Grey Duck Garlic sells organic gourmet seed garlic

Garlic Enhances Iron Metabolism

Garlic Protects Against Iron Overload

and Why Should You Worry About Iron?

Are your rats looking tired and anemic? Nahdi et al. (2010) reported that rats given a crude garlic solution (1 g/kg weight) with supplemental iron for three weeks had a 200% increase in plasma iron and a 50% increase in liver iron when compared to rats given only supplemental iron. Grey Duck Garlic, Chesnok Red garlic bulbs on dried garlic stalks

Picture: A group of sweet tasting Chesnok Red bulbs hang out on dried garlic stalks. We feed harvested garlic stalks to Jane's cows (who seem to enjoy tossing them over their heads).

Possible mechanisms: Diallyl disulfide, an active compound found in garlic, increased iron transfer in a human cell culture model (cell culture model = polarized Caco-2 cells which form a membrane that resembles the enterocyte cells lining the small intestine). The increased iron transport may have resulted from a slight increase in iron channel mRNA and protein expression. Iron channels, known as ferroportin, form a tube across the cell membrane to help move iron from the intestinal cells to the bloodstream.

Take home message: Garlic may increase iron absorption by increasing iron transport into the bloodstream.

Garlic Protects Against Iron Overload

Rats given excess iron were protected by supplementation with fresh garlic. Compared to rats with a normal diet, rats eating too much iron showed negative changes in liver serum ALAT, ASAT, triglyceride and LDH levels as well as radical cation scavenging ability in liver cytosol. When rats were given too much iron and also treated with fresh garlic all of these problems were reduced or eliminated. This showed a hepatoprotective effect of garlic against excessive liver iron (Ghorbel et al. 2011).

S-allylcysteine (SAC), a sulphur containing amino acid derived from garlic, alleviates negative changes in iron metabolism caused by diabetes in rats (Saravanan et al. 2013). Basically SAC normalize iron metabolism in diabetic rats by significantly increasing levels of glucose, iron, ferritin, bilirubin and HO in the liver (p<0.05) and decreasing levels of insulin, transferrin and δ-ALA-D in tissues.

Warning: Little is known about the long term effect of alliums, such as garlic or onions, on rats. Since there is a lot of conflicting advice and no published data on this topic we don't recommend feeding alliums to rodents like rats or guinea pigs. Please see our information on garlic and pets before feeding garlic to your favorite (hopefully) plague free rodent. Feel free to eat garlic yourself though!

Why should you worry about iron?

Iron deficiency is very common, especially in young and middle aged women. It is estimated that up to 25% of women may be severely iron deficient. In contrast, only 1-2% of men are severely iron deficient. Much of the iron in the body is recycled. Iron is lost through sloughing off of body tissues (like skin and mucosal cells) and blood loss (injury or menstruation).

Severe iron deficiency results in anemia, not having enough red blood cells to carry oxygen in the body. However, many women have subclinical iron deficiency. They do not have the symptoms of anemia and may not be diagnosed as iron deficient. This is because low iron concentrations affect the mitochondria first (who use iron to produce energy) and the red blood cells second. When mitochondria don't have enough iron energy production decreases causing physical and mental fatigue.

Giving women with subclinical iron deficiency iron supplements increases athletic performance and energy level.

Risk factors for iron deficiency:

  • Black and Hispanic women are at greater risk than Caucasian women
  • Vegetarians have lower levels of iron than omnivores (vegans have a 40% chance of iron deficiency)
  • Pregnant women need extra iron
  • People who do intense exercise lose more iron
  • People who have Celiac disease or who suffer from gastrointestinal disorders and tumors can't absorb as much iron (the intestinal lining is damaged)
  • Children from 6 months to four years old (babies are born with a 6 month supply of iron)


Symptoms of iron deficiency: Tired all the time, cold all the time, shortness of breath, headaches, irritable, weak, poor athletic performance, anemia, and sore tongue.

Why you need iron: Iron is used for oxygen transport in blood (hemoglobin), creating energy from food (iron transports electrons in the mitochondrial electron transport chain), DNA synthesis, as an antioxidant and as a beneficial pro-oxidant.

How iron is absorbed: Iron is taken up in the upper part of the small intestine (duodenum and upper jejunum) by special intestinal cells called enterocytes. Iron can be in two oxidative states, Fe+3 or Fe+2. Most iron is taken up as Fe3+. Cells store iron as ferritin. After being transported from the cell to the bloodstream through iron channels called ferroportin, iron is bound by the protein apotransferrin. The apotransferrin/iron compound in the bloodstream is known as transferrin. Your body also recycles iron from dead cells.

Enhance iron absorption:

  • Eat more meat. Heme iron, found in meat as myoglobin or hemoglobin, is absorbed more efficiently than non-heme iron found in vegetable sources.
  • Get enough vitamin C from fresh fruits and vegetables. Vitamin C and acidity enhances iron absorption by changing the oxidative state of iron from Fe+2 to the bioavailable form, Fe+3.
  • Consume copper found in cocoa, nuts, oysters, sesame seeds, sunflower seeds and dried tomatoes. Copper is needed in hephaestin, a protein that is necessary for ferroportin to transfer iron from cells to the bloodstream (Sheers 2013).
  • Make sure to eat your zinc; found in oysters, crab, red meat, dark chocolate, peanuts and wheat germ. Zinc enhances ferroportin transcription (Sheers 2013).
  • Cook your food in a cast iron pan. Acidic and tomato based foods, like spaghetti sauce, leach iron from the pan into the food.


Iron absorption is only 5-10% of iron intake in non-deficient people. When people are iron deficient absorption can increase to 35%. Substances that enhance iron absorption include meat and vitamin C.


  • Ghorbel H, Feki I, Friha I, Khabir AM, Boudawara T, Boudawara M, Sayadi S. Biochemical and histological liver changes occurred after iron supplementation and possible remediation by garlic consumption. Endocrine. 2011;40:462-71. Pubmed. doi: 10.1007/s12020-011-9483-0
  • Nahdi A, Hammami I, Brasse-Lagnel C, Pilard N, Hamdaoui MH, Beaumont C, El May M. Influence of garlic or its main active component diallyl disulfide on iron bioavailability and toxicity. Nutr Res. 2010;30:85-95. Pubmed. doi: 10.1016/j.nutres.2010.01.004
  • Saravanan G1, Ponmurugan P, Begum MS. Effect of S-allylcysteine, a sulphur containing amino acid on iron metabolism in streptozotocin induced diabetic rats. J Trace Elem Med Biol. 2013;27:143-7. Pubmed. doi: 10.1016/j.jtemb.2012.07.009
  • Scheers N. Regulatory Effects of Cu, Zn, and Ca on Fe Absorption: The Intricate Play between Nutrient Transporters. Nutrients. 2013;5:957-970. Pubmed. doi: 10.3390/nu5030957


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