Friday, August 17, 2018
/ WavebreakMediaMicro, stockadobecom
Boston According to the results of a prospective cohort study in a low-carbohydrate diet that is currently popular because it allows rapid nutritional success] Lancet Public Health (2018; doi: 10.1016 / S2468-2667 (18) 30135-X) increases the risk of mortality and a high carbohydrate content in the diet. The origin of the proteins and fats that replace the carbohydrates seems essential.
The nutritional recommendations have changed in recent years. Long since considered a low-fat diet to improve cholesterol and prevent atherosclerosis, a low-carbohydrate diet is now used to combat the current obesity and diabetes epidemic.
PURE research from last year (Prospective Urban Rural Epidemiology) has provided important arguments for this. The study, which looked at 135,000 people across 5 continents, found that high carbohydrate diet was associated with a higher risk of death. However, the study was conducted in populations with a relatively high intake of carbohydrates. This was due to the involvement of East Asian crops, where rice is the most important source of energy. That is why people feed far more fat than Europeans and North Americans.
The American ARIC (Atherosclerosis Risk in Communities Study) study provides more representative data here. Over the past quarter century, the study supported a group of 15,428 adults aged 45 to 64 with different socio-economic backgrounds and European or African backgrounds from four American districts.
At the beginning of the study and six years later, the participants had a detailed list of the Nutrition Questionnaire, from which the ratio, but also the origin of carbohydrates, fats and proteins can be determined. Sara Seidelmann of Brigham and Womens Hospital, Boston, and colleagues have linked the data to the 6,283 deaths that occurred after a median follow-up of 25 years.
First of all, the ARIC study confirms the findings of the PURE study. Research: High levels of carbohydrates in the diet were associated with an increased risk of death. A 50-year-old participant with carbohydrates treated more than 65% of the energy on average 32.0 years, compared to 33.1 years for a participant with carbohydrate levels of 50-55%.
PURE study, which does not cover this low range, was also associated with a low intake of carbohydrates due to an increased risk of death. A 50-year-old participant who consumed less than 30% of the carbohydrate energy had a life expectancy of 29.1 years. The lowest risk of death was found in a carbohydrate fraction of 50%.
A meta-analysis that included other small studies besides ARIC and PURE came to the same conclusion. Those who consumed more than 70% of the carbohydrate energy had a 23% higher risk of dying: hazard ratio 1.23 (95% confidence interval 1.11 to 1.36). At a level of less than 30%, the risk of death had increased by 20%: hazard ratio 1.20 (1.091.32).
Further analysis showed that the type of fats and proteins that carbohydrates in a low-carbohydrate diet replaces to have a big impact. Seidelmann distinguishes between a vegetarian and a meat-based diet.
The vegetarian diet was associated with an 18% reduced risk of death in a low-carbohydrate diet (hazard ratio 0.82, 0.780.87), while in a meat diet the risk of death was reversed 18% (hazard ratio 1.18 , 1,081.29)
The reasons for the benefits of the vegetarian diet can not be explained by the research. Seidelmann suspects that a high percentage of animal fats and proteins stimulate inflammatory processes in the body and accelerate biological aging due to oxidative stress. Lack of deficiencies in vitamin and trace elements can be the result of underconsumption of fruit and vegetables.
In one epidemiological study, despite the consideration of competitive risk factors in the study, these were age, gender, training, waist circumference, smoking, exercise, diabetes, location, geographical region and total calorie intake, there is always the possibility that other diet-related causes can explain the changed mortality risk.
Andrew Mente and Salim Yusuf of McMaster University, Hamilton, Canada, generally recommend to reduce dites, Although carbohydrates are not technically essential nutrients (as opposed to proteins and fats), a certain intake must be ensured, for example to cover short-term energy needs during physical activity. However, the study suggests that carbohydrates account for 50 percent of the sweet spot for a healthy diet.