▎ WuXi AppTec content team editor
Being overweight and obese are major risk factors for many chronic diseases. The global prevalence of overweight and obesity has nearly tripled over the past 40 years, making it one of the most serious and unresolved public health challenges of the 21st century.
Overweight or obesity is associated with a variety of physiological, environmental, dietary behaviors and other factors, and the consumption of sugary drinks is an important risk factor. Many studies have shown that sugary drinks have been linked to weight gain, type 2 diabetes, cardiovascular disease, and an increased risk of certain types of cancer.
Recently, Professor Frank B. Hu and Professor Vasanti S. Malik of Harvard University published a review in Nature Reviews Endocrinology, which discussed in depth the impact of sugary drinks on the global obesity and chronic disease epidemic. This paper analyzes trends in sugary beverage intake, reviews the evidence and potential biological mechanisms of sugary drinks associated with obesity, metabolic cardiovascular disease and cancer, and suggests alternative beverage options.
Screenshot source: Nature Reviews Endocrinology
At present, there is no consensus on the definition of sugary drinks in various countries. In this review, the researchers defined it as any beverage with added caloric sweeteners, such as sucrose, high-fructose corn syrup, fruit juice concentrates, and starch sugars, which count as sugary drinks. One serving (355 ml) typical sugar-sweetened beverage such as soda, containing 35.0 g to 37.5 g of sugar and 140 kcal to 150 kcal.
The study first noted that intake of sugary drinks has been higher worldwide since the early 2000s. While intake has declined slightly in high-income countries, overall intake levels are still higher than recommended intakes, and intake and supply of sugary drinks are steadily rising in middle-income countries due to economic developments compared to high- or low-income countries.
Next, the paper focuses on the effects of sugary drinks on metabolic cardiovascular diseases (including obesity, cardiovascular disease, diabetes, gout, etc.) and cancer.
Cardiometabolic diseases refer to a clinical syndrome in which metabolic abnormalities and cardiovascular damage have a causal relationship, excluding other cardiovascular causes, and with cardiovascular and cerebrovascular events as the main outcome. The pathogenesis of the disease is complex, and metabolic abnormalities mediated by energy metabolism imbalances play an important role, and the main risk factors are lack of exercise, smoking and unhealthy diet.
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There is a strong association between sugary drinks and a variety of diseases
01
corpulent
Many meta-analyses synthesize evidence on sugary drinks and weight gain/obesity. In general, each additional serving of sugary drinks per day is associated with weight gain of 0.12 kg to 0.85 kg in adults within 1 year. The study suggests that limiting the intake of sugary drinks may be an effective way to prevent weight gain at all ages and also contribute to the healthy development of children's weight.
02
Type 2 Diabetes
A large body of literature suggests that consuming sugary drinks is associated with a higher risk of type 2 diabetes, either through weight gain or through other independent metabolic pathways. Studies have shown that adding one serving of sugary drinks per day is associated with an 18% increased risk of type 2 diabetes.
03
Cardiovascular diseases
A growing body of evidence links the intake of sugary drinks to the risk of cardiovascular disease. Meta-analyses found that adding one serving of sugary beverages per day was associated with an 8% to 9% increased risk of cardiovascular disease and a 15% increase in the risk of coronary heart disease. In addition, sugary beverage intake has been found to be associated with increased blood pressure (6.9 mmHg increase in mean systolic blood pressure; 5.6 mmHg average diastolic blood pressure) and dyslipidemia.
There have also been studies that point to a link between intake of sugary drinks and mortality. Participants had an 8 percent increased risk of death from cardiovascular disease for each additional sugary drink per day; participants who consumed ≥ 2 sugary drinks per day had a 31 percent increased risk of death from cardiovascular disease compared to those who did not consume or consumed less than one sugary drink per month.
04
Non-alcoholic fatty liver disease
Studies have found that each additional serving of sugary drinks per day is associated with a 39% increased risk of non-alcoholic fatty liver disease, possibly because sugar contains too much energy, which may affect metabolism, induce liver steatosis, and thus increase serum concentrations of liver function biomarkers such as alanine aminotransferase.
05
gout
Regular consumption of fructose-containing beverages is associated with hyperuricemia and gout. The meta-analysis found that people with the highest sugary drink intake had twice the risk of gout compared to the lowest intake of sugary drinks; increased weekly intake of sugary drinks was associated with a 4 percent increased risk of gout.
06
cancer
Consuming sugary drinks may increase the risk of developing certain cancers due to excessive obesity and metabolic disorders, with obesity, insulin resistance, and type 2 diabetes being risk factors for different cancers. The study found that the intake of sugary drinks was associated with a 14% increase in breast cancer risk and an 18% increase in prostate cancer, and that sugary drink intake was also associated with an increased risk of colorectal and pancreatic cancer. No association between sugary drinks and bladder cancer or renal cell carcinoma has been observed.
Sugary drinks disrupt health through these mechanisms
The intake of sugary drinks is associated with a variety of diseases, and understanding their underlying biological mechanisms during the onset and development of the disease can help intervene in metabolic disorders, control the disease, and improve prognosis.
