UCLA - total omega 6 PUFAs may be contributing to the high risk of BC in the US

[R.B.]

BASED ON PEOPLE AND BREAST TISSUE SAMPLES.

Posted here as is easy to understand and from a know institution.

Our fat is generally accepted to reflect what we have eaten. (and so a more accurate basis for assessment than reported diet) Breast fat is reported to show changes in three months. Other fat stores may change much more slowly.

More indication diet and in particular omega three six balance may have a role in BC.

RB

"We conclude that total n-6 PUFAs may be contributing to the high risk of breast cancer in the United States and that LC n-3 PUFAs, derived from fish oils, may have a protective effect."


http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_DocSum

1: Nutr Cancer. 2002;42(2):180-5. Related Articles, Links

Long-chain n-3-to-n-6 polyunsaturated fatty acid ratios in breast adipose tissue from women with and without breast cancer.

Bagga D, Anders KH, Wang HJ, Glaspy JA.

Division of Hematology-Oncology, Department of Medicine, University of California, Los Angeles School of Medicine, Los Angeles, CA 90095, USA.

Animal studies suggest that dietary polyunsaturated fatty acids (PUFAs) of the n-6 class, found in corn and safflower oils, may be precursors of intermediates involved in the development of mammary tumors, whereas long-chain (LC) n-3 PUFAs, found in fish oil, can inhibit these effects. This case-control study was designed to examine the relationship between the PUFA composition of breast adipose tissue and the risk of breast cancer. Using fatty acid levels in breast adipose tissue as a biomarker of past qualitative dietary intake of fatty acids, we examined the hypothesis that breast cancer risk is negatively associated with specific LC n-3 PUFAs (eicosapentaenoic acid and docosahexaenoic acid) and positively associated with n-6 PUFAs (linoleic acid and arachidonic acid). Breast adipose tissue was collected from 73 breast cancer patients and 74 controls with macromastia. The fatty acid levels were determined by gas-liquid chromatography. A logistic regression model was used to obtain odds ratio estimates while adjusting for age. The age-adjusted n-6 PUFA (linoleic acid and arachidonic acid) content was significantly higher in cases than in controls (P = 0.02). There was a trend in the age-adjusted data suggesting that, at a given level of n-6 PUFA, LC n-3 PUFAs (eicosapentaenoic acid and docosahexaenoic acid) may have a protective effect (P = 0.06). A similar inverse relationship was observed with LC n-3-to-n-6 ratio when the data were adjusted for age (P = 0.09). We conclude that total n-6 PUFAs may be contributing to the high risk of breast cancer in the United States and that LC n-3 PUFAs, derived from fish oils, may have a protective effect.

PMID: 12416257 [PubMed - indexed for MEDLINE]

[StephN]

Good info, RB.
I have been trying to follow this discussion and think back to my diet in the 5 years prior to diagnosis.
My husband has juvenile diabetes and thus there is hardly been a speck of junk food (a big culprit for the omega 6 input) around this house for 20 years. We may have a few chips from time to time or I may have a doughnut from time to time, but this is the exception.
We keep a few cookies around for hubby in case of low blood sugar and I eat very few of them. I did not eat much candy.
We eat mostly fresh vegies and meals are from scratch.

So, I am wondering how I could have gotten a high omega 6, if I have that. Testing WOULD be interesting. There is also the aspect of individual integration of the various fats according to body chemistry.

The major change I have made in diet is to switch over to nearly ALL ORGANIC plus meat and eggs without hormones. pesticides, etc.

Perhaps HER2 driven disease feeds on some other factor. Post menopausal fat redistribution and small gain is all I can think of that started happening prior to my diagnosis.

[R.B.]

Smart Fats A Schmidt gives some addresses for tests. I have no idea how much they are or how accurate. Gluteal tissue might be the best source for a long term indicator, but you would have to check.

Clearly the omega three six issue is not going to be a factor for all. The differential figure fro inflamation related conditions that one sees regularly quited between Japanese, Inuit and the west is a about 70% - so there is always the other 30%.

