Sunday, October 19, 2008

Exercise and Brain Aging

There is now abundant research pointing to the beneficial effects of aerobic exercise on cerebral health. This recent study finds that taking up exercise can improve cognition and cerebral health. There is a striking relationship between cardiovascular and cerebral health. The reason for this is obvious: the brain consumes approximately 20% of our oxygen intake, so maintaining maximal blood supply to the brain is critical. One of the reasons Ginkgo Biloba works is because it reduces platelet activating factor, thereby improving cerebral circulation.

Exercise and do it often. You don't have to run marathons, in fact intense exercise can do more harm than good. Light exercise is okay but it is important to push yourself, just going for a casual walk is good but going for a brisk walk is much better.

Exercise effects on cognitive and neural plasticity in older adults
Kirk Erickson and Arthur F Kramer
British Journal of Sports Medicine (2008).
The abstract:

Older adults frequently experience cognitive deficits accompanied by deterioration of brain tissue and function in a number of cortical and subcortical regions. Because of this common finding and the increasing aging population in many countries throughout the world, there is an increasing interest in assessing the possibility that partaking in or changing certain lifestyles could prevent or reverse cognitive and neural decay in older adults. In this review we critically evaluate and summarize the cross-sectional and longitudinal studies that assess the impact of aerobic exercise and fitness on cognitive performance, brain volume, and brain function in older adults with and without dementia. We argue that six-months of moderate levels of aerobic activity are sufficient to produce significant improvements in cognitive function with the most dramatic effects occurring on measures of executive control. These improvements are accompanied by altered brain activity measures and increases in prefrontal and temporal grey matter volume that translate into a more efficient and effective neural system.

Low antioxidant status and high sunlight exposure = Retinal Degeneration

I don't know if the below is a true statement because I have never heard it before but it does highlight why even blue light is damaging to vision. Lesson: obtain sunnies with blue light filtering capacity. Take it as high risk that by the time you reach 70 there is a distinct possibility you have some degree of cataract formation and retinal degeneration. The key is to contain the progress of these conditions as much as possible. That can be done but even with the best of care some of us are going to need cataract surgery and may develop AMD. Genes! In particular, a diet specifically addressing the oxidative balance in your blood is very important.

Most importantly control cholesterol, I have seen enough research to indicate that high cholesterol, particularly the small LDL variant (vLDL), readily penetrates the Retinal Pigment Epithelium and thus sets off unwanted cascades of nasties.

http://www.sciencedaily.com/releases/2008/10/081013171431.htm

... The eye is particularly vulnerable to the damaging effects of sunlight. Ultraviolet radiation is absorbed by the lens, but visible or “blue” light penetrates to the retina so allowing us to see. Protection against the harmful effects of blue light is provided by the antioxidant vitamins C and E, the carotenoids (lutein and zeaxanthin) which filter blue light, and zinc. --------

The Aging Brain


This study from the Neurobiology of Aging highlights the significance of white matter in the aging process of the brain. The news item can be read here. White matter is the extensive sheath that surrounds the long and not so long axons of nerve cells. The presence of white matter markedly improves the speed at which signals can traverse through long axons. The process of myelination is long and we can in our late 20's or even early 30's before this process is completed.



Myelin creation is not a one off event, it is subject to continual degradation and renewal. The cells that produce myeline are called oligodendrocytes, a type of glial cell. Unfortunately oligodendrocyte cells demonstrate some particular vulnerabilities to insult. In those with Multiple Sclerosis, a common autoimmune condition, the immune processes responds to various "danger signals" emitted by oligodendrocytes and this can establish an ongoing destruction of these cells and myelin production. The initial triggers for this condition remain unknown but there are a number of strategies that Multiple Sclerosis sufferers can undertake which may alleviate the progress of the condition.

As we age the balance between myelin degradation and renewal falls out of kilter, the result being that we start losing the myelin covering. Of interest is the association between dementias and changes in white matter, it may even be the case that in some individuals the destruction of myelin is so extensive as to initiate a series of inflammatory processes that in turn induce dementias.

There is an important lesson here. The brain controls the body, maximising cerebral health is critical to maintaining good health as we age.

Saturday, October 4, 2008

Lipofuscin And Aging

Lipofuscin is the deposition of waste products in the cell that are not degraded. The critical factor seems to be rate at which proteins and lipids are degraded by the various "house keeping" functions in the cell. In these days the emphasis on the dynamics of aging is typically excessive oxidation events and lipofuscin receives little attention. Lipofuscin is something that needs to be addressed because as lipofuscin deposits increase the cell becomes increasingly unable to do its job.

In the graphic below I have extracted a table from a very old study. It highlights the huge increase in lipofuscin aggregation with age. They used acetyl l carnitine has a therapeutic intervention and the results were quite good but only at very high dosages. Other and much more recent research has found that acetyl l carnitine can also play an important role in preventing Age Related Macular Degeneration (AMD). In those studies they created a compound called Phototrop, a combination of acetyl L carnitine, omega 3 fatty acids, and co-enzyme Q10.

Word of warning: you should always use alpha lipoic acid with ALC because ALC increases mitochondrial function and mitochondria are the key region where oxidants are formed.

The table below is from

Japan J Pharmacol, 38, 365-71(1988)


Another worrying study concerning mobile phones

There are now a number of studies pointing to the dangers of mobile phones. Of particular concern is the widespread and frequent use of mobile phones amongst teenagers. This study reveals a disturbing quality about the microwave radiation emitted from mobile phones: the markers of oxidative stress, MDA(malondialdehyde) and XO(xanthine oxidase) remain up to 40 days after exposure to the microwave radiation in a rat model. One factor causing this sustained expression of inflammatory markers was the persistent reduction in catalase, a key antioxidant pathway in our cells.

