Omega-3 vetzuren tegen depressies en ontstekingen.*
Uit
een kleine studie onder 43 mensen blijkt dat er duidelijk verband is tussen lage
bloedwaarden aan omega-3 vetzuur en een verhoogd aantal markers voor depressies
en ontstekingen. Het verband was nog duidelijker bij mensen die al gestresst
waren, zoals bij bijna de helft van de 43 mensen die mantelzorg verleende.
Belangrijk is om meer balans te brengen in de verhouding omega-3 /omega-6
vetzuren. Het westerse dieet bevat tegenwoordig wel 20 keer meer omega-6 dan
omega-3 vetzuur terwijl bij een goede verhouding dit slechts 3 keer meer zou
moeten zijn.
Omega-3
Fatty Acids Affect Risk Of Depression, Inflammation
A
new study suggests that people whose diets contain dramatically more of one kind
of polyunsaturated fatty acid than another may be at greater risk for both
clinical depression and certain inflammatory diseases.
The report, published in the journal Psychosomatic Medicine, suggests
that we need to balance out our intake of omega-6 and omega-3 fatty acids. The
current typical American diet contains 20 times more omega-6 than omega-3, a
ratio that researchers say should be lowered to 4-to-1, or even 2-to-1.
This is the most recent in a long series of experiments Ohio State University
researchers have conducted on the links between psychological stress and
immunity. The addition of dietary questions to studies that have previously
focused solely on emotional and biochemical markers may yield important new
clues about the immune system.
"In this study, we're looking at the intersection of behavior, immune
function and diet. In past experiments, we concentrated only on the first two,"
explained Jan Kiecolt-Glaser, professor of psychiatry and psychology at Ohio
State and lead author on the paper.
"It now appears that diet is a very important variable in the equation as
to how people respond to depression and stress."
The study, conducted in OSU's Institute for Behavioral Medicine Research,
focused on a group of 43 middle-aged to elderly men and women, nearly half of
which were the caregiver spouses of people with Alzheimer's or other dementias.
By including caregivers who typically report greater stress and more depression
than similar adults who are not caregiving, the researchers could look at how
depression and diet might interact to affect inflammation.
Blood samples were drawn from each person in the study and tested for
interleukin-6 (IL-6), tumor necrosis factor -alpha (TNF-alpha ) and the receptor
molecule for IL-6. Participants also completed a survey questionnaire that
gauged their level of depression.
The analysis showed that participants who had much more omega-6 -- compared to
omega-3 -- fatty acids, and who also were reporting more symptoms of depression,
had much higher levels of IL-6 and TNF-alpha, two cytokines which enhance
inflammation.
"The data suggest that higher depression and a poorer diet in terms of
omega-3 can work together to promote inflammation. Other researchers have shown
that clinically depressed people -- those with more severe depression -- often
have lower omega-3 levels in their blood, and several studies have shown that
supplementing diets with omega-3 improves depression," Kiecolt-Glaser said,
although the reason isn't clear.
"People who are depressed don't eat well, or it might be that there is
something about depression that affects how well people process such foods."
In recent years, research has shown that an increase in omega-3 fatty acids in
the diet has specific health benefits, especially in patients with depression,
cardiovascular disease and inflammatory and autoimmune diseases.
Martha Belury, an associate professor of human nutrition, endocrinology,
diabetes & metabolism at Ohio State and co-author of the study, said the
design of the study was important.
"We looked at people who were experiencing real depression, not those whose
depression arose as a part of some experiment, and we could clearly see a
relationship between lower omega-3 fatty acids and certain markers of depression
and inflammation."
Belury said that current recommendations allow up to two servings each week of
cold-water fish the best source of omega-3 such as salmon or trout. This would
not apply to pregnant women, she said, where concerns are greater about the
heavy metal contamination such fish might contain. Omega-3 is also available as
nutritional supplements
"This study has shown that even in people who did not take supplements,
maybe just a little bit more omega-3, could help reduce their markers for both
stress and depression," Belury said.
"The important message for consumers is that they don't have to take
mega-doses of omega-3 to have some impact. It might not take a whole lot to have
a significant clinical impact," Belury said.
The researchers are now starting a larger, more comprehensive randomized and
controlled trial of omega-3 in adults between the ages of 50 and 80 in hopes of
testing the questions raised in this pilot study.
Ron Glaser, professor of internal medicine, molecular virology, immunology and
medical genetics; David Beversdorf, an assistant professor of neurology; Stanley
Lemeshow, dean of the College of Public Health, and Kyle Porter, a statistician
in the Center for Biostatistics, were also part of the project. The research was
supported in part by the National Institutes of Health.
(April 2007)
(Opm. Meer over omega-3
vetzuur en over vetzuren in het algemeen.)