Does Fish Oil Prevent Alzheimer’s Disease?
When I was young I was told that eating fish made you clever, in the same way that eating carrots made you see in the dark. Luckily I always liked fish, though whether it had the desired effect upon my intellect it is not for me to say.
At any rate, the connection between eating fish and brain function has long been part of common folklore, and it is probably for this reason that large numbers of people approaching old age take fish oil capsules in the hope of warding off Alzheimer’s disease. This, no doubt, is an example of the belief or superstition that, if only we got our diet right, we should never fall ill. Immortality is but a diet away.
A meta-analysis of trials of fish oil capsules or margarine in the prevention of cognitive decline has just been published in, or on, the Cochrane Library, a website devoted to examining the evidence for (or of course against) the use of drugs and medical procedures in the prevention and treatment of illnesses. The quality of the analyses published in, or on, the Cochrane Library is generally accepted as the best possible.
The authors aggregated the results of three trials that met their methodological criteria. The trials had to be double-blind and placebo-controlled, and involved 3,536 participants who were cognitively unimpaired and over the age of 60. Subjects took fish oil capsules or margarine (or placebo) for 6, 20 or 40 months.
There was no evidence that fish oils prevented cognitive decline as measured by the Mini-Mental State Examination, the measuring instrument usually used in such trials, and other simple tests. The only significant side-effect of taking fish oil was mild gastrointestinal disturbance; overall levels of side-effects were as great among those taking placebo as those taking fish-oil.
There are severe limitations in what can be concluded for the meta-analysis, however. Because the cognitive decline in both treatment and control groups was so small, the trials did not have sufficient power to detect any possible benefit, much less to draw definite conclusions about the ability of fish oils to prevent Alzheimer’s disease. Moreover the fish oil was taken by subjects for at most 40 months; perhaps if it were taken for longer, and the follow-up were also for longer, a difference would manifest itself. Since the trials excluded people with dementia that was already manifest, it was impossible to conclude from the results whether or not fish oil is of benefit in established dementia.
The authors did not conclude that people should not take fish oil supplements, because they said that such fish oils might have benefits other than in the prevention of cognitive decline. And since longer trials might be necessary to establish definitively the uselessness (or otherwise) of fish oils in the prevention of cognitive decline, those who put their faith in them are not yet forced by the evidence to abandon it or risk joining the ranks of the irrational.
For the moment, nutritionists recommend the consumption of fish twice a week, including of oily fish — salmon, herrings, mackerel or sardines — at least once a week. I confess I find such recommendations suspect: how do the nutritionists know that three times a week would not be better, or once a week as good as twice?
The decision as to what to eat cannot be taken on the basis of placebo-controlled double blind trials, first because such trials usually establish very little (and that little is often contradicted by subsequent trials), and second because there are purposes to eating other than the preservation or improvement of health. Meals are not medical procedures, and the dinner table is not, or not yet, an operating table.






Hello Theodore,
), use it or lose it.
I think the recommendation to eat as varied a diet as possible and to include plenty of fresh fruit and nuts, especially walnuts is still the best. Keeping the brain active seems to have a positive effect. Perhaps the brain is like a muscle (too similar in many politicians and climate scientists
As cannabis is legal when prescribed, in some places, could you do a report on how THC produces psychosis when taken in large doses over an extended period, and what level of intake is considered safe?
A side by side comparison with alcohol and prescription meds like valium would be interesting. I know a few valium users that are psychotic, though whether they where like that before using the drug I don’t know.
Yes, i would like to see that too. A truthful study on cannabis compared to alcohol and pharmaceuticals would be great.
I thought fish oil was supposed to protect the heart, not against dementia.
Fish oil rich of Omega 3 fats have thinning blood effect (so less dementia from micro brain strokes) and reduction of systemic inflammation (Alzheimer is connected to inflammation).
The problem with researches is the length of the research. Four years is really short. And the age when oil fish is consumed is not trivial. It is like talking about diabetes (Alzheimer is a form of diabetes of the brain) and blindness.
Preventing the damage occurring to a 55 years old in the next five years will not change much the outcome. It is the damage accumulated in the fifteen or more years before that matter.
