FISHY FISH OIL STUDIES
Something is fishy about the recent headlines claiming omega-3 fish oil is ineffective in reducing mortality from cardiovascular disease. Regardless of the actual content of the medical journal reports, the public reads and hears the headlines only, and they are negative. The news reports emanated from a pooled analysis of 89 studies involving fish oil and heart disease. Here are some of the headlines:
* Fish oil may not be so healthy after all- Daily Mail UK
* Doubts cast on oily fish benefits- BBC News
* Wonder ingredient not the good oil once touted- Weekend Australian
The news reports went on to say:
“Scientists have found little evidence that oily fish is good for your health.”
“Scientists who reviewed 89 studies of Omega 3 fats found no clear evidence that they are of any use at all.”
Up until 2003 studies showed a clear preventive effect for omega-3 fish oil in mortality reduction from cardiovascular disease. Then in 2003 the DART-2 trial was published which skewed all the pooled statistics in another direction. These statistics should have never been combined with other studies because the DART-2 trial dealt only with men with stable angina. The advertised cardiac mortality difference between males with angina who consumed fish oil and those who did not was a relative +26%, but in hard numbers it was only +2.5%. [European Journal Clinical Nutrition 57: 193-200, 2003]
Angina (chest pain) can originate from coronary artery injury and is significantly reduced by administration of high-dose oral vitamin C, which has been demonstrated in both animal and human studies. [Coronary Artery Disease 15: 21-30, 2004; American Journal Cardiology 87:1154-9, 2001] Low vitamin C levels are associated with angina. [Journal Cardiovascular Risk 3: 373-77, 1996] The males in the DART-2 trial were strongly non-compliant in regards to advice to consume more fruit, which would be rich in vitamin C. Therefore, fish oil may have been inappropriately selected to reduce mortality among angina patients. The fact males with angina ignore advice to eat foods rich in vitamin C is sufficient evidence that vitamin C deficiency is a behavioral/nutritional disorder.
Furthermore, among the 89 pooled studies, 44 involved supplemental omega-3 oils. Others involved dietary intake. Only 8 of these studies were large (greater than 500 subjects). So the results of one large study, like DART-2 (3000+), skewed the pooled results. Some studies involved daily intake of omega-3 oils as low as 400 milligrams, and one study 7000 milligrams. But when the all the participants in these studies were divided into four groups of varying intake of omega-3 oils, the lowest intake group only consumed ~100 milligrams per day and the highest group ~600 milligrams per day. Essentially, all four groups, on average, consumed very low amounts of omega-3 oils! [British Medical Journal, Online First March 24, 2006] The small difference between these groups would hardly be expected to show much difference in mortality.
By the way, where were the news reporters when researchers in Germany reported in the April issue of Critical Care Medicine that omega-3 fish oils, given in hefty doses (7000+ milligrams for a 160-pound/70kilo adult) to hospitalized critical care patients for about 9 days, lowered mortality rates from 18.9% to 12.0% ( 37% reduction)! Fish oil also reduced length of hospital stay and need for antibiotics. [Critical Care Medicine 34: 972-79, 2006] Fish oil saves lives!