Butter isn’t as bad for us as we’ve been told and doesn’t increase the risk of heart disease, according to a new study by researchers at Tufts University in the US.
The research, published in the journal PLOS ONE, finds that butter consumption is only very slightly associated with total mortality, not associated with heart disease, and actually reduces the risk of type-2 diabetes.
On average across all nine studies butter consumption was 10-15 grams a day, or about one tablespoon. The study found mostly small or insignificant associations of each daily serving of butter with the risks they analysed.
The research reviewed nine studies of over 600,000 people, in which participants were followed for an average of ten years. The average age of participants was between 44 and 71 years.
The study’s lead researcher, Dr Laura Pimpin, said: ‘This [research] suggests that butter may be a “middle-of-the-road” food: a more healthful choice than sugar or starch, such as the white bread or potato on which butter is commonly spread and which have been linked to a higher risk of diabetes and cardiovascular disease; and a worse choice than many margarines and cooking oils — those rich in healthy fats such as soybean, canola, flaxseed — and extra virgin olive oils, which would likely lower risk compared with either butter or refined grains, starches, and sugars.
‘Overall, our results suggest that butter should neither be demonised nor considered “back” as a route to good health. More research is needed to better understand the observed potential lower risk of diabetes, which has also been suggested in some other studies of dairy fat.’
This is a meta-analysis of studies already published. The authors looked at a standardised intake of butter only, on average around 10-15g/day, in various countries, and sought to establish an association between the consumption of butter and the incidence of cardiovascular disease, stroke, diabetes, coronary heart disease and, collectively, all-cause mortality.
Overall, there was a small one per cent increase in all-cause mortality associated with daily butter consumption, in addition to a slight negative association with type-2 diabetes; ie, butter seems to be protective in some way for diabetes. The authors suggested this may be down to the protective effect of dairy fats, higher HDL cholesterol, lower VLDL (very low density lipoprotein), and increased vitamin D content. However, the diabetes part of the paper only looked at four studies from 11 country-specific cohorts.
The argument the authors make is that butter has previously been judged in terms of what it is made of rather than its observed effect on people. A limitation of the study was that it could not compare butter with its main alternative, margarine. It also did not look at the relationship between amount of butter consumed and overall risk.
It did, however, try to compare its data with the established evidence and with the effects of refined grains, sugars and starches on cardiovascular health in order to contextualise the risk in some way. The authors advised that the risk was light compared to ‘alternative choices’; ie, they argued that butter may be healthier than the batch-processed loaf it is spread on.
The advice in some ways is conflicting. For instance, when butter is substituted for a daily intake of olive oil of 8g/day there is apparently a reduced risk of diabetes of eight per cent.
‘Is butter back?’ is the question that is always asked. I don’t think we can quite say that it is. From this study my question would be: do you need butter every day? While one per cent is a small figure in terms of all-cause mortality, tiny reductions here and there will add up in the long time. The protective benefits of consuming some dairy products I would perhaps seek from a better source.
Research score: 2/5