Latest Review Finds Fish Oils Don’t Help Dementia

Fish oils are the current wonder supplement, good for all that ails you. I have actually taken them when the evidence appeared to support a benefit in prevention of cardiovascular disease, but the evidence is not looking as strong these days even for that indication, which has been the most strongly supported of the many suggested uses in humans. Other uses include prevention or treatment of dementia, arthritis, inflammatory diseases, and many others.

I have reviewed in detail suggestions that fish oils might have a benefit for arthritis in dogs, and it is weak but not definitive either way. Others have reviewed the use of fish oils in dogs with allergic skin disease, and there is reasonable evidence of some mild benefits for that condition. There have been suggestions that fish oils, as supplements or added to dog food, can affect the development of canine cognitive dysfunction, but there is no robust research evidence to support this.

A recent Cochrane review looking at fish oil supplementation and dementia in humans did not find evidence to support a beneficial effect despite a number of quite large clinical studies.

Emma Sydenham. Alan D Dangour. Wee-Shiong Lim. Omega 3 fatty acid for the prevention of cognitive decline and dementia.

Three randomized clinical trials involving over 4000 people were reviewed. Some subjects were supplemented and followed for as long as 2 ½ years. Despite this, no evidence of benefit was found. Few adverse events were seen either, apart from gastrointestinal upset. The conclusion of the review was:

Direct evidence on the effect of omega-3 PUFA on incident dementia is lacking. The available trials showed no benefit of omega-3 PUFA supplementation on cognitive function in cognitively healthy older people. Omega-3 PUFA supplementation is generally well tolerated with the most commonly reported side-effect being mild gastrointestinal problems.

Certainly not the last word, but yet another fairly strong piece of evidence suggesting that even one of the most intensively studied and widely used supplement has yet to definitively demonstrate the benefits claimed for it. And while data of similar strength is unlikely to be developed for dogs with cognitive dysfunction, the tentative conclusion based on extrapolating from the human research has to be that fish oils could have benefits in this condition, but it is at least as likely that they do not.




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7 Responses to Latest Review Finds Fish Oils Don’t Help Dementia

  1. Anthro says:

    Just had a vet recommend Omega 3’s for my dog’s suspected food allergy (she licks her paws–or did for a while). I asked her if she had clear evidence and she claimed she did. I don’t trust anyone anymore, but this article doesn’t give me a definitive answer either, but I think I’ll just give the dog a bit of salmon a couple times a week (just as I do for myself). I think I’ll drop the pricey “ultra hypo-allergenic” dog food as well and just avoid the main allergens. I’m going to try making my own from the recipe in Feed Your Pet Right.

  2. skeptvet says:

    The evidence concerning the value of fish oils for allergic dermatitis can be found here:

    Treatment of canine atopic dermatitis: 2010 clinical practice guidelines from the International Task Force on Canine Atopic Dermatitis. (Olivry T, Deboer DJ, Favrot C, Jackson HA, Mueller RS, et al; for the International Task Force on Canine Atopic Dermatitis. Treatment of canine atopic dermatitis: 2010 clinical practice guidelines from the International Task Force on Canine Atopic Dermatitis. Vet Dermatol. 2010 Apr 23

    I’ve written about the review here:

    They do have some demonstrable value for reducing symptoms and the dose of other medications that may be needed, but they are only a part of a multimodal approach.

    As for diet, you can’t test for what dietary proteins your dog is allergic to, so just picking some to avoid isn’t likely to be effective. It is relatively straightforward to test for food allergies. If there is a significant improvement in symptoms consistently over 3-6 months on a hydrolyzed protein diet, then food allergens likely play a role, especially if symptoms recur when other foods are subsequently fed. If there is little to no response to such a diet trial, food allergens aren’t likely a major issue.

  3. v.t. says:

    Anthro, I have to echo skeptvet’s comments – what allergens can you omit when you don’t know what they are? That’s the purpose of the trial diet (the pricey one you’ve mentioned). To be honest, a home-made diet may end up deficient in nutrients anyway, and certainly can cost as much or more to provide than the diet your vet has recommended.

    Little harm in trying omega 3 capsules – if your vet can recommend a trusted brand, go for it, you’d have less worry about contaminated fish. And when I say trusted brand, I mean one that has an excellent reputation, contains what it says it contains, etc. Follow vet’s recommendations on brand and dosing/frequency etc.

  4. DK says:

    I have a 15 year old dog who is really struggling with cognitive issues. He’s lost his hearing in the last year and gets very anxious at night – barking and scratching at random doors in the house in the middle of the night. I’ve read several of your articles on neutricks and omegas not working as claimed but I was wondering if you do have any studies or suggestions of what may work to help him cope better in the evenings. During the day he seems to be fine – happy, playful, enjoys walks etc. thanks so much!

  5. skeptvet says:

    I’m sorry you have to deal with this troubling condition. Canine cognitive dysfunction (CCD) is a syndrome analogous in many ways to Alzheimer’s Disease in humans, and while there are a number of therapies with some evidence suggesting they may benefit some dogs, there is no cure, and most treatments recommended have not been sufficiently tested for us to know if they are effective or not. The limited state of the evidence is a major reason why so many untested over-the-counter remedies are marketed for this condition.

    The best evidence, though still somewhat limited, is for a medication called Anipryl (selegilene). There are also some studies suggesting dietary therapy may help. FInally, behavioral therapy and management of the pet’s routine and environment are important elements of treatment. The following article discusses various treatments, but I would recommend working with your veterinarian to tailor a treatment plan specific to your pet. Good luck!

    A review of CCD diagnosis and treatment.

  6. L says:

    @ DK
    I found this site helpful a few years ago when I was going through a similar situation
    I ignored the advertisements for supplements and such.

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