Previous research has found increased risk of brain tumours in the young. While the telecommunications industry strenously denies any danger from using mobile phones increasing research is painting a very different picture. Some authorities have even claimed that the widespread use of mobile phones is paving the way for an epidemic of brain tumours.

Thanks to Dr. Lefever for forwarding this study to me.

The full study can be downloaded here.

Electric Eels and Electronic Implants

This study from Nature Nanotechnology is fascinating. They claim to have found a way to model the cells in electric eels that create electricity so that artificial cells can be used to power medical implant devices.

The news item can be read here.

Wednesday, October 1, 2008

Financial Risk Taking and Testosterone

Previous studies have found that the higher one's position in the social ladder, the higher the Testosterone levels tend to be. In light of this study then it is not surprising that we find ourselves in this current financial predicament because financiers, for reasons which escape this humble mind, earn extraordinarily high incomes. Think about it, there are any other number of professions that should be paid more because the people in these professions have much greater responsibility and experience much greater stress than those in the finance industry. Those poor souls can't go running home to mama(the Central Banks) when they stuff up, they go broke. Financiers go running to mama and expect a handout for being naughty boys. This has to stop and I hope this crisis makes everyone take a long hard look at the financial industry.

Here is a news release on the study.

The Future of Global Warming

It has always been my belief that we will never sufficiently reduce carbon dioxide output to address global warming. The simple fact is that we must find ways to capture existing CO2 AND reduce carbon dioxide output. This technology is amongst many currently under investigation.

Supplements for Osteoarthitis - Conflicting Results Again

I've seen this a number of times with various over the counter supplements. Some studies paint a good picture, others show equivocal results, and other studies claim the supplement is a dud. There is far too much hype concerning the purported value of all those supplements out there but the research is indicating that some supplements can be of great value not only in addressing specific pathologies but also general health. For example, Juvenon (see picture on the right) is a supplement compound backed up by credible research. While I haven't tried juvenon itself I have tried to the two components of it. It took a while for the effects to kick in but it definitely worked.

Osteoarthritis is a very common condition and many alternative therapists advocate the use of the supplements glucosamine and chondroitin sulfate. Studies have been mixed but mostly negative. This latest study suggests a mild favourable effect for glucosamine.

How does the consumer know what to do in these circumstances? Here are some guidelines:

  1. Look for reliable well conducted clinical trials on the supplement. If these don't exist then be very careful. Typically I will never advocate the use of a compound that has not been subject to clinical trials.
  2. NEVER trust the sellers of a product to provide reliable information. NEVER NEVER NEVER.
  3. Ask others who have used the supplement for their impression of it. This may help but remember individual responses to various drugs and supplements vary so widely that there is no guarantee what works for one person will work for you. This, incidentally, is also true of clinical trials. That something has worked in a clinical trial is no guarantee it will work for you. Remember, clinical trials are statistically based and hence the results apply to the treatment group, the results may not even be applicable to individuals within the treatment group.
  4. As long as you are convinced the supplement is safe and even in the absence of clinical trials there is no harm in giving it a go. It may just work for you even work clinical trials make low claims to efficacy or even state no efficacy. I appreciate this sounds contradictory but we are individuals and sometimes, even if by placebo effect, people do find benefits in supplements that have no scientific support for their use.

Vitamin C May Inhibit Chemotherapy

For some time there has been a controversy regarding the use of antioxidants during chemotherapy. Concerns have been raised because antioxidants protects cells against stress and so taking large doses during chemo may impede the effectiveness of chemotherapy.

This study appears to bear that out. What they found is that vitamin C, both in vitro and in a mouse model, allowed the tumour cells to survive by protecting the mitochondria. That makes a great deal of sense because mitochondria are a "gateway" for death signals and anything that preserves mitochondrial function typically helps keep the cell alive.

Sounds simple but isn't, there is also the possibility that in some cancers activating certain functions of mitochondria, in particular the release of pro-apoptotic factors, can activate cell death pathways. Additionally some studies have found that high doses of intravenous vitamin C can be effective in killing cancer cells. What a dilemma, take antioxidants to try and prevent healthy cells from chemotherapy damage and run the risk of helping the cancer cells to survive.

Ironically part of the problem here lies in the singular tense word "cancer". Even cancer originating in the same body tissue of the same person may be a different type of cancer. Because of this, strategies to target cancer are never going to constitute a single magic bullet, we will always have to tailor the strategy to the specific type of cell present in the tumour. So in some instances antioxidants may not present a problem because in some cancers the mitochondria are disabled or poorly functioning. In other cancers improving mitochondrial function may induce death signals like APAF1, BAX, BAD. Even then it can become complicated because some cancers have high expression of the small heat shock protein, hsp27. This protein can bind these death signals so preventing cell death.

Just to confuse the picture there is clinical evidence that the intravenous administration of vitamin C can kill cancer cells. The reasons behind this are unclear but it is known that high doses of vitamin C, particularly in the presence of free iron, can drive oxidative processes via Haber-Weiss and Fenton reactions, thereby inducing cell death. To achieve such high doses though intravenous injection is required because the body will not absorb large amounts of vitamin C orally. Hence all those people taking large doses of oral vitamin C are wasting their money. For a look at the use of intravenous vitamin C read of this article. A short comment in the Canadian Medical Journal puts forward the case for using intravenous vitamin C in cancer therapy.

It is never going to be easy! So when you see all those internet advertisements proclaiming a universal cure for cancer don't go there. It simply isn't true, each type of cancer requires a different strategy. That is why the success in cancer treatments is not uniform. Great strides have been made in treating some cancers while other types, for example brain tumours, virtually no progress has been made in 20 years. In all this remember what Mencken once wrote:
"For every human problem, there is a neat, simple solution; and it is
always wrong"