Tuesday, February 07, 2012

Cancer 'slowed by cooked tomatoes' (?)

This is a very preliminary finding from a study in laboratory glassware only

A nutrient in cooked tomatoes has been shown in laboratory studies to slow the growth of - and even kill - prostate cancer cells, scientists said today.

Dr Mridula Chopra and colleagues at the University of Portsmouth tested the effect of the nutrient lycopene on the simple mechanism through which cancer cells hijack a body's healthy blood supply to grow and spread. They found that lycopene, which is what gives tomatoes their red colour, intercepts cancer's ability to make the connections it needs to attach to a healthy blood supply.

The researchers, from the university's School of Pharmacy and Biomedical Sciences, are now calling for tests to check if the same reaction occurs in the human body.

Director of the research Dr Chopra said: "This simple chemical reaction was shown to occur at lycopene concentrations that can easily be achieved by eating processed tomatoes."

Lycopene is present in all red fruits and vegetables, but its concentrations are highest in tomatoes and it becomes more readily available and biologically active when it comes from processed tomatoes with a small amount of cooking oil added.

Dr Chopra said: "I stress that our tests were done in test tubes in a laboratory and more testing needs to be carried out to confirm our findings, but the laboratory evidence we have found is clear - it is possible to intercept the simple mechanism some cancer cells use to grow at concentrations that can be achieved by eating sufficient cooked tomatoes."

The research, which is published in the British Journal of Nutrition, was part-funded by Heinz after the food manufacturer asked for more research to follow up earlier studies by the same researchers which showed a significant increase in lycopene levels in blood and semen samples after subjects ate 400g (14oz) of processed tomatoes for two weeks.

Dr Chopra and her colleagues Simone Elgass and Alan Cooper said they had a firm agreement they would publish their results irrespective of the outcome.

Cancer cells can remain dormant for years until their growth is triggered through the secretion of chemicals which initiate the process of linking cancer cells with endothelial cells which act as healthy gatekeeper cells lining blood vessels. This allows the cancer cells to reach out and attach to the blood supply.

In the laboratory experiments, lycopene was shown to disrupt this linking process, without which cancer cells cannot grow.

The researchers explained that all cancer cells use a similar mechanism (angiogenesis) to "feed" upon a healthy blood supply.

They said there was added importance of this mechanism for prostate cancer because lycopene tends to accumulate in prostate tissues.

Dr Chopra said: "The important thing is for sufficient lycopene to reach where it can matter. We know that in case of prostate tissues it gets there. "We have tested this in the labs but we don't yet know if the same action will happen in the body.

"Individuals will vary in how much lycopene their bodies make available to fight cancer cell growth and the ability of lycopene to 'intercept' in this way in the body is likely to vary between tomato products - both processing and cooking with fat have previously been shown to make lycopene more effective biologically.

"The type of tomatoes which offer the most effective lycopene also differs and more tests need to be done to find the best breed of tomato for this purpose."

It was suggested in their previous research that smokers might have to consume more tomatoes than non-smokers to achieve the benefits of lycopene due to the presence of high oxidative stress in smokers.

Eleanor Barrie, senior science information officer at Cancer Research UK, said: "Some existing cancer drugs target the formation of new blood vessels, but more research is needed to show how they could be used to help cancer patients.

"This small study doesn't directly tell us if lycopene has any effect against cancer, but research like this can help us to understand more about how the chemical affects blood vessel formation."


Ideology marches on: U.S. School lunches to have more vegetables, fruits

The usual faith that they can identify what is healthy food. They can't. Do they know of the huge American study which showed that women who eat lots of vegetables have an INCREASED risk of stomach cancer, for instance? Do they know that the best evidence shows that there is no health advantage in a low fat diet and that a low salt diet is actually dangerous to you? Etc., etc.

The school lunch is poised for a big makeover. The U.S. Department of Agriculture on Wednesday unveiled new nutrition standards that will require schools to add more fruits and vegetables to lunch while gradually reducing the amount of sodium and trans fat. The rules also set calorie limits for the millions of meals served annually through the National School Lunch Program.

