Category: Health and Medicine

Sciencebase news and views on health and medicine, including posts on Covid-19, bird flu, cancer, asthma, obesity, vaccines, and much more.

Anal cancer in women

Many readers will probably be aware that actress and model Farrah Fawcett died in 2009 of anal cancer. But a recent update from Cancer Research UK revealed that anal cancer rates in the UK have increased by nearly 300% over the last 40 years. The increase is much higher in women than in men, rising from 4 in a million to 18 in a million for females (4 to 12 in a million in males). Presumably, similar increases are seen elsewhere in other countries.

Experts believe the reason for the dramatic rise is likely to be caused by the increasing prevalence of the human papillomavirus (HPV), a virus that is usually transmitted through sexual activity. An estimated 90 per cent of anal cancer cases in the UK are linked to HPV infection.

Now, this is a mixed taboo subject, cancer, sex, disease, bumholes etc. Perhaps not a topic for the family dinner table, but certainly one that should be broached more readily. If shifting sexual practices are largely to blame, then sexually active people ought to know more about HPV and the fact that it can cause cancer of any entry point in the body.

anal-cancer

A recent tweet from @RealMissChief today remarked on a tattoo a female displayed on her lower back that she saw in a bar. The tattoo was actually of stars but RMC wittily interpreted this to mean “I do butt stuff”. Maybe the tattooee does or doesn’t we will never know, but either way we can but hope that she uses protection if she does that kind of “butt stuf”, or at the very least knows her partners’ HPV status. This anecdote does offer a putative tabloid scare story about how getting a tat on your lower back could lead to anal cancer. But, while it might be flippant to suggest such a thing, perhaps the increasing proclivity for such body art simply correlates with general shifting attitudes towards sex at a time when HPV is prevalent. The numbers are small but worryingly on the increase…

Anal cancer rates quadrupled since mid 70s.

Don’t die of asthma

Every breath you (don’t) take…

A report that hit the headlines in the UK this week should be something of a wake-up call to anyone with asthma and the people who care for them. The study revealed that current healthcare guidelines for asthma are not being used properly in some cases and that this can put lives at risk.

asthma-treatment

Asthma symptom-relieving medications (such as the common blue inhaler (Ventolin) are being over-prescribed by some doctors while patients that ought to be on asthma-preventing inhalers (usually corticosteroids, not to be confused with bodybuilding steroids) are not always being prescribed those inhalers despite having poorly controlled symptoms – coughing, breathlessness, wheezing, tight-chestedness. More detail on the report and the NHS critique of media coverage here.

10 cancer myths busted

Cancer Research UK has an interesting post busting ten of the most irritating and persistent pieces of deceived wisdom about cancer:

Myth 1: Cancer is a man-made, modern disease

Myth 2: Superfoods prevent cancer

Myth 3: ‘Acidic’ diets cause cancer

Myth 4: Cancer has a sweet tooth

Myth 5: Cancer is a fungus — and sodium bicarbonate is the cure

Myth 6: There’s a miracle cancer cure…

Myth 7: …And Big Pharma is suppressing it

Myth 8: Cancer treatment kills more than it cures

Myth 9: We’ve made no progress in fighting cancer

Myth 10: Sharks don’t get cancer

Don’t believe the hype — 10 persistent cancer myths debunked.

Amygdalin – anticancer “vitamin” B17

Amygdalin the so-called safe and natural anticancer vitamin B17, is none of those things. It is not a vitamin in any sense of the word. It has no anticancer properties. It is poisonous.

The compound, formula C20H27NO11, is a glycoside initially isolated from the seeds of the tree Prunus dulcis in the nineteenth century, also known as bitter almonds. Enzymes (namely glucosidases) found in the gut and in some foods break down amygdalin to release hydrogen cyanide. See also synthetic derivative, laetrile.

“Cochrane Collaboration” had this to say:

“The claims that laetrile or amygdalin have beneficial effects for cancer patients are not currently supported by sound clinical data. There is a considerable risk of serious adverse effects from cyanide poisoning after laetrile or amygdalin, especially after oral ingestion. The risk—benefit balance of laetrile or amygdalin as a treatment for cancer is therefore unambiguously negative.”

Research Blogging IconMilazzo S., Ernst E., Lejeune S., Boehm K., Horneber M. & Milazzo S. (2011). Laetrile treatment for cancer, DOI: 10.1002/14651858.CD005476.pub3

Tim Minchin – philosopher

Ooh get him in his robes and mortar board…no, I mean it, “get” him, ignore the robes and mortar board, ignore the long hair if that’s not your thing. But, give his philosophy a listen to, all the way through…I perhaps do his speech an injustice quoting so briefly from it, do take the time. Tim is witty, insightful, hopeful…romantic…

“Searching for meaning in life is like looking for a rhyme scheme in a cook book, you won’t find it and it’ll bugger up your soufflé…I think it’s absurd seeking meaning in the set of circumstances that just happen to exist after 13.8 billion years worth of unguided events…here’s my idea of romance: you will soon be dead. Life will sometimes seem tough and gawd it’s tiring and sometimes you will be happy and sometimes you’ll be sad and then you’ll be old and then you’ll be dead. There is only one sensible thing to do when faced with this empty existence and that is to fill it…with learning, sharing, compassion, running, love and travel and wine and sex…and arts and kids and giving and mountain climbing…”

Go on, take Tim’s advice: climb a mountain!

H7N9 bird flu

Is another bird flu on the rise? Report from Nature on H7N9 type A influenza virus and reported outbreak in China.

