A study has been released which appears to show an association between lower carb diets and a higher risk of mortality.
There have been some provocative headlines in certain media write-ups, such as “Low-carb diets shorten life expectancy”, but this kind of message cannot be backed up by the study.
This form of study can only show observational findings and cannot give claims that low carb diets lead to lower life expectancy. Indeed, the researchers acknowledge this.
The research is based around a study, the Atherosclerosis Risk in Communities (ARIC) study, which started between 1987-1989 with a food questionnaire. The study included 15,428 people, aged 45-64 years old, from four different communities in the US.
The participants filled out a second questionnaire after six years and then had their health monitored over the next 19 years.
The results showed that people that had reported eating high and low percentages of energy coming from carbohydrate had higher likelihoods of earlier death.
A big weakness of the study is that it doesn’t include information on other areas of health such as how much exercise was being taken by the different groups and how much they were smoking or drinking alcohol.
Another problem is that the study looked at percentage of energy coming from carbohydrate. People having a diet based around fast food such as meat and fries could easily find themselves in the lower carbohydrate groups. Such people would not be following actual low carb diets and these people could well have been more likely to be the heavy smokers and drinkers.
The study showed the highest risk of earlier death were in the groups of people eating more meat. This doesn’t in itself suggest that meat itself is unhealthy, it shows that the people that were eating a lot of meat were generally less healthy.
In order to make sense of the findings, we’d need to know more about the health behaviours of the people. As the study did not delve into understanding the wider health of the participants, the research laves many more questions than it can give answers.
The low carb lifestyles that are being followed by people to gain greater health is likely to be very different to the diets of the people included in the study. Indeed, recent research has shown clear health benefits among people following a healthy, low carb lifestyle that is low in processed foods.