Do women who regularly eat a low carbohydrate, high protein diet have a greater risk of cardiovascular disease
Research published in the British Medical Journal says that “Women who regularly eat a low carbohydrate, high protein diet are at greater risk of cardiovascular disease (such as heart disease and stroke) than those who do not.”
High protein diet and cardiovascular disease risk, is it high risk?
However the actual numbers are small (an extra 4-5 cases of cardiovascular disease per 10,000 women per year).
Low carbohydrate-high protein diets are frequently used for body weight control. Although they may be nutritionally acceptable if the protein is mainly of plant origin (e.g. nuts) and the reduction of carbohydrates applies mainly to simple and refined ones (i.e. unhealthy sweeteners, drinks and snacks), the general public do not always recognize and act on this guidance.
Studies on the long term consequences of these diets on cardiovascular health have generated inconsistent results. So a team of international authors carried out a study on just under 44,000 Swedish women aged between 30 and 49 years from 1991-92 (with an average follow-up of 15 years).
Women completed an extensive dietary and lifestyle questionnaire and diet was measured on the low carbohydrate-high protein (LCHP) score where a score of two would equal very high carbohydrate and low protein consumption through to 20 which would equal very low carbohydrate and high protein consumption.
After these variables were included, results showed that 1270 cardiovascular events took place in the 43,396 women (55% ischaemic heart disease, 23% ischaemic stroke, 6% haemorrhagic stroke, 10% subarachnoid haemorrhage and 6% peripheral arterial disease) over 15 years.
The incidence of cardiovascular outcomes increased with an increasing LCHP score.
The authors conclude that LCHP diets “used on a regular basis and without consideration of the nature of carbohydrates or the source of proteins” are associated with cardiovascular risk. This study doesn’t, however, address the questions concerning the possible benefit of short-term effects of LCHP diets that can be used to control weight or insulin resistance, which the authors say needs further investigation.
An accompanying editorial argues that the short term benefits of weight loss seem outweighed by longer term cardiovascular harms. Anna Floegel from the German Institute of Human Nutrition and Tobias Pischon from the Max Delbrück Center for Molecular Medicine in Germany, say that the discrepancy between conclusions from different types of studies in this field “need to be resolved before low carbohydrate-high protein diets can be safely recommended to patients.”
In the meantime, they suggest that any benefits gained from these diets in the short-term “seem irrelevant in the face of increasing evidence of higher morbidity and mortality from cardiovascular diseases in the long term.” (1,2)
1. Source British Medical Journal News Release June 27, 2012
2. Lagiou P, et al. Low carbohydrate-high protein diet and incidence of cardiovascular diseases in Swedish women: prospective cohort study. BMJ 2012; 344 doi: 10.1136/bmj.e4026 (Published 26 June 2012)