Ask a public-health/nutrition student

[Catholic_Lady]

Thank you for your answer, sir.

[Natachan]

Question:
Since I was a kid I was unable to eat bony fish. My parents tried to give me tuna and I'd throw it up. As a teenager we tried smoked salmon but all that gave me was pink vomit. Recently I tried catfish and other freshwater fish. I would eat a small amount and then something would make me stop. My stomach would just say, "nope, no more." When I did eat too much I threw it up again. Too much being one whole filet.

Never before have I had a problem with shellfish. I can eat tons of shrimp, or whole lobsters no problem. But recently mussels and some crab cooked at Chinese food places have made me feel off. Kind of how I feel before I reach the point of naseau for bony fish.

I've always assumed I had an allergy to bony fish (since it's usually an either or for bony or shellfish in terms of allergy) but now I'm wondering if something else isn't going on.

[Aractus]

It sounds like an intolerance rather than an allergy. You can have a skin-prick test done to determine whether you have a true allergy. Your intolerance could be psychological rather than physiological, but I have no way of knowing. For example, if your parents gave you tuna that was off, you could have subconsciously learned that all tuna was bad, that kind of thing is quite common with food poisoning (and it may not even have been the tuna - perhaps some off mayonnaise was added to it or some other food consumed at the same time was off).

[Dystopia]

Aractus, what do you think dissuades people from smoking? How do you explain that sometimes higher pricing doesn't equal lower consumption? Why do some governments raise taxes but refuse to pay for quitting smoking produts?

[Aractus]

Because it costs money (a lot of money), and the government doesn't get a benefit from it. Lung cancer (where the risk of mortality is) is a disease of old age. It is well known that most people who smoke take up smoking as adults (although some people do before they're 18), and it usually takes at least 20-30 years after a person starts smoking to be diagnosed with lung cancer. The average age at the time of diagnosis is about 70. I believe (from memory) that the average number of years lost is about 10 years. On average, most of the years lost are in retirement, not in working age. Therefore, lowering the smoking rate lowers the lung cancer incidence in old age, and that in turn creates a larger burden on the healthcare system (particularly aged care).

It's ridiculously expensive, off-hand I believe in Australia the cost to reduce smoking by about 1% point (so for example lowering the rate from 16% to 15%) is about $1 billion because you have 230,000 people, of which most (so say 150,000) will live ten years longer into retirement, costing that extra $1 billion (which is only an actual cost of ~$650-700 per person per year).

Governments are reluctant to do things that hurt the bottom-line. They will raise the tobacco tax, because the increase in tax offsets their losses in the cost of aged-care.

I can't speak for your country, but in Australia Nicotine patches are listed on the Pharmaceutical Benefits Scheme, so they are subsidised. But even if they weren't, they're still a lot cheaper than cigarettes themselves, thus the cost of patches (or gum/inhalers) shouldn't be a barrier to using them. Gum & inhalers are not, which should send the message to smokers that patches are viewed by experts to be a more effective treatment option.

[Athene]

Do you have a theory as to why anemics eat so much ice? No one really seems to have an answer for that. What are the best dietary sources of iron, for those who can't tolerate iron supplements?

[Aractus]

Iron is an interesting mineral. The body breaks down RBCs and recycles much of the iron so that 90% of a person's daily iron needs are met by the recycling of existing iron. The body really doesn't want to excrete it, thus some people end up absorbing too much iron even with a healthy diet, and the only way to thin it out is to have blood removed from the vein.

In answer to your question, your first course of action could be to look at the grains in your diet and replace them with iron-rich ones if you haven't already. So iron-fortified bread, iron-fortified breakfast cereal, and brown rice instead of white rice. Coffee can block iron absorption, so you'd want to make sure you don't have a coffee with breakfast or other meals - space it out. Red meat and oysters are excellent sources of iron, and of course plant foods don't contain any heme-iron (which is the more absorbable kind). However green leafy vegetables do contain significant amounts of nonheme-iron and are also a good source of iron. It should be noted that we don't know a lot about iron absorption, while I believe the current estimates are that heme-iron 15% of dietary iron, there are those arguing that it could contribute much more than that, and do note that meat contributes both kinds of iron (so that 15% of heme-iron probably represents meat contributing 30% or so total dietary iron in the average healthy diet).

