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“A critical weekly review of important new research findings for health-conscious readers”

VITAMIN D REDUCES RISK OF COGNITIVE DECLINE & DEMENTIA

Regular readers of this column are already well aware of the preventive effects of Vitamin D with respect to falls in the elderly, certain cancers, and cardiovascular disease.  (My new book, “A Cancer Prevention Guide for the Human Race,” which is scheduled to be published in August, 2010, contains an exciting and comprehensive update on the role of Vitamin D in cancer prevention.)  Now, a newly published research study, which appears in the current issue of the Archives of Internal Medicine, has linked low Vitamin D levels in the blood with an increased risk of cognitive decline and dementia in adults over the age of 65.

A total of 858 adults at or over the age of 65 participated in this prospective public health study, which was conducted over a period of 7 years.  All of these study volunteers underwent extensive evaluation of their cognitive function, using validated, standardized tests, when they entered into the study.  All patients also underwent testing of their blood for Vitamin D levels.  This extensive evaluation and testing was then repeated every 3 years during the course of this important clinical research study.

The results of this study indicated that patient volunteers with low Vitamin D levels in the blood (less than 25 nmol/liter), when compared with volunteers with normal blood levels of Vitamin D (75 nmol/liter, or higher), experienced significant declines in their intellectual function over the course of this study.  Indeed, the patient volunteers with decreased Vitamin D levels in their blood were as much as 60 percent more likely to experience progressive cognitive decline or dementia over the relatively brief duration of this study, when compared with the patients who had normal levels of Vitamin D in their blood! 

The results of this study are very similar to the findings of a similar study, which has just been published in the journal Neurology.  In this particular study, an inadequate level of Vitamin D in the blood of elderly men and women was associated with a significantly increased risk of cognitive decline and dementia from all causes, including Alzheimer’s disease and stroke.  Moreover, abnormalities of the brain, as detected by MRI scans, were also more commonly observed in patients who were deficient in Vitamin D.

Vitamin D deficiency is very common in older men and women.  An estimated 80 percent of people over the age of 65 have inadequate levels of Vitamin D in their blood, while as many as 45 percent of older men and women also have severe Vitamin D deficiency.

The results of these two studies strongly suggest that adequate levels of Vitamin D in the blood may be associated with a significantly reduced risk of aging-associated cognitive decline and dementia in older men and women, in addition to improving muscle strength, decreasing the risk of certain cancers, and decreasing the risk of cardiovascular disease. 

Not everyone should take large doses of Vitamin D, however, as the unmonitored use of this potent hormone-like vitamin can cause dangerous elevations in the level of calcium in the blood, as well as calcifications in the soft tissues of the body, kidney failure, pancreatitis, and gastrointestinal ulcers.  (Prior to starting Vitamin D supplements, you should certainly discuss the risks and benefits of Vitamin D supplementation with your physician.)

To learn more about the critical role of Vitamin D and the risk of cancer, look for the publication of my new landmark book, “A Cancer Prevention Guide for the Human Race,” in the August of this year. 

Disclaimer: As always, my advice to readers is to seek the advice of your physician before making any significant changes in medications, diet, or level of physical activity

Dr. Wascher is an oncologic surgeon, a professor of surgery, a cancer researcher, an oncology consultant, and a widely published author

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I and the staff of Weekly Health Update would like to take this opportunity to thank the more than 100,000 new and returning readers who visit our premier global health information website every month.  As always, we enjoy receiving your stimulating feedback and questions, and I will continue to try and personally answer as many of your inquiries as I possibly can.

Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers” 

CHEMOTHERAPY FOR BREAST CANCER & MEMORY LOSS

“Chemo Brain” is a term often used by breast cancer patients to describe the decreased memory, and other cognitive dysfunctions, associated with chemotherapy for this common form of cancer.  However, there has been very little prospective, objective clinical research into this phenomenon.  Furthermore, what little research that has been done in this area, to date, has primarily focused upon subjective self-assessments, by breast cancer patients, of their own level of cognitive function following chemotherapy.  Moreover, until recently, the complaints of breast cancer patients regarding their self-perceived memory loss following chemotherapy were often dismissed by many physicians. 

Now, a newly published prospective clinical research study from the M.D. Anderson Cancer Center suggests that physicians may have vastly underestimated the frequency, severity, and duration of cognitive dysfunction following standard breast cancer chemotherapy.  This clinical study, which appears in the current issue of the journal Cancer, prospectively enrolled 42 women with newly diagnosed breast cancer.  All of these women then underwent standardized neuropsychological evaluation before, during, and after chemotherapy.  Importantly, this study not only tested these breast cancer patients in the early period after they completed their chemotherapy, but also one year after their chemotherapy had ended.  The findings from this small study strikingly illustrate just how common, and how enduring, memory loss and other forms of cognitive dysfunction are following chemotherapy for breast cancer.

