Do B Vitamins Slow Cognitive Decline?

Written by Dr. Steve Chaney on . Posted in current health articles, Supplements and Health, Vitamins and Health

The B Vitamin Controversy

Author: Dr. Stephen Chaney

 

cognitive-declineDo B Vitamins slow cognitive decline?  Heart disease, cancer and strokes are all pretty scary. Even if we survive, our quality of life may never be the same. But, we can endure many physical afflictions if our mind stays sharp. For most of us the ultimate irony would be to spend a lifetime taking good care of our body, only to lose our mind.

Last week I told you about a study showing that a holistic approach, which to me includes healthy diet, weight control, exercise, supplementation, socialization and memory training, significantly reduces cognitive decline in the elderly (https://healthtipsfromtheprofessor.com/hope-alzheimers/).

This week I’d like to focus on one aspect of that holistic approach, namely B vitamins. If you are like most people, you are probably confused about the role of B vitamins in preserving mental function. On the one hand you are seeing headlines proclaiming that B vitamins slow cognitive decline as we age. On the other hand you are being told “Don’t waste your money. B vitamins won’t slow cognitive aging.” What are you to believe?

 

Why Might Certain B Vitamins Slow Cognitive Decline?

To help you understand how B vitamins might slow cognitive decline I’m going to need to get a little biochemical. Don’t worry. I’ll be merciful.

#1: The story starts with a byproduct of amino acid metabolism called homocysteine.

Multiple studies have shown that elevated blood levels of homocysteine are associated with cognitive decline and Alzheimer’s. Elevated homocysteine levels are found in 5-10% of the overall population and elevated homocysteine levels double the risk of Alzheimer’s.

In our bodies homocysteine is converted to the amino acid methionine in a reaction involving folic acid and vitamin B12. Homocysteine is converted to the amino acid cysteine in a reaction involving vitamin B6. Thus, elevated homocysteine levels are most frequently associated with deficiencies of these three B vitamins caused by inadequate intake or increased need for those B vitamins.

#2: Many of us are deficient in the B vitamins that lower homocysteine levels.

There are many situations in which inadequate intake or increased need of those vitamins can occur. For example:

Vitamin B12:

vitamin-B12

  • The most frequent cause of B12 deficiency is the age related loss of the ability to absorb vitamin B12 in the upper intestine. This affects 10-30% of people over the age of 50.
  • Chronic use of acid-suppressing medications such as Prilosec, Nexium, Tagamet, Pepcid and Zantac also decreases B12 absorption and increases the risk of B12 deficiency. Millions of Americans use those drugs on a daily basis.
  • Finally, vegetarians can become B12 deficient because most naturally occurring B12 is found in meat and dairy products.
  • Overall, B12 deficiency has been estimated to affect about 40% of people over 60 years of age.

Folic Acid:

  • In the past, many Americans consumed diets that were low in folic acid. However, this has been minimized in recent years by the fortification of grain products with folic acid. Today, the primary concern is with factors that increase the need for folic acid.
  • For example, birth control pills along with some anti-inflammatory and anticonvulsant medications interfere with folic acid metabolism and increase the need for folic acid.
  • In addition, deficiency of the enzyme methylenetetrahydrofolate reductase (MTHFR) substantially increase the amount of folic acid needed to reduce homocysteine levels to normal. About 10% of the US population has this enzyme deficiency.

Vitamin B6:

  • Birth control pills along with some drugs used to treat high blood pressure and asthma interfere with vitamin B6 metabolism and increase the need for vitamin B6.
  • Vitamin B6 is found in reasonable amounts in meat, beans, green leafy vegetables, brown rice and whole grain flour. Unless you are consuming a balanced diet containing all of those foods your intake of B6 may be inadequate. About 25% of Americans have low blood levels of B6.

#3: Multiple studies have shown that supplementation with folic acid, B12 and B6 can lower homocysteine levels.

Based on this information it has been hypothesized that supplementation with folic acid, B12 and B6 would decrease the rate of cognitive decline in people with elevated homocysteine levels. It is a logical hypothesis, but is it correct?

The Evidence That B Vitamins Don’t Slow Cognitive Decline

The recent headlines saying that B vitamins don’t slow cognitive decline came from a meta-analysis that included the results of 11 clinical trials with 22,000 individuals B-vitamins-cognitive-decline(Clarke et al, American Journal of Clinical Nutrition, 100: 657-666, 2014). That sounds pretty impressive! But to properly assess the conclusions of this study you need to understand the strengths and weaknesses of meta-analyses.

