Monday, March 23, 2015

Important News on Roundup

The International Agency for Research on Cancer (IARC), part of the World Health Organization, has classified glyphosate  - commonly known as Roundup – as “probably carcinogenic to humans”. Glyphosate is one of the world’s most widely used herbicides  -used in growing corn, soy, vegetables, fruits, winemaking, and in home gardens. It has been used in forests to clear underbrush, in cities to deter pavement weeds, and on railroad tracks to kill unwanted vegetation.  It is used on sugarcane to increase crop yield and through crop desiccation to increase sucrose concentration before harvesting.

Monsanto developed glyphosate, which it calls Roundup, in the 1970’s. Since 1980, Monsanto has developed genetically modified soy, corn, canola, cotton, sugar-beets and alfalfa.  These GMO crops are designed to resist the herbicide Roundup, which is used to kill weeds and increase crop yields.  The seeds of these modified crops  must be purchased again each year from Monsanto by the farmer.  The development of super-weeds, resistant to Roundup, has recently been a growing problem, requiring heavier spraying of glyphosate and  other herbicides such as 2-4D (a component of Agent Orange, used as a defoliant in the Vietnam war.) 
Monsanto’s patent on glyphosate expired in 2000, and many other companies now make the product worldwide.   

Here’s what the new IARC report said, as published in the journal Lancet Oncology:
“For the herbicide glyphosate, there was limited evidence of carcinogenicity in humans for non-Hodgkin lymphoma .  The evidence in humans is from studies of exposures,
 mostly agricultural, in the USA , Canada, and Sweden published since 2001.  In addition, there is convincing evidence that glyphosate also can cause cancer in laboratory animals.  On the basis of tumors in mice, the US
Environmental Protection Agency originally classified glyohosate as possibly carcinogenic to humans in 1985.  After a re-evaluation of that mouse study, the US EPA changed its classification to evidence of non-carcinogenicity in humans in 1991. The US EPA Scientific Advisory Panel noted that the re-evaluated  glyphosate results were still significant using two statistical tests recommended in the IARC Preamble.  The IARC  Working Group that conducted the evaluation considered the significant findings from the US EPA and several more recent positive results in concluding that there is sufficient evidence of  carcinogenicity in experimental animals. Glyphosate also caused DNA and chromosomal damage in human cells, although it gave negative results in tests using bacteria.  One study in community residents reported increases in blood markers of chromosomal damage (micronuclei) after glyphosate formulations were sprayed nearby.”

This is a complex subject, which is why I have quoted the IARC’s document precisely.  You can see the different opinions of the IARC and the US FDA.  Companies making glyphosate have criticized the report in the last few days.   Whether the US EPA will make any regulatory changes remains to be seen.   

Here in West Marin we are immensely lucky to be able to buy organic food.  However, the re-evaluation of glyphosate  by the WHO’s IARC is bound to  have an impact on the world and its food supply,  and on the movement to label genetically modified foods.

Here are some topics to think about:. 
*Are there safer herbicides and pesticides that can be used on cereal crops that are feeding the world?
*To what extent can organic agriculture and integrated pest management feed the world?
*Much of US GMO corn and soy is fed to animals destined for human consumption.  If meat prices rise due to a ban on dangerous herbicides, can we switch as a society to eating less meat and more plant protein?
*Is world population growth inevitable, or can education and family planning for women in developing countries help to slow this growth?
*Why are we so reluctant to talk about  family planning as a factor in our environmental crises? 

Stay tuned.  The discussion on glyphosate is only beginning.

Sadja Greenwood, MD, MPH  past issues on this blog
p.s. Here are two unrelated topics you may enjoy reading about:
 *Science Daily 3/12/15 You are when you eat – limiting flies to specific eating hours protects their hearts against aging, study finds.
 *Caya Diaphragm - safe and hormone free contraception   

Sunday, March 1, 2015

Another Reason to Love Green Vegetables, Nuts and Olive Oil

An amazing dietary study was launched in Spain in 2003, to look at the effects of a Mediterranean diet on the prevention of cardiovascular disease. Researchers also looked at all cause mortality, diabetes, cancer, dementia and other diseases.   7000 asymptomatic participants ages 55 -80 were selected and followed for 5 years.  The subjects were divided into 3 groups – one given extra-virgin olive oil - one liter per week, one given supplemental nuts (walnuts, almonds, and hazelnuts) about 2 tablespoons a day,  and one advised to follow a low-fat diet.  The first two groups were instructed to follow the Mediterranean diet, high in vegetables and fruits, fish, legumes, grains, and olive oil, and low in meat and dairy products.  Wine was permitted, sweets limited.  The control group was instructed on a low fat diet.  After 5 years, participants following the diets enhanced with olive oil or nuts had a 30% lower risk of dying from cardiovascular disease or having a heart attack or stroke, compared to those on a low fat diet.   They also had less cognitive decline.  These are impressive results.

Researchers also looked at the Vitamin K intake of participants in this study.  People with the highest intake of foods containing Vitamin K were 46% less likely to die of cancer and 36% less likely to die from any cause than those with the lowest intake.  Again - impressive results.

Vitamin K – named for the German word for coagulation – helps blood to clot by activating certain proteins made in the liver.  It is found in a variety of foods, but mainly in leafy green and cruciferous vegetables. People taking Coumadin to reduce the propensity of blood to form clots are counseled to eat a consistent amount of leafy greens daily to match their dose of Coumadin. 

Vitamin K has also been studied for its role in bone metabolism.  A Japanese study found that people from regions where vitamin K foods were eaten in abundance had fewer hip fractures.  Several other studies from Europe have shown similar results.  While supplementation with vitamin K is not considered necessary for most people, eating green vegetables is always a plus. 
Sadja Greenwood, MD  MPH