioxidant in human cells. Carcinogenesis, 30(2):308-14, epub Dec 4, 2008.
10. Bohn, L., et al, Phytate: impact on environment and human nutrition. A challenge for molecular breeding. J Zhejiang Univ Sci B, 9(3):165-91, 2008, review.
11. York, J.D., Regulation of nuclear processes by inositol polyphosphates. Biochem Biophys Acta, 1761(5-6):552-9, 2006.
12. Kun Gao, The citrus flavonoid naringenin stimulates DNA repair in prostate cancer cells. The Journal of Biochemical Nutrition.  Vol.17:2, 2006, p. 89-95