We Are What We Eat

<p>Stem cells home in on sites of injury in order to rebuild damaged tissue leading many to the assumption that the more stem cells you have circulating through your body the healthier you are.</p><p><img height="220" alt="Eat Right!" hspace="5" src="images/articles/38a142a.jpg" width="220" align="right" vspace="5" border="0" />I am frequently asked whether dietary supplements, which are claimed to increase circulating stem cell numbers, have the ability to make us healthier and prolong life. Quite frankly, I do not know the answer because, as far as I am aware, this has not been adequately demonstrated in any scientifically acceptable manner; but this does not prevent us from a deeper examination of the issue. </p><p><em>First, can supplements increase the number of circulating stem cells?</em> <br />There is some experimental evidence that suggests that this may be the case, at least for a short while after the supplements have been taken. </p><p><em>Second, is that why some people using these supplements feel so much better?</em> <br />Do you drink coffee, or Red Bull? And how does this make you feel? Do you experience a “lift”? The link might not be obvious, but what if the dietary supplement you are taking also contains a stimulant that has nothing to do with stem cells, but elevates your mood by interacting with the same receptors in your brain that happy pills rely on?</p><p><em>Third, is the increase in stem cells significant enough to have any positive repercussions in the body?</em> <br />Here, unfortunately for the moment, I must draw a blank as I am not aware of any sound scientific data that unequivocally demonstrates this to be the case. One may, of course, ask the opposite question, namely: could an excess of stem cells be harmful? Here there is some indirect evidence that is suggestive. Let me explain.</p><p>Many cancers rely on the development of a new network of small blood vessels (capillaries) in order to grow. This growth of new capillary blood vessels is called angiogenesis. Interestingly, this process is also required for the growth of a foetus in the womb. The principle is quite simple: as foetal tissues grow, they outstrip their blood supply, which prevents further growth. Through an extraordinary series of well-defined signals, new blood vessels begin growing to provide oxygen and nutrients to the developing foetus and promote continued growth. This self-regulatory system is an absolute requirement for the creation of a new being, and ensures that all the bits and pieces are in the right place.</p><p>So, how does this relate to our debate? Well, several years ago it was shown that new blood vessels that form in cancers might rely, in part, on stem cells circulating in the blood for their continued growth. See where I am going? Could this mean that by increasing the number of circulating stem cells we might, in fact, promote the growth of cancers and even increase their ability to spread? Quite honestly, I do not know, and I have no direct evidence to suggest that this may be the case. But as you can see, the thought has crossed my mind. </p><p>Imagine if we extend this scenario to the foetus. Could we possibly affect (increase) the growth of a developing baby by taking dietary supplements? Could we produce designer babies, perhaps ensuring a constant supply of players for our rugby-focussed nation? Scary you might say, and I would agree. </p><p>The point I am trying to make is that it is absolutely critical to have reliable data (from well-designed studies) to back up any hypotheses, and not to rely on assumptions that seem to “fit well”. And we have to wonder what they “fit well”? A deep-seated and noble need to see that we and our children are healthier and live longer? Or well-conceived marketing strategies aimed at increasing the bottom line?</p><p>I am all for innovation and the development of new products that ensure happier, healthier and more productive lives but I am also aware that, in our quest for happiness, we often overlook the details because we have learnt to rely on professionals to take care of this for us. What if these professionals have also overlooked the details? And what if, by some remote chance, the professionals we trust are motivated more by their quest for material rather than intellectual or scientific wealth?</p><p>Science is not infallible, and certainly cannot explain everything, but there is always a need for honestly procured data from well-designed clinical trials. Evidence-based medicine, which again is not infallible, requires that all new (and existing) forms of treatment be based on reliable evidence. This is all that is requested for the implementation of new therapies by health professionals who have the best interests of their patients at heart. Is this too much to ask?</p><p>Anything that improves the quality of our lives should not be ignored and, if dietary supplements do this for you, (with the added proviso that this does not have a negative effect on your finances) then go for it. </p><p>Please be careful not to allow yourself to be made to believe that you are taking a wonder drug that will do amazing things to your body, if these claims have not been adequately substantiated. Sometimes it is better to err on the side of caution than to be lured into a sense of false hope.</p><p>Part four in a series of articles written by Professor MS Pepper of the University of Pretoria. Copyright: the content remains the property of the author and may not be reproduced in any format without his express and written consent. </p>

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