AP Biology class blog for discussing current research in Biology

Tag: mortality

DYING to Know Your Predicted Lifespan? Look No Further!

Have you ever wondered how long you’ll be around for? Well, scientists at the German Cancer Research Center, Saarland Cancer Registry, and the Helmholtz Research Center for Environmental Health have made great strides in predicting human mortality. How so? Through a controlled study in which they analyzed patterns in DNA methylation.

DNA methylation, an epigenetic phenomenon, occurs in the body in order to inhibit the transcription of DNA. Methyl groups attach to specific combinations of DNA building blocks called CpGs. In this experiment, the scientists analyzed the DNA from blood cells taken from 1,900 participants fourteen years prior. As they were all older adults, many of the participants had died within that fourteen years. The scientists analyzed methylation at 500,000 of the CpGs, trying to figure out if there was a correlation to chances of survival. Spoiler alert: at 58 of these CpGs there proved to be a strong correlation between methylation level and mortality.

One interesting discovery was that 22 out of the 58 influential CpGs were identical (in terms of amount of methylation) to the CpGs of smokers that the scientists had analyzed in a previous study. What does this mean? Smoking definitely leaves its mark on your genome. However, the good news is that DNA methylation can be reversed, so if a smoker quits his or her risk of dying could drop significantly.

The second major finding of this study was that only 10 out of the 58 CpGs can actually determine mortality risk. The scientists took the 10 CpGs with the strongest correlation with mortality and created an epigenetic risk profile. This profile can predict “all-cause mortality”. Participants who were overly-methylated at five or more of these spots were seven times more likely to die in the fourteen year span than their properly-methylated counterparts.

This study is a major breakthrough in understanding human mortality, because analyzing DNA methylation is so much more accurate than looking at SNPs. The researchers plan on using their new knowledge to find out how to improve methylation profiles at these CpGs.

Does it surprise you that only 10 spots on the genome can have such a profound effect on duration of life? Do you think there could be an even more accurate predictor of mortality than DNA methylation levels? Let me know in the comments!

Don't Smoke!

Credit: Nina Matthews Photography, URL:

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Do You Really Want that Third Piece of Bacon?

This is a picture of a hamburger, which is a form of red meat often consumed by individuals everywhere. Found on Wikimedia Commons.

How many  people do you know that eat bacon every day?

What about a hamburger?

Did you know that the Harvard School of Public Health has recently discovered that red meat consumption can strongly contribute to cardiovascular disease and cancer, ending one’s life prematurely? These days, it is much healthier to eat “poultry, nuts, fish and legumes.” We need alternative sources of protein.

According to Nutrition researcher and author An Pan, who works at the Harvard School of Public Health,

“…eating high amounts of red meat has been associated with type 2 diabetes, coronary heart disease, stroke and certain cancers in other studies.”

It is scary to think that every time someone consumes red meat daily, there is a 13% increased chance of death. Eating processed meat is even worse because if eaten daily, there is a 20% increased chance of death. Every time someone consumes heme iron, carcinogens that are released from the meat during cooking, saturated fat, sodium and nitrates from his or her steak, these risk percentages rise. It has been researched that these risks can be weighted more heavily depending on “age, body mass index, family history of heart disease or major cancers.”

Now, we know that the protein replacements of fish (7%), poultry (14%), nuts (19%), legumes (10%), low-fat dairy products (10%) and whole grain (14%) have great percentages for lower risks of premature death. If people “eat less than 0.5 serving per day of red meat, 9.3% of deaths in men and 7.6% of deaths in women can be prevented.”

Mortality is an important factor for every individual to consider. Why waste life away to eat a slice of bacon each morning?



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