Fish oil reduces age-related blindness

October 14, 2009

New U.S. study shows that intake of fish oil may reduce the incidence of age-related blindness by 30%

There seems to be no end to blessings from fish oil.

Fish oil is the end stages in the development of omega-3 fatty acids which is transformed from alpha-linolenic acid in a number of processes to E.g. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) which then are converted to prostaglandin E 3 with a wide range of health-promoting properties.

The fish oils EPA and DHA are some of the strongest anti-inflammatory nutrients, we can consume. This is probably one of the reasons why they reduce the risk of blood clots, but they also reduces blood triglycerides, reduces inflammation in rheumatic diseases, enhances children’s learning capacity, reduces the risk of pre-eclampsia (pregnancy–induced high blood pressure) and premature birth, and gives brighter children from pregnant women who took fish oil and much more.

It is indeed difficult to see the end of the health-promoting properties, we can get from fish oil, and new scientific findings seems to emerge all the time which support its use.

Thus, even last week when researchers from the National Eye Institute in Bethesda, MD, USA, 7 October published a study in the American Journal of Clinical Nutrition.
Scientists have over 12 years studied 1,837 people with moderate to severe risk of age-related central blindness in the form of central atrophy or macular degeneration.

For both types of blindness, it appeared that the incidence was 30% lower in the group that took the most fish oil (0.11% of total caloric intake) compared with the group that took the least.

Although previous studies have been uncertain in its conclusions, the authors believe that the figures can be generalized, this is both a cheap and readily available intervention opportunity against risk families with high incidence of these diseases.

In times when the collective consensus have shouted in our ears that we should eat less fat, it is important to use common sense, read the research properly and stand firm.

Fat is healthy, and fat is vital!

One should obviously not wallow in margarine, french fries and chips, but make sure to eat well from the healthy fats as olive oil and especially fish oil.

It can be ingested as a liquid, as capsules, or as very attractive food.

Fish is not only healthy but also tastes very good indeed. Many people are nevertheless troubled by the increasing presence of heavy metals in fish, but if you avoid the large predatory fish as swordfish and tuna, there is significantly less in for example salmon and trout, especially if they are caught in clean rivers and lakes.

There are however problems with farmed fish, which often contains pretty much omega-6 fat, due to the fish feed composition. And this we should avoid. We already get far too much omega-6, especially linoleic acid, found in the cheap cooking oils with corn and sunflower oil, so as to avoid further bias, we must select the oily fish that are caught in the wild and not farmed.

We must remind you that in a previous newsletter we described two studies that showed that even eggs contain substances that prevent the age-related central blindness, so it may be, we soon will see a Danish ban against bread with eggs and herring. In Denmark food is not allowed to prevent a disease!

Enjoy your meal.

By: Claus Hancke, MD 

References:
• Sangiovanni JP, Agron E, et al. Omega-3 Long-chain polyunsaturated fatty acid intake and 12-y incidence of neovascular age-related macular degeneration and central geographic atrophy: a prospective cohort study from the Age-Related Eye Disease Study, Am J Clin Nutr, 2009 Oct 7 (E-pub. Ahead of print)
• Mares JA, Larowe TL, et al. Predictors of optical density of lutein and zeaxanthin in retinas of older women in the Carotenoids in Age-Related Eye Disease Study, an ancillary study of the Women’s Health Initiative. Am J Clin Nutr., 2006, 84(5): 1107-1122.
• Wenzel AJ, Gerweck C, et al. A 12-wk egg intervention increases serum zeaxanthin and macular pigment optical density in women. J Nutr., 2006; 136(10):2568-73.

Fish oil is good for the heart and the brain

August 21, 2006

There is no doubt that fish oil is good for the heart. This has been shown by a new extensive survey on the subject. But no one knows how much is ideal.

The scientific interest for fish oil is enormous. Since September of last year, almost 800 articles about fish oil have been publicised in established journals.

This is with very good reason. Notably, fish oil contains two types of fatty acid, both of which are attributed with having a positive effect against many serious chronic diseases. If this is even in part true, it should be considered very imprudent not to receive fish oil every day. The primary disease that it is believed to prevent is cardiovascular disease, but there is also good reason to believe that fish oil works against, for example, depression, dementia, arthritis, and diabetes, even though there is no concrete evidence as of yet in these areas.

