Refined sugar and cadmium issue


Minister of Agriculture opened an interesting debate when he announced in Parliament that imported white sugar sourced from Brazil could be the culprit of cadmium poisoning, which is one of the metallic elements implicated in chronic kidney disease (CKD) prevalent among farmers in NCP and Uva Provinces of Sri Lanka. This, no doubt, has been based on claims made by his Additional Secretary Dr. Wijeratne, who made similar claims in the recent press.

While the consuming public should be thankful to them for alerting them to some very remote possibility and bringing the unsavoury health effects of cadmium to the notice of the public, so that there is general awareness created through the press, the purpose of this brief note is to show that their claims are farfetched.

Let me show this by quantifying the available data. As Dr. Kelvin once said, science begins only with quantification and other expressions are only unorganized thoughts. So let us get organized by quantifying our thoughts.

The confusion on this subject is confounded as available refined white sugar specifications announced by Sri Lanka Standards Institution, do not contain the range for this element. So, one has to use that given in Codex standard 212 (Ref.Essays on Sri Lanka Sugar Sector- Dr MWN Dharmawardene SRI 2005) which specifies that limits established by Codex Alimanentarius Commission should apply which is set by the limits recognized as harmless to health. This is now set at 35 micrograms per day for an average person of 70 kgs.

Now we know per capita consumption of sugar in Sri Lanka is estimated at 30kg. Thus, on the average, a person consumes 0.082 kgs. of sugar per day. If one assumes cadmium content in refined sugar is at similar levels to that permitted for arsenic by Sri Lanka sugar specifications, which is one mg per kg, then the amount of cadmium contained in the daily sugar quota of an average man is no more than 0.082 mg or 82 micrograms.

Now, on face value it seems that this is more than twice the permitted amount as per Codex. However, it has been clearly established by long term clinical studies on this subject that less than 1% of ingested route is absorbed by way gut. Thus the maximum that enters body circulation and becomes the cadmium burden is no more than 0.82 micrograms per day which is at least 42 times less than the currently accepted safe level for cadmium.

Thus, it is quite clear that refined white sugar imported into the country has no connection to cadmium poisoning and these are mere fictions which are not evidenced based but concocted stories by the guilty conscious in trying to divert issues from emerging evidence that source of cadmium is the contaminated phosphatic fertilizers used by farmers and some such agro-chemicals used here. Any sane person could see for himself that if sugar is the culprit, then CDK cannot be confined to just a few regions in Sri Lanka. I would make a more detailed review on this subject later on, as time does not permit.

But let me mention briefly that cadmium absorption by the human body is naturally through ingested and inhalation routes. Ingestion is mainly through vegetables and cereals consumed which are known to accumulate cadmium but fortunately less than 1% so ingested passes into the body via gut. But the inhalation route mainly dominated by tobacco smoking gives double the dose of cadmium into the body. It is well known that rice preferentially accumulate cadmium while tobacco chewing and smoking make people most vulnerable to cadmium poisoning.

These being the facts, Ministry of Agriculture, rather than going on a wild goose chase should immediately implement the recommendations of the WHO study to avert the impending crisis. This is not the first time in the history of the world this has happened but it has been reported in Japan and China and other rice- growing countries the world over.

Dr. MWN Dharmawardene

Founder Director Sri Lanka Sugarcane Research Institute

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