OBESITY, LIFESTYLE & HEART DISEASE
There has been much written about the link between obesity and heart disease, and the consensus has generally been that increasing levels of excess weight are associated with increasing levels of coronary artery disease and heart attacks (myocardial infarction). More recent research studies have attempted to quantify the extent of added risk associated with specific degrees of obesity, and some have also evaluated the benefits, if any, of varying levels of physical fitness among obese patients (please see my Archives for a review of some of these recent research studies). In general, most of these recent studies continue to show that increasing levels of obesity are associated with increasingly greater risks of coronary artery disease (as well as an increasing incidence of high blood pressure, diabetes, stroke, arthritis, some forms of cancer, and premature death). While obese people can somewhat reduce health risks with regular and vigorous exercise (the so-called “fit fat” person), most clinical research studies have observed that overall health risks still remain greater than those observed in lean people. A new study, published in the journal Circulation, evaluates multiple lifestyle factors and their effects on health in obese people.
conducted by researchers from
Taken together, the results from this very large Danish public health study confirm other recent studies that have shown that, even among obese people, lifestyle factors can have a significant influence on cardiac health. However, none of these positive lifestyle changes, such as exercise, a heart-healthy diet, or abstinence from tobacco, can completely erase the harmful effects of obesity. There is no substitute for shedding excess weight if you want to maintain your coronary arteries in the best possible shape. However, if you are already actively working on eliminating excess weight, you can still incrementally decrease your risk of heart disease by adopting a healthy lifestyle while you work towards achieving a healthier BMI.
EFFECTS OF LIFESTYLE & NUTRITION ON PROSTATE CANCER
There have been numerous studies on the effects of various nutritional supplements on prostate cancer cells growing in a Petri dish in the laboratory, and in human prostate cancer cells implanted into mice. However, there is precious little data on the effects of nutritional and other lifestyle interventions, if any, on actual prostate cancer tumors growing in living human beings. As I have often mentioned before, there have been hundreds of previous research studies that have observed positive responses to experimental treatments in laboratory cell cultures and in mice and rats, but have subsequently failed to show any beneficial impact when applied to human subjects. However, a new and exciting study, just published in the Proceedings of the National Academy of Sciences, provides a rare glimpse into the effects, at the genetic level, of nutritional and lifestyle interventions on prostate cancer tumor cells taken from the prostate glands of men with this disease.
intriguing study was performed by physicians and scientists at the
Gene expression profiling revealed that the activity of 48 individual genes had significantly increased following completion of the 3-month lifestyle modification program, while 453 genes had become less active. The researchers then looked at all of the 501 genes that had undergone changes in their levels of expression, and assessed their functions as they related to cancer cell growth and progression. After analyzing the functions of these 501 genes, the researchers determined that many of them were directly involved in critical pathways used by cancer cells to grow and divide.
Although this was only a small pilot study, it is one of only a handful of “in vivo” clinical research studies that have objectively studied the impact, at the level of gene activity, of healthy lifestyle modifications on active cancers growing within living human beings. As such, the implications of this study’s findings are potentially enormous. Although it is not possible to tell if these 30 men will experience a reduction in the growth or spread of their cancers as a result of these lifestyle modifications, the objective improvement in the “genetic profile” of their prostate cancers, following 3 months of intensive diet and exercise modification, is an exciting finding in and of itself. The implications of this study’s results offer hope that rigorous lifestyle modifications may help to both prevent some cancers and to reduce the biological aggressiveness of cancers that have already developed. However, this is only a small “proof of concept” research trial. A larger randomized clinical research trial will now have to be performed using a similar approach, but with a “control group” of patients who do not undergo any lifestyle or nutrition modifications. Additionally, this future randomized study will have to follow all of the participating patients for a sufficiently long period of time to allow any clinically significant differences between patient groups to become evident. Meanwhile, this fascinating little study offers a tantalizing look (at the genetic level) at the potential impact of diet and lifestyle changes on the biology of cancer cells growing within the human body.
GINKGO BILOBA, ULCERATIVE COLITIS & COLORECTAL CANCER
For the most part, the anti-inflammatory and anti-cancer effects of herbal supplements and vitamins with known antioxidant activity have turned out to be quite disappointing in human research trials, despite favorable results from previous laboratory research using cell cultures and laboratory mice and rats.
tree is an ancient plant with no known living relatives, and is often
as a “living fossil.” Some
trees in China are estimated to be nearly 3,000 years old, and
specimens of this unique tree are numerous.
For thousands of years, the unique bi-lobed leaves of the
have been used for medicinal purposes, initially in traditional Chinese
medicine, and more recently, throughout the remaining world. Ginkgo leaves are known to
activity, converting cell-damaging “free radical” oxygen molecules,
potentially toxic byproducts of normal metabolism, into less toxic
substances. A new
study published in the
journal Carcinogenesis has
the effects of ginkgo biloba extract in preventing and treating
colitis in mice. This
laboratories at the
In this study, inflammatory colitis was induced in laboratory mice. The group of mice that was fed a standardized extract of ginkgo biloba had much lower levels of inflammatory substances in their circulation than the mice that were not given the ginkgo supplement. Moreover, much lower numbers of immune cells associated with immune-mediated inflammation, known as CD4+ T-lymphocytes, were present in the mice that had received ginkgo supplements. The activation of macrophages, which also participate in the inflammatory response, was also significantly reduced in the mice that received ginkgo biloba. In this study, the use of ginkgo biloba extract was found to significantly decrease the degree of inflammatory colitis in this mouse model of ulcerative colitis.
At this time, there are no active clinical trials assessing the effects of ginkgo biloba in human patients with ulcerative colitis, or other inflammatory bowel diseases, such as Crohn’s disease. Based upon the intriguing results of this laboratory study, a human clinical trial to assess ginkgo biloba in patients with inflammatory bowel disorders should be initiated now.
Dr. Wascher is an oncologic surgeon, professor of surgery, a widely published author, and the Director of the Division of Surgical Oncology at Newark Beth Israel Medical Center
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Copyright 2008. Robert A. Wascher, MD, FACS. All rights reserved.
Dr. Wascher's Archives:
4-27-2008: Stents vs. Bypass Surgery for Coronary Artery Disease; The “DASH” Hypertension Diet & Cardiovascular Disease Prevention; Testosterone Therapy for Women with Decreased Sexual Desire & Function
4-6-2008: Human Papilloma Virus (HPV), Pap Smear Results & Cervical Cancer; Human Papilloma Virus (HPV) Infection & Oral Cancer; Hormone Replacement Therapy (HRT) & the Risk of Gastroesophageal Reflux Disorder (GERD)
12-16-2007: Honey vs. Dextromethorphan vs. No Treatment for Kids with Night-Time Cough, Acupuncture & Hot Flashes in Women with Breast Cancer, Physical Activity & the Risk of Death, Mediterranean Diet & Mortality