It turns out Mom was right – you should eat your broccoli. But what Mom may not have known is why broccoli is so healthy, and how its lesser known, younger offshoot may be a powerful anti-cancer agent.

Researchers at the Linus Pauling Institute at Oregon State University have found that sulforaphane – a compound found in cruciferous vegetables such as broccoli, bok choy and brussels sprouts – has strong anti-cancer properties.

Even more promising results have been found in broccoli sprouts. The tiny, thread-like broccoli sprouts sold at stores next to alfalfa sprouts have more than 50 times the amount of sulforaphane than found in mature broccoli.

Emily Ho, a researcher with the Linus Pauling Institute and an assistant professor in the Department of Nutrition and Exercise Sciences at OSU, will describe these dietary inhibitors for cancer prevention at the conference on “Diet and Optimum Health,” organized by the Linus Pauling Institute. The conference will be held May 16-19 at the Hilton Hotel in Portland. Ho will speak at 10:30 a.m. Friday, May 18.

Ho’s main area of research is on the dietary prevention of prostate cancer. The Asian diet could be a key in this prevention. White males born in the United States have dramatically higher rates of prostate cancer than Asian men. But when Asian men live in the U.S. for five years or more, their rates of prostate cancer rise significantly, Ho says.

Past studies in Ho’s lab have focused on dietary elements in cancer prevention such as green tea and soy.

In her new study, which was published in the Journal of the Society of Experimental Biology and Medicine, Ho and her colleagues at Linus Pauling Institute looked at cruciferous vegetables. While many cruciferous vegetables have sulforaphane, broccoli and broccoli sprouts have the highest amount and thus could be a major player in the prevention of prostate and colon cancer.

Ho said drugs classified as histone deacetylase (HDAC) inhibitors are being looked at as potentially preventing cancer. She said their research shows that these same effects of inhibiting HDAC might be obtained by consumption of cruciferous vegetables.

“I would say if you’re at all worried about cancer or at high risk of cancer, especially of prostate or colon cancer, then increasing your dietary intake of broccoli and other vegetables could be a good idea,” Ho said.

“It certainly can’t hurt. And drugs can have negative side effects and be difficult to administer.”

While Ho said the research is not at the point where she can make a specific recommendation on how much broccoli or bok choy to eat, she personally tries to have two servings of cruciferous vegetables a day.

In human subjects, just eating some broccoli sprouts on top of a bagel with cream cheese resulted in HDAC inhibition.

“The compound in broccoli may be one of the strongest anti-cancer fighters we have,” Ho said.

Oregon State University (2007, May 18). Eat Your Broccoli: Study Finds Strong Anti-Cancer Properties In Cruciferous Veggies. ScienceDaily. Retrieved July 25, 2010, from http://www.sciencedaily.com­ /releases/2007/05/070517100315.htm

A compound derived from broccoli could help prevent or treat breast cancer by targeting cancer stem cells — the small number of cells that fuel a tumor’s growth — according to a new study from researchers at the University of Michigan Comprehensive Cancer Center.

The study tested sulforaphane, a component of broccoli and broccoli sprouts, in both mice and cell cultures. Researchers found sulforaphane targeted and killed the cancer stem cells and prevented new tumors from growing.

“Sulforaphane has been studied previously for its effects on cancer, but this study shows that its benefit is in inhibiting the breast cancer stem cells. This new insight suggests the potential of sulforaphane or broccoli extract to prevent or treat cancer by targeting the critical cancer stem cells,” says study author Duxin Sun, Ph.D., associate professor of pharmaceutical sciences at the U-M College of Pharmacy and a researcher with the U-M Comprehensive Cancer Center.

Results of the study appear in the May 1 issue of Clinical Cancer Research.

Current chemotherapies do not work against cancer stem cells, which is why cancer recurs and spreads. Researchers believe that eliminating the cancer stem cells is key to controlling cancer.

In the current study, researchers took mice with breast cancer and injected varying concentrations of sulforaphane from the broccoli extract. Researchers then used several established methods to assess the number of cancer stem cells in the tumors. These measures showed a marked decrease in the cancer stem cell population after treatment with sulforaphane, with little effect on the normal cells. Further, cancer cells from mice treated with sulforaphane were unable to generate new tumors. The researchers then tested sulforaphane on human breast cancer cell cultures in the lab, finding similar decreases in the cancer stem cells.

