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- Maca (Lepidium meyenii)
- High Altitude
- Interleukin-6 (IL-6)
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Date:
09-15-2014 | HC# 051413-504
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Re: Maca Consumption Improves Health Status and Reduces Serum IL-6 Levels at High Altitudes
Gonzales GF, Gasco M, Lozada-Requena I. Role of
maca (Lepidium meyenii) consumption
on serum interleukin-6 levels and health status in populations living in the
Peruvian Central Andes over 4000 m of altitude. Plant Foods Hum Nutr. 2013;68(4):347-351.
Maca (Lepidium meyenii) is a plant found in the high altitudes of the
central Peruvian Andes. The hypocotyls (root-like stems) from the maca plant are
a traditional food consumed in this region for nutritional and medicinal
benefits. High altitudes can cause chronic
mountain sickness (CMS: excessive
production of red blood cells), high oxidative stress, high interleukin-6 (IL-6: a marker of inflammation and health
problems), and may contribute to the aging process. The aim of this cross-sectional study was to
investigate the effect that maca consumption has on health status, CMS, and
serum levels of IL-6 in subjects living at a high elevation.
Subjects came from the district of Junín in Peru, a region in the Peruvian Andes that
is 4,100 m above sea level. There were a total of 50 subjects (21 men and 29
women) in the age range of 35-69 years evaluated. Within this group of people,
27 were maca consumers that had been consuming this food for an average of 25.8
± 3.2 years (range 2-55 years). Moreover, 50% of these subjects consumed it
within the 7 days and month prior to the study. Maca was prepared at the
subject's home and generally consumed as a juice for its nutritional properties
and to a lesser extent for its medicinal effects. Subjects were randomly
recruited and determined as maca consumers or non-consumers based on a
questionnaire.
Blood samples were obtained from all
subjects, in addition to height and weight measurements. Health status was
assessed with a health-related quality of life (HRQL) questionnaire. In
particular, a short-form health survey (SF20) was used, which
measures physical function, pain, general health, vitality, and
emotional/mental health. This form was validated in populations from both high-altitude
and sea-level residences. Lower limb strength was also assessed from a stand up from a chair and sit down (SUCSD) test.
Hemoglobin and blood pressure were measured on site. Serum testosterone (T)
levels (ng/ml) and estradiol (E2) levels, as well as serum IL-6 levels, were
also measured from the blood samples. Subjects were further evaluated for CMS
and given a CMS score based on any CMS symptoms the subjects experienced.
Age and sex ratios were similar between
consumers and non-consumers of maca (P>0.05). Compared to non-consumers, the
maca consumers had lower values for systolic blood pressure (P<0.05), serum
T levels (P<0.05), T/E2 ratio (P<0.05), serum IL-6 (P<0.05), and CMS
scores (P<0.01), as well as higher serum E2 levels (P<0.01) and health
scores (P<0.01). In addition, more maca consumers (96.5%) successfully
completed the SUCSD test compared to non-consumers (60.86%) (P<0.01).
Subjects that were grouped together based
on IL-6 values >10 pg/ml had a significantly lower percentage of subjects
that successfully completed the SUCSD test compared to subjects that were
grouped with lower IL-6 values (<10 pg/ml) (P<0.05). Subjects with IL-6 values >10 pg/ml also did not consume
any maca, whereas subjects with the lowest IL-6 levels (≤5 pg/ml) consumed maca
in the greatest quantities and for the longest time. Multiple regression
analysis indicated that maca consumption was inversely associated with serum
IL-6 when controlling for chronological age, whereas health status scores were
inversely related with age. Moreover, it was found that serum IL-6 levels were
higher in men.
The average consumption of maca was 41.68 ±
8.49 days per year. The serum IL-6 levels for those consuming maca during the
week of the study were 1.61 ± 0.51 pg/ml and for those consuming maca the month
before the study were 2.98 ± 0.82 pg/ml (P>0.05). Additionally, a significant
difference was found in the IL-6 levels of subjects that consumed maca within
the week of the study compared with non-consumers (10.07 ± 3.62 pg/ml)
(P<0.05).
The results of this study are encouraging,
although prospective studies would be necessary to show cause and effect. The
authors conclude that maca consumption was associated with lower serum IL-6,
better health scores, and lower CMS scores. Moreover, lower T and T/E2 ratios
suggest beneficial effects (associated with lower CMS scores). A review on the ethnopharmacology of maca also reported similar results for high-altitude health
scores and indicated that maca also reduced fractured bones, improved memory, protected
against ultraviolet exposure, improved sexual function, and improved
reproduction.1 This suggests that maca has additional biological
activities that could be evaluated in people living at high altitudes. This
article lacks information about the preparation of the maca juice and the
uniformity of the product that was actually consumed by the people in the
trial. Also, since maca can be consumed as a soup or cooked as a vegetable, it
is likely that it could have been consumed in either of these manners as well.
—Laura M. Bystrom, PhD
Reference
1Garner-Wizard M. Review of maca – a promising adaptogen. HerbClip. March 15, 2012 (No. 111143-444). Austin, TX: American Botanical Council.
Ethnobiology and ethnopharmacology of Lepidium
meyenii (maca), a plant from the
Peruvian highlands by Gonzales GF. Evid Based Complement Alternat Med. 2012;2012:193496. doi: 10.1155/2012/193496.
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