The meta-analysis by Hooper,
et al 2012 included 4 other fat modification trials, the last of which is this
trial called MeDiet (short for Mediterranean Diet)
Studies Associated with the Trial
The Mediet Project (2002) [1]
A traditional Mediterranean
diet decreases endogenous estrogens in healthy postmenopausal women (2006) [2]
Dietary enterolactone affects
androgen and estrogen levels in healthy postmenopausal women (2009) [3]
Methods
The MeDiet project
investigated whether a Mediterranean diet would reduce estrogen levels as: (1)
previous research has found that estrogen levels are positively associated with
the initiation and development of breast cancer; and (2) observational studies
that found the incidence of breast cancer to be lower in southern Italy
compared to northern Italy, which was related to dietary differences [1]
[2]
106 postmenopausal women (aged
44-71) who met the eligibility criteria* were randomised to a Mediterranean
diet group (the experimental group) or a control group for 1 year [1]
[2]
“Women in the intervention group adhered to a traditional, restricted
Mediterranean diet for 6 mo, whereas women in the control group continued to
follow their regular diet. In particular, intervention women attended a weekly “cooking
course,” followed by a social dinner, and were trained by professional chefs in
the correct use of natural ingredients of a traditional Mediterranean diet.
Women were then instructed to consume the same food at home using a series of
recipes based on a traditional Sicilian diet. This diet included whole cereals,
legumes, seeds, fish, vegetables, and other Mediterranean seasonal food
containing several biologically relevant anticancer agents. Furthermore, women
were asked to avoid the use of refined carbohydrates and additional animal fat,
and to limit the use of salt. The dietary intervention was intended to 1)
reduce the intake of both refined sugar and saturated and total fat; 2)
increase the consumption of mono- and polyunsaturated fat; 3) increase the
intake of fruits and vegetables (notably cruciferous plants); and 4) increase
the intake of food rich in phytoestrogens.” [2]
Macronutrient intake is
presented below. In summary, both groups
significantly decreased their calorie intake though to a greater extent in the
experimental group (302 vs. 164). In the
experimental group this was achieved by reducing intake of animal protein, animal
fat and carbohydrates, whereas the control group just reduced intake of protein
and carbohydrate. In both groups the
significant reduction in carbohydrates was due to reductions in both starch and
sugar [2]
* “Eligibility criteria were: (1) postmenopausal for at least 2 years;
(2) no history of bilateral ovariectomy; (3) no hormone replacement therapy for
the previous 1 year; (4) no history of cancer; (5) no adherence to a vegetarian
or macrobiotic diet or to any other medically prescribed diet; and (6) no
treatment for diabetes, thyroid disease, and chronic bowel disease” [1]
Results
The experimental diet
significantly reduced several estrogen metabolites in urine (except E2 which
significantly increased) as well as total urinary estrogen (see table below) [2]. Total urinary androgens slightly increased
(NS) [3]. There were also some positive correlations
between androgens and enterolactone*
intake [3]
* Lignin precursors of enterolactone
are found in the fibre of plant foods and are metabolised to enterolactone by
gut bacteria. Enterolactone seems to
work by inhibiting aromatase, which converts testosterone to estrogen, and
therefore seems gets some attention, both in research regarding estrogen
associated cancers such as breast and prostate cancer; and also as a potential
anti-aging therapy for men
Neither of the three papers
reported any data on endpoints. What we
have comes from Hooper, et al (who would have contacted the authors), which is
presented below. There weren’t many hard
endpoints which is most likely due to the small size (N = 106), not strictly
being a secondary prevention trial and its short duration (1 year)
Experimental (N
= 51)
|
Control (N = 55)
|
|
Stroke
|
0
|
1
|
Combined CVD
Events
|
0
|
3
|
Cancer Diagnosis
|
0
|
2
|
Hooper, et al included MeDiet
as a reduced and modified fat trial, but wasn’t much of either. Reduced
fat: the experimental group reduced total fat intake from 82.2g to 67.9g,
but due to the overall reduction in calories (from both protein and
carbohydrate as well), the percentage of fat only decreased by 0.95% from
37.40% to 36.45%. Modified fat: the experimental group reduced SFA intake from 27.7g
to 18.4g, but there was no reciprocal increase in either MUFA or PUFA intake. In fact, MUFA intake decreased from 40.7g to
37.2g and PUFA intake decreased from 9.1g to 8.6g. The ‘fat modification’ was all relative to
total calories. Therefore, it’s
inappropriate to include MeDiet in either a meta-analysis on reduced fat or
modified fat trials, since it is neither.
Instead, it would be more appropriate to classify it as a ‘reduced
calorie, reduced SFA trial with a highly multifactorial dietary intervention
plus potential behaviour modification’, making it an ‘inadequately controlled
trial’
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