Debate on link of rice, bread, noodle to cancer rages
Can regular consumption of rice, noodle and bread increase the risk of developing chronic diseases such as cancer, diabetes, hypertension, kidney damage, stroke and obesity? In recent times there have been claims and counter claims that long-term consumption of such foods with high glycemic index, potassium bromate, and arsenic increases risk of developing these non-communicable diseases. CHUKWUMA MUANYA (Assistant Editor) examines the possibilities.
How diet with high glycemic index, arsenic increases risk of chronic diseases, by researchers
Rice, bread and noodles have become the commonest meals eaten almost everyday by most Nigerians.
But recent studies found that these carbohydrates with high glycemic index are responsible for the rising cases of obesity, diabetes, hypertension, kidney damage and cancer.
A study published in the journal Cancer Epidemiology, Biomarkers & Prevention investigated the potential link between glycemic index and lung cancer revealed a 49 per cent increase in risk among people consuming rice, white bread and noodles.
Lead study author, Dr. Stephanie Melkonian, of University of Texas MD Anderson Cancer Centre, United States (U.S.), said: “We observed a 49 per cent increased risk of lung cancer among subjects with the highest daily GI compared to those with the lowest daily GI.
“Diets high in glycemic index result in higher levels of blood glucose and insulin, which promote perturbations in the insulin-like growth factors (IGFs).
“Previous research suggests increased levels of IGFs are associated with increased lung cancer risk. However, the association between glycemic index and lung cancer risk was unclear.”
The researchers surveyed 1,905 patients newly diagnosed with lung cancer and compared the results with 2,413 healthy individuals.
Senior study author, Dr. Xifeng Wu, said: “The associations were more pronounced among subjects who were never smokers, diagnosed with squamous cell carcinoma or had less than 12 years of education.
“This suggests that it is the average quality, instead of quantity, of carbohydrates consumed that may modulate lung cancer risk.”
Wu added: “The results from this study suggest that, besides maintaining healthy lifestyles, such as avoiding tobacco, limiting alcohol consumption and being physically active, reducing the consumption of foods and beverages with high glycemic index may serve as a means to lower the risk of lung cancer.”
The glycemic index or glycaemic index (GI) is a number associated with a particular type of food that indicates the food’s effect on a person’s blood glucose (also called blood sugar) level. A value of 100 represents the standard, an equivalent amount of pure glucose.
According to Wikipedia, foods with high GI from 70 and above include: glucose (dextrose, grape sugar), high fructose corn syrup, white bread (only wheat endosperm), most white rice (only rice endosperm), corn flakes, extruded breakfast cereals, maltose, maltodextrins, sweet potato (70), white potato (83).
However, diets high in fruits and vegetables may decrease risk, while increased consumption of red meat, saturated fats and dairy products have been shown to increase lung cancer risk.
Foods with low GI include: fructose; beans (black, pinto, kidney, lentil, peanut, chickpea); small seeds (sunflower, flax, pumpkin, poppy, sesame, hemp); walnuts, cashews, most whole intact grains (durum/spelt/kamut wheat, millet, oat, rye, rice, barley); most vegetables, most sweet fruits (peaches, strawberries, mangos); tagatose; mushrooms; chili pepper.
Also, the United States Food Standards Agency (FSA) has called on consumers to avoid eating instant noodles, as it is harmful to health. Studies have shown that high sodium consumption is linked to a variety of diseases such as hypertension, heart disease, stroke, cancer and kidney damage.
A food dye and wax is just one of many ingredients/chemicals linked to cancer has been found in instant noodles. Instant noodle is a highly processed food that lacks nutritive value. Every single serving of instant noodle is high in carbohydrates, sodium and other food additives, but low on essential elements such as fibre, vitamins and minerals.
Instant noodles have, acid regulators, flavour enhancers, thickeners, humectants, colours, stabilizers, anti-oxidants, emulsifiers, flour treatment agents, preservatives and anti-caking agents which are sodium additives. High-sodium foods cause hypertension, heart disease, stroke, cancer, kidney damage and other health problems.
Meanwhile, billions of people eat rice daily, but it contributes more arsenic to the human diet than any other food. Conventionally grown in flooded paddies, rice takes up more arsenic (which occurs naturally in water and soil as part of an inorganic compound) than do other grains.
High levels of arsenic in food have been linked to different types of cancer, and other health problems.
The International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) classifies arsenic and inorganic arsenic compounds as “carcinogenic to humans”, based on evidence from human studies that it can cause cancer of the lung, bladder, and skin.
But researchers have found cooking rice by repeatedly flushing it through with fresh hot water can remove much of the grain’s stored arsenic — a tip that could lessen levels of the toxic substance in one of the world’s most popular foods.
Also, Natural News claims that over 80 per cent of popular bread brands contain cancer-causing chemicals. A food additive used in bread called potassium bromate has been shown to cause cancer in laboratory animals.
A testing of products in India found potassium bromate in 84 per cent of 38 popular brands of bread, buns, pizza crusts and other baked goods.
Potassium bromate has already been banned in numerous countries, including the entire Nigeria, European Union (EU), the United Kingdom (U.K.), Canada, China and Brazil.
However, another study published in International Journal for Cancer disagrees that regular consumption of rice, bread, noodles and other high GI foods increases cancer risk.
The researchers found that long-term consumption of total rice; white rice or brown rice was not associated with risk of developing cancer.
Another study published in British Journal of Cancer concluded: “Our findings suggest that the consumption of rice does not have a substantial impact on the risk of colorectal in the Japanese population.”
Also, a new study from the Harvard School of Public Health, United States, shows people who eat lots of white rice may significantly raise their risk of developing type 2 diabetes.
The study was published in the British Medical Journal.
Harvard researchers analyzed four earlier studies on white rice consumption that involved more than 352,000 people from China, Japan, U.S., and Australia, who did not have diabetes. The researchers found after follow-up periods that ranged from four to 22 years, that almost 13,400 people had type 2 diabetes.
People who ate the most rice were more than 1.5 times likely to have diabetes than people who ate the least amount of rice. What’s more, for every 5.5 ounce (155.9 grammes/0.1559 kilogrammes) serving of white rice – a large bowl – a person ate each day, the risk rose 10 percent.
“This applies for both Asian and Western cultures, although due to findings suggesting that the more rice eaten the higher the risk, it is thought that Asian countries are at a higher risk,” the researchers wrote.
Study author Dr. Qi Sun, a diabetes researcher at Harvard School of Public Health, told WebMD that eating white rice could cause a sudden spike in blood sugar. Because white rice is rapidly converted to sugar, it could mean a person get’s hungry sooner than if they ate a low-sugar food like porridge, The Telegraph reported. This effect could lead to people overeating, another risk factor for type 2 diabetes.
People who eat lots of rice aren’t the only ones at risk. Sun said starchy carbohydrates such as white bread; white pasta and white potatoes likely have the same effect if eaten enough.
What should people do? Sun touts moderation: “Eating white rice one to two times per week is fine.”
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