“This research suggests a potential new treatment that could be combined with other compounds to target breast cancer stem cells. Developing treatments that effectively target the cancer stem cell population is essential for improving outcomes,” says study author Max S. Wicha, M.D., Distinguished Professor of Oncology and director of the U-M Comprehensive Cancer Center.

The concentrations of sulforaphane used in the study were higher than what can be achieved by eating broccoli or broccoli sprouts. Prior research suggests the concentrations needed to impact cancer can be absorbed by the body from the broccoli extract, but side effects are not known. While the extract is available in capsule form as a supplement, concentrations are unregulated and will vary.

This work has not been tested in patients, and patients are not encouraged to add sulforaphane supplements to their diet at this time.

Researchers are currently developing a method to extract and preserve sulforaphane and will be developing a clinical trial to test sulforaphane as a prevention and treatment for breast cancer. No clinical trial is currently available.

Journal Reference:

1. Y. Li, T. Zhang, H. Korkaya, S. Liu, H. F. Lee, B. Newman, Y. Yu, S. G. Clouthier, S. J. Schwartz, M. S. Wicha, D. Sun. Sulforaphane, a Dietary Component of Broccoli/Broccoli Sprouts, Inhibits Breast Cancer Stem Cells. Clinical Cancer Research, 2010; 16 (9): 2580 DOI: 10.1158/1078-0432.CCR-09-2937

Light has been cast on the interaction between broccoli consumption and reduced prostate cancer risk. Researchers writing in BioMed Central’s open access journal Molecular Cancer have found that sulforaphane, a chemical found in broccoli, interacts with cells lacking a gene called PTEN to reduce the chances of prostate cancer developing.

Richard Mithen, from the Institute of Food Research, an institute of BBSRC, worked with a team of researchers on Norwich Research Park, UK, to carry out a series of experiments in human prostate tissue and mouse models of prostate cancer to investigate the interactions between expression of the PTEN gene and the anti-cancer activity of sulforaphane. He said, “PTEN is a tumour suppressor gene, the deletion or inactivation of which can initiate prostate carcinogenesis, and enhance the probability of cancer progression. We’ve shown here that sulforaphane has different effects depending on whether the PTEN gene is present.”

The research team found that in cells which express PTEN, dietary intervention with SF has no effect on the development of cancer. In cells that don’t express the gene, however, sulforaphane causes them to become less competitive, providing an explanation of how consuming broccoli can reduce the risk of prostate cancer incidence and progression.

According to Mithen, “This also suggests potential therapeutic applications of sulforaphane and related compounds.”

Journal Reference:

1. Maria H. Traka, Caroline A. Spinks, Joanne F. Doleman, Antonietta Melchini, Richard Y. Ball, Robert D. Mills and Richard F. Mithen. The dietary isothiocyanate sulforaphane modulates gene expression and alternative gene splicing in a PTEN null preclinical murine model of prostate cancer. Molecular Cancer, 2010; (in press) [link]

ScienceDaily (June 2, 2010) — Breast cancer cells — even the most aggressive type — died after treatments with peach and plum extracts in lab tests at Texas AgriLife Research recently, and scientists say the results are deliciously promising. Not only did the cancerous cells keel over, but the normal cells were not harmed in the process.

AgriLife Research scientists say two phenolic compounds are responsible for the cancer cell deaths in the study, which was published in the Journal of Agriculture and Food Chemistry. The phenols are organic compounds that occur in fruits. They are slightly acidic and may be associated with traits such as aroma, taste or color.

“It was a differential effect which is what you’re looking for because in current cancer treatment with chemotherapy, the substance kills all cells, so it is really tough on the body,” said Dr. David Byrne, AgriLife Research plant breeder who studies stone fruit. “Here, there is a five-fold difference in the toxic intensity. You can put it at a level where it will kill the cancer cells — the very aggressive ones — and not the normal ones.”

Byrne and Dr. Luis Cisneros-Zevallos originally studied the antioxidants and phytonutrients in plums and found them to match or exceed the blueberry which had been considered superior to other fruits in those categories.

