Killer Cola?

Thirst for knowledge: researchers have found out whether it is harmful to drink Coca-Cola

Daria Morgacheva, MednovostiOn January 31, 1893, entrepreneur Asa Griggs Candler registered the trademark "Coca-Cola".

For 122 years, the recipe of the original drink has changed noticeably. The first Coca-Cola, invented by pharmacist John Stith Pemberton in 1886 and sold in pharmacies as a cure for morphinism, neurasthenia, depression and digestive problems, consisted of sugar syrup, coca leaves (coca bush) and a caffeinated cola nut. By the end of the XIX century, it was discovered that cocaine is not the most innocent stimulant. They began to struggle with its widespread use, so in 1903 cocaine was excluded from the composition of the drink. Nowadays, the exact formula of Coca-Cola is a trade secret. It is only known that it includes sugar, sugar color, phosphoric acid, caffeine, natural flavors and carbon dioxide.

Being one of the most expensive brands in the world (fourth place according to the latest Forbes estimate), Coca-Cola has been criticized more than once. From the latest news: since January 1, 2015, a law has been in force in the Vologda Region that prohibits the sale of non-alcoholic tonic drinks containing caffeine, including cola, to persons under 18 years of age.

Is Coca-Cola so dangerous that it is necessary to limit its consumption on a par with alcohol and tobacco? We have collected data from scientific studies that consider the effect of cola and other sugary carbonated drinks on human health.

Obesity, liver steatosis, metabolic syndromeAccording to numerous studies, the main culprit of the modern obesity epidemic is not hamburgers and French fries, but sweet soda.

Scientists led by George Bray, a professor at the Pennington Biomedical Research Center (USA), found that daily consumption of a liter of sweet soda for six months increases the risk of developing metabolic syndrome (metabolic disorder in which fat is deposited on the abdomen and increases the likelihood of developing cardiovascular diseases and diabetes) and liver steatosis (fatty hepatosis, accumulation of fat in liver cells).

At the same time, according to the American Society for the Study of Obesity (Obesity Society), how much the use of cola will affect your waist depends on genetic factors. But do not despair, the effect is reversible: the refusal of these drinks leads to weight loss.

Kidney diseasesIn a large-scale joint study of scientists from Italy and the USA led by Pietro Manuel Ferraro, it was shown that those who drank more than one serving of Coca-Cola a day had a 23% higher risk of kidney stones than those who consumed less than one serving a week.

At the same time, those who preferred other types of sweet soda had an even higher risk – 33%. The study monitored the health of 194095 people for eight years, during which time 4462 cases of urolithiasis were recorded.

The risk of developing kidney disease was also high in those who preferred soda with artificial sweeteners, while chronic kidney disease developed less often in those who drank low-calorie Coca-Cola (Coca-Cola Light). In the same study, it was shown that those who drank more than one cup of coffee a day were 26% less at risk of developing kidney disease. Scientists reported that about 80% of kidney stones consisted of calcium oxalate – calcium salt and oxalic acid.

The use of Coca-Cola leads to the immediate elimination of calcium from the body. Japanese scientists from Hirosaki University Graduate School of Health Sciences showed that two hours after healthy subjects drank one can of Coca-Cola, the amount of calcium in their urine increased. This is due to the fact that Coca-Cola, like some other sodas, contains a lot of orthophosphoric acid (H ₃ PO ₄, used in high concentrations, for example, in dentistry for etching teeth) – it masks a huge amount of sugar and promotes the excretion of calcium. As a result, when consuming a large number of such drinks, kidney diseases and osteoporosis develop.

Coca-Cola – both regular and low–calorie - is a drink with a high content of phosphates, therefore it is contraindicated in patients with chronic renal failure. Such patients need a low-phosphate diet, as the kidneys cannot cope with the removal of phosphates from the body. An increase in the level of phosphates in the blood (hyperphosphatemia) is associated with a decrease in calcium levels, a sharp drop in blood pressure, heart failure and can lead to death. At the same time, manufacturers of refreshing drinks and fast food often hide the true content of phosphates, and as a result, it is difficult for people to choose the right products. According to a survey of patients with chronic renal failure conducted by Japanese scientists under the leadership of Yoshiko Shutto, 93% were afraid of the high sugar content in Coca-Cola and other sodas, while only 25% realized that these drinks contain a large amount of orthophosphoric acid. Almost half of the patients answered that they consumed 1-5 cans of soda a week, despite the fact that 78% of respondents were warned about the dangers of a high-phosphate diet.

HypokalemiaA review conducted by Vasilis Tsimihodimos and his colleagues from the Ioannina University Medical School (Greece) shows that drinking large amounts of Coca-Cola can lead to hypokalemia (a decrease in the concentration of potassium in the blood).

In a mild form, it manifests itself as weakness, fatigue, muscle pain. In severe form, this condition can lead to necrosis of the heart and skeletal muscles. Hypokalemia is promoted by three components of Coca-Cola: glucose, glucose-fructose syrup and caffeine.

Coca-Cola contains a large amount of glucose (up to 110 grams / liter), excessive consumption of which can lead to osmotic diuresis (excretion of a large amount of urine with a high concentration of excreted substances) and excretion of potassium from the body with urine. In addition, high glycemic loads can lead to hyperinsulinemia (an increase in the level of insulin in the blood), which, in turn, causes potassium to be redistributed into cells.