  • The strength of a meta-analysis is pretty obvious. By combining the results of many clinical trials and thousands of patients you greatly increase the statistical power of the study.
  • However, the strength of a meta-analysis is only as good as the studies it includes. It’s the old “GIGO” principle (Garbage In, Garbage Out). If the individual studies are poorly designed, the conclusions of the meta-analysis will be misleading.

Unfortunately, many of the studies in this meta-analysis were poorly designed. They fall into two groupings:

Problem #1: Many of the studies included in the meta-analysis were not designed to test the actual hypothesis.

Remember that the original hypothesis was that supplementation with folic acid, B12 and B6 would decrease the rate of cognitive decline in people who were deficient in those B vitamins and had elevated homocysteine levels. Nobody was predicting that B vitamin supplementation would make any difference for people who already had adequate B vitamin levels and low homocysteine levels.

Five of the studies were not designed to look at that hypothesis at all. They were very large studies designed to look at the hypothesis that B vitamins might reduce the risk heart attack and stroke in patients with cardiovascular disease. Some of those patients had elevated homocysteine levels, but many did not.

It’s no wonder they did not show any significant effect of B vitamins on cognitive decline. They weren’t designed for that purpose, but they contributed the vast majority of patients and most of the statistical weight to the conclusions of the meta-analysis.

Problem #2: Some of the studies were too short to draw any meaningful conclusions.

Three of the studies were well designed in that they specifically looked at patient populations with elevated homocysteine levels and documented B vitamin deficiency, but they only lasted for 3 to 6 months. There simply was not a large enough cognitive decline in the control group in such a short time span for one to see a statistically significant effect of B vitamin supplementation.

Do B Vitamins Slow Cognitive Decline?

B-vitamins-slow-cognitive-declineThat leaves three studies from the original meta-analysis, plus another clinical study published after the meta-analysis was complete, that were actually designed to test the hypothesis and were long enough to give meaningful results. Three of those four studies showed a positive effect of B vitamin supplementation on cognitive function.

Study #1: This study was a 3-year study in patients with elevated homocysteine levels, folic acid deficiency and normal B12 levels (Durga et al, The Lancet, 369: 208-216, 2007). They were given 800 ug/day of folic acid or a placebo. Folic acid levels increased 576% and homocysteine levels decreased by 25%. At the end of 3 years the change in memory, information processing speed and sensorimotor speed was significantly better in the folic acid group than the control group.

Study #2: This was a 2-year study in patients with elevated homocysteine levels (McMahon et al, New England Journal of Medicine, 354: 2764-2769, 2006). B vitamin deficiencies were not measured. The patients were given either 1000 ug 5-methyltetrahydrofolate, 500 ug of B12 and 10 mg of B6 or a placebo. Homocysteine levels decreased significantly, but there was no effect of B vitamins on cognitive function in this study.

Study #3: This study was a 2-year study in patients over 70 with mild cognitive decline (Smith et al, PLoS ONE 5(9): e12244. doi:10.1371/journal.pone.0012244, 2010). B vitamin deficiencies were not measured. The patients were given either 800 ug of folic acid, 500 ug of B12 and 20 mg of B6 or placebo. B vitamin supplementation increased folic acid levels by 270% and decreased homocysteine levels by 22%. Brain volume was measured by MRI. Overall, B vitamin supplementation decreased brain shrinkage by 30%. The rate of brain shrinkage in the placebo group and the protective effect of B vitamins were greatest in the patients with elevated homocysteine at entry into the trial.

Study #4: This was an expansion of the previous study (Douaud et al, Proceedings of the National Academy of Sciences, 110: 9523-9528, 2013). In this study the same investigators focused on the regions of the brain most vulnerable to cognitive decline and the Alzheimer’s disease process. They found that B vitamin supplementation reduced brain atrophy in those regions by 7-fold (a whopping 86% decrease in brain shrinkage) over a 2-year period. Once again, the rate of brain shrinkage in the placebo group and the protective effect of B vitamins were greatest in the patients with elevated homocysteine at entry into the trial.

Are B Vitamins Only Effective In People With Elevated Homocysteine Levels?

The published data certainly suggest that B vitamins may reduce cognitive decline in people with elevated homocsteine levels, but what about other people with B vitamin deficiencies? For reasons that are not entirely clear, not everyone with folic acid, B12 and/or B6 deficiencies has elevated homocsyteinine levels.