“The following step was to choose some of these high antioxidant commercial varieties and study their anticancer properties,” Cisneros-Zevallos said. “And we chose breast cancer as the target because it’s one of the cancers with highest incidence among women. So it is of big concern.”

According to the National Cancer Institute, there were 192,370 new cases of breast cancer in females and 1,910 cases in males in 2009. That year, 40,170 women and 440 men died from breast cancer. The World Health Organization reports that breast cancer accounts for 16 percent of the cancer deaths of women globally.

Cisneros-Zevallos, an AgriLife Research food scientist, said the team compared normal cells to two types of breast cancer, including the most aggressive type. The cells were treated with an extract from two commercial varieties, the “Rich Lady” peach and the “Black Splendor” plum.

“These extracts killed the cancer cells but not the normal cells,” Cisneros-Zevallos said.

A closer look at the extracts determined that two specific phenolic acid components — chlorogenic and neochlorogenic — were responsible for killing the cancer cells while not affecting the normal cells, Cisneros-Zevallos said.

The two compounds are very common in fruits, the researchers said, but the stone fruits such as plums and peaches have especially high levels.

“So this is very, very attractive from the point of view of being an alternative to typical chemotherapy which kills normal cells along with cancerous ones,” Byrne added.

The team said laboratory tests also confirmed that the compounds prevented cancer from growing in animals given the compounds.

Byrne plans to examine more fully the lines of the varieties that were tested to see how these compounds might be incorporated into his research of breeding plums and peaches. Cisneros-Zevallos will continue testing these extracts and compounds in different types of cancer and conduct further studies of the molecular mechanisms involved.

The work documenting the health benefits of stone fruit has been supported by the Vegetable and Fruit Improvement Center at Texas A&M University, the U.S. Department of Agriculture and the California Tree Fruit Agreement.

Journal Reference:

Giuliana Noratto, Weston Porter, David Byrne, Luis Cisneros-Zevallos. Identifying Peach and Plum Polyphenols with Chemopreventive Potential against Estrogen-Independent Breast Cancer Cells. Journal of Agricultural and Food Chemistry, 2009; 57 (12): 5219 DOI: 10.1021/jf900259m

Dean-Clower E, Doherty-Gilman AM, Keshaviah A, Baker F, Kaw C, Lu W,
Manola J, Penson RT, Matulonis UA, Rosenthal DS. . Integr Cancer Ther. 2010 May 18. [Epub ahead of print]

Acupuncture is underutilized as an adjunct cancer therapy. The main study objectives were to determine the feasibility of administering acupuncture as palliative therapy to patients with advanced ovarian or breast cancer and to assess the effect on symptoms and quality of life (QOL).

METHODS: This study was a pilot, single-armed prospective clinical trial for patients with advanced
cancer to receive 12 acupuncture sessions over 8 weeks with follow-up at weeks 9 and 12. Ambulatory patients with advanced ovarian or breast cancer were enrolled to receive treatments at an outpatient academic oncology center. Symptom severity was measured before and after each acupuncture session. A composite QOL assessment tool,
consisting of validated instruments, was completed at 5 time points.

RESULTS: Forty patients enrolled in the study. Twenty-eight patients (70%; 95% confidence interval [CI] = 53%-83%) completed 4 weeks of treatment, and 26 patients (65%; 95% CI = 48%-79%) completed 8 weeks. Eight patients (20%) withdrew before receiving acupuncture, and 6 patients (15%) discontinued treatment early because of disease progression or scheduling demands. Among all 32 assessed patients, there was self-reported improvement immediately post-treatment in anxiety, fatigue, pain, and depression and significant improvement
over time for patients with anxiety (P = .001) and depression (P =.02). Among patients experiencing baseline symptoms, there was improvement in anxiety (P = .001), fatigue (P = .0002), pain (P = .0002), and depression (P = .003). QOL measures of pain severity and interference, physical and psychological distress, life satisfaction,
and mood states showed improved scores during treatment, with sustained benefit at 12 weeks.

CONCLUSIONS: This pilot study demonstrates that an 8-week outpatient acupuncture course is feasible for advanced cancer patients and produces a measurable benefit that should be evaluated in controlled trials. PMID: 20483875 [PubMed - as supplied by publisher]

By Jane Byrne , 05-May-2010

Sulforaphane, a compound derived from broccoli and broccoli sprouts, could help prevent or treat breast cancer by inhibiting cancer stem cells (CSCs), found a new US study.