The changes, which will be phased in over three years beginning July 1, are the first major revisions the agency has made to the federal lunch program in more than 15 years.

The switch is part of a national focus on childhood obesity and the associated risk of high blood pressure, high cholesterol and type 2 diabetes. While the federal government has tried to make lunches more healthful over the years, an analysis by the USDA shows the meals are still generally high in sodium and saturated fat.

"These are final standards now that make the kind of changes that we attempt to do in our own homes and our own households," said Kevin Concannon, USDA undersecretary for food, nutrition and consumer services.

One controversial proposal is not in the final rules. The USDA originally wanted to limit starchy vegetables, such as potatoes, to no more than one cup a week. But the agency backed off after potato growers lobbied heavily against it.

The USDA also wanted to require schools to serve a higher minimum of fruits and vegetables. But food-service officials warned the requirement would lead to more wasted food, as many students would just dump it in the trash. In response, the agency lowered the minimum but still requires schools to "offer" a larger portion of fruits and vegetables.

Around the nation and in Arizona, school food-service directors are poring over the new rules.

"We'll be analyzing them and taking a look at the current menu and seeing what we need to change," said Linda Jeffries, a spokeswoman for the Alhambra Elementary School District in central Phoenix, where about 92 percent of students qualify for free or reduced-price lunches.

On Tuesday, second-graders at Westwood Primary School near 23rd Avenue and Camelback Road filed through the lunch line, picked up cartons of milk and grabbed lunch trays with a wheat roll, baked beans, a cookie, a chicken drumstick and a scoop of fruit cocktail.

Exactly how this menu would fare under the new rules isn't clear; Alhambra officials still need to evaluate them. But the fruit cocktail and baked beans may need a makeover. Students got only 1/3 cup of each side dish. Under the new rules, the school would likely need to offer ¾ cup of the beans and ½ cup of fruit. If students wanted a smaller portion, they could take ½ cup of one or the other.

The school also would need to make sure it served a dark green and red or orange vegetables and beans or peas weekly. Other parts of the menu may be fine. For example, the school already serves the fat-free and 1 percent milk that will be required under the new rules.

Some parents say the new rules will restrict choice, and more children will just bring their own lunch to school as a result.

"The kids want variety," said Scott Kelly, who has two boys, ages 7 and 13, in Kyrene Elementary School District.

Food-services officials say that because the changes will be phased in over a couple of years, students may not notice many changes next year.

In addition, the state already has additional nutrition standards for public schools that, in some cases, are stricter than what the federal government requires. For example, the federal guidelines allow schools to serve whole milk; Arizona schools can serve milk with no more than 2 percent fat. The new federal rules will limit milk to fat free or 1 percent fat.

The National School Lunch Program has been around since 1946, but the nutrition requirements have changed over time based on the latest science about diet and health-related risks. Schools that take part get cash and free agricultural commodities, like meat and cheese. In return, lunches must meet federal nutrition requirements, and they must offer free or reduced-price lunches to lower-income families.

While there is no federal mandate that schools must be part of the National School Lunch Program, Arizona law requires district elementary and junior highs to participate. That could change if a bill recently introduced in the Arizona Legislature becomes law. Schools would be able to opt out of the federal program.

Sen. Rich Crandall, R-Mesa, said he sponsored the legislation because state law requires K-8 district schools to take part while excluding charter and high schools. He believes everyone should be treated the same. He also said the new standards could be too onerous, and schools will have no recourse.

Critics of the bill, such as the Arizona Education Association, worry the legislation would result in students not receiving lunch. The state's largest teachers union wants to add language to the bill that would require schools to serve lunch , even if they aren't part of the federal program.

Diane Pratt-Heavner, a spokeswoman for the School Nutrition Association, a Maryland-based group of food-service professionals, said: "These standards will make sure every student has access to healthy meals when they go into the cafeteria."


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