Anything we eat will only reflect what it has eaten in fat terms. So grass fed arguably would come above organic where some of the feed is corn etc. Curiously I have seen suggestions that the Argentinians show lower level of inflamatory diseases - grass fed farm animals?

Nuts and seeds are high in omega six AND their oils, (so margerines are usually high in six depending of what they are made - as well as the trans issue).

High level sources of omega three are very limited in the plant world, and hence it is much easier to ingest six than three in the average diet.

Re the individual - of course we all are different but there are some constants. Omega threes and sixes or their basic building blocks cannot be made in the body. As a species we a just not equipped.

Children must draw their fats from their mother in creation and if breast fed (a whole other issue). There are suggestions that mothers who have insufficient omega threes are further compromised by the demands of their children.

Some individuals just do not convert the shorter omega threes into longer chain products effectively etc etc etc.

From all I read the key is the balance between the threes and sixes, not the ultimate quantities.

So my guess is that someone would probaly show a significant three six imbalance if on a very low fat diet, some meat, with nuts but no fish, using some polyunsatureates grapeseed, but no dairy, but margerine for example.

I have had to go through a similar consideration of what I ate, and have been surprised where vegetable oils are used in food. Olive in oil (sunflower) Beans in oil (sunflower) - in baked products etc etc.

There are a huge range of trials suggesting benifit in inflamatory conditions from increasing omega three DHA and EPA, as well as reducing the sixes (balancing the threes and sixes).

It is complex and individual, and there are so many potential other factors.

Thanks for your input.

RB

[Lauriemn]

Hi RB, what do you eat? After seeing this latest study, I am trying to increase my omega 3s. I eat fish and take supplements, but was looking up the ratio of omega 3/ omega 6 in somewhat healthy foods and was suprised to see that certain vegetables had more 6 than 3 and that brown rice had 20 times more 6 than 3. I was also disappointed to see that avocados were higher in 6s than in 3s.

The only foods that I have found from the foods that I eat regularly that have higher omega 3 than 6 is fish and broccoli. Please tell me that there are other foods that also have more 3s than 6s.

thanks, Laurie

[Cathya]

RB;

I think I can see where my fats were out of wack. As I am alergic to fish I do not eat it....can't even stand the smell. Also, I have always thought that nuts (especially almonds) were healthy so snack sometimes on them....or seeds...particularly sunflower. I eat beans, mostly chicken...very little red meat. Now I take the fish oil capsules....Omega 3-6-9 and Vitamin D in fish oil.

Cathy

[R.B.]

Re high omega three foods

Flaxseed / oil
Perillia
Some seaweeds maybe
Some algae


Soy and walnut have some but are also high in sixes.

The above with the exception of some algae do not contain DHA and EPA and so its back to fish supplemented with fish oil to balance, offal from grass fed animals etc., and keeping the sixes low.

There are not that many high omega three foods that is the essence of the problem.

I have recently been reading trials looking at the influences of omega three and six on the eicosanoid pathway, and it seems that as well as balancing moderation in fat intake is good, and at lower overall omega six intakes three has more effect.

Me - greens, highly coloured veg and fruit, sea weed (yum surprisingly), very small amounts olive oil, 5 -10 tps fish oil, fish, whey protein in vegetable juice, as much variety as possible, green powder this is the best one for me I found to date,
http://www.vitacost.com/Store/Produc...r=074306800046
occasional root veg and beans but I am trying to avoid poly and disaccharidases for a while (Breaking the Viscious Cylcle Elaine Gotterschall)

http://www.healingcrow.com/scdwisdom/scdwisdom.html

A selection ground herbs spices etc.


Things are further complicated by stored body fats as they will reflect your historic diet, and dietary change may result in weight loss / the body drawing on stored fats, so you might want to consider getting more three than six for a while months to a year or two.

The primary side effect of fish oil is blood thinning, which can be a factor for those on blood thinners etc.

As usual please do discuss dietary changes with your advisor.

RB