Tomatoes protect skin against sun damage

Skin cancer is the most common form of cancer in the U.S., affecting one out of every five Americans, and its incidence is rising. Ultraviolet (UV) radiation is responsible for the development of most skin cancers and also skin aging. [1]

Ultraviolet radiation from the sun exerts these aging and carcinogenic effects on the skin via oxidative stress, inflammation, and damage to DNA. As such, there has been much interest in the scientific community in using antioxidants from plant foods to protect against this damage. Photoprotection has been previously demonstrated in animal studies by multiple antioxidant supplements, including green tea catechins, proanthocyanadins, resveratrol, and silymarin. In addition to their antioxidant effects, these substances can also absorb UV radiation (when applied topically), enable DNA damage repair, and reduce inflammation. [2]

Lycopene, well-known for its prostate cancer-protective effects, is a carotenoid antioxidant present in red and pink fruits such as tomato, grapefruit, and papaya. It is especially concentrated in cooked tomato products like tomato paste. Lycopene is a powerful antioxidant that in vitro has been shown to prevent or repair damage to DNA that potentially leads to cancer development. Lycopene also stimulates production of antioxidant enzymes, inhibits signals that promote tumor progression, and promotes programmed death of cancerous cells. [3]

Researchers tested whether the antioxidant actions of lycopene in tomato paste could lessen the skin-damaging effects of UV radiation in human subjects. A group of healthy women consumed tomato paste daily for twelve weeks, and their skin’s reddening response to UV light was measured at the beginning and end of the study. After twelve weeks of tomato supplementation, the skin’s resistance to UV-induced reddening was enhanced. The tomato paste supplementation also resulted in reduced mitochondrial DNA damage and reduced activity of an enzyme that degrades the skin’s extracellular proteins, a process that contributes to skin aging. These results suggest that regular tomato consumption can help to reduce the skin-damaging effects of the sun. [4]

Tomatoes are rich not only in lycopene but in thousands of other protective compounds, both discovered and undiscovered, that likely have powerful heart disease- and cancer-preventive effects. Be sure to eat both fresh, raw tomatoes and cooked tomatoes to get the full spectrum of tomatoes’ phytochemicals.

 

References:

1. Skin Cancer Foundation: Skin Cancer Facts. October 14, 2010]; Available from: http://www.skincancer.org/Skin-Cancer-Facts/.
2. Nichols, J.A. and S.K. Katiyar, Skin photoprotection by natural polyphenols: anti-inflammatory, antioxidant and DNA repair mechanisms. Arch Dermatol Res, 2010. 302(2): p. 71-83.
3. van Breemen, R.B. and N. Pajkovic, Multitargeted therapy of cancer by lycopene. Cancer Lett, 2008. 269(2): p. 339-51.
4. Rizwan, M., et al., Tomato paste rich in lycopene protects against cutaneous photodamage in humans in vivo. Br J Dermatol, 2010.

 

Prediction: Breast cancer rates will skyrocket in the next 20 years

October is National Breast Cancer Awareness month, and I want to raise awareness that childhood diets are the major cause of adult cancers, including breast cancer. [1] I also want to raise awareness that women are not powerless against breast cancer – mammograms for ‘early detection’ are not the only defense and do not even offer significant benefits. The most important thing to be aware of is that women can achieve meaningful risk reduction with powerful preventive lifestyle measures.

The American Institute for Cancer Research estimates that 40% of breast cancers are preventable through diet and lifestyle measures. I propose that we could prevent much more than 40% of breast cancers in the future, if we can ingrain healthy habits in our children at a young age.

Early studies found wide international variations in breast cancer rates, originally generating the hypothesis that nutrition is a major determinant of breast cancer risk. Obesity is a significant risk factor for breast cancer:

  • Gaining one pound per year during adulthood can double breast cancer risk after menopause.
  • Obesity alone is thought to be responsible for 17% of breast cancers.
  • Obesity is associated with greater tumor burden and poorer prognosis in breast cancer patients. [2, 3]
  • Production of inflammatory molecules and estrogen by body fat, as well as elevated insulin and insulin-like growth factor (IGF-1) levels are thought to contribute to obesity-related breast cancer risk. [2]

Plenty of experts have predicted that the explosion of childhood obesity we have seen in recent years will result in crisis proportions of heart disease and diabetes in the future, but cancer seems to be ignored. Today, over 30% of children are overweight or obese. [4] Clearly, with all the research demonstrating that obesity is a major risk factor for breast cancer, our young girls are in danger.