Americans spend billion of dollars on supplements, vitamins, minerals, herbal concoctions, anti-oxidants ,magical berries, fat burners, nostrums, flotsam and jetsam. Billions down the drain for worthless crap. Worthless crap. Immortality in a pill, capsule or teaspoon. There is a sucker born every minute. Not to mention, fish oil is murdering the fish population.
A European immigrant friend told me, “Americans have the most expensive urine on Earth.”
That joke goes back to the 1950s, at least, and it was first told by Americans, not Europeans.
Meals are not medical procedures, and the dinner table is not, or not yet, an operating table.
Yes! Love that final paragraph. Those of us lucky enough to enjoy oily fish — if you don’t, maybe try a new recipe, or even cook it? — can still enjoy our meals. Re walnuts: love those too; who cares about the veracity of the claims, they make good eating. Golden Mean and all that.
I fights to the finach cause I eats my spinach.
I thought it was “eats me spinach.”
Actually, it’s “I’m strong to the finich cause I eats me spinach”.
Enough about spinach. I can stands what I can stands and I can’t stands no more.
If you had not eaten so much fish you would be reduced to writing for the New York Times.
We know thingd like citrus and certain other vitamins or minerals ward off some horrible and debilitating diseases. There are probably one or two more dietary magic bullets out there yet to be discovered.
In an age of hyper over study of everything under the sun, often with contradictory conclusions, some old bromides like an apple a day (keeps the doctor away) and the benefits of a swig of cod liver oil still have credence.
Omega 3′s fatty acids in fish oil are touted mainly for…cholesterol ?
Recently, I’ve read “studies” saying a glass of wine a day is actually good for pregnant women (yea !) and that there is a tendency to overdo Calcium supplementation (pushed and pushed by doctors), too much CA related to heart attacks.
One thing everybody can agree on, that the best source of balanced vitamins & minerals is food itself and that much of the wild and wooly supplementation now done is at best negligible, at worst, harmful.
…there are purposes to eating other than the preservation or improvement of health.
Yes.
But you can savor delicious food and still consider what Hippocrates (allegedly) said:
“Think of your food as medicine and your medicine as food”.
My mother will be 104 next month. She can’t get enough of candy, chocolate, ice-cream, pastry with loads of sugar in her coffee. All the doctors that warned her of the health hazards of eating sweets have since died.
#9 and #10, count me in, too –i love sugar and eat it instgead of food whenever i can. Did you know you can pour dry instant coffee directly into a can of sweetened condensed milk, put it in the freezer, and just take a teaspoonful bite anytime you wan? It will not freeze solid, with or without the coffee –it just freezes to a taffy-like state. You can have a bite or two of that in place of a heavy meal, enjoy the taste and ice cream-like temp, feel great, save time and dirty pots pans & dishes galore, and if you’re a mind to, gain or lose weight as you please, via the skipped meals and the handy easy ‘pang-satisfying at a single spoonful’ sure-fire hunger-killer concoction.
And fish, ugh –as well as the water they swim in. Water’s fine but it wants some sort of sugar mixed in, and a lot of it –and maybe some tea as well. That and a ready bag of tangerines or somesuch sweet citric acid, a jug of one-a-day vitamins for insurance, and a carton of Marlboro red 100s, and i’m good to go for a week –as long as nobody is around cooking –blah –and i have to manners-dine on some sort of beast-in-shrubbery healthy gourmet slop.
The instant coffee and condensed milk in the freezer idea is genius.
Why thanks, skook –makes up for my youngest daughter, who found it in the freezer and made a face like a two-pound bug had hit her windshield at 90 mph. You know the look –disgust with a little admiration of how much guts it takes to do that.
Good news, indeed. I hate fish.
“How do the nutritionists know that three times a week would not be better, or once a week as good as twice?”
Probably the same way a 104-degree F bath became the recommended treatment for hyperthermia. I once heard a physician explain that he’d been at the conference where that was decided. One group lobbied for body temperature, 98.6 F. Another lobbied for a blistering 110 F. They ended up splitting the difference and recommending 104 F.
Once a week, twice a week, three times a week. Pick the one in the middle.
–Michael W. Perry, editor of Eugenics and Other Evils by G. K. Chesterton
I take fish oil daily. Because of this I came up with some really profound thoughts on the subject. My only problem is that I can’t remember any of them.
