Effect of Polyphenols on Iron Absorption From Finger Millet
Condition: Iron-deficiency
MeSH terms: Anemia, Iron-Deficiency; Iron Deficiencies
Study type: Interventional

Summary: 
      In India, one of the fast growing countries, 53% of all women have anaemia as per the
      National Family Health Survey. A recently published study on the burden of disease in India
      concluded that the burden of Iron deficiency anaemia (IDA) is 3 times higher than the average
      globally for other geographies at a similar level of development, and that women are
      disproportionately affected. Finger Millet (Eleusine coracana), more commonly known as Ragi,
      is a type of a millet crop grown in India, is considerably rich in minerals and its
      micronutrient density is higher than that of the world's major cereal grains: rice and wheat.
      Ragi also contains different antinutrients such as phytates and polyphenols, which have been
      known to have an inhibiting effect on the absorption of iron. On an average, white finger
      millet contains 0.04-0.09% polyphenols and brown varieties have 0.08-3.47%. The dark variety
      of ragi is the most widely consumed type. The white ragi is the lesser consumed type.
      However, the levels of polyphenols, which inhibit the absorption of iron, are ten times lower
      in the white ragi as compared to the dark ragi. Thus, it is important to evaluate the extent
      of inhibition of the polyphenols on the iron absorption. This information would be beneficial
      for policy making and promotion of cultivation of the type of ragi that could be most
      effective for the consumers
    

Detailed description: 
      Finger Millet (Eleusine coracana), more commonly known as Ragi, is a type of a millet crop
      grown in India, including other countries especially in East Africa. Ragi has been perceived
      as a potential "super cereal" by the United States National Academies being one of the most
      nutritious among all major cereals. From the nutritional perspective, finger millet is
      considerably rich in minerals and its micronutrient density is higher than that of the
      world's major cereal grains: rice and wheat .

      Millets (Ragi or finger millet and Jowar or sorghum) were consumed by 59% of rural and 28% of
      urban population in Karnataka. Ragi consumption was seen predominantly in south Karnataka
      with 27% of rural and 17% of urban population reporting consumption.

      Ragi is the richest source of calcium among cereals with up to 10-fold higher calcium content
      than brown rice, wheat or maize and three times than that of milk. It is also rich in iron
      and fiber, making this crop more nutritive as compared to other most commonly used cereals.
      Finger millet is enriched in the essential amino acids like lysine and methionine which are
      important in human health and growth but remain absent from most other plant foods . In
      addition, it also contains useful amounts of the two polyunsaturated fatty acids- linoleic
      acid and α-linolenic acid , metabolized products of which facilitate normal development of
      the central nervous system. Despite the well-documented health benefits of finger millet,
      only a limited progress has been made in context to its nutraceutical applications as
      functional food. Although, it may have remained underutilized by the general population due
      to either unawareness or apprehension, its immense potential for enhancing the nutritional
      and therapeutic attributes by acting as functional food cannot be ignored.

      Ragi also contains different antinutrients such as phytates and polyphenols, which have been
      known to have an inhibiting effect on the absorption of iron. On an average, white finger
      millet contains 0.04-0.09% polyphenols and brown varieties have 0.08-3.47% . It was found
      that found proto-catechuic acid (45.0 mg/100 g) is the major free phenolic acid in ragi. In
      another study of total phenolic compounds in finger millet, it was found to have 85% benzoic
      acid derivatives (gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid,
      syringic acid) while rest of the fraction were either cinnamic acid derivatives (ferulic
      acid, trans-cinnamic acid, p-coumaric acid, caffeic acid, sinapic acid) or flavonoids
      (quercetin, Proanthocyanidins like condensed tannins) . Among bound phenloic acids, ferulic
      and p-coumaric acid are the major fractions and account for 64-96 and 50-99% of total ferulic
      and p-coumaric acid content of finger millet grains, respectively.

      The dark variety of ragi is the most widely consumed type. The white ragi is the lesser
      consumed type. However, the levels of polyphenols, which inhibit the absorption of iron, are
      ten times lower in the white ragi as compared to the dark ragi. Thus, it is important to
      evaluate the extent of inhibition of the polyphenols on the iron absorption. This information
      would be beneficial for policy making and promotion of cultivation of the type of ragi that
      could be most effective for the consumers

      The study duration will be 26 days from the first day of the first meal administration till
      the last blood withdrawal . For each appointment, the participants will spend about 30
      minutes at the Human Nutrition Laboratory at ETH Zurich, between 7 and 9 am for breakfast
      meal consisting of pancakes made out of the ragi. the white ragi meal and the black ragi meal
      will be extrinsically labelled with isotopes 57 Fe and 58 Fe respectively. The participants
      will consume the ragi meal as breakfast. The first type of ragi meal will be given for 5
      consecutive days,. They will have a weekend break of two days (during which they will resume
      their usual eating habits). After that, they will consume the second test meal as breakfast
      for another five consecutive days. Thus, there will be 10 meals in total. The breakfast meals
      will be consumed between 7 and 9 am together with a glass of 300 mL bottled water after which
      they have to wait another 3 hours before they can consume anything. The procedure will remain
      the same for all the days. Participants will always be asked to fast the day before coming
      for the feeding, that is, no food intake after 8 pm and no beverage intake after midnight the
      evening before. On day of screening, day 1 and the end point day 26 of the study, blood
      samples will be collected after an overnight fast for the determination of Hb, PF, CRP and
      isotopic ratio
    

Intervention name(s): Black Ragi; White Ragi
Intervention type(s): Other; Other
Intervention description(s): Pancakes made out of the dark ragi; Pancakes made out of the white ragi
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: The study will have a randomized, cross-over design and will be conducted at the Human Nutrition Laboratory, ETH Zurich (scientific responsibility). From an initial screening of 150 women, 25 non-pregnant non-lactating women with a marginal iron status (PF <25 ng/ml) will be recruited. In total, participants will consume the 2 intervention products in a random, balanced order. Participants will consume the first intervention product as a breakfast meal for 5 days in a week, and the second intervention product as a breakfast meal as well for 5 days the following week. A blood sample will be collected 14 days after the last meal administration day which will be used to measure the shift in the isotopic ratio
Masking: None (Open Label)
Primary purpose: Other
Keywords: polyphenols; iron deficiency; finger millet; iron bioavailability