Does full-fat yoghurt reduce depression risk in women?
Does full-fat yoghurt reduce depression risk in women?
A CURIOUS study at the University of Navarra seems to show that regularly eating yoghurt can cut the risk of suffering depression for women – but it has to be the full-fat variety, because low-fat yoghurt has the reverse effect, researchers claim.
Led by Professor Miguel Ángel Martínez González, head of the Faculty of Medicine at the Pamplona college, the experiment took 14,359 men and women who had not been diagnosed with depression and studied them over a 10-year period.
The participants habitually consumed full-fat or low-fat yoghurt or prebiotic fibre sources.
A total of 727 cases of depression were diagnosed over the 10 years, but the risk was found to be 22% lower in women – although not in the case of any of the men – who ate at least one full-fat yoghurt a day, with the risk reducing in line with consumption level.
In contrast, a direction relationship was seen between the consumption, and amount eaten, of low-fat yoghurt, especially in the first few years of the study.
No relationship at all was found between the consumption of prebiotics and depression.
The experiment was based upon the growing belief that diet can influence brain chemistry, and thus the onset of depression, with risk factors relating to changes in intestinal bacteria – a theory supported by the results of testing on rats and mice in laboratories.
Yoghurt, specifically, was studied because of its probiotic content, meaning it contains live bacteria which 'eats' bad bacteria in the intestines.
Prebiotics relate to dietary fibre which feeds the naturally-present intestinal bacteria.
But the 'yoghurt study' should still be taken with a pinch of salt – extraneous factors are unlikely to have been entered into and depression is often subjective, influenced by environmental, not just biological elements.
For example, the women who ate low-fat yoghurt and were found to be more prone to depression may have been on a diet, have had latent eating disorders or generally been unhappy with their body size, indicating self-confidence or perfectionist issues which often underly mental illness, whilst the women eating full-fat yoghurt are less likely to have weight-related concerns.
Low-fat yoghurt also often tends to be sugar-free or low in sugar, in contrast to full-fat yoghurt, and contains less calcium; sugar gives a swift endorphine release and is often craved during hormonal changes linked to depression, whilst calcium affects the functioning of the nervous system.
Also, it is not known to what extent the rest of their diets were studied, since yoghurt and dietary fibre are only part of what they would have eaten daily over the course of 10 years.