Yes! I had three good reasons why fish oil wouldn’t work:
One was old age, and I can’t remember the other one.
Quit showing off, at least you got one right.
A personal anecdote wrt fish oil (I’m 47 fwiw)…
After taking it fairly regularly for several months, I’ve noticed that my reflexes are quite noticeably better, at least in the case of fumbling something but then being able to catch it in time w/o missing or spilling – or knocking it over to make an even worse mess.
I know another guy who claims his balance improved a lot.
I suppose its a matter of helping reduce some deficit in the brain, if not an actual boost or net gain.
I also think i get some of the alleged antiinflammatory benefits as well.
I have read alternative health experts who claim that Alzheimer’s, like most modern chronic afflictions, is caused by the repeated insulin spikes brought on by eating excessive amounts of starch and sugar.
I have cut my intake of starch and sugar substantially and lost weight, gained vigor, and generally feel better.
Year ago doctors said that eating too many eggs was bad for you. Now they say that eggs are really good for you. Years ago people said there was nothing wrong with eating red meat. Now too much red meat is bad for you. Seems to me, if you eat anything in excess it’s bad for you, and if you eat anything in moderation, it won’t kill you. But no matter what you eat, I don’t think anything will extend your life by that much, and unless you eat like a big fat pig, nothing you do eat will end your life any sooner.
Moderation is the name of the game. After that, everything else is up to your genes and your biological background. So be happy and have some steak and eggs. You may not live any longer, but at least you’ll die happy.
The medical profession is always making recommendations, only to do a complete one eighty on that recommendation, usually five years later. Best advice: take all medical recommendations with ……. a grain of salt
If it wasn’t for apathy I wouldn’t care about anything.
Studies, double, triple, quadruple-blind…inside, outside, placebo, mambo, WTFC?
I’ll tell you who: Those who are addicted to everything. Maybe not drugs but they took up bicycling because it was good for the calves. They swim 2, 3, 4 times a day because it’s “the best exercise the body can get”.
Granted, the people who move around have something on the species Couchus Potatus. There is a direct corollary between being out of shape and obese and how much exercise a person gets.
And some of it is gene-driven. All my grandparents lived into their 90′s. All were very active people but not exercise freaks. Nor were they constantly on the lookout for the next potion, lotion or pill that would “guarantee” them long and healthy life. Knew a guy in the USAF…lifted weights, exercise freak…told everyone that bee pollen was the stuff…it was magic it was the cure-all to end-all. He was 27…had a heart attack and died.
We are in the new Victorian Era where the scientists are competing for ever-limited recognition space and tenure. The biggest similarity being they laugh at the “little people” who say things like, “I just do things in moderation and stay away from X, Y and Z”. The scientists are convinced they know better because of all the fancy script on the wall.
I ignore it all. It’s just annoying.
Since my mid forties I have been told twice that I would die if I didn’t take the recommended drugs for the autoimmune disease with which I was afflicted at that moment in time. I lived a healthy and active life and believed there had to be an underlying cause to my declining health and so I said, “No, thank you,” to the allopathic professionals and went in search of answers.
Ten years and a slew of autoimmune disorders later (including the two that were out to get me), a naturopath suspected I might be allergic to gluten. I underwent a DNA test and, TA DAAA!- I was gluten intolerant which meant I had been slowly poisoning myself to death since birth. Fast forward three years to the present and I am so incredibly healthy my doctor told me not to come back for 2 years! At 60 I rollerblade, bike, cross-country ski and romp enthusiastically with my 10 grandchildren. Turns out food IS medicine…and it can also be poison.
OK, I get that there may be ways to improve quality of life for a while, but I can’t help but wonder – just exactly what is it permissible to die from these days?
Boredom?
LOL –not around you, i bet –!
coconut water – milk – and meat
Pacific lobster tails – other light fish – ono – mahimahi – sashimi tuna – similar – rice and soy sauce
some bbq good beef – chicken – pork – fish
a good salad — perhaps a bit of poi or sweet potato – mashed white potato with light gravy
a nice Pinot Grigio mixed with orange juice — and sometimes apple or carrot –
as well as apples / apple sauce and carrots – grapes — nuts and seeds —
lots of clean drinking water — and swim in the ocean daily where it is clean and warm
seems to work so far – and writing this is making me hungry —
i go home to Hawaii today — and that makes me very happy – happiness may be the real key – perhaps it is the sunshine, warm rains, breezes, salt air, melodic music – relaxing atmosphere — lack – o – stress -
bits: “…a nice Pinot Grigio mixed with orange juice…”
bits, are you sure it has to be a nice pinot if you intend to mix it with orange juice? My frugality gene rebels.
