Right now many health-conscious men are consuming incredibly amounts of Arachidonic Acid (AA) in their diet. The reason for this is primarily the rise of the Atkins and Low Carb Diets: it is now popular to consume significants amounts of chicken and turkey in the belief that this natural living and a "Paleo lifestyle" that mimics what mankind has done for millenia before our Western, industrial lifestyles. However, what most of these men do not realize is that modern poultry is unnaturally high in Arachidonic Acid, significantly higher than beef actually. (Farm raised salmon is as well, because they corn feed the salmon!)
Furthermore, many men also consume multiple whole eggs per day, not realizing that an egg yolk is higher still in AA. Some men now are also taking Arachidonic Acid supplements in order to build muscle! (You can build lots of muscle without any AA: see my link on Safe Muscle Building.)
So what's wrong with consuming all this extra arachidonic acid? In a word: inflammation. Arachadonic Acid has been shown in many studies to increase systemic inflammation, the kind that is so deadly. Hopefully, you have read enough to know that Inflammation is the Root of All Evil.
NOTE: Arachidonic Acid is both necessary and essential. Again, it is TOO MUCH dietary AA that causes problems.
Yes, some inflammation is good and helps you to fight infections. And, yes, some inflammation is necessary to build muscle. But the problem is that
a) Modern grain fed animals are unnaturally high in AA.
b) Our modern, Western lifestyle raises inflammation levels, through. low omega-3's, refined carbs, etc.
The key thing is that researchers have implicated chronically raised inflammation as a root cause in almost everything you fear: heart disease, autoimmune disease (arthritis, diabetes, Crohn's, etc.), many cancers and, yes, erectile dysfunction. For example, in heart disease one of your body's inflammatory molecules, TNF alpha, plays a key role in fighting damage to your arterial wall and does so by triggering the plaque building process that advances arteriosclerosis and hardens your arteries. (See my link on TNF Alpha Inhibitors for some additional information.)
The concerns over the dangers of arachidonic acid started with Dr. Barry Sears. If you'll recall from his famous Sears dietary plan, he brought to the public's attention the research that showed how diet can greatly influence inflammation. If you read his blog, he states "It has been known for nearly 20 years that Statins are the only drug that increase the levels of arachidonic acid (AA) by stimulating the enzyme delta 5-desaturase (2-4). This means greater cellular inflammation that leads to insulin resistance (thus increasing diabetes) and disturbances in signaling mechanisms in nerve cells (thus decreasing memory)." 
And Dr. Sears was certainly not the only one: Dr. David Chilton documented his success in clinical practice by attacking inflammation in his bestseller Inflammation Nation. One of the pillars of his program was lowering dietary arachidonic acid.
And it's not just a few doctors stating this. One study on rheumatoid arthritis patients found that participants were helped by fish oil along with lowering arachidonic acid.  The authors made it clear that "a diet low in arachidonic acid ameliorates clinical signs of inflammation in patients with RA and augments the beneficial effect of fish oil supplementation." In other words, lowering AA helps omega-3's. This is an important point as you'll see below.
What is the controversy about then? Well, it goes back to a well-known Paleo blog that cites a study where the researchers concluded that "Taken together with the studies on blood lipids, platelet reactivity and bleeding time, including this latest study, it seems appropriate to conclude that a signiï¬cant increase in arachidonic acid intake by healthy adults, up to an intake of, say, 1Â·5 g/d appears unlikely to have any adverse effect." 
Now this is a very curious conclusion to me. The author actually cites several studies that supposedly show that AA exhibits no real dangers. Yet notice what one of the cited studies says in its summary:
"The mechanisms for these potential beneï¬ts are complex and not well deï¬ned. It is well established that ï¬sh oil supplementation lowers plasma triglyceride levels, and more recent work demonstrates anti-inï¬‚ammatory effects, including reduced circulating levels of inï¬‚ammatory cytokines and arachidonic acid-derived eicosanoids, and elevated plasma adiponectin." 
