May 3, 2012

Can Omega-3 and Nutrients Prevent or Delay Alzheimer's Disease

Ingesting one gram of omega-3 per day (equal to approximately half a fillet of salmon per week), is associated with 20 to 30 percent lower blood beta-amyloid levels.

By Bob DeMarco
Alzheimer's Reading Room

My name is Bob DeMarco. I am not a doctor or a scientist. I am an Alzheimer's caregiver. Which I guess makes me some guy with an opinion.

Can what you eat, how much you exercise, how much you use a computer, how you use your brain (puzzles, etc.) effect the odds on whether or not you suffer from Alzheimer's? I think so.

If you read the studies published on this website, you'll learn that you can lower the odds of suffering from dementia. Now this might sound harsh, but if you do the right things you might die before you are diagnosed with dementia.

Lets take my mother, Dotty, as an example. If Dotty had died before the age of 87 years old neither of us would be here. We would never have known that Dotty would become deeply forgetful. Dotty is 95 years old.

Dotty did have something going against her in this scenario -- genetics. The women on Dotty's side of the family live a long long time. All of them. They don't suffer from heart disease, and they don't get serious illnesses. They live on. I guess you could conclude that Dotty lived too long. I don't think so. Frankly, while it is trying, difficult, sometimes burdensome, and even downright scary, we are doing fine.

Together, Dotty and I figured out how to stare Alzheimer's right in the face and tell it to go to hell. I might add we proved two things. We survived and Alzheimer's is not an automatic death sentence. We are not the only One's by the way.

Nikolaos Scarmeas
When you read the results of the study presented below here is what you will find.

People who had higher levels of 10 nutrients in their system: saturated fatty acids, omega-3 and omega-6 polyunsaturated fatty acids, mono-unsaturated fatty acid, vitamin E, vitamin C, beta-carotene, vitamin B12, folate and vitamin D had lower levels of beta-amyloid in their blood.

"Ingesting one gram of omega-3 per day (equal to approximately half a fillet of salmon per week), is associated with 20 to 30 percent lower blood beta-amyloid levels".

Last night Dotty and I ate salmon and brocolli for dinner. Dig.

If you eat a Mediterranean diet and get out in the sun, bright light,  for 15 minutes or so a day, walla, you did it. You did the right thing. You changed the odds of suffering from Alzheimer's.

Yesterday we published an article, Computer Use and Exercise May Reduce the Odds of Memory Loss, that showed study participants who did not exercise and did not use a computer, 20.1 percent were cognitively normal and 37.6 percent showed signs of mild cognitive impairment. Of the participants who both exercise and use a computer, 36 percent were cognitively normal and 18.3 percent showed signs of MCI.

Wouldn't you rather be in the 37.6 percent. By they way, this study did not indicate that if you use a computer and exercise you won't get Alzheimer's. It indicated you might be able to change the odds of suffering from dementia.

None of these studies operate in a vacuum. You have a genetic make up and you do all kinds of things during your life. For example, a small study showed that men who played football in the National Football League (NFL) were about 6 times more likely to suffer from dementia at a young age.

What about men that play high school football, college football or rugby? Are they increasing their own odds of suffering from dementia or CTE? Early studies might be showing they are.

Let's take a man like Bob Blackwell (Carol's husband) was he genetically predisposed to Alzheimer's by birth? I'll let Carol answer that question.

My point here is simple and straightfoward, it seems to me that you want to consider how you might change the odds of suffering from dementia. Who knows, you push it back five years you might die first. You might push it back far enough that it never happened.

Of course, you might end up living longer. What a conundrum, huh?

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Omega-3s Linked to Lower Amyloid Levels

People who had a lot of omega-3 fatty acids in their diets tended to have lower plasma levels of beta-amyloid proteins, possibly reducing their risk of Alzheimer's disease, researchers said.

In a cross-sectional study of more than 1,200 cognitively normal individuals older than 65, omega-3 fatty acid intake was significantly predictive of plasma levels of the 40- and 42-residue forms of beta-amyloid protein (AB40 and AB42, respectively), according to Nikolaos Scarmeas, MD, of Columbia University in New York City, and colleagues.

Adjusting for age, education level, and other factors pushed the relationship between AB40 and omega-3 intake into a strong but nonsignificant trend (beta statistic -10.13, P=0.13). But the association with AB42 remained significant, Scarmeas and colleagues reported online in Neurology (beta statistic -7.70, P=0.02).

The same group had previously published results indicating that a Mediterranean-type diet was associated with lower risk of cognitive impairment and Alzheimer's disease.

Because one of the hallmarks of Alzheimer's disease is beta-amyloid plaque deposits in the brain, Scarmeas and colleagues sought to determine if dietary factors were related to blood levels of AB40 and AB42.

Their study population was drawn from participants in the Washington Heights/Hamilton Heights Columbia Aging Project in New York City, first recruited in 1992 with a second group enrolled in 1999.

As part of this study, participants completed a detailed diet questionnaire and also provided blood samples. The latter were drawn a mean of 1.2 years after collection of dietary information.

The researchers excluded participants already showing dementia when the dietary questionnaire was administered, since their mental status could affect their self-reporting on diet.

A total of 1,219 participants out of the original 2,778 were included in the current analysis. In addition to 345 with prevalent dementia, another 1,025 could not be included because beta-amyloid levels in plasma weren't measured.

In addition to omega-3 intake, Scarmeas and colleagues also estimated intake of nine other nutrients: folate, beta-carotene, monounsaturated fats, saturated fats, omega-6 fatty acids, and vitamins C, D, E, and B12.

Only omega-3 intake was significantly associated with plasma AB40 or AB42 levels in any analysis.

The raw data suggested a powerful link:

AB40: beta -24.74, P<0.001

AB42: beta -12.31, P<0.001

But analysis of participant characteristics revealed a number of covariates. Adjusting for age, race-ethnicity, education level, APOE genotype, total caloric intake, and recruitment wave attenuated the relationships noticeably.

The beta value for AB40 shrank to -11.96 and the P value increased to 0.06. 

The beta value for AB42 also declined, to -7.31, but it remained significant at P=0.02.

Adding adjustments for alcohol drinking and use of certain drugs and nutritional supplements changed the strength of the associations only slightly.

 The researchers' conclusion: "The potential beneficial effects of omega-3 [fatty acid] intake on Alzheimer's disease and cognitive function in the literature might be at least partly explained by an AB-related mechanism," they wrote.

Scarmeas and colleagues noted several limitations to the study, including its cross-sectional design and its reliance on a single measurement of plasma AB40 and AB42 levels, which they characterized as "a moving target" during development of cognitive decline.

Also, the researchers relied on participants' self-reports on diet and examined only 10 of many nutrients contained in food.

Finally, Scarmeas and colleagues acknowledged that plasma beta-amyloid proteins do not necessarily reflect amyloid protein levels in the brain.

Nutrient intake and plasma β-amyloid

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Original content Bob DeMarco, the Alzheimer's Reading Room