▲Biological mechanisms of the development of intake of sugary drinks and obesity, metabolic cardiovascular disease and cancer. (Screenshot source: References[1])
Increased calorie intake
Compared with solid foods, sugary drinks usually have a lower feeling of fullness, people will unconsciously consume more energy, although the mechanism of this lack of compensatory response is still unknown, but the consumption of fructose itself may increase weight by reducing the body's resting energy expenditure and inducing leptin resistance.
Sugar addiction
Consuming sugary drinks may activate the dopamine reward system and trigger addictive behaviors that make us want to eat more and more and change our dietary tastes and habits.
High blood glucose load
Sugary drinks have a higher glycemic index and also contain higher energy, which leads to a higher blood glucose load after drinking. Hyperglycemic load causes glucose and insulin levels in the blood to rise rapidly, altering metabolism (reduced energy expenditure), increasing hunger and weight.
Independent metabolic action of fructose
In the presence of glucose, the absorption of fructose (high fructose corn syrup or sucrose) in the intestine is enhanced, and fructose is converted into glucose, lactic acid and fatty acids in the liver, which are quickly and completely absorbed; however, when fructose is consumed in excess, the fatty acids synthesized from scratch in the liver increase, which can lead to atherosclerotic dyslipidemia and insulin resistance.
It has also been found that ingesting fructose can promote the accumulation of visceral adipose tissue and ectopic lipid deposition in the human body. The metabolism of fructose in the liver also depletes the energy in the liver cells, which leads to increased uric acid production.
Increased uric acid production
Fructose is the only sugar known to increase the production of uric acid in the liver. Hyperuricemia is not only a precursor to gout, but may also be associated with hypertension, type 2 diabetes, and obesity by inducing kidney disease, endothelial dysfunction, and activation of the renin-angiotensin system. In addition, excessive production of uric acid is also associated with a decrease in nitric oxide levels in endothelial cells, which may partly explain the link between fructose-containing beverages and coronary heart disease.
Sugary drinks can promote the occurrence and development of various diseases, partly through weight gain, partly through the independent metabolism of glucose and fructose, and possibly because sugary drinks promote insulin resistance and exacerbate the production of inflammatory biomarkers.
These drinks can be substituted for sugary drinks
Artificial sweetener drinks
Artificial sweeteners contain almost no calories, but are many times sweeter than natural sugars such as aspartame, acesulfame potassium, cyclamate and saccharin. Studies have shown that replacing sugary drinks with artificial sweeteners was associated with participants' weight loss, reduced prevalence and mortality from type 2 diabetes.
But different artificial sweeteners may cause different physiological effects, such as saccharin and sucralose appear to stimulate sweetener receptors and activate the first time-phase insulin response (CPIR, glucose-induced β rapid release of insulin "stocks" in cells). Studies have found that sucralose can reduce weight moderately compared to sucrose intake, but saccharin can moderately gain weight, while aspartame has no effect on weight.
While the use of artificial sweeteners instead of sugary drinks may be a useful strategy for reducing cardiometabolic risk, further research is needed to better understand the effects of individual sweeteners and the consequences of consuming artificial sweeteners throughout life. The ultimate goal is to switch to drinking water or other healthy beverages.
fruit juice
Whether 100% fruit juice is a substitute for sugary drinks is currently a controversial topic. Studies have found that juice intake is associated with weight gain and an increased risk of type 2 diabetes, while eating fruit has the opposite conclusion. Part of the reason may be that the dietary fiber in the fruit reduces the rate of absorption of fructose, while the large amount of fructose in the juice is rapidly absorbed, resulting in an increase in the concentration of fructose in the liver, which affects metabolism.
Higher juice intake was associated with a higher risk of death compared to lower juice intake. However, studies have also reported that drinking fruit juice is beneficial for reducing cardiometabolic risk. Due to the different nutrient content and sugar content of different fruit juices, further research on different types of fruit juices is recommended.
Water, tea and coffee
Water is sugar- and calorie-free and is the best drink for hydration. Studies have found that replacing one sugary drink with water every day is associated with weight loss and a reduced risk of type 2 diabetes. Using different types of sparkling water or beverages containing artificial sweeteners may help us gradually develop the habit of drinking water.
Many studies have shown that drinking 2 to 5 cups of tea a day due to the large amount of bioactive substances in coffee and tea is associated with a reduced risk of type 2 diabetes and cardiovascular disease; if coffee is used daily instead of a sugary drink, it is associated with a 17% lower risk of type 2 diabetes. In the absence of any contraindications (such as groups such as pregnant women and children), and limiting the content of caloric sweeteners and creamers, coffee and tea can be a healthy alternative to sugary drinks.
summary
There is strong evidence that consuming sugary drinks can affect metabolic cardiovascular disease and cancer through a variety of mechanisms. There is an urgent need for us to take action to prevent obesity, and reducing the intake of sugary drinks is an important step in improving the overall quality of the diet.