Researchers believe that eliminating the CSCs is key to controlling cancer and in findings published in Clinical Cancer Research they found that, in both mice and cell cultures, sulforaphane targeted and killed the cancer stem cells and prevented new tumours from growing.

Recent studies, report the authors, indicate that CSCs have the capacity to drive tumour resistance and relapse/recurrence of cancer, with evidence building for the theory that a variety of cancers are driven and sustained by a small proportion of CSCs.

According to the American Cancer Society, 94,280 Americans will be diagnosed with breast cancer this year and 40,610 will die from the disease.

The researchers argue that a lack of efficacy of current chemotherapies in advance and metastatic disease requires novel approaches to specifically target CSC populations.

The anticancer efficacy of sulforaphane, derived from broccoli/broccoli sprouts, has been evaluated in various cancers and the risk of premenopausal breast cancer was shown to be inversely associated with broccoli consumption, they added.

Furthermore, as a chemoprevention agent, sulforaphane possesses many advantages, such as high bioavailability and low toxicity. “Sulforaphane from broccoli extracts is efficiently and rapidly absorbed in the human small intestine and distributed throughout the body,” said the authors.

Clinical trials

These previous studies, said the researchers, provide a strong rationale for investigating the chemoprevention property of sulforaphane in clinical trials, and the authors said that its chemoprevention properties against cancer are through both ‘blocking’ and ‘suppressing’ effects.

The concentrations of sulforaphane used in the study were higher than what can be achieved by eating broccoli or broccoli sprouts, said the team, and they added that prior research suggests the concentrations needed to impact cancer can be absorbed by the body from the broccoli extract, but side effects are not known.

While the extract is available in capsule form as a supplement, concentrations are unregulated and will vary, claim the researchers.

And they revealed that they are currently developing a method to extract and preserve sulforaphane and that they will then be developing a clinical trial to test it for the prevention and treatment for breast cancer.

“This research suggests a potential new treatment that could be combined with other compounds to target breast cancer stem cells. Developing treatments that effectively target the cancer stem cell population is essential for improving outcomes,” says lead researcher Dr Max Wicha, distinguished professor of oncology and director of the U-M Comprehensive Cancer Center.

The study

The researchers said that they took mice with breast cancer and injected varying concentrations of sulforaphane from the broccoli extract, using used several established methods to assess the number of cancer stem cells in the tumours.

The authors explained that an Aldefluor assay and mammosphere formation assay were used to evaluate the effect of sulforaphane on breast CSCs in vitro, while a nonobese diabetic/severe combined immunodeficient xenograft model was used to determine whether sulforaphane could target breast CSCs in vivo, as assessed by Aldefluor assay, and tumour growth upon cell reimplantation in secondary mice.

The potential mechanism was investigated using Western blotting analysis and β-catenin reporter assay, they added.

The researchers found that sulforaphane (1-5 μmol/L) decreased aldehyde dehydrogenase–positive cell population by 65 per cent to 80 per cent in human breast cancer cells and reduced the size and number of primary mammospheres by 8- to 125-fold and 45 per cent to 75 per cent, respectively.

Daily injection with 50 mg/kg sulforaphane for two weeks reduced aldehyde dehydrogenase–positive cells by >50 per cent in nonobese diabetic and severe combined immunodeficient xenograft tumours, they found.

And, the researchers added that sulforaphane eliminated breast CSCs in vivo, thereby abrogating tumour growth after the reimplantation of primary tumour cells into the secondary mice, they added.

“Our study identified the down regulation of Wnt/β-catenin self-renewal pathway by sulforaphane as one of the possible mechanisms for its efficacy,” they concluded.

The researchers noted treatment with sulforaphane had little effect on the normal cells.

Source: Clinical Cancer Research
Published online ahead of print: doi: 10.1158/1078-0432.CCR-09-2937
Title: Sulforaphane, a Dietary Component of Broccoli/Broccoli Sprouts, Inhibits Breast Cancer Stem Cells
Authors: Y. Li, T. Zhang, H. Korkaya, S. Liu, H. Fang Lee, B. Newman, Y. Yu, S. G. Clouthier, S. J. Schwartz, M. S. Wicha, D. Sun

The traditional Chinese herb Scutellaria (called skullcaps in the West) contains a combination of plant chemicals that together can significantly slow the growth of several different cancers, according to a study published in the January 2009 issue of Planta Medica.

