Posted on 10/05/2010 9:52:19 AM PDT by decimon
EAST LANSING, Mich. — Fish oil - long encouraged by doctors as a supplement to support heart and joint health, among other benefits - induced severe colitis and colon cancer in mice in research led by Michigan State University and published this month in the journal Cancer Research.
Jenifer Fenton, a food science and human nutrition researcher at MSU, led the research that supports establishing a dose limit for docosahexaenoic acid (DHA), one of the omega-3 fatty acids present in fish oil, particularly in people suffering from chronic conditions such as inflammatory bowel diseases.
"We found that mice developed deadly, late-stage colon cancer when given high doses of fish oil," she said. "More importantly, with the increased inflammation, it only took four weeks for the tumors to develop."
Specifically, the research team found an increase in the severity of the cancer and an aggressive progression of the cancer in not only the mice receiving the highest doses of DHA but those receiving lower doses as well. The mice used in the study were prone to inflammatory-like bowel disease; inflammation is an important risk factor for many types of cancers, including colon cancer.
"Our findings support a growing body of literature implicating harmful effects of high doses of fish oil consumption in relation to certain diseases," Fenton said. "Currently, there is a call by academics and the food industry to establish dietary guidelines for omega-3 consumption. This is primarily motivated by the fact that most Americans are deficient in omega-3 fatty acids, and there is substantial evidence supporting the beneficial effects of the consumption."
The findings were surprising, specifically because DHA has been shown to have some anti-inflammatory properties, according to Fenton: "We hypothesized that feeding fish oil enriched with DHA to mice would decrease the cancer risk; we actually found the opposite. These mice were less equipped to mount a successful immune response to bacteria that increased colon tumors."
Fenton cautions people may not need to avoid fish oil; what the research shows is needed are guidelines on dosing. With any nutrient, there is a "bell curve" effect. On the left of the curve are those deficient in a nutrient; on the right are those in excess.
She said people already receiving enough omega-3 fatty acids through their normal diet and foods have no need for added supplementation.
"With fish oil, we don't yet know how much is appropriate," said Fenton, also a researcher with the Michigan Agricultural Experiment Station. "There are many examples of taking supplements, nutrients or chemicals in excess that can promote cancer (for example, beta-carotene supplementation in smokers). Supplementation is most useful when the person taking them is deficient in that specific nutrient."
The research team's findings could have an important preventive health impact, specifically in light of the high rates of colon cancer in the United States. Individuals with inflammatory bowel disease have an increased risk of developing colon cancer, and when the cancer metastasizes it can be fatal.
The next step, Fenton said, is to test omega-3 fatty acid levels in people with inflammatory bowel disease. To that end, she is continuing to build relationships - via MSU's College of Osteopathic Medicine campus in Macomb County - with gastrointestinal specialists to develop a cohort of patients.
"To help develop guidelines, we need to see how these findings correlate to human populations," she said.
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Michigan State University has been advancing knowledge and transforming lives through innovative teaching, research and outreach for more than 150 years. MSU is known internationally as a major public university with global reach and extraordinary impact. Its 17 degree-granting colleges attract scholars worldwide who are interested in combining education with practical problem solving.
Don’t stop unless she is a mermaid.
That and their intelligence enhanced lab mice friends may plot an elaborate and brilliantly maniacal revenge upon you.
Sleeper.
Eat twinkies.
Smoke stoggies.
P*ss on Bloomberg.
As is commonly recommended, when taking fish oil supplements, they should be coupled with supplements of Vitamin D3 and natural source, mixed isomer E. This provides antioxidant and anticancer protection.
“Balancing the scales ping”
Good pun!
“Balancing the scales ping”
Good pun!
Hmmm! Fish oil helps my ADD son focus. But, according to this expert, he is already getting enough of what he needs, so I should just drop this and say, “But, the expert said....”
Except our food doesn’t contain as much omega-3’s as it used to. We can’t produce it, so we get it from our food. Our food (animals) used to get omega-3’s from eating grass. Now most animals are fed corn and soy. No more omega-3’s!
Could there be some other component of fish oil, such as high levels of mercury, that could be the culprit?
Omega-3 supplements, free of all of the other components of fish oil, might be perfectly OK taken at any level.
This article certainly doesn't make anything clear.
Interesting. I tried to start taking Cod Liver Oil and then just plain fish oil capsules for their medicinal benefit but my body just can’t tolerate either.
I can take just a tablespoon of Cod Liver Oil or two capsules in the morning and have terrible indigestion for the entire day.
NOTHING gives me indigestion except fish oil.
Dayum! That was the last thing I dared to eat.
Eggs have cholesterol, can’t eat red meat, vegetables have salmonella or been sprayed with something, colonel Sanders is mean to chickens and they are raised/killed inhumanely, I’m durn near skin an bones now. I’m convinced that anyone who eats food is going to die one day.
Is it purified? Or has it just been squeezed from a mercury-laden fish?
If fish oil has a fishy smell or burp-back taste, it probably is not purified.
Have they done any studies on mercury poisoning in mice?
Also, there are many ingredients in a fish oil, and there are many different types of fish who supply that oil.
My guess is that some pharmaceutical company funded the study, because they make loads of money on cholesterol medication and Omega 3's are giving them a run for there money.
I've been eating food my entire life and haven't died even once.
This means that the mice already had a disease that made them susceptible to colon cancer. Even if correct, the application of this finding from mice to people cannot be assured, especially those without a chronic inflammatory condition like IBD. As a practical remedy for any concern, I would take Vitamin D3 and mixed isomer E supplements along with fish oil.
Had they used a plant-based Omega3 item, the results might have been totally different. Like flax seeds.
I give my dog 3000mg of fishoil a day for her skin allergies. She loves them; eats them right out of my hand like a treat. After reading this, I hope I’m not doing more harm than good. I’d hate to give her colon cancer.
I already had part of my colon removed to make room for the inflamed parts, so a little fish oil shouldn’t make any difference.
Are omega-3 and DHA the same thing? Maybe that’s my confusion with the results.
I’ve heard that large quantities of bacon have been shown to counteract the effects of fish oil.
Mice eat fish?...Who knew
Sometimes an animal test subject might not be a true human analog... like using dogs as a test subject for human and chocolate....not going to end well
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