Carol
With all the caveats because the trials have not been done, the extent of opinions, the discussion, the complexity, my simple observations based on my reading would be
2 grams of DHA minimum a day which equates to about 5 TPS of a quality cod or fish oil (which will supply EPA DHA and a mix of other fats including omega nines)(or vegetarian DHA EPA alternative)
There are arguments for taking double that or more at least till you get your body fats balanced out - see posts of Greek Diet comparing lower and higher doses. (But you MUST talk to your medical advisor as fats are very powerful and there are limited but serious side effects with omega threes for some due to reduction in clotting etc.)
Watch the sixes like a hawk and make every effort to more or less balance with omega threes. Use the links to look up fat contents if you are not sure. Look at all labels - dried fruit, olives in oil, "health foods" etc omega high omega six oils are everywhere.
For salads low temp fast cooking olive but better added after cooking or at end. A hint of butter now and then if you like.
Include some antioxidants to protect the omega threes etc - there are suggestions they work better with antioxidants (but again please check with advisors)
Make sure you are getting adequate selenium as low selenium is reported as tipping the fat lengthening to omega six.
Try and ensure your digestion is working well. Omega threes will help with IBS etc. but you may need to look at cutting out likely antagonists, grain, milk products, and one author suggests cut out complex sugars (Elaine Gottschall breaking the viscous cycle).
Include flax seed or oil to ensure a supply of ALA 18:3 n3 (see posts on flax and flaxseed as to phyto-oestrogens)
And nuts mixed in moderation full of good things but generally high in sixes.
GLA fro me the jurys out. For the specific group who cannot make long chain sixes and other specialist complaints it is reported as of benifit, but I cannot get excited on what I have seen as I do about the generality of the threes and sixes. Evening primrose etc are high in sixes as well as GLA so if you do take please factor that in.
Apart from that as wide a diet as possible fresh and whatever sort meets the budget, different herbal teas. Maybe a good green powder with digestive enzymes, Lactobaccillus lots of herbs etc, and personal choice as to Coq10, Alpha Lipoic acid, and things that work at a cellular level, etc and antioxidants. There are some interesting look products but it is a matter of budget Lots of greens (roughage), Highly coloured fruit and veg, fish varies but including oily, mixed ground herbs and spices, nuts in moderation and what ever else you feel happy with preferable from whole food.
Whey protein has been shown to be benificial and is a good source of protein, branched chain aminos etc which sports people and body builders use, can be added to juiced vegetables (addback some of waste as fibre and to get additional benifit).
My latest "discovery" is sea weed which is actually delicious, and should be theory be a good source of micro minerals etc. It comes as herbs, spagetti shaped, chopped into powder, flat sheets it is delicious as an extra vegetable in a casserole, different flavours and textures. This is a UK site but there must be vendors all over the place.
http://www.seaveg.co.uk/ And lots of interesting ideas for those who enjoy experimenting with food.
There are lots of books on diet - The Omega Diet - Cracking the Metabolic Code - The Zone Inflamation Diet - Dr Gaynors Cancer Prevention Program are ones that stuck in my mind.
My impression is that it is important not to get too hung up on a particular food source as many have not been investigated yet becuase they are no sufficiently "sexy" to market e.g. cabbage. Button mushrooms show aromatase inhibition for example. My intuition is that variety is important too.
Again please do discuss significant dietary changes particular supplements with your onc.
If you want to go armed with trials or check things for yourself this is a useful resource.
http://www.ncbi.nih.gov/
You will find a surpring number of trials on omegas threes DHA etc 14,000 plus, and some of them double blind. Many say this could be signficant and helpful more reserch required but it seems to stop there. I suppose no money to be made - no funding - human nature . Unless the research is BOTH and on a large enough scale AND based on body tissue samples as well as asking people waht they ate it is inherently unreliable. Many of the big trials are based on what did you eat and paying people to participate - unsurprisingly the results of these trial often contradict the more rigorous trials looking at tissue samples as well - the cry arises it makes no difference which if you are a drugs company with an investment of millions to intervene in the same pathways may be a welcome sound. Until governments get involved and fund some serious large scale research using tissue samples and relating them to outcomes not much will change. Cynical I'm afraid - but based on comments from students that they lied in paid dietary trials to remain on the trial - and observation of human nature, me included.
Finally if there is a lot you dont understand dont worry there is lots I don't understand and I have been reading about it for something like a year.
RB