The associations were not influenced by socio-demographic and major lifestyle factors, supplement use, and depression status, report scientists from Indiana University, the Center for Magnesium Education and Research, Kaiser Permanente Division of Research, University of Minnesota, University of Alabama at Birmingham, and Columbia University Irving Medical Center.
“Since hostility is associated with many health conditions, findings from this study highlight another pathway for the potential benefit of magnesium intake to the development of chronic diseases such as diabetes and cardiovascular disease,” wrote the authors.
Hostility is an intriguing metric
While the study shows correlation and not causation, Mark Miller, PhD, principal at Kaiviti Consulting, LLC, told NutraIngredients-USA that the association warranted further study.
Commenting independently, Dr Mark Miller told us: “It is always wise to be cautious when interpreting association studies, yet this is a large study and the outcome - Hostility - is an intriguing metric that may be related to known benefits of magnesium on depression and anxiety.
“The study was large, with 4,716 young adults participating. Examining quartiles of dietary magnesium intake there was a clear inverse relationship with the expression of hostility. Comparing the highest to lowest quartiles, the highest intake of magnesium had hostility scores nearly two times lower,” added Dr Miller.
“The interesting aspect was that this was independent of depression status at year 5, so it may be possible to differentiate hostility from depression.
"I would regard this finding to certainly warrant further investigation and hopefully a prospective RCT to define what doses of supplemental magnesium are associated with improved hostility outcomes in young adults."
‘Necessary for over 300 biochemical reactions’
The results add to an ever-growing body of science supporting the potential health benefits of the mineral. The National Institutes of Health (NIH) lists magnesium as being necessary for more than 300 biochemical reactions in the body, from helping maintain normal muscle and nerve function, to keeping heart rhythm steady, supporting a healthy immune system, and keeping bones strong. The mineral is also needed for blood sugar management and healthy blood pressure.
However, 70-80% of the US population is reported to not be meeting the recommended intakes of magnesium.
The study included almost 5,000 young adults aged between 18 and 30 years at the start of the study who were participating in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Magnesium intakes were estimated using a dietary history questionnaire plus supplements at the start of the study, while hostility levels were assessed at the start of the study and again after five years using the Cook-Medley scale.
The participants were divided into five groups (quintiles) based on average magnesium intakes, measured as milligrams of magnesium per 1000 kcal per day, with the average values for each quintile being 93.2, 113.5, 132.3, 155.7, and 198.5, respectively.
Crunching the numbers indicated a dose-dependent reduction in measures of hostility with increasing magnesium intakes, with the inverse association was more pronounced with higher omega-3 intakes, said the researchers.
Commenting on the potential mechanism of action, the authors noted that there are multiple biologically plausible ways magnesium may impact hostility. For example, the mineral may play hypothalamic–pituitary–adrenal (HPA) axis to impact stress hormones linked to hostility. Next, magnesium may also impact the metabolism of serotonin, they said, which has been linked to depression.
Another potential mechanism of action could include a role for magnesium as a blocker of the N-methyl D-aspartate (NMDA) receptor, thereby regulating glutamate and GABA pathways.
“Accumulating evidence indicated the essential contribution of NMDA receptor to human major depression. In addition, an animal study suggested that anti-depressant-like action of magnesium was antagonized by NMDA,” they wrote.
Finally, magnesium may also play a role as an anti-inflammatory, which may benefit hostility measures.
“To the best of our knowledge, the relation between magnesium and hostility has never been directly addressed in any previous epidemiological study,” wrote the researchers. “However, our study is consistent with a recent prospective study in 2320 Eastern Finnish men aged 41 to 62 years with 20 years of follow-up that showed greater magnesium intake was associated with a significantly lower risk of receiving a hospital unipolar depression diagnosis, which manifested with symptoms closely related to hostility,” they added, referencing a 2016 paper by Yary et al. published in the Journal of Affective Disorders.
Source: Nutrition Research
May 2021, Volume 89, Pages 35-44, doi: 10.1016/j.nutres.2021.01.001
“Magnesium intake was inversely associated with hostility among American young adults”
Authors. C. Lyu et al.