Showing posts with label cancer. Show all posts
Showing posts with label cancer. Show all posts

Guess who is hiding the magic pill to longevity?

Imagine a medicine which protects you against cardiovascular disease, cancers, diabetes, depression and dementia. A medicine which works best when taken regularly and long before any symptoms of any of those diseases appear. A medicine which is cheaper than any supplement or aspirin. Would you take it?


Then why don't you? The name of that medicine is exercise, and ...
...OK, OK, I hear you saying "not again, I have heard that mantra before. Tell me something I don't know!" Which is exactly what I want to do: To tell you something you AND I don't know, because nobody seems to have the answer to the sixty-four-thousand dollar question: Why don't we take this medicine?
Now here is this hot item called swarm intelligence, the phenomenon which, we are being told, makes a horde of blooming idiots come up with solutions worthy of an Einstein's. That should work just fine for us. So, let's put it to the test. I'll tell you first a few facts and my thoughts, after which it is your turn, and then we can look at the results over the next few days, or so.
Now, just so that we all start form the same page, let me recap the effects of exercise. 

Exercise & Heart Disease

Exercise, done right, has been found to reduce the risk of dying from any cause by at least one third with a 9% reduction for every one hour of vigorous exercise performed per week [1]. To be fair, studies which calculate such risks are inherently flawed. They assess exercise through questionnaires, which makes it difficult to reliably judge the amount and intensity of exercise, and whether people stick with a given exercise level and for how long. That's why I like to look at the exercise-health correlation using fitness as the marker. Because fitness is a direct consequence of exercise, and it is something we can objectively measure in the lab.
A fit 45 years old man has only one quarter the lifetime risk of dying from cardiovascular causes compared to his unfit peer [2]. And 20 years later, at the age of 65, being fit means having only half the risk of an unfit 65-year old. So much about exercise and the number one killer of men and women alike, cardiovascular disease. How about the runner-up: cancer?

Exercise & Cancer

The association of fitness with cancer is not as well researched as with cardiovascular disease. But the available data clearly point to a substantial effect. In a study performed in 1300 Finnish men who were followed for 11 years, the physically fit ones, when compared to their least fit peers, had a 60% reduced risk of dying from non-cardiovascular causes, which means mostly cancer [3]. An almost identical value of risk reduction for cancer death had been found in a 16-year study of 9000 Japanese men aged 19-59 [4]. The ones in the highest quartile of physical fitness had a risk of dying from cancer that was 60% lower than the risk of their peers in the lowest quartile.
The fact that fitness correlates so strongly with the risk of dying from cancer might tell us that the intensity of exercise plays a large role. In a study, which followed 2560 men for close to 17 years, the intensity of physical activity was clearly related to cancer mortality. But only in those who were physically active for at least 30 minutes per day did the higher intensity of exercise lower the cancer death risk by close to 50%. Do less than those 30 minutes, and high intensity might not get you away from cancer death. Obviously, low-intensity exercise does neither increase your fitness level nor does it decrease your risk of dying from cancer. The message to all those who play 18 holes on a daily basis: Get a (sports-)life!

Exercise & Dementia

Even less well examined than the exercise-cancer association is the exercise-dementia association. But also here we begin to see a remarkable effect. Results from the first relatively small trials show that physically active elderly have substantially reduced risk of Alzheimer and other forms of dementia, possibly in the range of a 50% risk reduction [5]. 

Why Don't We Exercise?

