Pectin, a type of fiber found in fruits and vegetables and used in making jams and other foods, kills prostate cancer cells according to a new University of Georgia study.
"What this paper shows is that if you take human prostate cancer cells and add pectin, you can induce programmed cell death," said Debra Mohnen, a professor of biochemistry and molecular biology. "If you do the same with non-cancerous cells, cell death doesn’t occur."
Mohnen's study, published in the August issue of the journal Glycobiology, found that exposing prostate cancer cells to pectin under laboratory conditions reduced the number of cells by up to 40 percent. Mohnen, a UGA Cancer Center researcher, her UGA colleagues and Vijay Kumar, chief of research and development at the VA Medical Center in Augusta, found that the cells self-destructed in a process known as apoptosis. Pectin even killed cells that aren’t sensitive to hormone therapy and therefore are difficult to treat with current medications.
A substance known as modified citrus pectin has been under study for treating prostate cancer for about a decade. Mohnen’s study adds to the growing body of evidence on the health benefits of pectin. Cancer studies using rats and cell cultures have found that pectin can reduce metastasis and prevent lung and colon tumors. Another study found that pectin induces apoptosis in colon cancer cells. Mohnen’s is the first to show that pectin induces apoptosis in prostate cancer cells and brings scientists closer to understanding what makes the common component of plants an effective cancer fighter.
In her lab at UGA’s Complex Carbohydrate Research Center, Mohnen and her team analyzed three different types of commercially available pectin, namely Thorne brand (heat-treated), Pectasol (pH treated) and standard grade unmodified citrus pectin. Mohnen found large differences in anti-cancer activity. They found that treatment under mild base conditions (as in Pectasol) decreased the anti-cancer properties of pectin while heat treatment (Thorne brand) significantly increased anti-cancer activity.
Pectin, Mohnen explains, is one of nature’s most complex molecules and has the potential to bind to several sites on cells and to elicit several different cellular responses at the same time. Mohnen and her team are working to identify the smallest structure within pectin that can induce apoptosis with the ultimate goal of developing pectin-based pharmaceuticals or foods with enhanced health benefits.
Mohnen said that more evidence is needed to support the use of specific pectin supplements, but said that most Americans would do well to increase their intake of fruits and vegetables.
“Even though we hear constantly that we’re supposed to eat lots of fruits and vegetables, it wasn’t until we started working on these studies that it finally hit home how really important that was,” she said. “By simply increasing your intake of fruits of vegetables, you’re going to get a lot of pectin and you’re going to get all of the other beneficial phytochemicals at the same time.”
The research was funded by the Georgia Cancer Coalition-Georgia Department of Human Resources, the University of Georgia-Medical College of Georgia Joint Intramural Grants Program and the federal Department of Energy.
The authors state that they have no financial conflicts of interest.
Sources: University of Georgia
Pectin induces apoptosis in human prostate cancer cells: correlation of apoptotic function with pectin structure. Glycobiology 2007 17(8):805-819; doi:10.1093/glycob/cwm054
More on this topic -- in reply to the reader who pressed us to identify the brands, I give a more detailed summary of the Georgia researchers' article in One Brand of Modified Citrus Pectin Kills Prostate Cancer Cells, Another Brand Has “Little Activity” Researchers Say.
Although one of the authors said that the way we should obtain a high intake of pectin is to eat a lot of fruit and vegetables, that's not what the research was about. It demonstrated that "commercially available" Fractionated Pectin Powder (FPP) was potent at killing prostate cancer cells in the lab.
While the advice to focus on food as the best source of pectin is reasonable, there is no harm in taking pectin powder supplements. Pectin intake is beneficial for digestive health and may help transport dietary sources of cholesterol out of the body.
Unfortunately, I have found it impossible to identify sources of FPP that meet the definition in the article. All the FPP I have tracked down looks suspiciously like Pectasol or Pectasol look-alikes. Pectasol was specifically found in the research to be ineffective at killing PCa cells.
This University of Georgia finding really only applies to apoptosis of cancer cells in a dish. It certainly fits in with other research that indicates that a diet high in fruits and vegetables may help prevent multiple conditions -- heart disease, diabetes, cancer. It might be helpful for prostate cancer patient who, post-primary treatment, hope to avoid recurrence.
These researchers suggest, eat more fruits and vegetables. Fruits differ in their pectin content.
Apples, quince, plums, gooseberries and oranges contain more pectin than soft fruits like grapes and strawberries. However, berries and grapes have other healthful properties.
Even in fruits and veggies considered "high" in pectin, it's relatively low. Typical levels of pectin:
in apples, apricots approx. 1%
oranges 0.5 - 3.5%
carrots approx. 1.4%
Squash is under study as a source of pectin for the food processing industry.
A product called modified citrus pectin, announced as a tumor-shrinker c. 1995, is sold to and used by prostate cancer patients.
Refs: Pienta K et al, J Natl Cancer Inst. 1995 Mar 1;87(5):348-53 .
Search at PUBMED for "cancer, citrus pectin" to see the brief history of research with modified citrus pectin.
University of California San Diego has an entry for modified citrus pectin in its complementary and alternative medicine section.
American Cancer Society also has an entry on modified citrus pectin .
The abstract [at PUBMED] drove me crazy.
Why be so coy about a "commercially available" product? At least the abstract lets you know that PectaSol isn't the one.
But there is a back-door way of finding out - maybe. Searching on 'Thorne', etc, I got to:
http://glycob.oxfordjournals.org/cgi/content/abstract/cwm054v1
Same abstract. No mention of Thorne, but in the Google hit list, you see:
"Fractionated Pectin Powder from Thorne ..."
Coincidentally, because of the study, I had added the Thorne product to my regimen (makes PectaSol taste like fine wine). Only today did I connect the study to Thorne. I still take PectaSol though.
-Patrick
Patrick,
I don't understand why the abstract "drove you crazy," except it's not enough to answer your questions. PubMed is actually an excellent place to start, for 2 reasons. Firstly, they give (in this case) a direct link to the journal, Glycobiology, that you found by a "backdoor" route (Googling "Thorne"). Look on the upper right hand side of the PubMed abstract page for this link.
Secondly, PubMed pulls up related studies (right hand side of the abstract page). This enables readers to trace the history of new data and check for supporting and/or contrasting findings.
Now, it's true that while medical journals are not in the business of promoting specific commercial products (or should not be), in a case like this people will want to know which of the products tested worked better than the others. Thanks for your input!
Hi Jacquie,
I wasn't clear. Getting to the journal wasn't the issue. The only way to get a glimpse inside the text is to have guessed a keyword. Sure enough the FPP was purchased from Thorne. That was the backdoor.
Regards, -Patrick
Pingback: One Brand of Modified Citrus Pectin Kills Prostate Cancer Cells, Another Brand Has "Little Activity" Researchers Say | psa-rising.com » EatingWell » food news