The authors say this herb might prove an important addition to current cancer treatments. “On the basis of our preliminary results, we expect maximum benefit from Scutellaria…in combination with standard therapy such as surgery, chemotherapy, and immunotherapy,” says Prahlad Parajuli, PhD, assistant professor in the Department of Neurosurgery at Wayne State University and Karmanos Cancer Institute in Detroit, Michigan.

Past studies have shown that Scutellaria has potent antibacterial, anti-inflammatory, and anti-cancer properties, which come primarily from natural plant chemicals (phytochemicals) called flavonoids. Most of the research conducted on Scutellaria so far has focused on the roots of the herb, which are rich in the flavonoid wogonin. However, the leaves and stems are also thought to be high in cancer-fighting phytochemicals, according to study co-author Nirmal Joshee, PhD, assistant professor of Plant Science at Fort Valley State University in Georgia.

To learn more about this herb and how it might combat cancer, the researchers analyzed leaf, stem, and root extracts from 13 different Scutellaria species. They found that each extract contained different combinations of six flavonoids: apigenin, baicalein, baicalin, chrysin, scutellarein, and wogonin. Most extracts contained three or four different flavonoids. Two extracts contained all six flavonoids.

They then treated human breast, prostate, and brain cancer cells, as well as non-cancerous cells, with the Scutellaria extracts. Nine of the extracts significantly halted the spread of cancer cells. The higher the dose and longer the duration of treatment, the more effectively the extracts killed cancer cells. Four extracts—all from the Scutellaria leaf—were particularly effective at triggering the death (apoptosis) of brain cancer cells.

The researchers also looked at how the flavonoids in Scutellaria—both individually and in combination—affected cancer cells. A combination of four flavonoids, each at a low dose, blocked the growth of brain cancer cells by almost 50 percent. However, when those same flavonoids were given individually at the same dose, they had no effect on the cancer, which suggests that each one possesses a different anti-cancer mechanism and the effects are amplified when the different flavonoids work together.

Future studies will help determine which combination, or combinations of phytochemicals have the greatest cancer-fighting ability. “Combining phytochemicals with synergistic anti-cancer activity would allow use of individual components at a very low dose, which would eliminate or reduce toxicity,” explains Dr. Parajuli.

Certain flavonoids in Scutellaria also appeared to target specific types of cancer. For example, baicalein significantly slowed the growth of brain cancer cells. This may be because individual flavonoids affect mechanisms that are unique to each cancer, the authors say.

Based on the promising results of studies done so far, the researchers say they may launch a human clinical study to investigate Scutellaria as an adjuvant cancer treatment within a few years.

Source:
Parajuli P, Joshee N, Rimando AM, Mittal S, Yadav AK. In vitro antitumor mechanisms of various Scutellaria extracts and constituent flavonoids. Planta Medica. 2009;75:41-48.

An article, published in Comprehensive Reviews in Food Science and Food Safety, evaluated current research on flaxseed and any potential benefits it may have against diabetes and certain cancers.

Flaxseed has been the focus of increased interest in the field of diet and disease research due to the potential health benefits associated with some of its biologically active components: oil containing approximately 59 per cent a-linolenic acid (ALA) and the presence of plant lignan secoisolariciresinol diglycoside (SDG).

The authors, researchers from Canada, England and China, summarized that the health benefits from flaxseed ligans are due to their antioxidant activity, primarily from the hydroxyl radical scavengers and also due to their estrogenic and antiestrogenic compounds and the structural similarity to 17-b-estradiol.

Their paper states that SDG, once ingested, is converted in the colon into active mammalian lignans, enterodiol (END) and enterolactone (ENL) which have shown promise in reducing growth of cancerous tumors, especially hormone-sensitive ones such as those of the breast, endometrium, and prostate.

They concluded that flaxseed lignans could be a significant part of a treatment regimen for cancer based on the large number of small scale studies but they stress that further research is needed in clinical settings to support the role of flaxseed in cancer prevention in human populations.