Prior to beginning chemotherapy, 21 percent of these patients had some detectable degree of cognitive dysfunction.  By the end of their chemotherapy treatments, a whopping 65 percent of these 42 patients displayed measurable declines in memory function, organizational ability, and cognitive processing speed.  One year later, 61 percent of these women continued to display measurable declines in cognitive function.  Worse yet, among this group of women with persistent cognitive dysfunction one year after completion of their chemotherapy, 71 percent continued to display progressively worsening of cognitive function when compared to their level of function immediately after finishing chemotherapy.  Finally, the remaining 29 percent of this group of women with long-term evidence of cognitive dysfunction actually displayed a delayed-onset of cognitive decline when they were tested one year after chemotherapy (i.e., when compared to the results of their neuropsychological testing immediately after chemotherapy).

Although this clinical research study enrolled a small cohort of patients, its prospective nature, and its use of validated neuropsychological tests, make it a powerful research study for its size.  The findings of this study also fit well with previous laboratory research studies that have shown both acute and delayed changes in the actual structure of the brains of animals treated, proportionately, with the same chemotherapy drugs commonly used to treat breast cancer in humans.  Whether or not the significant declines in cognitive function that were observed, one year after chemotherapy in the 61 percent of women who participated in this study, will eventually stabilize, improve or worsen is unknown at this time.  Longer follow-up of these 42 breast cancer patients will have to be performed to answer this important question.  However, this small prospective study clearly indicates that the majority of women who undergo standard chemotherapy for breast cancer appear to experience significant and prolonged declines in their level of cognitive function, including memory loss, decreased organizational skills, and a general slowing of their cognitive processing speed, and that these adverse changes persist for at least a year after completion of chemotherapy.

The findings of this study should spur additional research into the precise cause(s) of this chemotherapy-associated impairment in cognitive function, as well as strategies to reduce the severity and duration of these adverse health effects following chemotherapy for breast cancer.  Meanwhile, it is important for me to stress that chemotherapy unquestionably extends survival, and saves lives, among women who are appropriately advised to undergo such treatment for breast cancer.  In my opinion, no patient should read this column, and then go on to refuse chemotherapy that has been appropriately recommended because of the findings of this clinical research study.  

To learn more about the prevention, screening, diagnosis and treatment of breast cancer, look for the publication of my new landmark evidence-based book, “A Cancer Prevention Guide for the Human Race,” in the summer of this year.

Disclaimer: As always, my advice to readers is to seek the advice of your physician before making any significant changes in medications, diet, or level of physical activity

Dr. Wascher is an oncologic surgeon, a professor of surgery, a cancer researcher, an oncology consultant, and a widely published author

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http://www.redcross.org/

http://www.imcworldwide.org/haiti 

Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers”

CONCORD GRAPE JUICE IMPROVES MEMORY

Polyphenols are plant-based dietary compounds with known antioxidant and anti-inflammatory properties.  These biological properties of polyphenols reduce the ongoing damage to the DNA in our cells that results from the toxic byproducts of metabolism, including free radicals.  Polyphenols have, therefore, been the subject of intense research as potential prevention agents for a variety of human ailments, including cardiovascular disease, dementia, and cancer.  (The evidence-based role of dietary polyphenols in cancer prevention is discussed in great detail in my soon-to-be-published book, “A Cancer Prevention Guide for the Human Race.”)

Foods that are naturally rich in polyphenols include most blue and red berries, grapes (including red wine), pomegranates, walnuts, peanuts, olive oil, green tea, dark chocolate and cocoa, coffee, and beer (as well as other fruits and vegetables). 

Recent animal research has suggested that polyphenols derived from grape seeds can reduce the development of plaques in the brain (at least in mice) that are associated with the development of Alzheimer’s disease.  Now, a newly published prospective, randomized, double-blind clinical research study suggests that Concord grape juice, which is rich in polyphenols, may be able to improve early memory decline in older adults.

In this small study, which has been published in the British Journal of Nutrition, 12 elderly adults with declining memory were divided into two groups.  The “experimental group” received daily Concord grape juice supplements for a period of 12 weeks.  The second group, the “control group,” received placebo supplements that were identical in appearance to Concord grape juice, but which contained no juice.  Neither the 12 patient volunteers nor the research assistants were aware of which patients received grape juice and which patients received the placebo while the study was being conducted.

Standardized, validated tests of memory, and other aspects of cognitive function, were administered to all 12 patient volunteers participating in this study.  These cognitive function tests revealed statistically significant improvements in verbal learning skills among the patients who received 12 weeks of Concord grape juice (when compared to the placebo group).  Although not statistically significant, improvements were also noted in both verbal and spatial recall among the patient volunteers who received the grape juice supplements in this small clinical study with a brief duration of patient follow-up.

