Health for life

Consumption of fatty fish and fish-oil supplements linked to 71 percent higher risk

A second large, prospective study by scientists at Fred Hutchinson Cancer Research Center has confirmed the link between high blood concentrations of omega-3 fatty acids and an increased risk of prostate cancer.

Published July 11 in the online edition of the Journal of the National Cancer Institute, the latest findings indicate that high concentrations of EPA, DPA and DHA – the three anti-inflammatory and metabolically related fatty acids derived from fatty fish and fish-oil supplements – are associated with a 71 percent increased risk of high-grade prostate cancer. The study also found a 44 percent increase in the risk of low-grade prostate cancer and an overall 43 percent increase in risk for all prostate cancers.

The increase in risk for high-grade prostate cancer is important because those tumors are more likely to be fatal.

The findings confirm a 2011 study published by the same Fred Hutch scientific team that reported a similar link between high blood concentrations of DHA and a more than doubling of the risk for developing high-grade prostate cancer. The latest study also confirms results from a large European study.

"The consistency of these findings suggests that these fatty acids are involved in prostate tumorigenesis and recommendations to increase long-chain omega-3 fatty acid intake, in particular through supplementation, should consider its potential risks," the authors wrote.

"Weve shown once again that use of nutritional supplements may be harmful," said Alan Kristal, Dr.P.H., the papers senior author and member of the Fred Hutch Public Health Sciences Division. Kristal also noted a recent analysis published in the Journal of the American Medical Association that questioned the benefit of omega-3 supplementation for cardiovascular diseases. The analysis, which combined the data from 20 studies, found no reduction in all-cause mortality, heart attacks or strokes.

"Whats important is that we have been able to replicate our findings from 2011 and we have confirmed that marine omega-3 fatty acids play a role in prostate cancer occurrence," said corresponding author Theodore Brasky, Ph.D., a research assistant professor at The Ohio State University Comprehensive Cancer Center who was a postdoctoral trainee at Fred Hutch when the research was conducted. "Its important to note, however, that these results do not address the question of whether omega-3s play a detrimental role in prostate cancer prognosis," he said.

Kristal said the findings in both Fred Hutch studies were surprising because omega-3 fatty acids are believed to have a host of positive health effects based on their anti-inflammatory properties. Inflammation plays a role in the development and growth of many cancers.


It is unclear from this study why high levels of omega-3 fatty acids would increase prostate cancer risk, according to the authors, however the replication of this finding in two large studies indicates the need for further research into possible mechanisms. One potentially harmful effect of omega-3 fatty acids is their conversion into compounds that can cause damage to cells and DNA, and their role in immunosuppression. Whether these effects impact cancer risk is not known.

The difference in blood concentrations of omega-3 fatty acids between the lowest and highest risk groups was about 2.5 percentage points (3.2 percent vs. 5.7 percent), which is somewhat larger than the effect of eating salmon twice a week, Kristal said.

The current study analyzed data and specimens collected from men who participated in the Selenium and Vitamin E Cancer Prevention Trial (SELECT), a large randomized, placebo-controlled trial to test whether selenium and vitamin E, either alone or combined, reduced prostate cancer risk. That study showed no benefit from selenium intake and an increase in prostate cancers in men who took vitamin E.

The group included in the this analysis consisted of 834 men who had been diagnosed with incident, primary prostate cancers (156 were high-grade cancer) along with a comparison group of 1,393 men selected randomly from the 35,500 participants in SELECT.

You’ve probably seen “a good source of omega 3′s” imprinted on various boxes and bags around the super market and wondered “what are omega 3′s and why should I give a damn?

Omega-3 fatty acids are considered essential fatty acids: Omega 3′s come from a family of unsaturated fatty acids.  Even the healthiest diets need a moderate amount of healthy fats, and omega 3′s are crucial to healthy, sustainable living.  They’re considered “essential” fats – Essential fats are so defined as they are vital for, but cannot be made by, the human body. Only plants can make the vital omega 3 and 6 parent fatty acids, human enzymes can then convert these to other fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) which are building blocks of the brain and nervous system. 

Omega 3 Source

 They are needed for the integrity of every cell membrane in the body so particulalry important for the health of vital organs such as the heart and brain.They are necessary for human health but the body can t make them -- you have to get them through food. Omega-3 fatty acids can be found in fish, such as salmon, tuna, and halibut, other seafood including algae and krill and there are plenty of vegan sources of Omega 3′s including spirulina (algae), nuts, flax, and vegetables. Vegan sources of omega-3s include canola oil, broccoli, cantaloupe, kidney beans, spinach, grape leaves, Chinese cabbage, cauliflower, spirulina, and walnuts.