The two fatty acids are called EPA (eicosapentic acid) and DHA (docosahexa-enoic acid). Together they compose one third of the contents of fish oil and two thirds of the concentrated fish oil products, which can be found in capsule form.

Much attention has been given to DHA which, contrary to EPA, is found in large amounts in the brain (14% of the cerebral cortex’s fat content) and in even greater amounts in the retina (22%). Breast fed children have much higher concentrations of DHA in their brains than bottle fed children (babies cannot produce DHA themselves). It is hard to believe that there are no consequences of receive too little.

There are an incredible number of adults who take supplements of fish oil daily to maintain their cardiac health.

But does it work?

Six months ago a group of English researchers maintained that it does not. They had looked at all of the relevant studies and then calculated the averages of their results. In their opinion, the results showed that fish oil neither protects the heart nor lengthens life span. This is just the opposite of what was previously believed.

This meta-analysis was strongly criticized and, as discussed in another of The Danish Vitality Council’s newsletters (“Fish Oil – Still indispensible”) there were so many question raised by the analysis that it lacked credibility.

Doubts regarding the dosage
This is now supported by a summary article from the distinguished American Journal of Clinical Nutrition. According to the head authors, a group of researchers undertook an extensive survey, taking “a large step forward” in spreading light into the darkness. There is no longer much doubt that fish oil reduces the overall risk of premature death and the risk of death due to a blood clot in the heart, and that it possibly reduces the risk of stroke.

Completing this survey was an extensive project. The researchers first read summaries of 8,039 scientific articles. They then picked 842 relevant articles from these to be read in their entirety. 46 articles of these 842 met the strict quality requirements and were studied further. The researches requirements regarded the length of the studies (at least one year), the dose of the fish oil given, and proper documentation.

How big are the advantages and how much fish oil should one take? This actually cannot be answered with certainty! The studies surveyed were too different regarding the dose given, the type of participants, the time taken, and so on to answer such questions. It is simply bad form to establish any averages, as the English researchers did. But if one wants to draw conclusions anyway, it is safe to guess that the overall risk of premature death and the risk of death due to cardiac disease can be reduced by 15-20% or more.

It is however nearly certain that fish oil helps those who have had a blood clot in the heart and wish to avoid another. But what about the dose, how much should one take?

Until more information surfaces, we should rely on the American Heart Association’s recommendations, which are based on estimates. Heart patients should receive 1 gr. EPA + DHA daily. This is the equivalent of about two large capsules of 1 gr. concentrated fish oil. Everyone else should receive at least half this amount. This can be achieved by eating fatty fish for dinner 1-2 times weekly.

There is a lot of knowledge lying in wait, not just about fish oil and the heart. More results will surface in the next year. While we wait we wait in the knowledge that it is important to get enough.

By: Vitality Council

References:
1. Wang C et al. n-3 fatty acids from fish or fish-oil supplements, but not á-linolenic acid, benefit cardiovascular disease outcome in primary- and secondary-prevention studies: A systematic review. Am J Clin Nutr 2006;84:5-17.
2. Deckelbaum R et al. n-3 fatty acids and cardiovascular disease: navigating toward recommendations. Am J Clin Nutr 2006;84:1-2.
3. Distribution, interconversion, and dose response of n-3 fatty acids in humans. Am J Clin Nutr 2006;83(suppl):1467S-76S.

www.ajcn.org

Fish Oil – Still Indispensible!

April 7, 2006

A British study claims that fishoil does not protect the heart. Formally, it is founded on the sum of all earlier studies. In reality it relies on only one, where the participants of the study probably cheated.

As time goes by, studies of all sorts of things pile up. At some point no one can keep track of them. Even people with a good memory remember only the studies they like. This calls for a meta-analysis – a calculation of a sort of average of what all reliable studies have shown.

This has now happened in a British study of fish oil. Does fish oil protect the heart? Does it prolong life? Yes, we know that it does!

At least, so we think. According to the new meta-analysis fish oil has “no clear effect on mortality, risk of heart attack or the incidence of cancer” – rest assured, you do not need to eat fish!

