Combating Iron Deficiency: Rice With Six Times More Iron Than Polished Rice Kernels Developed

According to the World Health Organization, approximately two billion people suffer from iron deficiency. They tire easily, experience problems in metabolizing harmful substances in their bodies and eventually suffer from anemia. Women and children are particularly affected in developing countries, where rice is the major staple food. Peeled rice, also called polished rice, does not have enough iron to satisfy the daily requirement, even if consumed in large quantities. For many people, a balanced diet or iron supplements are often unaffordable.Rice actually has a lot of iron, but only in the seed coat. Because unpeeled rice quickly becomes rancid in tropical and subtropical climates, however, the seed coat - along with the precious iron - has to be removed for storage. Researchers working with Christof Sautter and Wilhelm Gruissem in the laboratory of plant biotechnology at ETH Zurich have now succeeded in increasing the iron content in polished rice by transferring two plant genes into an existing rice variety. Their work was published July 21 in the online edition of Plant Biotechnology Journal.

Genes help to mobilize and store iron

The rice plants express the two genes to produce the enzyme nicotianamin syn-thase, which mobilizes iron, and the protein ferritin, which stores iron. Their synergistic action allows the rice plant to absorb more iron from the soil and store it in the rice kernel. The product of nicotianamine synthase, called nicotianamin, binds the iron temporarily and facilitates its transportation in the plant. Ferritin acts as a storage depot for iron in both plants and humans. The researchers controlled the genes introduced in such a way that nicotianamin synthase is expressed throughout the rice plant, but ferritin only in the rice kernel. Together, the expression of the genes has a positive impact on iron accumulation in the rice kernel and increases the iron content more than six-fold compared to the original variety.

No negative impacts anticipated

The ETH scientists are excited about the new rice variety. The prototypes behave normally in the greenhouse and show no signs of possible negative effects. "Next we will have to test whether the rice plants also perform well in the field under agronomical conditions", says Wilhelm Gruissem. The ETH Professor does not expect the plants to have a negative impact on the environment. It is unlikely that they will deplete the soil of iron, as iron is the most abundant metallic element in it.

Distribution to farmers still many years away

The rice plants will have to undergo many greenhouse and field tests for bio-safety and agronomic performance before the high-iron rice varieties eventually become available to farmers. The current prototypes are unsuitable for agricultural production yet. Although the new rice variety already has an iron content that is nutritionally relevant, Gruissem wants to increase it further. After all, many people who suffer from iron deficiency can only afford one meal per day. If the scientists manage to increase iron in the rice kernel up to twelve-fold, one rice meal will be sufficient to satisfy the daily iron requirement.

The experience with the high-vitamin A "Golden Rice", which was developed at ETH Zurich in collaboration with researchers at the University of Freiburg (Germany), has shown that it takes years before genetically engineered rice can actually be planted by farmers. The regulatory hurdles and costs involved in making genetically modified plants available to agriculture and consumers are very high. The ETH scientists aim to make their high-iron rice plants available to small-scale and self-sufficient farmers free of charge.

Green Tea: Mixed Reviews For Cancer Prevention

Lifestyle choices are pieces of the cancer prevention puzzle, but exactly which steps to take remain unclear, even to scientists. Still, more and more individuals are incorporating small changes into their daily routine — such as drinking green tea — in hopes of keeping cancer risk at bay.Is it working? A large new Cochrane review of studies that examined the affect of green tea on cancer prevention has yielded conflicting results.

Researchers looked at 51 medium- to high-quality studies that included more than 1.6 million participants. The studies focused on the relationship between green tea consumption and a variety of cancers, including breast, lung, digestive tract, urological prostate, gynecological and oral cancers.

The comprehensive review analyzed studies conducted from 1985 through 2008. Many of the reviewed studies took place in Asia, where tea drinking is widespread and part of the daily routine for many.

The review appears in a recent issue of The Cochrane Library, which is a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.

“Despite the large number of included studies the jury still seems to be out on the question of whether green tea can in fact prevent the development of various cancer types,” said lead review author Katja Boehm, Ph.D. Since people drink varying amounts of green tea, and different types of cancers vary in how they grow, it is impossible to state definitively that green tea is “good” for cancer prevention.

“One thing is certain…green tea consumption can never account for cancer prevention alone,” said Boehm, a member of the Unconventional and Complementary Methods in Oncology Study Group in Nuremburg, Germany.

Three types of tea — black, green and oolong — come from the plant Camellia sinensis, and all contain polyphenols. Catechins, a subgroup of the polyphenols, are powerful antioxidants. Some say the polyphenols in green tea are unique, preventing cell growth and thus having the potential to prevent cancer.

The review found that green tea had limited benefits for liver cancer, but found conflicting evidence for other gastrointestinal cancers, such as cancer of the esophagus, colon or pancreas. One study found a decreased risk of prostate cancer for men who consumed higher quantities of green tea or its extracts.

The review did not find any benefit for preventing death from gastric cancer, and found that green tea might even increase the risk of urinary bladder cancer. Despite conflicting findings, there was “limited moderate to strong evidence” of a benefit for lung, pancreatic and colorectal cancer. None of the studies that simply observed a group of people over time found a benefit for breast cancer prevention. However, both of the case control studies — which compare people without a condition to people with it — found a positive association between green tea consumption and a decreased risk of breast cancer.

Nagi Kumar, Ph.D., director of Nutrition Research at Moffitt Cancer Center in Tampa, Fla., is optimistic about the potential for green tea in cancer prevention. “The substances found in green tea are certainly promising,” Kumar said. “The field now has progressed to where we [can]…test the effectiveness and safety of green tea polyphenols using a drug form similar to the constituents in tea to see if we can prevent cancer progression. Time will tell.”

Kumar said the Cochrane review was “more an inventory of studies completed rather than a systematic scientific review,” adding that “the discussion lacks a scientific approach in the interpretation of the discordant findings.”

Kumar also noted that several groups are conducting randomized clinical trials, including one comprising six institutions: the Moffitt Cancer Center and the James A Haley VA Medical Center, University of Chicago, Jefferson in Philadelphia, University of Florida and Louisiana State University.

Both scientists agreed that more research is a good idea. Boehm said she highly recommends the conduction of a large, well-designed, study with adequate green tea consumption levels.

“The review provides where we have been in this field of research and where we are going and how much more we have on hand,” Kumar said. “Although not as thorough as I would like it, it is a good quality review.”

Therefore, while the questions about green tea consumption and cancer prevention remain unanswered, one thing remains clear: It is fine to consume green tea if you enjoy it and it might prove beneficial in the over time.

“If not exceeding the daily recommended allowance those who enjoy a cup of green tea should continue its consumption,” Boehm said. “Drinking green tea appears to be safe at regular, habitual and moderate use at its recommended dosage of up to 1200 ml/day.” That comes to a little over five cups a day.