What a lovely dream-like comment! I was hearing Don Ho in the dream, until someone shouted “Book him, Danno!”
Food can indeed kill you off early or keep you alive longer. You are what you eat.
I’m particularly impressed with a certain Dr. Budwig from Germany and her diet recommendations. She died of an accident in her 90′s and, hey, I’ll listen to anyone who makes it to her 90s. It turns out that it’s not all about protein or carbohydrates. It’s all about the fat baby. Eating the Budwig muesli (you can’t buy it you have to make it) has cleared up my pre-cancer skin blobs, reversed my hair loss, and ended multiple trips to the bathroom at night.
To dismiss ALL dietary recommendations is hazardous to your health. My 2¢.
IT WILL HELP BRING ON GOUT! Once you get it, it will not just go away
Fish oil to make you smart? I haven’t seen any fish yet, that ever had much of an I.Q. I’ll bet you haven’t either.
In fact; If there is any truth to ingesting an oil from an animal, why don’t they refine seal oil? They can learn the most tricks. But, then seals eat fish. Darn; Back to square one.
I’m waiting for the research that proves why Liberals and Democrats so much smarter than anyone else.
It shouldn’t be too hard, with all those stellar I.Q’s they have.
I think they eat their fish raw. Maybe that’s the trick.
In a more perfect world, the fish would be eating the Democrats raw.
I think it’s all mapped out in your genetic makeup, for better or for worse.
I’ve never heard of fish oil as a prevenative for alzheimers. I’ve been taking it for about three years because I heard it relieved joint inflammation.
As a former infantryman I have bad knees. By my late thirties I could barely walk down a flight of stairs in bad weather. My knees are more supple since taking fish oil than any time in the last 20 years, I am in my mid fifites now. It’s worked for me. Yes, it does reduce blood clotting. I’ve had some impressive bleeding sessions while pruning roses.
My knees too, are ruined –from high school and multiple cartilege and ligament surgeries. If you’ll tell me what you’re taking, i’ll go get some and take it.
I took total knee replacement surgery. Best f’ing thing I ever did. Up until 2005, I played racquetball, skied, rode my bike, walked two miles every morning, more on weekends. Two years ago, I couldn’t walk down a flight of stairs, drove a golf cart with a handicap flag from tee to green, and spent most of my time sitting or lying down.
I can now walk 18 holes with ease. I still have some discomfort and a very reduced range of motion (can’t ride a bike or play racquetball) but I’m thrilled with what I’ve recovered.
Also, I went through all the BS regimes such as cortisone, Synvisk, physical therapy, accupuncture. Skip all that. Just get the knee(s) replaced and get on with your life.
“Meals are not medical procedures”
says it all, as Dr. Dalrymple has done so often.
There is no “magic” pill, period, and a balanced diet should certainly be the most important source of human nutrition. But in our experience, even many physicians and nurses who tend to be skeptical of supplements agree that for them a major exception is fish oil, and far from being a “fad,” this is a substance whose health benefits have been recognized for generations in various parts of the world, and clinical studies are increasingly bearing this out. But all fish-oil supplements are not created equal, nor are all studies – benefits accrue only at a certain level of purity and concentration, yet some studies persist in testing inadequate dosages of omega-3′s; we recommend a minimum of 1.2 grams daily. We’ve canvassed all the latest research and offer it on our web site: http://www.megafort.es/Web/eng_inicio.aspx.
Some of the few supplements I take are fish oil and glucosimine with condritin. I had alot of back pain and could hardly sit. The doctor gave me prescription pain killers and anti-inflammatories that me me feel terrible, so I promptly quit and went the more natural route, plus a 30 min, walk every day. Within 6 months, I was pain-free and I haven’t stopped this regimen for 3 yrs.
I’ve always believed that nations speak louder than studies.
In Japan, where I lived and worked, the folks ate loads of fish.
They lived longer and were highly intelligent. Plus, their women had great hair.