Research shows that omega-3 fatty acids reduce inflammation and may help reduce the risk of chronic diseases such as heart disease, cancer and arthritis.The omega 3 parent fatty acid is called alpha linolenic acid (LNA or ALA) and comes from vegan seeds such as flax, hemp and pumpkin, from nuts such as walnuts, and to a lesser extent from soya and green vegetables. 

Through a series of enzyme-controlled reactions the human body converts this LNA into a number of vital fatty acids including EPA and DHA. Among their many roles EPA is needed for brain function, concentration, and vision, and is also converted into a powerful anti-inflammatory agent. DHA is needed as a building material , particularly for brain structure and so is especially important in pregnancy for the baby’s brain and nervous system development, infants who do not get enough omega-3 fatty acids from their mothers during pregnancy are at risk for developing vision problems and nerve damage.



Additionally, the benefits of omega-3s include reducing the risk of heart disease and stroke while helping to reduce symptoms of hypertension, depression, attention deficit hyperactivity disorder (ADHD), joint pain and other rheumatoid problems, as well as certain skin ailments. Some research has even shown that omega-3s can boost the immune system and help protect us from an array of illnesses including Alzheimer’s disease.

Fish contain unsaturated fatty acids, which, when substituted for saturated fatty acids such as those in meat, may lower your cholesterol. But the main beneficial nutrient appears to be omega-3 fatty acids in fatty fish. Omega-3 fatty acids are a type of unsaturated fatty acid thats thought to reduce inflammation throughout the body. Inflammation in the body can damage your blood vessels and lead to heart disease.

Omega-3 fatty acids may decrease triglycerides, lower blood pressure, reduce blood clotting, boost immunity and improve arthritis symptoms, and in children may improve learning ability. Eating one to two servings a week of fish, particularly fish thats rich in omega-3 fatty acids, appears to reduce the risk of heart disease, particularly sudden cardiac death.

Alzheimers
Polyunsaturated fatty acids found in many fish may prevent damage to brain cells. Eating fish can also reduce the risk of high blood pressure, which is linked with dementia. A French study of 2000 people showed that those who ate seafood at least once a week had a significantly lower risk of dementia over a seven-year period than those who didnt.

Dementia - elderly people who eat fish or seafood at least once a week may have a lower risk of developing dementia, including Alzheimers disease.

Cardiovascular disease - eating fish every week reduces the risk of heart disease and stroke by reducing blood clots and inflammation, improving blood vessel elasticity, lowering blood pressure, lowering blood fats and boosting good cholesterol.

Cancer - the omega 3 fatty acids in fish may reduce the risk of many types of cancers by 30 to 50 per cent, especially of the oral cavity, oesophagus, colon, breast, ovary and prostate.

Asthma - children who eat fish may be less likely to develop asthma.    

Just how do omega-3s perform so many health “miracles” in people? One way, experts say, is by encouraging the production of body chemicals that help control inflammation — in the joints, the bloodstream, and the tissues

But even as important is their ability to reduce the negative impact of yet another essential type of fatty acid known as omega-6s. Found in foods such as eggs, poultry, cereals, vegetable oils, baked goods, and margarine, omega-6s are also considered essential. They support skin health, lower cholesterol, and help make our blood “sticky” so it is able to clot. But when omega-6s aren’t balanced with sufficient amounts of omega-3s, problems can ensue.  In general, Americans eat too much Omega 6 and not enough Omega 3.
You can replace some omega-6s from cooking oils with a third fatty acid known as omega-9 (oleonic acid). This is a monounsaturated fat found primarily in olive oil.

If you think you can get all of your omega 3′s only through fish oil supplements?  Think again.  There are other healthy components of whole foods containing Omega 3′s that make it better for your body and soul – flax, for example, is heavy in fiber which helps lower cholesterol, regulate blood sugars, and improve digestion. 
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If you have diabetes, including more omega-3s in your diabetic meal planner can reduce your risk of certain diabetic complications, as well as:

• Decrease insulin resistance
• Improve mood and lower rates of depression
• Improve symptoms of inflammatory diseases, like asthma and lupus
• Reduce apoproteins, cholesterol and triglyceride levels
• Reduce risk of heart attack
• Reduce risk of macular degeneration
• Reduce risk of some types of cancer
• Reduce risk of stroke.

So just add some Omega 3′s to your diet today!