The prevalence of early puberty, another established risk factor for breast cancer, has been consistently increasing over the past 100 years. Today, by the age of 8, 18.3% of Caucasian girls, 42.9% of African-American girls, and 30.9% of Hispanic girls have already entered puberty. Obesity, soft drinks, and excessive animal protein are the likely culprits (Read more).

This is a grim indication of things to come – when these girls reach adulthood, tragically we will see an upsurge in breast cancer cases. With the increases in fast food and processed food consumption in America in the last 20 years, I predict a tragic explosion in pre-menopausal breast cancers in our country in the next 20 years.

Breast tissue is most vulnerable to carcinogenic influences when it is growing and developing – during childhood and adolescence. Children are also especially susceptible to weight gain during adolescence. [5] Thus, this window of time is when a healthy diet is absolutely crucial. Animal studies have demonstrated that a high-fat diet or a body fat promoting diet during puberty promotes abnormal development of breast tissue and production of inflammatory molecules, which in turn may promote tumor growth.[6, 7] Adolescent diet was examined in the Nurses’ Health Study – greater consumption of vegetables during high school was associated with a decreased risk of breast cancer, and high glycemic index foods were associated with an increased risk. [8]

The typical American childhood diet of chicken fingers, French fries, and mac and cheese is not harmless – it is creating a cancer-friendly environment in children’s bodies.

As parents, we must feed our children healthful foods from an early age. This is the most effective protection from future chronic disease that we can provide for them. Healthy eating is a lifetime commitment, and we can give our children a head start. Our goal should be to instill healthy habits in our children so that they grow up at a healthy weight, appreciating healthy food and exercise, and hold on to those habits as adults. In order to do this, we must set a positive example, focusing on nutrient-dense, health-promoting foods.

New research is revealing the protective effects of natural foods against breast cancer. For example, mushrooms have anti-estrogenic activity, and regular mushroom consumption is associated with a 60% decrease in cancer risk. [9] Cruciferous vegetables such as watercress, other leafy greens, and broccoli contain compounds known to inhibit cancer cell growth. [10, 11]

Instead of wearing a pink ribbon, eat vegetables, onions and mushrooms – and make sure to feed some to your kids.

 

References:


1. Maynard, M., et al., Fruit, vegetables, and antioxidants in childhood and risk of adult cancer: the Boyd Orr cohort. J Epidemiol Community Health, 2003. 57(3): p. 218-25.
2. Cleary, M.P. and M.E. Grossmann, Minireview: Obesity and breast cancer: the estrogen connection. Endocrinology, 2009. 150(6): p. 2537-42.
3. Abrahamson, P.E., et al., General and abdominal obesity and survival among young women with breast cancer. Cancer Epidemiol Biomarkers Prev, 2006. 15(10): p. 1871-7.
4. Ogden, C.L., et al., Prevalence of high body mass index in US children and adolescents, 2007-2008. JAMA, 2010. 303(3): p. 242-9.
5. Jasik, C.B. and R.H. Lustig, Adolescent obesity and puberty: the "perfect storm". Ann N Y Acad Sci, 2008. 1135: p. 265-79.
6. Olson, L.K., et al., Pubertal exposure to high fat diet causes mouse strain-dependent alterations in mammary gland development and estrogen responsiveness. Int J Obes (Lond), 2010. 34(9): p. 1415-26.
7. Michigan State University: High-fat diet during puberty linked to breast cancer risk later in life. 2010; Available from: http://news.msu.edu/story/8233/.
8. Frazier, A.L., et al., Adolescent diet and risk of breast cancer. Cancer Causes Control, 2004. 15(1): p. 73-82.
9. Zhang, M., et al., Dietary intakes of mushrooms and green tea combine to reduce the risk of breast cancer in Chinese women. Int J Cancer, 2009. 124(6): p. 1404-8.
10. Clarke, J., R. Dashwood, and E. Ho, Multi-targeted prevention of cancer by sulforaphane. Cancer Letters, 2008. 269(2): p. 291-304.
11. Higdon, J., et al., Cruciferous vegetables and human cancer risk: epidemiologic evidence and mechanistic basis. Pharmacological Research, 2007. 55(3): p. 224-236.