And they called for further research to be undertaken to assess any potential adverse effects from over consumption of the seed: “More in vivo studies are needed to ascertain the propitious effects of lignans secoisolariciresinol and to see if there are any dangers in possible overdoses.”

Breast cancer

Studies (Adlercreutz and others 1992; Saarinen and others 2000) on flaxseed benefits for breast cancer that the authors reviewed showed the presence of flaxseed lignans in MCF-7 tumors and observed lignan binding to estrogen receptors (ER). This suggests, said the reviewers, that the lignan function may be ER-mediated.

“Although the lignans have been shown to be protective against breast cancer, minor structural alterations may influence overall activity (Saarinen and others 2005). Thus, many of the aforementioned benefits might be the results of specific structural features needed for lignans to bind to ER,” they claim.

Prostate cancer

Evaluating studies looking at flaxseed ligans effect on prostate cancer, the researchers said that lignans enterodiol and enterolactone were believed to be partly responsible for the growth inhibition of 3 human prostate cancer cell lines.

They report that Morton and others (1997) found that higher enterolactone levels in prostatic fluid were associated with populations with a low risk of prostate cancer.

Another small clinical study, note the reviewers, showed that prostate cancer cell proliferation decreased and apoptosis increased in men fed 30 g of flaxseed per day, and they reported that a subsequent study by the same researchers supported the role of flaxseed in combination with a low-fat diet as a means to control prostate growth.

Although not as extensively reviewed, the reviewers also report that flaxseed has been shown to inhibit colon and skin cancers in cell cultures and animal studies that have been conducted in this area.

Diabetes

Low-glycemic-index foods containing soluble fibre may not only prevent certain metabolic ramifications of insulin resistance, but also reduce insulin resistance, noted the authors, citing a study whereby flaxseed was shown to reduce the postprandial blood glucose response in humans.

“A consumption of 50 g/d ground flaxseed by young females over a 4-wk period caused a reduction in blood glucose levels (Cunnane and others 1993). Similar findings were observed in postmenopausal women fed a 40 g/d flaxseed fortification diet (Lemay and others 2002),” they stated.

Safety

There has been concern noted over certain components of flaxseed such cyanogenic glycosides, said the reviewers.

The authors stress that cyanogenic glycosides are not exclusive to flaxseed and are found in brassica vegetables and cassava, with many of the health concerns regarding cyanogenic glycosides stemming from studies showing that cassava was toxic to animals and humans.

“Cassava contains significantly more cyanogenic glycosides than flaxseed. Furthermore, the release of hydrogen cyanide from flaxseed would be minimal and below the toxic or lethal dose.

At the recommend daily intake of about 1 to 2 tablespoons, approximately 5 to 10 mg of hydrogen cyanide is released from flaxseed, which is well below the estimated acute toxic dose for an adult of 50 to 60 mg inorganic cyanide and below the 30 to 100 mg/d humans can routinely detoxify,” stress the authors.

They also cite a study from Daun and others (2003) that reported that a person would have to consume 8 cups (1 kg) of ground flaxseed to achieve acute cyanide toxicity.

Source: Comprehensive Reviews in Food Science and Food Safety
Published online ahead of print
Title: Flaxseed Lignans: Source, Biosynthesis, Metabolism, Antioxidant Activity, Bio-Active Components, and Health Benefits
Authors: A. Tour´e, X. Xueming

ScienceDaily (Apr. 19, 2010) — Vitamins and calcium supplements appear to reduce the risk of breast cancer, according to findings presented at the American Association for Cancer Research 101st Annual Meeting 2010.

“It is not an immediate effect. You don’t take a vitamin today and your breast cancer risk is reduced tomorrow,” said Jaime Matta, Ph.D., professor in the Ponce School of Medicine in Puerto Rico. “However, we did see a long-term effect in terms of breast cancer reduction.”

Matta said the findings suggest that the calcium supplements are acting to enhance DNA repair capacity, a complex biological process involving more than 200 proteins that, if disrupted, can lead to cancer.

“This process involves at least five separate pathways and is critical for maintaining genomic stability,” said Matta. “When the DNA is not repaired, it leads to mutation that leads to cancer.”

The study included 268 women with breast cancer and 457 healthy controls. Women were more likely to have breast cancer if they were older, had a family history of breast cancer, had no history of breastfeeding and had lower DNA repair capacity.

