by Simon J. Evans, PhD

Alzheimer’s is a debilitating disease where circuits in the brain literally get ‘tangled up’ and cause cognitive problems. Research into the causes and possible treatments for Alzheimer’s is intensive and beginning to provide rays of hope for families hit with this disorder.

The Triple Threat

One tool that researchers have used extensively is a mouse model, which is genetically destined to get Alzheimer’s disease due to three separate genes. There are several paths to Alzheimer’s, but having a gene that increases your risk for getting the disease does not guarantee you will get it. It still depends on many lifestyle factors, including your physical activity, nutrition and level of physical health. However, the Alzheimer’s mouse model, called the 3xTg-AD mouse, has the deck stacked against it with multiple genes increasing its risk and almost guaranteeing disease.

A couple of recent studies used these mice to look at the role of some specific dietary factors in helping or hurting the mice’s chances. The first study looked at low omega-3 to omega-6 ratios in the context of a low or high fat diet. The second study used vitamin B3 (nicotinamide) to try and counter some of the cognitive problems the mice develop as Alzheimer’s progresses.

Fish for Brains

Julien et al. from Lavel University in Quebec published a study in the Neurobiology of Aging, in which they reported a double whammy of low omega-3s and high fat that seems to make the genetically susceptible mice fair worse. Unfortunately, the diet they discovered as further increasing Alzheimer’s risk is not that different from what most westerners are eating.

Many folks in North America eat too much saturated fat and not enough good omega-3 fat from fish. When researchers gave this kind of diet to the Alzheimer’s mice, the brains of the mice had several increased markers of Alzheimer’s pathology. In teasing out the dietary problems, researchers found that either a high fat diet or a diet low in omega-3s, caused problems. When they combined the two, feeding low omega-3s in the context of a high fat diet, those problems compounded.

These data are consistent with previous observational studies in humans that show people who eat less omega-3s have increased rates of Alzheimer’s disease. Unfortunately, studies have not shown success of using omega-3 supplementation to treat Alzheimer’s once it takes hold. However, there has been some success in treating early mild dementia. These studies, along with the new data from mice suggest that we should get plenty of omega-3s into our diet earlier to help drive down the risk of Alzheimer’s later.

Vitamin B3 gets an A

Still, there may be good news on the Horizon for those who are already heading down the Alzheimer’s road. Green et. al. from UC-Irvine published a study in the Journal of Neuroscience that demonstrated some remarkable effects of vitamin B3 at protecting the genetically prone mice from getting Alzheimer’s.

Now, before you rush out and start dosing up, realize this is a preliminary study that used whopping amounts of vitamin B3. Researchers fed mice at about 100 times the RDA and at about 10 times doses previously shown to cause some toxicity in humans. Still, the study is promising because it helps reveal some ways in which we might approach preventing Alzheimer’s disease in high-risk populations.

Researchers dosed up the 3xTg-AD mice with large amounts of nicotinamide, an active form of vitamin B3, in their drinking water. These mice performed as well as normal mice on many memory and other cognitive tests. Conversely, the Alzheimer’s prone mice that didn’t get the vitamin B3 showed the expected cognitive decline associated with Alzheimer’s.

Food Matters

The cool thing about both of these studies is that they open the door for more research using nutritional approaches to treat and prevent Alzheimer’s disease. It’s clear that genetics plays a role in some, but not all cases of dementia. But it’s also clear that we don’t have to accept our genetic predispositions in many cases. It is not fate. They way we choose to live our lives, including what we choose to eat, will play a large role in our cognitive future.

References:
Journal of Neuroscience (2008), 28(45): 11500-11510.
Neurobiology of Aging (2008), In Press.

Tweet This Post

By Simon J. Evans, PhD

A lot research has focused on omega-3 fats as good for body and brain function. Scientists have scrutinized these fats in everything from heart disease and diabetes to depression, bipolar illness, schizophrenia, ADHD and Alzheimer’s. The latest papers to add to the experimental pile come from a recent edition of the American Journal of Clinical Nutrition.

The new studies evaluate omega-3s in people in their 70s and 80s and relate to cognitive function, mood and mental well-being. The bottom line to the new findings is that having higher levels of omega-3s in your blood protects you from many cognitive problems of old age. The downside is that you can’t just start taking them in your 70s and expect quick results. However, longer use may still be beneficial.

So what’s the best way to boost omega-3 levels in your blood. First, you have to understand that there are different kinds of omega-3s that come from different sources. The kind of omega-3s that are good for your brain are called ‘long-chain’ omega-3s, most commonly DHA and EPA, and fish is the best source for these.

You may have heard that things like flaxseed oil and walnuts are high in omega-3s as well. Although this is true, these foods are only high in ‘short-chain’ omega-3s, which are not the kind that appear to have the most brain benefit.

To complicate things even further, most animals can convert the short-chain to long chain forms, but humans are not very good at this. If we want to increase long-chain omega-3s in our blood and increase our odds of aging with a healthy brain, eating sources of long-chain omega-3s is our best bet. Fish is the #1 source.

If you don’t eat about 3 servings of fish per week, you should really consider taking a fish oil supplement on a regular basis. If you are a vegetarian who does not eat fish at all, don’t fret, there are also algal oil supplements out there that have the long-chain omega-3s. After all, fish can’t make omega-3s either. They get them by eating marine plants (or eating other fish that eat marine plants). Fish are just good at concentrating omega-3s in their meat, so are a great source for us folks that don’t like chewing on seaweed.

Fish has been considered brain food for the better part of a couple of centuries. Whether you like it or not, our bodies are designed to run best on a diet high in marine sources. If you look at the cultures around the world who enjoy longevity and vibrant health into their old age, you will find fish as a staple in all of them.

There is nothing new to this advice. Only that we are now beginning to understand why fish and the omega-3s they give us, are important for many aspects of our mood and metabolism. Once again, science finally catches up to age-old wisdom to support what we have known all along – Fish is brain food, eat it and prosper.

Reference: American Journal of Clinical Nutrition (2008). 88: pp 595, 706, 714, 722.

Tweet This Post