Males using flax oil should read this.

[Guest guest]

Alpha-linolenic acid is the major plant omega 3 fatty acid. Flax seed oil is the

richest natural source of this fatty acid, but it is also present in large

amounts in a variety of other plant oils. Increased intake of this fatty acid

has been associated with a decrease in blood cholesterol levels and may reduce

the risk of heart attack. Similarly, there is some evidence to suggest that

alpha-linolenic acid may slow the growth of cancers of the breast and colon.

These observations have led a number of physicians and dietitians to recommend

flaxseed oil or alpha linolenic acid extracts to all cancer patients.

In previous newsletters and in our book " Eating your way to better health " , we

have repeatedly pointed out that there are two problems with recommending alpha

linolenic acid to prostate cancer patients. First, there is no evidence that

increased alpha linolenic acid extracts or flaxseed oil provide any benefit.

Second, those clinical studies that are available suggest that alpha linolenic

acid may actually be dangerous.

An additional epidemiology study that examines the association of alpha

linolenic acid and prostate cancer risk has just been published. Dr. De

Stefani and colleagues from Registro Nacional de Cancer, Montevideo, Uruguay

examined the association between prostate cancer and alpha linoleic acid,

linoleic acid, total fat, saturated fat, and monounsaturated fat. Additionally,

they tested whether there was a difference between alpha linolenic acid obtained

from animal or vegetable sources. One of the reasons this study is interesting

is that Uruguay has one of the higher death rates from prostate cancer as well

as one of the highest rates of red meat consumption

..

This study found that the major risk factors associated with the development of

prostate cancer were family history of this disease and intake of alpha

linolenic acid. When the risk was adjusted for intake of linoleic acid,

saturated fat, monunsaturated fat and red meat intake, those with the highest

intake of alpha linolenic acid had a 440% increase in risk compared with those

at the lowest level. Also, alpha linolenic acid from both vegetable and animal

sources were associated with an increase in the risk of prostate cancer.

There are now six epidemiology studies that have examined the association

between dietary alpha linolenic acid and risk of prostate cancer. Five out of

six of these studies found an increase in the risk of prostate cancer associated

with alpha-linolenic acid. The one negative study is from Sweden. It is

important to note that the Swedish study did not show any benefit from alpha

linolenic acid, but rather found this fatty acid had no impact. Thus, six out of

six studies found no benefit to increased alpha linolenic acid, while five found

potential harm! I should also note that our laboratory as well as others find

that alpha linolenic acid is one of the most powerful growth stimuli for human

prostate cancer cells.

Every time I write on alpha linolenic acid and flaxseed oil, we receive a flood

of emails and letters asking if we are we really saying that these fats are

dangerous rather than helpful. After all, these other experts are all telling us

to take flaxseed oil. To this I can only repeat that the evidence currently

available certainly fail to document any benefit as far as prostate cancer

treatment. Further, laboratory and epidemiology studies continue to suggest that

it may be quite dangerous to increase your intake of alpha linolenic acid as it

may well increase the growth and spread of your cancer.

I have been asked to comment on flaxseed as compared to flaxseed oil. My major

concern is with the flaxseed oil, which permits patients to ingest very large

amounts of alpha linolenic acid in a short period of time. While flaxseed

contain alpha linolenic acid, it is quite unlikely that someone will eat enough

flaxseed to match the alpha linolenic acid content of even a modest dose of the

oil. Additionally, flaxseed contain a number of phytochemicals, such as lignans,

that are of potential value. One of the major lignans in flaxseed is

Secoisolariciresinol, a phytoestrogen and antioxidant.

While I am not as concerned about the safety of flaxseed, I certainly do not

recommend it as treatment for prostate cancer. In preparation for this issue of

the newsletter, I have reviewed every paper on the health benefits of flaxseed

in the National Library of Medicine database, Medline. There is no evidence that

flaxseed slows or prevents the growth and spread of prostate cancer. Rats fed

flaxseed for their entire life have smaller prostate glands, but the dose

required to do this altered the sexual performance and anatomy of both sexes.

Flaxseed and its lignans do appear to alter the development and spread of breast

cancer and melanoma in animal models and may have benefit for patients with

these diseases. There is considerable evidence that flaxseed intake can reduce

your risk of heart disease and ameliorate the damage caused by rheumatoid

arthritis. Some patients have written to say that they have heart disease and my

stance means they must chose whether to treat their heart and stay on flax or

treat their prostate and discontinue it. There are other effective options

available for preventing or treating atherosclerosis. For example,

cholesterol-lowering drugs, such as Pravacol, Lipitor, and Zocor are effective

at lowering the cholesterol and have a favorable influence on the outcome of

heart disease. I might also mention that there are other source of antioxidants

and phytoestrogens with greater evidence to support their use by prostate cancer

patients: green tea and soy products come to mind.