Other symptoms of folic acid, B12 and B6 deficiency are depression, pronounced fatigue, irritability, peripheral neuropathy (tingling and loss of feeling in extremities), and loss of fine motor coordination. If you have these symptoms and they are caused by B vitamin deficiency, B vitamin supplementation may relieve the symptoms.

B vitamin supplementation may also slow cognitive decline in individuals who are B vitamin deficient and have normal homocysteine levels, but that hypothesis has not been clinically tested.

The Bottom Line

1)     Forget the headlines telling you that B vitamins don’t slow cognitive decline. Also ignore headlines implying that B vitamins will help everyone be an Einstein well into their 90’s. As usual, the truth is somewhere in between.

2)    Supplementation works best for people with inadequate dietary intake and/or increased needs. That is just as true for B vitamins and brain health as it is for other health benefits of supplementation.

3)     Many people with deficiencies of folic acid, B12 and/or B6 have elevated homocysteine levels. If you do have elevated homocysteine levels, the data are pretty convincing that supplementation with folic acid, B12 and B6 may reduce the risk of cognitive decline. Unfortunately, homocysteine is not something that is routinely measured in most physical exams, but perhaps it should be.

4)     Not everyone with folic acid, B12 and/or B6 deficiencies has elevated homocsyteinine levels. Other symptoms of folic acid, B12 and B6 deficiency are depression, pronounced fatigue, irritability, peripheral neuropathy (tingling and loss of feeling in extremities), and loss of fine motor coordination. If you have these symptoms and the symptoms are caused by B vitamin deficiency, B vitamin supplementation might also slow cognitive decline. However, that hypothesis has never been clinically tested.

5)     It has been recognized recently that deficiencies of methylenetetrahydrofolate reductase (MTHFR) interfere with folic acid metabolism and cause elevated homocysteine levels. Contrary to what you may have heard, 5 methyltetrahydrofolate is not essential for reducing homocysteine levels in people with MTHFR deficiency. High levels of folic acid work just as well for most MTHFR-deficient individuals. [It is also interesting to note that the only well designed clinical study that did not find B vitamins to be effective in reducing cognitive decline was the one that substituted 5-methyltetrahydrofolate for folic acid.]

6)     B vitamin deficiency is common in the elderly due to impaired absorption and the use of multiple medications that interfere with B vitamin metabolism and can contribute to many of the symptoms commonly associated with aging. In this population, B vitamin supplementation is cheap and often effective.

7)     B12 deficiency is common in adults 60 and older. High doses of folic acid alone can mask B12 deficiency and lead to irreversible nerve damage. For that reason high doses of folic acid should be paired with high dose B12 and B12 nutritional status should be determined. [Contrary to what you may have heard, 5-methyltetrahydrofolate is just as likely to mask B12 deficiency as is folic acid.]

8)     Finally, assuring an adequate intake of B vitamins is just one component of a holistic approach for maintaining brain function as long as possible. Other important lifestyle components for preserving cognitive function are healthy diet, weight control, exercise, supplementation, socialization and memory training. (https://healthtipsfromtheprofessor.com/hope-alzheimers/).

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Comments (5)

  • Gloria Kelley Gonzalez

    |

    Some great information here.

    Reply

  • crissy handley

    |

    I am one who has absorbtion problems of B complex B12 and COQ10. Recently high homocysteine.. With supplementation of Shaklee Bcomplex (4-6 additional plus Vitalizer) and B12, my cognituve function has increased and depression totally in control. This totally makes
    so much sense!! Thank you!

    Reply

    • Dr. Steve Chaney

      |

      Dear Crissy,

      You are a perfect example of the point that I made in my blog post. It is the people who have a B vitamin deficiency (often caused by things like poor absorption) who are most likely to benefit from B vitamin supplementation.

      Dr. Chaney

      Reply

  • Rose Marie Strauss, R.N.

    |

    I have absorption problems.With one tablet of B6/B12 (Trader Joe,s ) suggested use, I take one tablet under the tongue(sublinquel) as a dietary supplement. I need to have my homo-cysteine checked again.I recently had a lab test.and I did not think to ask them to ad this to my lab test.
    It makes a lot sense.Everybody should be informed of
    this great .articles.

    Reply

    • Dr. Steve Chaney

      |

      Dear Rose Marie,

      Sub-lingual Bs are usually not necessary, but it is a good idea to monitor your homocysteine levels. We don’t know whether homocysteine causes cognitive decline, but it does correlate with cognitive decline.