As far as cancer goes, one is hardly surprised, but what about the heart? Ever since the two Danish doctors’, Bang and Dyerberg’s, studies on Greenland 35 years ago, everyone has known that fish oil protects the heart. This is confirmed by numerous studies. How can all these studies amount to a big fat zero when summarized?

Of course they cannot. A meta-analysis can be just as subjective as everything else. This means that others, with the same starting point can arrive at the opposite result. This is the case in a new, far more comprehensive, American report. There is no doubt that fish oil is beneficial for the heart. In fact, it is stated in this report that everyone should be tested to see if they get enough of it. The two important fatty acids in fish oil, DHA and EPA, have “clear beneficial effects”. Everyone should ingest at least 1.5 grams of fish oil every day, in case of heart disease, double that. This will lessen the risk of dying from heart disease by 25 %.

That was the Americans. They thoroughly reviewed the extensive biochemical knowledge and conclusions from animal and human studies. From this they made a general conclusion. What did the British do?

The Test Subjects Cheated
They completely ignored all basic knowledge and concentrated on the incidence of heart disease and mortality in humans. But were they neutral?

They reviewed a total of 48 randomized studies. But they did something strange: Only fifteen of the studies were included in the mortality calculations. Why the remaining 33 studies were not included is not known. Maybe some were excluded because of suspicion of being biased. But, in nine of the fifteen studies included, there was “medium or high” risk of bias. For example because the test subjects knew whether they were given fish oil, or, because of the draw, were given something ineffective.

On top of this, an unknown number of the 48 studies were not even with fish oil but with alpha-linoic acid – which is found in flaxseed oil and in rape oil. These oils can be converted to “fish oil” in the human body.

Besides, the most famous study of linoleic acid is missing – the so-called Lyon experiment where rape oil (and a Mediterranean diet with olive oil) lowered the mortality in patients who had had a coronary thrombosis by 73 %.

When everything is boiled down, twelve randomized studies with fish oil remain. But of these, nine are very small and without relevance. This leaves three. The biggest of these three studies, (GISSI) show a massive reduction in mortality in twenty percent of persons who had had a coronary thrombosis. In the table it only says fourteen percent, apparently because of a misunderstanding.

Only one of the larger studies (Burr et al 2003) came out with a negative result. Here the mortality increased by fifteen percent in men with sclerotic coronary arteries, when they were given fish oil.

However, this study is at the least controversial, partly because the participants knew if they were given fish oil or not. Since they had a dangerous heart disease, many of them would have been tempted to take supplements on their own. This could have been checked through blood tests, but only a spot test was taken after six months. After this the study continued for three to nine years. The spot test showed that the difference between the two groups was remarkably small. Moreover, the participants explained that even if they were not in the group given fish oil, they ate so much fat fish (14 grams a day) that this alone would have provided them with the amount recommended in the American report. So, in fact, both groups received “enough”, and the value of this study must be questioned.

Still, it was printed in the news paper. However, you should believe the American report.

Fish is good – of course!

By: Vitality Council

References:
1. Hooper et al. Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: Systematic review. BMJ online 24.3.06: BMJ, doi:10.1136/bmj.38755.366331.2F
2. Wang C et al. Agency for Health Care Research and Quality. US Department of Health Care Rsearch and Human Services. www.abrq.gov . Evidence report/technology assessment Number 94. Effects of omega -3 fatty acids on cardiovascular disease. March 2004.
3. Burr ML, Ashfield-Watt PA, Dustan FD, . , et al.: Lack of benefit of dietary advice to men with angina: results of a controlled trial. Eur J Clin Nutr 2003, 57: 193-200.

bmj.bmjjournals.com
www.ahrq.gov
www.nature.com/ejcn/index.html

Children Get Smarter From Taking Fish Oil

October 24, 2005

The omega-3 fatty acid DHA in fish oil is an important building block for the brain. DHA deficiency in the first years of life may impact the normal development of the child’s brain.

Are children getting smarter from eating fish? Recent studies suggest that fatty acids in fish oil can help certain children with ADHD or dyslexia. But what about infants?

