Illinois scientists put cancer-fighting power back into frozen broccoli ( Frozen Broccoli can’t form cancer-fighting phytochemicals)

Contact: Phyllis Picklesimer p-pickle@illinois.edu 217-244-2827 University of Illinois College of Agricultural, Consumer and Environmental Sciences

URBANA, Ill. – There was bad news, then good news from University of Illinois broccoli researchers this month. In the first study, they learned that frozen broccoli lacks the ability to form sulforaphane, the cancer-fighting phytochemical in fresh broccoli. But a second study demonstrated how the food industry can act to restore the frozen vegetable’s health benefits.

“We discovered a technique that companies can use to make frozen broccoli as nutritious as fresh. That matters because many people choose frozen veggies for their convenience and because they’re less expensive,” said Elizabeth Jeffery, a U of I professor of nutrition.

“Whenever I’ve told people that frozen broccoli may not be as nutritious as fresh broccoli, they look so downcast,” she added.

As little as three to five servings of broccoli a week provides a cancer-protective benefit, but that isn’t true for bags of broccoli that you pluck out of your grocery’s freezer, she noted.

The problem begins when soon-to-be-frozen broccoli is blanched, or heated to high temperatures, to inactivate enzymes that can cause off-colors, tastes, and aromas during the product’s 18-month shelf life, she explained.

The extreme heat destroys the enzyme myrosinase, which is necessary to form sulforaphane, the powerful cancer-preventive compound in broccoli, she said.

“We know this important enzyme is gone because in our first study we tested three commercially frozen broccoli samples before and after cooking. There was very little potential to form sulforaphane before the frozen broccoli was cooked and essentially none after it was cooked as recommended,” said Edward B. Dosz, a graduate student in Jeffery’s laboratory.

In the second study, the researchers experimented with blanching broccoli at slightly lower temperatures instead of at 86ºC, the current industry standard. When they used a temperature of 76ºC, 82 percent of the enzyme myrosinase was preserved without compromising food safety and quality.

Sulforaphane is formed when fresh broccoli is chopped or chewed, bringing its precursor glucoraphanin and the enzyme myrosinase into contact with each other. The researchers first thought that thawing frozen broccoli in the refrigerator might rupture the plant’s cells and kick-start the enzyme–substrate interaction. It didn’t work, Dosz said.

But they had previously had success using other food sources of myrosinase to boost broccoli’s health benefits. So the researchers decided to expose frozen broccoli to myrosinase from a related cruciferous vegetable.

When they sprinkled 0.25 percent of daikon radish—an amount that’s invisible to the eye and undetectable to our taste buds—on the frozen broccoli, the two compounds worked together to form sulforaphane, Dosz said.

“That means that companies can blanch and freeze broccoli, sprinkle it with a minute amount of radish, and sell a product that has the cancer-fighting component that it lacked before,” he said.

One question remained: Would sulforaphane survive the heat of microwave cooking? “We were delighted to find that the radish enzyme was heat stable enough to preserve broccoli’s health benefits even when it was cooked for 10 minutes at 120ºF. So you can cook frozen broccoli in the microwave and it will retain its cancer-fighting capabilities,” Dosz said.

Jeffery hopes that food processors will be eager to adopt this process so they can market frozen broccoli that has all of its original nutritional punch.

Until they do, she said that consumers can spice up their frozen, cooked broccoli with another food that contains myrosinase to bring the cancer-fighting super-food up to nutritional speed.

“Try teaming frozen broccoli with raw radishes, cabbage, arugula, watercress, horseradish, spicy mustard, or wasabi to give those bioactive compounds a boost,” she advised.

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Jeffery and Dosz of the U of I’s Department of Food Science and Human Nutrition co-authored both studies. Commercially produced frozen broccoli lacks the ability to form sulforaphane was published in the Journal of Functional Foods and is available online at http://www.sciencedirect.com/science/article/pii/S1756464613000510. USDA and the National Institute of Food and Agriculture (NIFA) funded this research.

Modifying the processing and handling of frozen broccoli for increased sulforaphane formation appears in the Journal of Food Science and can be viewed online at http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291750-3841/earlyview. Sakata Vegetables Europe supported this study.

High Fat diets can disrupt our Biological Clock : Through the adiponectin signaling pathway

2008 study posted for filing

Contact: Jerry Barach
jerryb@savion.huji.ac.il
972-258-82904
The Hebrew University of Jerusalem

Another reason to avoid high-fat diet — it can disrupt our biological clock

Jerusalem, December 28, 2008 – Indulgence in a high-fat diet can not only lead to overweight because of excessive calorie intake, but also can affect the balance of circadian rhythms – everyone’s 24-hour biological clock, Hebrew University of Jerusalem researchers have shown.

