I’m surprised that this is controversial

Recent findings that two-thirds of all cancers are likely due to random chance have brought some surprising pushback. There’s an emotional reason for hoping that it’s all controllable, but that’s simply not likely. Cells mutate at random; the body’s defence systems clear out most of them; but by a second chance, some are missed. Get used to it. Eating your veggies won’t prevent all cancers. Read “On the importance of luck.”

Mammograms: when and how often?

At what age should we start getting mammograms and how often should we get them? It’s necessary to balance the dangers of ionizing radiation against the benefits of detecting cancer early. Read “Mammography’s Limits are Becoming Clear.”

Food safety: The struggle to pasteurize milk

Pop quiz: The scientist who discovered that pasteurizing milk prevented it from transmitting diseases was told that if it were important, someone else would have discovered it already. What sex was the scientist?

Alice Catherine Evans proved that unpasteurized milk spread disease, and improved the health of any nation that was listening.

It was an exceptionally stubborn microbiologist named Alice Catherine Evans who was the first scientist in the United States to definitively show that microbes in unpasteurized milk can sicken humans as well as animals. She went on to fight for the heat-treating of milk to protect the public and stands today as the mother of pasteurization in the United States. And the male heroes embodied in De Kruif’s book were hardly supportive. She was mocked, belittled and assured that if she was right, “someone much more outstanding” would have made the discovery long before.

De Kruif included her [in Men against Death] to both acknowledge her contribution and protest her treatment. “Such,” he noted sadly, “is the silliness of scientists.”

Still, by the time his book was published, Evans had won her battle to such an extent that she had already been elected president of the Society of American Bacteriologists—a forerunner of the Society of Microbiologists—in 1928. And she had done that with significant support from male colleagues, willing to “honor one woman whose findings dramatically advanced their field of research and improved public health in this country,” wrote Maryland biologist and former National Science Foundation director Rita Colwell in a much later tribute of her own.

Christian obesity

Northwestern University reports an 18-year study that finds that young adults in the U.S. who are religious and go to church are 50% more likely to become obese as they age, compared to people who don’t.

Cancer vaccine works

Over three years, the rates of pre-cancerous lesions have fallen in Australian girls who have received the anti-cancer vaccine Gardasil.

The study  found cases of high-grade cervical lesions — which are not yet cancerous, but carry a high risk of becoming so — have fallen in females aged up to 20, but not for older women.

The vaccine can only protect women who are yet to be infected with the four main cancer-causing strains of the human papillomavirus, which means it is most effective when given to girls who have yet to become sexually active.

Australia was the first country in the world to roll out on a population-wide basis the cervical cancer vaccine Gardasil, which was made possible by the groundbreaking work of University of Queensland expert and former Australian of the Year Ian Frazer.

The program in Australia provided Gardasil free to girls aged 12 to 13, with a catch-up program available for women aged 13 to 26. A second vaccine, Cervarix, has since also become available for private purchase, making use of the same breakthrough by Professor Frazer.

The findings, presented at a conference in Montreal, Canada, late last week, found that while the rate of high-grade cervical abnormalities in women aged 18 to 20 years was 1.2 per cent in 2006, this had fallen to 0.99 per cent in 2009.

Among girls aged under 18 the drop was more pronounced, with rates falling from 0.85 per cent in 2006 to 0.22 per cent last year.

Complications of mumps

An article from the Guardian online outlines the complications of mumps, their odds, and their results.

Training effect

For just over a year now, I’ve been taking swimming lessons and practising under the direction of a coach.
I’m still enjoying the training effect, which hasn’t yet levelled off: the more I practice, the better I get. I’m not racing, but just improving my endurance and aerobic fitness. It’s odd: when I get into the pool next time, I swim better than when I got out the previous time

The chart shows distances swum on successive dates. Some of them are estimates. The times aren’t always the same; most of the sessions are 1 hour long, but some are longer and some are only half an hour. Some are in pools, either with lane swimming or maneuvering among swimmers, with or without a wetsuit, in smooth or rough water. Still, there’s a trend: on the average, I can swim farther and faster as time goes on.

How swimming improved in one year

I suppose to do this properly I should drop the obstructed swims, add a slowing factor to the wetsuit sessions, and use the per-hour rate for all dates. I don’t have a record of all the short lessons, but here’s an attempt:

Swimming improvement in one year, adjusted

The training effect was discovered by Dr. Cooper.

“None of this is speculation. The anatomic and biochemical characteristic of the training effect have been documented in the laboratory many times.”, Kenneth H. Cooper, M.D., M.P.H. President and Founder, The Cooper Aerobics Center.

What ages people? Smoking and obesity

This might be old news but it’s good to remind ourselves: Eat healthy food and don’t smoke!

Smoking accelerated the ageing of key pieces of a person’s DNA by about 4.6 years. For obesity it was nine years.

These genetic codes are important for regulating cell division and have been linked to age-related diseases.

The study in the Lancet was based on 1,122 twins from a database held by St Thomas’ Hospital in London.