In other words, fish oil works by dampening the effects of arachidonic acid, which are clearly pro-inflammatory. And the conclusion of this Paleo author, by the way, was basically that if you consumed enough fish oil, you were safe.
Personally, I think this is premature and risky. And I am not just saying that because of doctors such as Sears and Chilton along with the rheumatoid arthritis study. Many studies recognize the fact that arachidonic acid is a pro-inflammatory compound. Here are just a few:
"Arachidonic-acid-derived eicosanoids modulate the production of pro-inflammatory and immunoregulatory cytokines. Overproduction of these cytokines is associated with both septic shock and chronic inflammatory diseases. The n-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid, which are found in fish oils, suppress the production of arachidonic-acid-derived eicosanoids and EPA is a substrate for the synthesis of an alternative family of eicosanoids" 
"The cytotoxic Enterotoxin of Aeromonas hydrophila induces proinflammatory cytokine production and activates arachidonic acid metabolism in macrophages". 
The bottom line is that, if you read the research at all, you quickly come to the conclusion that AA increases inflammation and fish oil (omega-3's) dampen its effects. So are you going to eat a bunch of arachidonic acid just to prove that fish oil can save your life as the Paleo sites suggest?
This just not seem logical. It seems clear that if you want to decrease inflammation, you must simply increase omega-3's and lower arachidoic acid. And this is exactly what the above doctors are stating works in real life.
In fact, did you know that the ibuprofen, Advil, Alleve and other NSAIDs are merely nullifying the actions of arachidonic acid in your body? That's right - when arachidonic acid is released from membranes in your body, it triggers the COX enzyme which ramps up inflammation. All these NSAIDs do is inhibit this COX enzyme, thus lowering your body's inflammatory response and reaction to AA.
Lets cover just a few facts regarding AA::
1) Men can put on lots of muscle without eating any extra poultry, egg yolks or AA supplements. Many vegetarian and vegan bodybuilders are examples of this with huge physiques and yet consuming very little extra arachidonic acid in their diet.
2) The research on any dangers of arachidonic acid are still in the early stages. We simply do not all that we should about this complex subject.
3) We do know that in many cases Arachidonic Acid will significantly raise inflammation levels.
4) We know elevated inflammation is a huge risk factor for heart disease, autoimmune disease, cancer and erectile dysfunction.
Now, if you put 1 through 4 together, the answer is clear in my mind: play it safe and avoid much extra arachidonic acid. It is simply too dangerous at this time and just not worth the small muscle gains that you might get from consuming it. Seriously, are you going to risk blowing out your arteries or getting Crohn's or arthritis or cancer just to put on 42 pounds of muscle instead of 40?
Let me tell you what makes sense: put on 40 pounds of muscle and keep those arteries nice and clean and low in inflammation so you can do well in the bedroom. No woman is going to care about those extra two pounds of muscle, but she WILL care if you cannot get an erection because you have advanced arteriosclerosis and hardening of the arteries.
Yes, in twenty years, they may have figured out ways that you can consume AA without raising inflammation. Maybe if you exercise enough, you will not be harmed. Maybe if you consume enough fish oil and omega-3s you will be safe. In the meantime, why risk life and limb for very low benefits?.
2) RHEUMATOLOGY INTERNATIONAL, 2003, 23(10):27-36, "Anti-inflammatory effects of a low arachidonic acid diet and fish oil in patients with rheumatoid arthritis"
3) British Journal of Nutrition, Sep 2007, 98(03), "Dietary arachidonic acid: harmful, harmless or helpful?"
4) Ann Nutr Metab 1997;41:203â€“234, "n-3 Polyunsaturated Fatty Acids and Cytokine Production in Health and Disease"
5) Infect. Immun, May 2000, 68(5):2808-2818, "The Cytotoxic Enterotoxin of Aeromonas hydrophila Induces Proinflammatory Cytokine Production and Activates Arachidonic Acid Metabolism in Macrophages"
6) Cardiovasc Res, 2009 Oct 1, 84(1):33-41. Epub 2009 May 27. "omega-3 polyunsaturated fatty acid supplementation for the treatment of heart failure: mechanisms and clinical potential"