Epigenetics: Dutch transgenerational effects (Introduction)

by David Turell , Saturday, February 03, 2018, 23:51 (2486 days ago) @ David Turell

This has been mentioned before. but the Dutch famine in 1945 as the War ended left its marks and is now restudied:

https://www.nytimes.com/2018/01/31/science/dutch-famine-genes.html

"By the time the Netherlands was liberated in May 1945, more than 20,000 people had died of starvation.

"The Dutch Hunger Winter has proved unique in unexpected ways. Because it started and ended so abruptly, it has served as an unplanned experiment in human health. Pregnant women, it turns out, were uniquely vulnerable, and the children they gave birth to have been influenced by famine throughout their lives.

"When they became adults, they ended up a few pounds heavier than average. In middle age, they had higher levels of triglycerides and LDL cholesterol. They also experienced higher rates of such conditions as obesity, diabetes and schizophrenia.

"By the time they reached old age, those risks had taken a measurable toll, according to the research of L.H. Lumey, an epidemiologist at Columbia University. In 2013, he and his colleagues reviewed death records of hundreds of thousands of Dutch people born in the mid-1940s.

"They found that the people who had been in utero during the famine — known as the Dutch Winter Hunger cohort — died at a higher rate than people born before or afterward. “We found a 10 percent increase in mortality after 68 years,” said Dr. Lumey.

“'How on earth can your body remember the environment it was exposed to in the womb — and remember that decades later?” wondered Bas Heijmans, a geneticist at Leiden University Medical Center in the Netherlands.

"Dr. Heijmans, Dr. Lumey and their colleagues published a possible answer, or part of one, on Wednesday in the journal Science Advances. Their study suggests that the Dutch Hunger Winter silenced certain genes in unborn children — and that they’ve stayed quiet ever since.

"While all cells in a person’s body share the same genes, different ones are active or silent in different cells. That program largely is locked in place before birth.

***

"the researchers merged the results — and found a few methyl groups that were linked both to the famine and to health conditions later in life. “We were able to connect the three dots,” said Dr. Lumey.

"Dr. Lumey and his colleagues propose that these methyl groups disrupt how cells normally use genes. One methyl group that is linked to a higher body mass index may be able to quiet a gene called PIM3, which is involved in burning the body’s fuel.

"So here’s the theory: Perhaps the Dutch Hunger Winter added a methyl group to fetuses born to starving mothers, which made the PIM3 gene less active — and continued to do so for life.
The result? “Maybe your metabolism is in a lower gear,” Dr. Heijmans said.

***

"John M. Greally, the director of the Center for Epigenomics at Albert Einstein College of Medicine, noted that blood is made up of many different types of cells, each with its own epigenetic profile.

"Maybe the Dutch famine made some types of cells more common, he said, rather than altering the epigenetics.

"But Dr. Heijmans and his colleagues studied the same methyl groups in muscle cells, fat cells and other tissues they got from cadavers. In any given person, the pattern was roughly the same."

Comment: Lamarckism is alive and well through methylation of genes.