      Dr. Chaney

      Reply

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Latest Article

One of the Little known Causes of Headaches

Posted August 15, 2017 by Dr. Steve Chaney

Your Sleeping Position May Be Causing Your Headaches!

Author: Julie Donnelly, LMT – The Pain Relief Expert

Editor: Dr. Steve Chaney

 

Can sleeping position be one of the causes of headaches?  

A Sleeping position that has your head tilted puts pressure on your spinal cord and will cause headaches. I’ve seen it happen hundreds of times, and the reasoning is so logical it’s easy to understand.

causes of headachesYour spinal cord runs from your brain, through each of your vertebrae, down your arms and legs. Nerves pass out of the vertebrae and go to every cell in your body, including each of your organs. When you are sleeping it is important to keep your head, neck, and spine in a horizontal plane so you aren’t straining the muscles that insert into your vertebrae.

The graphic above is a close-up of your skull and the cervical (neck) vertebrae. Your nerves are shown in yellow, and your artery is shown in red.  Consider what happens if you hold your head to one side for hours. You can notice that the nerves and artery will likely be press upon. Also, since your spinal cord comes down the inside of the vertebrae, it will also be impinged.

In 2004 the Archives of Internal Medicine published an article stating that 1 out of 13 people have morning headaches. It’s interesting to note that the article never mentions the spinal cord being impinged by the vertebrae. That’s a major oversight!

Muscles merge into tendons, and the tendons insert into the bone.  As you stayed in the tilted position for hours, the muscles actually shortened to the new length.  Then you try to turn over, but the short muscles are holding your cervical vertebrae tightly, and they can’t lengthen.

The weight of your head pulls on the vertebrae, putting even more pressure on your spinal cord and nerves.  Plus, the tight muscles are pulling on the bones, causing pain on the bone.

Your Pillow is Involved in Your Sleeping Position and the Causes of  Headaches

sleep left side

The analogy I always use is; just as pulling your hair hurts your scalp, the muscle pulling on the tendons hurts the bone where it inserts.  In this case it is your neck muscles putting a strain on your cervical bones.  For example, if you sleep on your left side and your pillow is too thick, your head will be tilted up toward the ceiling. This position tightens the muscles on the right side of your neck.

sleeping in car and desk

Dozing off while sitting in a car waiting for someone to arrive, or while working for hours at your desk can also horizontal line sleepcause headaches. The pictures above show a strain on the neck when you fall asleep without any support on your neck. Both of these people will wake up with a headache, and with stiffness in their neck.

The best sleeping position to prevent headaches is to have your pillow adjusted so your head, neck, and spine are in a horizontal line. Play with your pillows, putting two thin pillows into one case if necessary. If your pillow is too thick try to open up a corner and pull out some of the stuffing.

 

sleeping on stomachSleeping on Your Back & Stomach

If you sleep on your back and have your head on the mattress, your spine is straight. All you need is a little neck pillow for support, and a pillow under your knees.

Stomach sleeping is the worst sleeping position for not only headaches, but so many other aches and pains. It’s a tough habit to break, but it can be done. This sleeping position deserves its own blog, which I will do in the future.

 

Treating the Muscles That Cause Headaches

sleeping position causes of headachesAll of the muscles that originate or insert into your cervical vertebrae, and many that insert into your shoulder and upper back, need to be treated.  The treatments are all taught in Treat Yourself to Pain Free Living, in the neck and shoulder chapters.  Here is one treatment that will help you get relief.

Take either a tennis ball or the Perfect Ball (which really is Perfect because it has a solid center and soft outside) and press into your shoulder as shown.  You are treating a muscle called Levator Scapulae which pulls your cervical vertebrae out of alignment when it is tight.

Hold the press for about 30 seconds, release, and then press again.

Your pillow is a key to neck pain and headaches caused by your sleeping position.  It’s worth the time and energy to investigate how you sleep and correct your pillow.  I believe this blog will help you find the solution and will insure you have restful sleep each night.

Wishing you well,

Julie Donnelly

 

About The Author

julie donnelly

Julie Donnelly is a Deep Muscle Massage Therapist with 20 years of experience specializing in the treatment of chronic joint pain and sports injuries. She has worked extensively with elite athletes and patients who have been unsuccessful at finding relief through the more conventional therapies.

She has been widely published, both on – and off – line, in magazines, newsletters, and newspapers around the country. She is also often chosen to speak at national conventions, medical schools, and health facilities nationwide.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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