Atkins Diet Approach Has Significant Risks: New Study
The Atkins diet approach--high protein and low carbohydrates--has been praised as an effective way to lose weight, but its numerous critics have noted the health hazards of this type of eating. Now a new study of nearly 44,000 women has found that those who regularly eat a high protein, low carbohydrate diet are at increased risk of heart disease and stroke compared with women who don't follow this Atkins diet approach.
Problems with a high protein, low carbohydrate diet
The long-term impact of eating a high-protein, low-carbohydrate diet has been studied by numerous research teams, and the results have been conflicting when it comes to health risks. In the Nurses' Health Study, for example, the authors did not note an increased incidence of ischemic heart disease among women who followed the Atkins diet approach.
However, three European studies discovered statistically significant increases in death associated with cardiovascular disease. Two possible reasons for the discrepancies between the United States and European studies may be the main type of protein the subjects consumed (plant vs animal) and how many study participants were obese.
One reason researchers are so interested in better defining the risks and benefits of a high-protein, low-carbohydrate diet is that many people, especially women, try it to lose weight, not realizing or choosing to ignore the potential hazards. Therefore, this latest study set out to shine a clearer light on the risks of an Atkins diet approach.
The study population consisted of 43,396 Swedish women who were 30 to 49 years old when they entered the study. All the women completed a comprehensive dietary questionnaire and were followed-up for an average of 15.7 years.
The reviewers evaluated the dietary data, focusing on carbohydrate and protein intake and breaking it down into small increments (tenths and units) for more precise calculations. They also adjusted the data for calorie intake, fat in the diet, and some non-dietary factors (e.g., smoking, alcohol use, exercise level, high blood pressure).
Overall, the authors found the following:
- A one-tenth decrease in carbohydrate intake or increase in protein intake was associated with a statistically significant increase in cardiovascular incidence
- A 2 unit increase in the low carbohydrate-high protein score was also associated with a statistically significant increase in cardiovascular risk
- For example: for each 20 gram (about 1 small bread roll) decrease in daily intake of carbohydrates and 5 gram (about 1 boiled egg) increase in protein, there was a 5% increase in the overall risk of cardiovascular disease
- During the follow-up period, a total of 1,270 cardiovascular events occurred: 703had ischemic heart disease, 294 ischemic strokes, 121 subarachnoid hemorrhages, 82 peripheral artery disease, and 70 hemorrhagic strokes
The authors concluded that women who follow a high protein, low carbohydrate diet on a regular basis and without consideration of the nature of the carbohydrates or the protein sources are at an increased risk of cardiovascular disease.
So is following an Atkins diet approach a wise decision for women? In an editorial that accompanied the new study, both of which appear in BMJ on June 26, Anna Floegel from the German Institute of Human Nutrition and Tobias Pischon from the Max Delbruck Center for Molecular Medicine issued a warning.
Floegel and Pischon noted that the discrepancies seen in studies conducted thus far "need to be resolved before low carbohydrate-high protein diets can be safely recommended to patients." They also indicated that any benefits individuals gain from an Atkins diet approach in the short haul "seem irrelevant in the face of increasing evidence of higher morbidity and mortality from cardiovascular diseases in the long term."
Floegel A, Pischon T. Low carbohydrate-high protein diets. BMJ 2012; 344:e3801 doi: 10.1136/bmj.e3801
Lagiou P et al. Low carbohydrate-high protein diet and incidence of cardiovascular diseases in Swedish women: prospective cohort study. BMJ 2012;344:e4026 doi: 10.1136/bmj.e4026
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