Ok, so here we are. Obviously, man is made to move. And whether you call exercise medicine or whether you call the lack of exercise a pathogen - which is clinician speak for something nasty that makes you sick - we already know a lot about how exercise does its work biochemically. That's beyond the scope of this post.
What interests me here is the question which I have asked at the beginning of this story: Why do we not take this "medicine" which is free-of-charge and which has a stronger effect than any of those pills for lowering cholesterol or blood sugar or blood pressure?
As researchers we have made no progress at all in answering this question.
The psychologists outdo each other with the creation of behavioral models, which give their inventors a lot of stature, but which have failed to get us one inch closer to the answer. Just to give you an impression, there is the Health Belief Model, the Theory of Reasoned Action, the Theory of Planned Behavior, the Transtheoretical Model of Behavioral Change, the Social Cognitive Theory, the Protection Motivation Theory, the Health Action Process Approach, and probably a few new ones in the making. Their common denominator: no reliable answer to our question.
That's why I would like to try swarm intelligence. If the "swarm" of readers of this blog post, that is you and me, is large enough, we might just come up with an answer that is worth pursuing in a more methodical way.
So, I'll go ahead and tell you a few suspicions which I have. And then, at the risk of baring my soul to the point where you might not find me a likable person, I will tell you what motivates me to do an early morning 90-minutes exercise session almost every day of the week.
But first the suspicions which I have why so few people get themselves to do even the bare minimum of exercise:
1.     Is it because we can't see, I mean literally see, the effects? Would some sort of visual feedback about the benefits and effects of exercise inside your body motivate you to exercise?
2.     Is it because we rather react than act? That is, we only do something to cure a disease once it's manifest rather than prevent it? But then, why do we have intelligence and one of its nifty byproducts called foresight in the first place?
3.     Is it because we are so focused on a pill or an operation as the only tools, which work against a disease, that we simply can't appreciate the value of something so simple and cheap as exercise?
4.     Why do we use the lousy excuse "no time" when we have several hours to spend in front of the TV EVERY day? Regardless of how busy we are with our work?
These are just a few questions which come to mind. They amount to asking why we don't exercise. 
But it will be equally helpful to ask the question: what is it, that KEEPS YOU exercising? 
Because from those who do, we can learn, how to motivate those who don't. Provided we get an honest answer. My suspicion is, the answers which we get in research, are mostly edited for "political correctness". The couch potatoes hide behind the time constraints, because being busy is not perceived as a character flaw, being lazy is. And what could possibly be a character flaw of the exerciser?
Well, I give you mine. The instinctive gratification with which my inner brute views the overweight person in front of me at the check-out queue or in the waiting room, the gratification that comes from being reminded of his risk for disease and suffering being a lot greater than mine (in German we have that word "Schadenfreude"), the gratification that comes from telling him, in my mind only, of course, "I have that strength of will that you don't". 
That's a gratifying incentive, to be sure. But it's not the only one. The main reason why I run every morning, no matter what the weather or the size of the hangover from Saturday's evening (yeah, it happens to all of us) is, that I have seen enough people who suffered a stroke or a heart attack. And I have seen their remorse of not having done enough while there was still time. I fear that. That's what keeps me running.
And what is it for you? Honestly. Let's hear it, and let's see whether we find a common thread, which research has overlooked so far. Remember, as a swarm we are supposed to be far more intelligent than as individuals.




Samitz G, Egger M, & Zwahlen M (2011). Domains of physical activity and all-cause mortality: systematic review and dose-response meta-analysis of cohort studies. International journal of epidemiology, 40 (5), 1382-400 PMID: 22039197

Berry JD, Willis B, Gupta S, Barlow CE, Lakoski SG, Khera A, Rohatgi A, de Lemos JA, Haskell W, & Lloyd-Jones DM (2011). Lifetime risks for cardiovascular disease mortality by cardiorespiratory fitness levels measured at ages 45, 55, and 65 years in men. The Cooper Center Longitudinal Study. Journal of the American College of Cardiology, 57 (15), 1604-10 PMID: 21474041

Laukkanen, J. (2001). Cardiovascular Fitness as a Predictor of Mortality in Men Archives of Internal Medicine, 161 (6), 825-831 DOI: 10.1001/archinte.161.6.825

SAWADA, S., MUTO, T., TANAKA, H., LEE, I., PAFFENBARGER, R., SHINDO, M., & BLAIR, S. (2003). Cardiorespiratory Fitness and Cancer Mortality in Japanese Men: A Prospective Study Medicine & Science in Sports & Exercise, 35 (9), 1546-1550 DOI: 10.1249/01.MSS.0000084525.06473.8E

Buchman AS, Boyle PA, Yu L, Shah RC, Wilson RS, & Bennett DA (2012). Total daily physical activity and the risk of AD and cognitive decline in older adults. Neurology, 78 (17), 1323-9 PMID: 22517108

Do vitamin supplements make you healthier?

The (non-)sense of vitamin supplementation?