 

Anti-cancer properties of watercress

Watercress is a super-duper food. Along with kale, collards, mustard greens, and turnip greens, watercress is one of the most nutrient-dense foods in the world. Most importantly, watercress is a specialist at preventing cancer.

Watercress belongs to the family of cruciferous vegetables, uniquely high in glucosinolates, which are precursors to cancer-fighting molecules called isothiocyanates (ITCs). Watercress is rich in a specific glucosinolate called gluconasturtiin, which is a precursor to the ITC phenethyl isothiocyanate (PEITC).[1] Epidemiologic associations between cruciferous vegetable intake and reduced cancer risk have sparked a surge in studies on the anti-cancer effects of specific cruciferous vegetables and their constituent isothiocyanates.

Anti-cancer properties of watercress had previously been established in cell culture experiments: In human breast cancer cells, watercress extract blocked the degradation of structural proteins, an early step in preparation for migration and subsequent invasion, which eventually leads to metastasis. [2] PEITC in watercress was also found to reduce tumor cell survival and decrease the action of hypoxia-inducible factor (HIF), which is a molecule that stimulates angiogenesis (blood vessel development), allowing a tumor to obtain a blood supply. [3]


A study investigated the effects of watercress on HIF activity in human subjects. Hypoxia (low oxygen levels) is a key stimulus for tumor growth – as a tumor grows, its oxygen and nutrient needs exceed those that it can receive by diffusion from adjacent healthy tissue. When tumor cells sense hypoxia, they send angiogenic signals to surrounding normal tissue in order to obtain a direct blood supply. HIF is an essential part of this process, activating the production of angiogenic proteins, consequently promoting tumor growth. [4]


Since the current study tested the effects of ingesting watercress on HIF activity in cells of human subjects, the data provided is more physiologically relevant, and strengthens the earlier cell culture results. Four breast cancer survivors ingested 80 grams of watercress (about 2 cups). Six and eight hours later, blood was drawn; PEITC levels were found to be elevated, and the effects of the watercress on white blood cells were measured. HIF activity was indeed reduced in these cells, confirming in humans the anti-cancer effects of watercress previously observed in cultured cells. [3, 5]

In short, PEITC from watercress prevents tumors from sending the signal to the body that requests a blood supply. Without a blood supply, the tumor cannot continue to grow. Watercress is a potent anti-cancer food!


For more information on the anti-cancer effects of cruciferous vegetables, read Newsletter #32.

 

References:
1. Higdon, J., et al., Cruciferous vegetables and human cancer risk: epidemiologic evidence and mechanistic basis. Pharmacological Research, 2007. 55(3): p. 224-236.
2. Rose, P., et al., Broccoli and watercress suppress matrix metalloproteinase-9 activity and invasiveness of human MDA-MB-231 breast cancer cells. Toxicol Appl Pharmacol, 2005. 209(2): p. 105-13.
3. Syed Alwi, S.S., et al., In vivo modulation of 4E binding protein 1 (4E-BP1) phosphorylation by watercress: a pilot study. Br J Nutr, 2010: p. 1-9.
4. Chen, L., A. Endler, and F. Shibasaki, Hypoxia and angiogenesis: regulation of hypoxia-inducible factors via novel binding factors. Exp Mol Med, 2009. 41(12): p. 849-57.
5. Watercress may 'turn off' breast cancer signal. 9/14/2010 9/30/2010]; Available from: http://www.soton.ac.uk/mediacentre/news/2010/sep/10_94.shtml.