According to researchers in the U.K., older people who have lost all their teeth are more than three times more likely to develop memory problems and dementia than those who still have teeth left.

The study's lead author, Dr. Robert Stewart of Kings College London, admits this study raises more questions than it answers, and that at this point they are not able to say what causes what. However, he states the take-home message is, "Particular attention may need to be paid to the health and nutrition of people with cognitive impairment because they may also have dental problems."

A lot of research now focuses on the associations between diet and dementia, especially Alzheimer's. But poor dental health may also boost your risk of cognitive problems, because:

Dental disease often causes prolonged inflammation and infection in your mouth, which may alter some factors in your blood, possibly causing problems in your brain.

People who lose their teeth tend to alter their diet. A less balanced diet can result in vitamin deficiencies and other problems that might alter or affect brain function.
Dr. Stewart hit the nail on the head with his statement that particular attention needs to be paid to the health and nutrition of people with cognitive impairment. I would add, though, that you need to pay particular attention to your health and nutrition in order to avoid mental, and dental, decline in the first place!

The pioneer researcher in this area was Dr. Weston Price, who was one of the leading nutritional researchers of the 20th century. His book is Nutrition and Physical Degeneration. Dr. Price was a dentist and traveled around the world in the early 20th century to document the damage that processed foods did to primitive cultures. He took tens of thousands of photos and some of the best are in his book. It is a fascinating read.

Which Came First? Poor Diet or Bad Teeth?

There has been loads of additional scientific evidence since Dr. Price's work that shows your diet can impact your dental health. In fact, if you were raised on a diet free of processed foods, grains, and sugars, you would likely avoid all dental decay and secondary periodontal problems to begin with.

And with tooth decay comes dental fillings and root canals, adding their own set of health problems -- many of which can have a negative effect on your brain function and cognitive health. It's a vicious cycle.

In addition to proper diet and exercise, avoiding and removing both mercury and aluminum from your body can help you stay mentally sharp. Even trace amounts of mercury can cause the type of damage to nerves that is characteristic of the damage found in Alzheimer's disease.

Sources of mercury include:
* Dental amalgam fillings
* Seafood
* Thimerosal-containing vaccinations and flu shots (which contain both mercury and aluminum)
And, by the way, did you know that many pharmaceutical drugs also promote tooth decay? Yet another good reason to avoid drugs.

What To Do If You Have "Silver Fillings"

My diet when I was younger was full of sugar and I had over two dozen teeth that had mercury fillings. In the mid 90s I finally became convinced that I should have those fillings removed. Unfortunately I had them removed and replaced with gold crowns by a conventional dentist. Although he technically did a fine job he, like any conventional dentist, was clueless about the dangers of mercury and as a result I had plenty of mercury dumped into my system which actually caused serious kidney damage.

I subsequently realized that gold crowns are not good for you so I had them removed and replaced with metal free composites. So if you have silver filling do NOT make the mistake I did and find a trained biological dentist who can safely remove the dangerous mercury in your mouth.

The Impact of Your Diet on Your Cognitive Health

Now, there's also plenty of research showing the links between your diet and your risk of mental decline, especially Alzheimer's.

For example, vegetarian diets have been shown to increase your Alzheimer's risk, whereas diets high in omega-3's lower your risk.

High intake of the omega-3 fatty acid DHA can help protect your brain from memory loss and cell damage caused by Alzheimer's disease, thereby slowing down its progression, and lowering your risk of developing the disorder. Researchers have also said DHA "dramatically reduces the impact of the Alzheimer's gene."

Omega-6 and omega-3 fatty acids are both essential for your health. However, the typical American diet is far higher in omega-6 than omega-3 (like DHA), throwing your ratios out of balance.

Your ideal ratio of omega-6 to omega-3 fats is 1:1. Today, the average intake ratio of omega-6 to omega-3 is anywhere from 20:1 to 50:1! This unbalanced intake could lead to several health problems, including Alzheimer's.

The easiest way to balance your ratio is to consume more omega-3 fats from good sources, and reduce your intake of omega-6 fats.

The primary sources of omega-6 are corn, soy, canola, safflower, and sunflower oil; these oils are overabundant in your typical diet, which explains the excess omega-6 levels. Avoid or limit these oils.

By far, the best omega-3 fats are those found in fish. That's because the omega-3 in fish is high in two fatty acids crucial to human health: DHA and EPA. Unfortunately, eating most fresh fish -- whether from the ocean, lakes and streams, or farm-raised -- is no longer recommended due to excessive mercury contamination.

Therefore, your safest bet for clean and pure omega-3 benefits is to take krill oil or fish oil. And, while I am well-known as a minimalist when it comes to supplements, fish oil and krill oil are "supplements" I strongly urge you to add to your daily diet if you want to prevent disease, and increase both the length and quality of your life.

Vegetarian diets, on the other hand, often cause B12 deficiency, which may increase your risk of cognitive problems. Vitamin B12 plays an important role in maintaining nerve cells, and low blood levels of B12 have been linked to mental decline.

In one study of men and women aged 75 and older, researchers found those with low levels of the vitamin were twice as likely to develop Alzheimer's as those with normal levels, over a three-year period. It is thought that the deficiency may lead to elevated homocysteine (an amino acid), which may in turn damage nerve cells.

Vitamin B12 is found in animal products (which is why vegetarians are so frequently deficient in this vitamin), such as:

* Meat
* Fish
* Eggs
* Milk
Another potential cause of B12 deficiency is the popular drug Prilosec (omeprazole), which has been clearly shown to decrease B12 absorption (Ann Pharmacother 1999 May;33:641-3). This might be due to its effects on decreasing your production of intrinsic factor, which is needed for proper B12 absorption. Other medications likely have similar adverse effects as well.

If you need to supplement your diet with vitamin B12, please be aware that oral or sublingual B12 does not work very well. Injectable B12 is really the gold standard, but I outline another option with DMSO that is inexpensive, and appears to be equivalent.

Vitamin K deficiency is yet another vitamin deficiency that has been pointed out as a possible contributing factor in Alzheimer's disease.