Scientists and public health officials worldwide are on alert after China announced on 31 March that two people had died and a third had been seriously sickened from infections with a new avian flu virus, H7N9, that has never been seen before in humans.

via Novel bird flu kills two in China : Nature News & Comment.

There are numerous subtypes of flu, labelled with an H number, referring to the specific type of protein hemagglutinin and an N number, neuraminidase enzyme type. There are 17 H antigens (H1 to H17) and nine different N antigens (N1 to N9) and any combination might be possible. The newest H antigen type, identified as H17 by researchers, was isolated from fruit bats in 2012.

Five major challenges to avoid food crunch

Growing population and an increasing poverty gap are major challenges for global food security especially when the issue of biofuels produced from crops is introduced. According to Tahereh Alavi Hojjat of DeSales University, in Center Valley, Pennsylvania, USA, governments around the world must address five major challenges if we are not to see an enormous increase in human suffering, disease and starvation:

1 Energy security – This directly affects food prices through fertiliser costs, farm energy use and transportation costs, as well as the use of land for growing biofuel crops, which is meant to circumvent our reliance on putatively dwindling fossil fuel supplies and mitigate against challenge #2, climate change.

2 Climate change – Will increase by tens, perhaps hundreds of millions, the number of undernourished people worldwide as higher average temperatures negatively impact on food crop yields.

3 Water security: is already becoming a major problem as the population grows and consumption rises. Half a billion people live in countries chronically short of water. By 2050, this number could be closer to four billion as a result of climate change and loss of fresh water resources.

4 Competition for land – A growing problem that will likely increase the incidence of civil unrest and international conflict as fertile land area dwindles and urbanisation predominates.

5 Demand for food – This will inevitably rise as the population increases toward 10 billion and a greater percentage of people demand meat.

Driven by these various factors, Hojjat suggests that we are heading for a “food crunch”, which will inevitably hit the poorest hardest. The international community must move quickly and effectively Hojjat urges. Hunger is not caused by scarcity in terms of production capacity, there is plenty of food being produced globally but it doesn’t reach those in most need while obesity levels continue to grow in certain parts of the world. “To solve the world hunger crisis, it is necessary to do more than send emergency food aid to countries facing famine. Leaders must address the globalised system of agricultural production and trade that favours large corporate agriculture and export-oriented crops while discriminating against small-scale farmers and agriculture oriented to local needs,” Hojjat says.

Research Blogging IconHojjat T.A. (2012). Global poverty and biofuel production: food vs. fuel, International Journal of Energy Technology and Policy, 8 (3/4/5/6) 209. DOI: 10.1504/IJETP.2012.052109

How nutritious is horse meat?

Just a quick round-up cribbed from NutritionData via KQED to address the issue of how nutritious is horse meat compared to beef in the wake of “StableGate” (horse DNA allegedly present in value burgers sold by UK and Iris supermarkets).

Horse meat is about 120 vs beef’s 130 kilocalories per 100 grams. They have similar cholesterol levels and pretty much the same protein content when comparing lean cuts. Horse meat has twice the iron of beef and more than twice the vitamin B12, but less B6, niacin and folate.

The levels of omega-3 fatty acids – supposedly linked to reduced risk of heart disease stroke and neurodegenerative diseases – are much higher in horse (360 mg/100g); just 21 mg in beef steak.

Numerous cultures are not in the slightest bit squeamish about eating horse meat, although Brits and Americans usually seem not to be among them. Personally, I think meat is meat, if you’re slaughtering one grass-eating mammal and then frying or stewing its rump it could just as easily be the sheep, cow or horse. I do think we could solve many of our climate, poverty and food security issues if we made goat the staple meat product given that it can produce meat and new goats at a high rate even scrabbling around on a few blades in the desert. Goats also have a slightly less cutesy image than horses, frolicking lambs and those ruminants with “cow eyes”…

The Other Red Meat.

Bird flu, swine flu, now seal flu H3N8

US scientists have identified a new strain of influenza in New England harbor seals – H3N8. They say the strain, presumably made the species leap from birds, might now be a reservoir for an emergent human flu virus.

H3N8 is an influenza type A virus (Orthomyxoviridae) endemic in birds, equines and dogs and although highly contagious was not as such considered a risk to people. A flu outbreak in people in 1889 or 1900 was blamed on this strain but evidence suggests that it was due to H2N2. If H3N8 has mutated and evolved from an avian form into one that infects harbor seals (Phoca vitulina), there is a chance that it could now infect people. Indeed, the virus already has the relevant structure to attack a protein in the human respiratory tract.

Experts have for some time recognised that emergent flu viruses need not only come from East Asia, swine flu, H1N1, being a case in point, the pandemic of 2009 emerging from South America. So, the emergence of a putative pandemic strain in the waters off New England, USA, is worrying, but perhaps not surprising.

It is worth noting that a paper in the same group of journals from 1984 reports on the emergence of an avian influenza virus (H4N5) in harbor seals in the early 1980s. There are presumably other instances so this would suggest that transfer to harbor seals from birds is not an uncommon leap.

BBC News – New flu virus found in seals concerns scientists.

Moscona et al, 2012, mBio; DOI: 10.1128/mBio.00166-12

Influenza A viruses are classified into subtypes based on the antibody response to the viral proteins hemagglutinin (HA), neuraminidase (NA). This distinction gives us the different names, e.g. H5N1, H1N1, H3N8 etc. There are 16 H and 9 N subtypes known, but only H 1, 2 and 3, and N 1 and 2 are usually found in people.