Vitamin supplements appeared to reduce the risk of breast cancer by about 30 percent. Calcium supplements reduced the risk of breast cancer by 40 percent. After controlling for the level of DNA repair capacity, calcium supplements were no longer as protective, but the link between vitamin supplements and breast cancer reduction remained.

“We’re not talking about mega doses of these vitamins and calcium supplements, so this is definitely one way to reduce risk,” said Matta.

American Association for Cancer Research (2010, April 19). Vitamin and calcium supplements may reduce breast cancer risk. ScienceDaily. Retrieved April 25, 2010, from http://www.sciencedaily.com­ /releases/2010/04/100418155436.htm

ScienceDaily (Apr. 21, 2010) — In the first study of vitamin K and Non-Hodgkin lymphoma risk, researchers at the Mayo Clinic campus in Minnesota have found that people who have higher intakes of vitamin K from their diet have a lower risk of developing Non-Hodgkin lymphoma. Non-Hodgkin Lymphoma is a cancer of the immune system and is the most common hematologic malignancy in the United States.

At the 101st Annual Meeting of the American Association for Cancer Research (AACR), the researchers report that the risk of developing Non-Hodgkin lymphoma was approximately 45 percent lower for participants who had vitamin K intakes in the top quartile of intake in the study (>108 ug/day), compared to participants who had intakes in the bottom quartile (<39 ug/day). This association remained after accounting for other factors such as age, sex, education, obesity, smoking, alcohol use and intake of foods with high amounts of antioxidants.

Vitamin K is a fat-soluble vitamin and is derived from either plants (phylloquinone or vitamin K1) or bacterial synthesis. This study estimated intake of the plant form of vitamin K from diet and supplement use. The most common sources of vitamin K1 in the diet include leaf lettuce and spinach, with smaller amounts found in other vegetables, vegetable oils and some fruits.

Researchers at the Mayo Comprehensive Cancer Center are studying the connection between diet and Non-Hodgkin lymphoma risk, and they became interested in a potential role for vitamin K. While vitamin K is best known for its essential function in several proteins involved in blood clotting (the name of the vitamin is derived from the German word “Koagulations”), it also appears to be important in other biological processes, including inhibition of inflammatory cytokines thought to play a role in Non-Hodgkin lymphoma, as well as pathways involved in cell cycle arrest and cell death.

“These results are provocative, since they are the first work we have done on the connection between vitamin K and Non-Hodgkin lymphoma, and this is a fairly strong protective effect,” says the study’s lead investigator, James Cerhan, M.D., Ph.D., a cancer epidemiologist. “However, as with all new findings, this will need to be replicated in other studies.”

The Mayo study enrolled 603 patients who were newly diagnosed with Non-Hodgkin lymphoma as well as 1,007 matched cancer-free “control” participants. Researchers asked the participants to answer a food questionnaire about their usual intake of over 120 food items two years prior to their cancer diagnosis or enrollment into the study (controls). They also asked about use of a variety of supplements. Vitamin K intake was estimated from this data.

While there was a clear trend showing that a greater intake of vitamin K from dietary sources was associated with a lower risk of Non-Hodgkin lymphoma, the use of vitamin K supplements presented a slightly different picture. Increasing intake of vitamin K from supplements did protect against Non-Hodgkin lymphoma, but reached a point where the highest intake offered no reduction in risk. “The significance of this finding is unclear,” notes Dr. Cerhan, “but suggests that taking high doses of supplements is unlikely to be helpful.” Dr. Cerhan also notes that people taking certain oral anticoagulants or seizure medications should closely follow their physician’s dietary recommendations with respect to vitamin K intake, since vitamin K can interfere with these drugs.

“Whether the protective effect we observed is due to vitamin K intake, or some other dietary or lifestyle exposure, cannot be definitely assessed in this study,” notes Dr. Cerhan. “But these findings add to a lot of other data that support a diet that includes plenty of green leafy vegetables in order to prevent many cancers as well as other diseases.”

The study was funded by the National Cancer Institute.

Mayo Clinic (2010, April 21). Vitamin K may protect against developing non-Hodgkin’s lymphoma, say Mayo Clinic researchers. ScienceDaily. Retrieved April 25, 2010, from http://www.sciencedaily.com­ /releases/2010/04/100419151117.htm