Danger in soft drink consumption

Liquid choices

Liquid choices

Is this some sort of conspiracy? I was at the Brussels airport and I was thirsty. There were two vending machines side by side with different bottled liquids. One contained what looked like bottled water and the other a range of soft drinks. I have long been suspicious of soft drinks so of course I went for the water bottles. But to find plain water was difficult. There were bottles with vitaminised water, herbal water, flavoured water, fibre enhanced water and you name it. At the bottom I found some organic water. I have no idea how water can be organic but I bought one anyway. In casting a glance over to the soft drink bottles I noticed that they were all cheaper than the water bottles. How can that be?

We need our daily water

First some obvious facts about fluid intake. Regular fluid consumption is essential for the body’s growth and maintenance. Water is involved in a number of processes. It helps the body get rid of waste, regulates temperature and provides a medium for biological reactions to occur in the body. Since we lose water through urine and sweat, it must be replaced through the diet. If you do not consume enough you can become dehydrated. Symptoms of dehydration can include headaches, tiredness and loss of concentration. Chronic dehydration can contribute to a number of health problems such as constipation and kidney stones.

Most people have no problem in replenishing the water stores by drinking plain tap water supplemented by consuming foods with high water content, such as fruits and vegetables. Perfectly fine to keep healthy. But what about the lure of soft drinks to keep up fluid levels?

Soft drink consumption and behavioural changes

New research findings suggest that consumption of even one soft drink per day may be associated with increased negative behaviour in young children. In a study covering several thousand five-year-olds, those that consumed one to four glasses of soft drink per day had higher aggressive measurement scores than children who drank no soft drink at all. On top of that, those children that consumed two or more glasses also had higher withdrawn behaviour scores with higher attention problem scores added in children that consumed four or more glasses a day.

I am often suspicious of epidemiological studies that report dubious associations. However, in this case there was a convincing dose-response effect. With increased soft drink consumption, the associations strengthened and the scores increased. This persisted when adjustments were applied for candy and fruit juice consumption as well as for a variety of social factors.

According to the researchers, per capita soft drink consumption is higher in the USA than in any other country. And the really frightening finding – almost half of the children drank one or more soft drink daily. Past research has already suggested associations between soft drink consumption and aggression, depression, and suicidal thoughts in adolescents. Also those findings showed a dose-response relationship, with the percentage engaged in aggression or suicidal behaviour increasing steadily with greater quantities of soft drinks consumed.

Parallel increases in soft drink consumption and obesity

But soft drinks are cheap you say and taste so good. So true and in here we find much of the problem. Soft drinks are aggressively marketed, and two companies – Coca-Cola and PepsiCo – dominate worldwide sales. As an example, Coca-Cola spent $2.2 billion on global promotions and sold $22 billion worth of beverages in 2004. And the soft drink companies have been very successful. Soft drink consumption in the United States tripled in recent decades.

Although the behavioural impact is quite serious, don’t think that I have forgotten the obesity epidemic that very much parallel increases in soft drink consumption. A range of studies have looked at the causal link between sugar-sweetened soft drink consumption and weight gain. A review of the research was undertaken by two Boston scientists. They found that 6 of 15 cross-sectional and 6 of 10 prospective cohort studies identified statistically significant associations between soft drink consumption and increased body weight. Observational studies thus supported the hypothesis that sugar-sweetened soft drinks cause weight gain as one important factor in an obviously multi-factorial syndrome.

So far so good, but even better would be if clinical trials could confirm the findings. Unfortunately, there was a paucity of clinical trial data available from only five clinical trials. Two studies involved adolescents and indicated that efforts to reduce sugar-sweetened soft drink intake slowed weight gain. The three small experimental studies in adults also suggested that consumption of sugar-sweetened soft drinks influenced weight gain. But no study looked at the accumulation of fat and the adult trials only lasted for a maximum of ten weeks and included no more than 41 participants.

Given the magnitude of the public health concern, larger and longer intervention trials should be considered to clarify the specific effects of sugar-sweetened soft drinks on body weight and other cardiovascular risk factors.

Plain water is good enough

Plain tap water is good enough

Plain tap water is good enough

Awaiting results from such studies we can all vote with our feet and walk away from soft drink consumption. And, by the way, don’t get fooled by expensive enhanced water that also might contain loads of sugar. It is a way for the very same commercial companies to maximise their return. This is a conspiracy to convince us that plain water is not good enough. I can assure you it is.

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