I'm often asked about my attitude to nutrient supplementation. "Do we need to supplement," is how it's often put to me.
My answer is that to prevent overt nutritional deficiency diseases such as scurvy and beri-beri, it is possible to get all we need from our diet. Less obvious deficiency states, however, may occur quite easily and might impact an individual's ability to be optimally nourished and therefore enjoy optimal health.
There is evidence that in the U.K. at least, the nutritional content of the diet has declined considerably over the last few decades. So, bearing all this in mind, I am generally warm to the idea of using nutritional supplementation, especially as an adjunct to, rather than a replacement of, a healthy diet. Not everyone is as enthusiastic as I am regarding the practice of nutritional supplementation. I often hear people contend that there is no evidence for its being beneficial, and that taking supplements only serves to make expensive urine. This attitude may come, at least in part, from a lack of evidence from randomized controlled trials, which are considered the gold standard for scientific studies. The reality is that very few trials have been done which might elucidate the benefits of multivitamins and minerals or of single nutrients. So, let us not conclude that nutritional supplementation doesn't work when it has not been adequately studied. Furthermore, even when such studies are done, they are not without limitations. One major issue here is that many health conditions have considerable latency, which basically means they develop gradually over many, many years. Because of this, any benefits of nutritional supplementation may not materialize for many, many years. So studies may not be conducted for long enough for any benefits to have come to fruition. Also, there are certain methodological issues to consider, which include the dose of nutrients and the form they come in. Using too little of a nutrient, particularly in a form than is not readily utilizable by the body, may produce results that don't show what benefits may have been had from decent doses of more bioavailable nutrients. Despite these limitations, there is indeed some evidence that nutritional supplementation can have benefits for health. Just such a study was published this month in the American Journal of Clinical Nutrition [1]. In this study, the effect of nutrient supplementation was assessed on the brain function of about 800 Australian and Indonesian children. For a period of a year, each child was given a daily drink of one of the following:
1. The nutrients iron, zinc, folate, and vitamins A, B6, B12, and C
2. The omega-3 fats DHA and EPA
3. Both the nutrients and the omega-3 fats
4. No additional nutrients (placebo)
The cognitive function of the children was assessed at the outset of the study as well as at six months and at the conclusion of the study, one year later. Omega-3 supplementation was found not to enhance brain function, but the vitamin and mineral supplementation was, with those supplemented in this way showing significant increases in scores on tests of verbal learning and memory. It is perhaps worth noting that the dosages of omega-3 used in this study (actually 88 mg per day of DHA and 22 mg per day of EPA) are much lower than the dosages generally believed to have benefits for the brain. So, not only does this study support the concept of nutritional supplementation, it also aptly demonstrates one of the potential limitations of nutritional supplementation trials.
Reference:
[1] Osendarp SJM, et al. Effect of a 12-mo. micronutrient intervention on learning and memory in well-nourished and marginally nourished school-aged children: 2 parallel, randomized, placebo-controlled studies in Australia and Indonesia. American Journal of Clinical Nutrition 2007; 86(4): 1082–93
Dr. John Briffa is a London-based doctor and author with an interest in nutrition and natural medicine.
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