The biological clock regulates the expression and/or activity of enzymes and hormones involved in metabolism, and disturbance of the clock can lead to such phenomena as hormone imbalance, obesity, psychological and sleep disorders and cancer.

While light is the strongest factor affecting the circadian clock, Dr. Oren Froy and his colleagues of the Institute of Biochemistry, Food Science and Nutrition at the Hebrew University’s Robert H. Smith Faculty of Agriculture, Food and Environment in Rehovot, have demonstrated in their experiments with laboratory mice that there is a cause-and-effect relation between diet and biological clock imbalance.

To examine this thesis, Froy and his colleagues, Ph.D. student Maayan Barnea and Zecharia Madar, the Karl Bach Professor of Agricultural Biochemistry, tested whether the clock controls the adiponectin signaling pathway in the liver and, if so, how fasting and a high-fat diet affect this control. Adiponectin is secreted from differentiated adipocytes (fat tissue) and is involved in glucose and lipid metabolism. It increases fatty acid oxidation and promotes insulin sensitivity, two highly important factors in maintaining proper metabolism.

The researchers fed mice either a low-fat or a high-fat diet, followed by a fasting day, then measured components of the adiponectin metabolic pathway at various levels of activity. In mice on the low-fat diet, the adiponectin signaling pathway components exhibited normal circadian rhythmicity. Fasting resulted in a phase advance. The high-fat diet resulted in a phase delay. Fasting raised and the high-fat diet reduced adenosine monophosphate-activated protein kinase (AMPK) levels. This protein is involved in fatty acid metabolism, which could be disrupted by the lower levels.

In an article soon to be published by the journal Endocrinology, the researchers suggest that this high-fat diet could contribute to obesity, not only through its high caloric content, but also by disrupting the phases and daily rhythm of clock genes. They contend also that high fat-induced changes in the clock and the adiponectin signaling pathway may help explain the disruption of other clock-controlled systems associated with metabolic disorders, such as blood pressure levels and the sleep/wake cycle

Cinnamon is lethal weapon against E. coli O157:H7

Contact: Angela Dansby aldansby@ift.org 312-782-8424 x127 Institute of Food Technologists

When cinnamon is in, Escherichia coli O157:H7 is out.  That’s what researchers at Kansas State University discovered in laboratory tests with cinnamon and apple juice heavily tainted with the bacteria.  Presented at the Institute of Food Technologists’ 1999 Annual Meeting in Chicago on July 27, the study findings revealed that cinnamon is a lethal weapon against  E. coli O157:H7 and may be able to help control it in unpasteurized juices.

Lead researcher Erdogan Ceylan, M.S., reported that in apple juice samples inoculated with about one million E. coli O157:H7 bacteria, about one teaspoon (0.3 percent) of cinnamon killed 99.5 percent of the bacteria in three days at room temperature (25 C).  When the same amount of cinnamon was combined with either 0.1 percent sodium benzoate or potassium sorbate, preservatives approved by the Food and Drug Administration, the E. coli were knocked out to an undetectable level.  The number of bacteria added to the test samples was 100 times the number typically found in contaminated food.

“This research indicates that the use of cinnamon alone and in combination with preservatives in apple juice, besides its flavoring effect, might reduce and control the number of E. coli O157:H7,” concluded Ceylan, a Ph.D. graduate assistant at K-State. “Cinna-mon may help protect consumers against foodborne bacteria that may be in unpasteurized juices and may partially or completely replace preservatives in foods to maintain their safety,” he said.

“If cinnamon can knock out E. coli O157:H7, one of the most virulent foodborne microorganisms that exists today, it will certainly have antimicrobial effects on other common foodborne bacteria, such as Salmonella and Campylobacter,” noted Daniel Y.C. Fung, Ph.D., professor of Food Science in the Department of Animal Sciences and Industry at K-State, who oversaw the research.

Last year, Fung and Ceylan researched the antimicrobial effects of various spices on  E. coli O157:H7 in raw ground beef and sausage and found that cinnamon, clove, and garlic were the most powerful.  This research led to their recent studies on cinnamon in apple juice, which proved to be a more effective medium than meat for the spice to kill the bacteria.

“In liquid, the E. coli have nowhere to hide,” Fung noted, “whereas in a solid structure, such as ground meat, the bacteria can get trapped in the fat or other cells and avoid contact with the cinnamon.  But this cannot happen in a free-moving environment.”

Regardless of the K-State findings, people who are at greater than normal risk for foodborne diseases– namely the elderly, young children, or immune-compromised– would be urged to avoid drinking unpasteurized juices or unthoroughly cooked hamburgers, which may contain harmful microorganisms.

For a copy of the study presented at IFT’s Annual Meeting, contact Angela Dansby at 312-82-8424 x127 or via e-mail at aldansby@ift.org .