While larger studies, with a longer duration of follow-up, will be required to confirm the findings of this small pilot study, the prospective, randomized, placebo-controlled, double-blind nature of this small study does give it considerably more predictive power than the much larger dietary survey-based epidemiological studies that are more commonly used in disease prevention research. 

In view of the extreme devastation and human misery brought about in Haiti by the recent earthquake, Weekly Health Update asks our tens of thousands of caring readers to give generously to established charities that are currently working in that country to assist the injured, the ill, and the homeless there.  There are many such legitimate charities, including the following two:

http://www.redcross.org/

http://www.imcworldwide.org/haiti

For a somewhat lighter perspective on Dr. Wascher, please click on the following YouTube link: 

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Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers”

GINKGO BILOBA, MEMORY & COGNITIVE HEALTH

Regular readers of this column know that I have a strong interest in lifestyle- and diet-based approaches to disease prevention, but that I insist on rigorous, high-quality research-based data before I can recommend a particular lifestyle or dietary modification to my readers (or to myself).  Many past columns have reviewed the findings of research studies with favorable results associated with specific nutritional or other lifestyle approaches to disease prevention.  However, this week’s column will report on a newly published prospective clinical research trial that calls into question the supposed clinical value of the traditional Chinese medicine herb Ginkgo biloba in reducing the cognitive decline associated with aging and Alzheimer’s disease.

Previously published public health research data, based upon low-powered research methods, have suggested that dietary supplementation with Ginkgo biloba might be able to improve memory and cognition, particularly in older adults.  However, more recent data, based upon more robust types of clinical research, have called this assumption into question (as well as previous claims that Gingko biloba can delay or reverse the cognitive decline associated with Alzheimer’s disease).  Now, a newly published prospective, randomized, double-blind, placebo-controlled clinical trial of Gingko biloba supplementation in older adults in the United States appears to have definitively resolved the controversy about the value of Gingko biloba in maintaining memory, and other high level cognitive functions, in older adults. 

Ginkgo biloba trees are often referred to as living fossils, as they are known to survive for 1,500 years or more, and their presence has been documented within fossil-bearing rocks more than 270 million years old.  Although ancient fossils containing the distinctive bilobed leaves of Ginkgo biloba trees have been found on multiple continents, modern day Gingko trees now grow naturally only in China (although they have been widely cultivated, over a period of centuries, throughout Asia, and particularly in Japan and Korea).    

A new highly-powered prospective clinical research trial evaluating Ginkgo biloba supplementation appears in this week’s issue of the Journal of the American Medical Association.  More than 3,000 adults between the ages of 72 and 96 years participated in this placebo-controlled research trial, with an impressive average patient follow-up duration of more than 6 years.  These patient volunteers were secretly randomized to one of two groups.  The patients in the “experimental group” received 120 mg of Ginkgo biloba extract twice daily during the course of this study, while the “control group” of patients received an identical-appearing placebo (“sugar pills) twice daily.  (As this was a double-blind study, neither the patient volunteers nor the researchers knew which patients were receiving Gingko pills and which were receiving the placebo pills until after the research study was completed.) 

Multiple validated cognitive screening exams were given to all of these older patient volunteers during each year of the study, and the rate of annual decline in cognitive function was then compared between the two groups of patient volunteers.  Areas of cognitive function that were specifically tested for in this high-powered prospective clinical research trial included memory, attention, visual-spatial abilities, language function, and overall executive brain function.  (Note: these same cognitive function tests are also routinely utilized to assess cognitive function in patients with Alzheimer’s disease.)

Unfortunately, there was absolutely no difference observed or measured in the rate of decline in cognitive function between the two groups of older patient volunteers, indicating the lack of any clinically detectable benefit in age-related cognitive decline associated with high-dose supplementation with Ginkgo biloba.

(As an editorial aside, the Journal of the American Medical Association (JAMA) is to be commended for publishing this rigorously performed clinical research trial and its Level One research findings, as there is a well-known bias against publishing clinical research studies with “negative findings,” such as this study, among prestigious medical journals.)

Although this is the second recent high-level prospective clinical research trial that has found absolutely no clinical benefit in preserving or improving cognitive function in older adults associated with Ginkgo biloba supplements, there may still be potential clinical applications for this ancient herbal remedy in view of its known ability to improve blood flow through networks of small blood vessels in the body.  There is also some research evidence available suggesting that Ginkgo biloba may have potentially important anti-inflammatory properties, and that these properties might be clinically useful in some chronic inflammatory diseases, such as ulcerative colitis (Ginkgo biloba, ulcerative colitis & colorectal cancer).  For now, however, the overwhelming available clinical research evidence indicates that Ginkgo biloba appears to offer no benefit to older patients in terms of either preserving or improving memory, or in improving other areas of higher cognitive function.

Disclaimer: As always, my advice to readers is to seek the advice of your physician before making any significant changes in medications, diet, or level of physical activity