There are many low-carb diets, but the Atkins diet, first published in the 1970s, is among the oldest. The Atkins diet has been designed to promote fat loss by eliminating most carbohydrate-containing foods and encouraging the consumption of protein and fat. Many people believe that, because of its higher fat content, the Atkins diet is not heart-healthy.
High Cholesterol
A blood lipid profile is characterized by the levels of total cholesterol, which can be divided into LDL, or low-density lipoproteins, and HDL, or high-density lipoproteins. Triglycerides are another type of fat circulating in the blood that are routinely measured to evaluate your cardiovascular risk. LDL cholesterol target will vary depending on your estimated cardiovascular risk. Healthy people will aim for less than 130 mg/dl. People with diabetes or other risk factors will aim for less than 100 mg/dl; and people at very high risk should aim for less than 70 mg/dl. Total cholesterol levels should range between 100 and 199 mg/dl; HDL cholesterol levels should be above 45 mg/dl; and triglycerides, below 150 mg/dl.
Atkins and LDL Cholesterol
Critics of the Atkins diet claim that it encourages the consumption of large amounts of fat, especially saturated fat. A study published in 2004 in the "Annals of Internal Medicine" compared a low-carb Atkins-style diet against a low-fat diet in 120 overweight subjects with high blood cholesterol levels. After 24 weeks, LDL cholesterol levels decreased slightly in the low-fat group, from 148.0 mg/dl down to 140.6 mg/dl, while they stayed stable with the Atkins diet, from 157.2 mg/dl at baseline to 158.8 mg/dl at the end of the study. This study shows that low-carb high-fat diets, like the Atkins diet, do not necessarily result in higher LDL cholesterol. It is also important to avoid looking at LDL cholesterol levels in isolation, because other factors, such as HDL cholesterol and triglycerides levels, are also important to consider when it comes to cardiovascular risk.
Atkins and Triglycerides
Triglycerides constitute an important risk factor associated with cardiovascular disease. Many studies have shown that despite their higher fat content, low-carbohydrate diets such as the Atkins diet are effective at reducing triglycerides. For example, a 24-week study showed a reduction of 74.2 mg/dl, from a baseline level of 157.8 mg/dl down to 83.6 mg/dl in the low-carb group, compared to a decrease of only 27.9 mg/dl observed in the low-fat group, as published in the "Annals of Internal Medicine" in 2004. People with elevated triglycerides can benefit from following the Atkins diet.
Atkins and HDL Cholesterol
High levels of HDL cholesterol are desirable because of their ability to protect against heart diseases. Low-fat diets, which are typically recommended to lower the risk of developing cardiovascular diseases, are unfortunately ineffective at improving HDL concentrations. The Atkins diet, however, with a lower carbohydrate intake and higher fat intake is able to boost HDL levels significantly. In the "Annals of Internal Medicine" study, HDL concentrations jumped from 55.4 mg/dl to 60.9 mg/dl in the low-carb diet group in a period of 24 weeks, while they decreased from 54.1 mg/dl to 52.5 mg/dl in the low-fat diet group.
References
- Atkins: The Program
- American Heart Association: LDL and HDL Cholesterol: What's Bad and What's Good?
- "The New Atkins for a New You"; Eric C. Westman et al; 2010
- Annals of Internal Medicine: A Low-Carbohydrate, Ketogenic Diet versus a Low-Fat Diet To Treat Obesity and Hyperlipidemia
- Cleveland Clinic: Heart and Vascular Health & Prevention