By: Vitality Council

Reference:
Mc Cann J C, Ames, Bruce N. Is docosahexaenoic acid, an n-3 long chain polyunsaturated fatty acid, required for development of normal brain function? An overview of evidence from cognitive and behavioural tests in humans and animals. Am J Clin Nutr 2005;82:281-95

www.ajcn.org
www.iom.dk

Fish Oil Prevents Stroke

April 25, 2005

Many believe that fish oil protects against stroke, but French researchers have now discovered how this works. Fish oil helps the brain to better cope with a reduced blood supply.

Fish oil must be close to being the world’s best medicine. If you get fatty fish two to three times a week, you protect yourself against suddenly suffering cardiac arrest. The risk is halved. But also the risk of a blood clot in the brain – by far the most frequent cause of so-called cerebral hemorrhage – and thus suffering a stroke, decreases. According to the largest, but not final study, so far, it is reduced by 40%.

It is consistent with animal research. Mice that are artificially exposed to a blood clot in the brain get less extensive brain damage if they in advance are fed with fish oil. Now French scientists have proven a mechanism that might explain this phenomenon.

Scientists from France’s National Science Research Center, CNRS, are behind the discovery. They have shown that the protection of the brain cells is due to the effect of fish oil on the cell’s potassium channels.

…………………………

By: Vitality Council

References:
1. Heurteaux, C et al. TREK-1, a K(+) channel involved inneuroprotection and generaql anesthesia. EMBO J. 2004, E-pub 2004, June 03.
2. Lauritzen, I et al. Polyunsaturated fatty acids are potent neuroprotectors. EMBO J 2000;19:1784-93.
3. Ka He et al. Fish consumption and risk of stroke in men. JAMA 2002;288:3130-6.
4. Salachas, A., et al. Effects of low-dose fish oil concentrate on angina, exercise tolerance time, serum triglycerides, and platelet function. Angiology, Vol. 45, December 1994, pp. 1023-31.

embojournal.npgjournals.com
jama.ama-assn.org
www.springerlink.com
www.iom.dk

Decisive Agreement About Fish Oil Has Now Been Reached

January 10, 2005

For the first time, there is agreement about chronic lack of fish oil increasing the risk of coronary heart disease. An official American report sets a recommended intake for all adults.

It looks like there is now decisive agreement among experts that there is a connection between coronary heart disease and a chronic lack of the fatty acids in fish oil. This is the conclusion of a report published in Current Atherosclerosis Reports which was prepared at the request of the federal health authorities of the USA.

According to the report, the indications for a connection between a lack of fatty acids and death caused by coronary heart disease have become stronger year by year. It is the two N-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) that are significant. According to the report, DHA and EPA have “clear heart-protective effects.”

It also states that both national American and international experts now recommend larger intakes of N-3 fatty acids. The recommended daily intake is 450 mg. a day (EPA + DHA), but for persons with recognized coronary heart disease, the recommendation is 1000 mg. a day. This equals 1.5 g. of ordinary fish oil for healthy persons and 3 g. in case of heart disease, respectively; this is half the contents of a concentrated fish oil capsule.

The report underlines that according to both cellular- and animal tests, the N-3 fatty acids are capable of preventing irregular heartbeat and that this has now also been confirmed in tests on humans; this fact is also mentioned elsewhere on this site. In particular, the fatty acids can counteract the extremely common and often uncomfortable atrial fibrillation. All in all, the risk of death as a result of coronary heart disease is reduced by 25% when taking sufficient amounts of fish oil, as mentioned.

The strength of this evidence is now so comprehensive that the report encourages measuring people’s blood content of fatty acids just as measuring the blood pressure, checking the cholesterol, etc. is being done at present to estimate the risk of coronary heart disease. Likewise, it is now appreciated that it must become a national priority to see to it that everyone gets a sufficient intake of fish oil.

By: Vitality Council

Reference:
Harris WS. Are omega-3 fatty acids the most important nutritional modulators of coronary heart disease risk? Curr atheroscler Rep. 2004;6:447-52.

lansbury.bwh.harvard.edu/docosahexaenoic_acid_reviews_L.htm

Dangerous to Stop Taking Fish Oil!

September 8, 2004

Recent media reports have been saying that, according to a Danish study, fish oil does not prevent cardial arrythmia. Many have gotten the impression that fish oil does not at all benefit the heart. This is very wrong! Considering the many who take fish oil for the health of their heart, it is of utmost importance that this mistake be corrected, as it may be dangerous to stop supplementing with fish oil!