Almost one in two American adults is a regular user of vitamin and mineral supplements, either in the form of single- or multivitamin/mineral formulations (MVMS). It all adds up to a market of US$ 9 Billion annually, or one third of the total US supplements market. Does all the pill-popping help their users to achieve better health or longevity? 
That's one question raised by Björn, one of the readers of my blog. Thanks, Björn, I wanted to write on this subject for some time. You just got me going on this a little earlier than I would have otherwise. And also thanks for the second question: Does the latest technology of delivering the drug (not to your house, but within your body to your organism's cells) via "nano-encapsulation" improve that health effect in any way? Let me try to answer these questions one by one.
When you talk about vitamins, you talk about essential micronutrients, for which the human organism has either no or only a very limited ability to produce (e.g. Vitamin D) on its own. If you want to group vitamins according to their solubility you'll find that they come in two flavors: water soluble and fat soluble. Of course, you could group them for any other biochemical characteristic, but grouping them according to their solubility makes immediate sense when you keep in mind that the fat soluble ones (A, D, E and K) can accumulate in your body's tissues, whereas the water soluble Vitamins typically can't. Whatever can accumulate, can also accumulate to the point where there is too much of it in a body's tissue. So, yes, too much of a good thing may turn into a not so good thing, as is the case for vitamins A and E for example. Or, too much of a good thing may just be flushed out of the body, as is the case with water-soluble vitamin C.
The supplement industry certainly does a good job convincing the public that supplementing one's diet with additional vitamin formulations is good for one's health. It's certainly good for the industry's bank accounts. In such cases it always pays to ask one simple question: Where is the evidence?  
In a meta-analysis of randomized clinical trials (RCT, the gold standard of clinical research methodology), the authors investigated the effects of vitamins E and A on the risk of cardiovascular disease and death in altogether 220,000 patients [1]. The effects? Zilch. The authors recommendation? The evidence does not support any recommendation for the use of Vitamins E and A. On the contrary, they found a slight increase in all-cause and cardiovascular disease mortality associated with vitamin A supplementation.
In another 2007 review on the subject, published in the American Journal of Clinical Nutrition, its author came to the same conclusion, stating that "Results to date are not compelling concerning a role for MVMs in preventing morbidity or mortality from cancer or CVD." [2] The two largest trials on Vitamin A and E supplementation in smokers, the Finnish Alpha-Tocopherol Beta-Carotene (ATBC Trial) and the US Carotene and Retinol Efficacy Trial (CARET) enrolled 29,000 and 18,000 smokers. In the Finnish trial, supplementation with Vitamin A increased the risk for lung cancers by 18% within a 5 to 8-year observation period [3]. And the US trial was halted after 2 years for the same reason: a 28% increase in lung cancer risk, a 26% increase in risk for dying from cardiovascular disease [4]. In 22,000 healthy men who had been observed for 12 years, supplementation with vitamin A showed neither benefit nor harm [5].  
So where is the evidence for you to believe that buying Vitamin E and A supplements will make you healthier and live longer? Maybe I'm blinded by a perverse distrust of everything a sales man tells me, but I can't see it.
So, how about multi-vitamins? In the group of people with the highest take-up rate of multivitamins: post-menopausal women? Again, the authors of a study which pooled the data from the Women's Health Initiative trial and observational study cohorts, come to the same conclusion "the WHI CT and OS cohorts provide convincing evidence that multivitamin use has little or no influence on the risk of cancer or CVD in postmenopausal women." [6].
Not even for infections is there any evidence that MVMS have any protective effect on those most vulnerable, the elderly [7]. 
Of course, keeping all this in mind, the nagging question remains: would there be an effect if only the delivery of the drug in the human body was improved? After all, if vitamins are essential for survival, and if vitamin supplementation does not improve health, then there are several possible reasons for this observation. For instance, we might get enough vitamins from our food, and adding vitamins has simply no effect. Or, maybe we have vitamin deficiencies but the supplements are ineffective in delivering their vitamin loads.
Which brings us to Björn's second question: "Does nano-encapsulation improve the effect of MVMS?
And may I add my nagging question: Or is "nano-whatever" just a cool gimmick of the industry to push a market, which currently grows only moderately? In the next post (Monday 16. April) I'll try to answer this question. So, stay tuned.