To sweeten Coca-Cola in the USA and Canada, glucose-fructose syrup is used: about 60% fructose and 40% glucose. When fructose and glucose are consumed in equal concentrations, special proteins facilitate their absorption in the intestine. But if there is more fructose than glucose, chronic osmotic diarrhea may develop (it occurs due to the high concentration of substances dissolved in the intestinal contents - in this case, fructose) and potassium losses.

Coca-Cola contains from 95 to 160 mg of caffeine per liter. It is known that the use of caffeine in the amount of 180-360 mg can lead to hypokalemia (low potassium content in the blood) due to the injection of potassium into cells, excretion of potassium by the kidneys or a combination of these mechanisms.

Excessive production of sex hormonesRecently, the media wrote about a study by scientists from Harvard Medical School, the authors of which showed that the use of sweet soda contributes to the early puberty of girls.

And according to a group of American researchers led by Karen Schliep, carbonated drinks with a lot of sugar affect the production of sex hormones in adult women. In the study participants who consumed more than one cup (240 ml) of sweet soda per day, estrogen production increased by 16% compared to those who drank less sweet soda. Even a small consumption of sweet soda increases the production of folicular estradiol in premenopausal women. An increased level of female sex hormones estrogen is directly associated with the risk of developing breast cancer, ovarian cancer and other diseases. The authors advise women to drink less sweet soda to avoid these diseases.

Bone and dental healthAccording to data published in the British Dental Journal, drinks with high acidity contribute to the erosion of tooth enamel.

Such a tooth lesion is not associated with caries – tooth enamel and dentin are destroyed, and most often all teeth are "touched". The study involved 1,149 adolescents aged 12-14 years. Teenagers who consumed soda regularly were twice as likely to have tooth decay, and those who drank about four or more glasses of soda – five times.

As we have already written, the use of tonic sweet soda is associated with the loss of calcium, and, as a consequence, the development of osteoporosis. The study, led by Professor Catherine Tucker from Tufts University, involved elderly people – 1,413 women and 1,125 men. It turned out that the use of Coca-Cola (but not other carbonated drinks) reduces the strength of the hip bones in women. The authors attribute this effect to the presence of orthophosphoric acid.

Bisphenol A and phthalatesThe packaging of drinks also matters.

According to The Coca-Cola Company, a substance containing bisphenol A is used for the inner coating of aluminum cans, and plastic bottles are made of PET – polyethylene terephthalate, which does not contain bisphenol A.

Bisphenol A is similar in structure to estrogens and can adversely affect the reproductive function of both women and men, provoke the development of tumors. Recently, the European Food Safety Authority (European Food Safety Authority) has once again revised the attitude to bisphenol A and decided that it does not pose harm to either adults or children, including in the womb. However, the agency called for reducing the daily consumption of bisphenol A from 50 mcg per kilogram of body weight to 4 mcg/kg.

Nevertheless, a comparison of two types of packaging – glass bottles and aluminum cans – published in the journal Hypertension by scientists from Seoul University showed that drinks from cans contribute to an increase in blood pressure and heart rate. Researchers attribute this effect to the presence of bisphenol A in the inner coating of aluminum cans. In addition, two hours after drinking such drinks, the amount of bisphenol A in the urine of the subjects increased by 16 times. In another study published in the Journal of Food Protection, it was shown that the amount of bisphenol A in beer stored in aluminum cans varies from 0.081 to 0.54 mcg/l.

Phthalates – components of PET packaging - are also structurally similar to estrogens and may increase the risk of breast cancer and endocrine disorders. A study by Portuguese scientists has shown that bottled water contains a small amount of phthalates and is not dangerous to human health. According to the results of Hungarian scientists, water in PET bottles with a capacity of 0.5 liters contains the largest amount of phthalates compared to water from two-liter bottles. According to Croatian researchers, there are also phthalates in soda samples stored in PET bottles. It was noted that, although such a concentration does not officially pose a risk to human health, the systematic use of products containing phthalates can lead to their accumulation in the body.

Questionable policyThiago Herick de Sa from the School of Public Health of the University of Sao Paulo (Brazil) protested against the policies of fast food corporations such as The Coca-Cola company and McDonalds.

According to the article “Does Coca-Cola promote physical activity?”published in The Lancet in June 2014, these corporations are trying to prove that the obesity epidemic that has engulfed children all over the world, and especially in developing countries (such as Brazil, India, China), is associated with a lack of physical activity, and not with the consumption of unhealthy foods and excessively sugary drinks. According to Tiago Eric de Sa, the strategy of fast food giants includes not only the sponsorship of sports (in particular, The Coca-Cola company has sponsored the Olympic Games since 1928), but also the influence on some scientific research, and resembles the strategy of tobacco companies, the harm from the products of which is more obvious and beyond doubt.

And yet, you should not feel superstitious fear in front of red and white jars. If you have healthy kidneys and you like the taste and invigorating effect of Coca-Cola, it is quite possible to afford to drink a can a week. Doctors recommend replenishing the calcium lost after taking one jar of Coca-Cola with a glass of milk. And don't forget that sweet soda is almost 10% sugar.

Portal "Eternal youth" http://vechnayamolodost.ru02.02.2015