By: Vitality Council

References:
1) Albert C. Fish oil – an appetising alternative to anti-arrhytmic drugs? Lancet 2004;363:1412-3.
2) Schrepf, R et al. Immediate effects of n-3 fatty acid infusion on the induction of sustained ventricular tachycardia. Lancet 2004;363:1441-2.

www.lancet.com
www.iom.dk

Fish Oil is Effective Against Cardiac Arrest (Heart Failure)

July 7. 2004

With an interesting study doctors from the University Hospital of München have shown that fish oil may very likely prevent incidents of heart failure considerably.

According to the medical journal The Lancet, a German study can lead the way to using fish oil as a harmless and more savoury alternative to traditional heart medicine.

If cardiac atherosclerosis is the cause of death, then, in every other case, death occurs as unpremeditated cardiac arrest and the person affected will simply fall to the ground. In approximately every other one of these cases, the cardiac arrest is both the first and last symptom of the disease, and a blood clot is often the triggering factor.

In an interesting study, doctors of the Munich University Hospital have demonstrated that fish oil is supposedly to a very lage extent capable of preventing these cases of cardiac arrest. This took place in an experiment with ten patients suffering from heart problems who all had a high risk of dying of their disease and for that reason had had a defibrillator surgically implanted; this device is capable of re-vitalizing the heart if it stops.

The experiment was supposed to examine whether fish oil can protect against the rhythm disturbances that can lead to cardiac arrest and death. All ten patients were predisposed to attacks in which the heart beats with up to 200 beats per minute. This is very often a premonitory symptom of so-called ventricular fibrillation which is the cause of almost all cases of cardiac arrest. In ventricular fibrillation, the cardiac action is transformed into a very fast but weak tremble.

In the German study, the hazardous rhythm disturbances to which the patients were predisposed were stimulated with electrical impulses. As expected, provoking the attacks were an easy task. In three out of the seven, however, they did not succeed, and it turned out that – contrary to the other seven – they were used to eating fish 2 – 3 times a week. The other seven people had triggered attacks which were interrupted by the defibrillator.

The sensational thing about this was that after having been given fish oil as intravenous transfusions, it was impossible to provoke attacks in now five out of the seven patients! Left were only two patients who apparently were not protected by fish oil. Despite the infusion (equalling 12 g. of ordinary fish oil), one of them had a very low blood level of fish oil.

In total, eight out of the ten patients were so effectively protected by fatty fish or fish oil that provoking the deadly attacks in them was impossible. However, this German study is only a pilot study. Larger and more thorough studies must succeed in order for the effect to be considered reliable.

The result matches other findings from very large studies. The most famous one is the Italian GISSI study from 1999; a randomized trial with 10,000 men who had recently survived a cardiac thrombosis. It stated with great certainty that taking fish oil supplements resulted in a total reduction in mortality of 20% and a reduction in the risk of sudden cardiac death of more than 50%.

According to the editorial commentary of the magazine, the German study that was published in The Lancet can lead the way to using fish oil as a safe and more appetizing alternative to traditional heart medicine. First and foremost, fish oil can substantially reduce the danger of having a cardiac thrombosis!

By: Vitality Council

 

References:
1. Albert C. Fish oil – an appetising alternative to anti-arrhytmic drugs? Lancet 2004;363:1412-3.
2. Schrepf R et al. Immediate effects of n-3 fatty acid infusion on the induction of sustained ventricular tachycardia. Lancet 2004;363:1441-2.

www.thelancet.com
www.iom.dk

Fish Oil for the Heart

March 7, 2003

Essential oils in fish oil can prevent heart disease in elderly people. Quite many consumers and doctors have good experiences with this, but now it has also been confirmed by a study, recently published in the American Journal of Clinical Nutrition.

The trial included 360 persons at the age of 65, and the researchers found that a high concentration of the fatty acids DHA and EPA is associated with a lower risk of dying of blood clots in the heart.

“Again, this is a good example of a preventive measure with natural substances such as fish oil, pays off” says Claus Hancke, chairman of the Vitality Council.

By Vitality Council

Reference:
American Journal of Clinical Nutrition, Vol. 77, No. 2, 319-325, February 2003.

www.ajcn.org
www.iom.dk