Prostate Health, Vascular Health and Walnuts

[Guest guest]

Colleagues, the following is FYI and does not necessarily reflect my own

opinion. I have no further knowledge of the topic. If you do not wish to

receive these posts, set your email filter to filter out any messages

coming from @nutritionucanlivewith.com and the program will remove

anything coming from me.

---------------------------------------------------------

Prostate Health, Vascular Health and Walnuts

Kim J Spaccarotella, Ph.D.

Department of Biological Sciences

Science Building, 1st floor, C-117

Kean University

1000 Avenue,

Union, New Jersey 07083

/ (FAX)

kspaccar@...\http://www.vitasearch.com/CP/experts/KJSpaccarotelloAT06-07-08\

..pdf\\

0 " The Effect of Walnut Intake on Factors Related to Prostate and

Vascular Health in Older Men, "

Nutr J, 2008;7(1):13. 46327 (8/2008)\

Kirk Hamilton: Can you please share with us your educational background

and current position?

Kim J Spaccarotella: I have a Ph.D. in nutritional sciences from The

Pennsylvania State University, and I am

currently an adjunct faculty member in the Department of Biological

Sciences at Kean University.

KH: What got you interested in studying the role of walnuts and the risk

to prostate cancer?

KJS: Prostate cancer is the most common type of cancer among men, and

although advances in its detection

have improved the prognosis considerably, many of the currently

available treatments have unwanted side

effects. Walnuts are a rich source of several nutrients that may inhibit

the growth of tumor cells. Thus, walnuts

could provide an inexpensive and practical method for increasing intake

of nutrients that may protect against

prostate cancer.

KH: What is the biochemical mechanism of how walnuts might have a

preventive effect on prostate cancer

risk?

KJS: Cell culture studies have demonstrated that both the alpha-and

gamma-tocopherol forms of vitamin E,

which walnuts contain, inhibit growth of malignant cells, including

prostate tumor cells. Walnuts also contain

ellagic acid, which has been shown to induce cell death in cancer cells,

and selenium, which, along with vitamin

E, is a powerful antioxidant. In addition, walnuts are a good source of

alpha-linolenic acid, which may regulate

the conversion of testosterone to an active form that, in turn, can

regulate cell growth.

KH: What is the significance of reducing the alpha-tocopherol to

gamma-tocopherol ratio and increasing the

free PSA to total PSA ratio?

KJS: Previous research has indicated that a lower ratio of

alpha-tocopherol to gamma-tocopherol may be

protective against heart disease. Because androgens may play a role in

the smooth muscle cell proliferation

associated with both the development of prostate tumors and

atherosclerosis,and because as many as 1 in 4 men

over the age of 60 have symptoms of both prostate enlargement and high

blood pressure, identifying options

that may prevent both diseases is important. PSA is a protease that is

essential for prostate growth and function.

Free PSA is the inactive form, and total PSA is the sum of active

(complexed) and inactive PSA. Research has

shown lower ratios of free to total PSA in men with prostate cancer,

suggesting that a higher ratio (i.e. more

inactive PSA) may be protective against prostate cancer.

KH: Do patients with prostate cancer, or prostatic disease have a high

alpha-tocopherol to gammatocopherol

ratio? Are these subjects low in vitamin E measured as alpha tocopherol?

KJS: Previous research has reported a decreasing risk of prostate cancer

with increasing concentrations of

both alpha- and gamma-tocopherol. To my knowledge, the ratio of alpha-

to gamma-tocopherol has not been

extensively studied in patients with prostate cancer.

KH: Can you tell us about your study and the basic results?

KJS: We assessed the effects of walnuts on factors related to prostate

and vascular health in men at risk for

prostate cancer. The major portion of the project was a walnut

supplement study in which subjects (n=21) were

randomized to consume either their usual diet or a walnut diet (75 g/d=

¾ cup = 3 oz) for 8 weeks and switched

to the other diet for the second 8-week period. Following the walnut

diet, the ratio of alpha- to gammatocopherol

was significantly decreased (p<0.01) compared to baseline, partly

reflecting the increase in serum

gamma-tocopherol, which approached significance (p=0.01). The ratio of

free to total PSA also approached

significance (p=0.07).

KH: Were there any side effects with the walnut supplementation? How

were they administered? In a single

dose or divided doses? With meals or away from meals?

KJS: The walnuts were well tolerated. Participants were instructed to

consume the walnuts with meals and to

spread consumption across the day.

KH: How would you use this information clinically? Should patients with

elevated PSAs and prostatic

disease or prostate cancer increase their walnut consumption?

KJS: Further research with a larger sample is needed to better

understand the role that walnuts, and the

nutrients they contain, may play in prostate health. However, a growing

body of evidence suggests that walnuts

are a healthy food and that consuming about 1.5 oz per day as part of a

diet low in saturated fat and cholesterol

without increasing overall caloric intake may reduce the risk of

coronary heart disease, another disease affecting

many men at risk for prostate cancer.

KH: Should patients with elevated PSAs and prostatic disease or prostate

cancer increase their

gamma-tocopherol consumption?

KJS: To date, several studies have noted a decreased risk of prostate

cancer with higher serum vitamin E, and

the World Cancer Research Fund/American Institute for Cancer Research’s

expert report on diet, physical

activity and cancer prevention (2007) concluded that there is limited,

though suggestive evidence,that

consumption of foods containing vitamin E decreases prostate cancer

risk. However, further research is needed

to better understand the effects of vitamin E on prostate health before

public health recommendations should be

made.

KH: Do you have any further comments on this very interesting research?

KJS: Our findings were consistent with those of other investigators who

have reported that isocaloric

substitution of walnuts for other fat sources in the diet does not lead

to weight gain. Although the possible

mechanisms for this are still under investigation, this is encouraging

news for those who enjoy consuming

walnuts as part of a healthy diet.

--

ne Holden, MS, RD

" Ask the Parkinson Dietitian " http://www.parkinson.org/

" Eat well, stay well with Parkinson's disease "

" Parkinson's disease: Guidelines for Medical Nutrition Therapy "

http://www.nutritionucanlivewith.com/