###Founded in 1939, IFT is a non-profit scientific society with 28,000 members working in food science, technology and related professions in industry, academia and government.  As the society for food science and technology, IFT brings sound science to the public discussion of food issues

Reposted for Filing 1999 Data

Increase in RDA for vitamin C could help reduce heart disease, stroke, cancer

 

CORVALLIS, Ore. – The recommended dietary allowance, or RDA, of vitamin C is less than half what it should be, scientists argue in a recent report, because medical experts insist on evaluating this natural, but critical nutrient in the same way they do pharmaceutical drugs and reach faulty conclusions as a result.

The researchers, in Critical Reviews in Food Science and Nutrition, say there’s compelling evidence that the RDA of vitamin C should be raised to 200 milligrams per day for adults, up from its current levels in the United States of 75 milligrams for women and 90 for men.

Rather than just prevent the vitamin C deficiency disease of scurvy, they say, it’s appropriate to seek optimum levels that will saturate cells and tissues, pose no risk, and may have significant effects on public health at almost no expense – about a penny a day if taken as a dietary supplement.

“It’s time to bring some common sense to this issue, look at the totality of the scientific evidence, and go beyond some clinical trials that are inherently flawed,” said Balz Frei, professor and director of the Linus Pauling Institute at Oregon State University, and one of the world’s leading experts on the role of vitamin C in optimum health.

“Significant numbers of people in the U.S. and around the world are deficient in vitamin C, and there’s growing evidence that more of this vitamin could help prevent chronic disease,” Frei said. “The way clinical researchers study micronutrients right now, with the same type of so-called ‘phase three randomized placebo-controlled trials’ used to test pharmaceutical drugs, almost ensures they will find no beneficial effect. We need to get past that.”

Unlike testing the safety or function of a prescription drug, the researchers said, such trials are ill suited to demonstrate the disease prevention capabilities of substances that are already present in the human body and required for normal metabolism. Some benefits of micronutrients in lowering chronic disease risk also show up only after many years or even decades of optimal consumption of vitamin C – a factor often not captured in shorter-term clinical studies.

A wider body of metabolic, pharmacokinetic, laboratory and demographic studies suggests just the opposite, that higher levels of vitamin C could help reduce the chronic diseases that today kill most people in the developed world – heart disease, stroke, cancer, and the underlying issues that lead to them, such as high blood pressure, chronic inflammation, poor immune response and atherosclerosis.

“We believe solid research shows the RDA should be increased,” Frei said. “And the benefit-to-risk ratio is very high. A 200 milligram intake of vitamin C on a daily basis poses absolutely no risk, but there is strong evidence it would provide multiple, substantial health benefits.”

An excellent diet with the recommended five to nine daily servings of fruits and raw or steam-cooked vegetables, together with a six-ounce glass of orange juice, could provide 200 milligrams of vitamin C a day. But most Americans and people around the world do not have an excellent diet.

Even at the current low RDAs, various studies in the U.S. and Canada have found that about a quarter to a third of people are marginally deficient in vitamin C, and up to 20 percent in some populations are severely deficient – including college students, who often have less-than-perfect diets. Smokers and older adults are also at significant risk.

Even marginal deficiency can lead to malaise, fatigue, and lethargy, researchers note. Healthier levels of vitamin C can enhance immune function, reduce inflammatory conditions such as atherosclerosis, and significantly lower blood pressure.

•           A recent analysis of 29 human studies concluded that daily supplements of 500 milligrams of vitamin C significantly reduced blood pressure, both systolic and diastolic. High blood pressure is a major risk factor for heart disease and stroke, and directly attributes to an estimated 400,000 deaths annually in the U.S.

•           A study in Europe of almost 20,000 men and women found that mortality from cardiovascular disease was 60 percent lower when comparing the blood plasma concentration of vitamin C in the highest 20 percent of people to the lowest 20 percent.

•           Another research effort found that men with the lowest serum vitamin C levels had a 62 percent higher risk of cancer-related death after a 12-16 year period, compared to those with the highest vitamin C levels.

Laboratory studies with animals – which may be more accurate than human studies because they can be done in controlled conditions and with animals of identical genetic makeup – can document reasons that could explain all of these findings, Frei said.

Critics have suggested that some of these differences are simply due to better overall diet, not vitamin C levels, but the scientists noted in this report that some health benefits correlate even more strongly to vitamin C plasma levels than fruit and vegetable consumption.

Scientists in France and Denmark collaborated on this report. Research at OSU on these issues has been supported by the National Center for Complementary and Alternative Medicine, a division of the National Institutes of Health.

About the Linus Pauling Institute: The Linus Pauling Institute at OSU is a world leader in the study of micronutrients and their role in promoting optimum health or preventing and treating disease. Major areas of research include heart disease, cancer, aging and neurodegenerative disease