[Dystopia]

I reminded myself of another question - Regarding cannabis and marijuana, some people use as an argument for its legalization and consumption that it doesn't have any ill effects on one's health or if it has the effects are minimal and little likely to happen, when compared to tobacco smoking. Is this true and to what degree? If not, what health issues will frequent weed smokers have?

[downbeatplumb]

Aractus pid='1126282' dateline='1448798115']Health beliefs are much like religious beliefs. Many people feel that they have an exclusive right to know the "truth"; and you always hear claims from people selling "miracle products" about how they know something that the mainstream establishment doesn't (just like religious leaders have knowledge about humanity that secular anthropologists, historians, and scholars can't possibly know).

What irks me, and has done for many years, is the terrible shit that gets advertised on TV. Whether its diets, or "nutrition" products, or pharmaceutical medicine, it has no place on TV. With so much misinformation out there it can be difficult for consumers to find the valid information (that is the information supported by evidence).

There are a number of organised groups that actively promote misinformation. I often target the Vegan and specifically 80/10/10 crowd, but the pro-ana, or the anti-medicine (e.g. Scientology or Jehovah's Witnesses or Anti-vax). A lot of the time these groups simply capitalise on common misconceptions, or ambiguous data from a Journal that doesn't mean anything significant.

Individuals can be duped by misleading information, and then become stubborn in their defence of their "knowledge" - I know I'm guilty of this.

Here's an example of misinformation...

    Consider this page that I found claiming "gluten confirmed to cause weight gain". Read it if you like. Notice how they don't even provide an actual link to the Journal article (Soares, et al., 2013). On the web page this sentence is bolded "The 'wheat belly' syndrome and how it leads to other health issues was the purpose of their research." but nowhere in the journal article itself does it ever say "wheat belly". And as it's not open-access how is anyone supposed to know that? Furthermore Soares, et al. found that "the gluten-free diet slowed body weight gain", they didn't make the finding that gluten caused it in the first place as claimed by the website.

    And this was in rats, not humans. A positive result in animals is meaningless when discussing possible dietary recommendation to be made to humans. All it means is that further research in humans might be a good idea. And even then you need a RCT (the minimum requirement) or a meta-analysis (preferred) to get enough evidence to make a dietary recommendation in humans.

    There are many many advantages to using animals first. Rats is how they isolated and identified what hormone was responsible for subduing hunger (Leptin) in the 90's, following decades of research. I imagine that if we didn't have animals to experiment on, that today we still wouldn't know what hormone tells the brain to stop eating. It takes a lot longer than animal experiments to determine a result from epidemiology, which is why animals are used to find areas for epidemiological study.

    "This study report, according to Sayer Ji proves that the major factor of obesity is gluten, not calories." Notice they're quoting a 3rd-party, they aren't even getting their information direct from the Journal. "Sayer Ji" has nothing to do with the research article. Soares, et al. do not make the claim that gluten is "the major factor of obesity", this is the claim they make (which itself is far too strong a claim to be making from an animal study): "Our data support the beneficial effects of gluten exclusion in reducing body weight and adiposity gain, inflammation and insulin resistance."

That's just one example that I recently found. A website quoting some other unqualified person explaining what a journal article says, all the while failing to explain that this was only in rats. Often times things have been discovered in animals that made scientists excited, only to find out that humans are different.

Anyhow ask away, I will try to provide recent peer-review literature wherever possible.[/hide]

A good book on this subject is "bad science" by Ben Goldacre. http://www.amazon.co.uk/Bad-Science-Ben-...ad+science

[Aractus]

I reminded myself of another question - Regarding cannabis and marijuana, some people use as an argument for its legalization and consumption that it doesn't have any ill effects on one's health or if it has the effects are minimal and little likely to happen, when compared to tobacco smoking. Is this true and to what degree? If not, what health issues will frequent weed smokers have?

Because in most places it's an illegal drug, it can't be studied using RCT's (randomised controlled trials). It does however have health effects, both positive and negative (and even tobacco has both positive and negative health effects too, so does alcohol, so does most other illegal or controlled drugs).

I worry about the fact that, at least here, the government wants people to be allowed to self-medicate the drug if prescribed it. That is they'll grow their own and take an indiscriminate amount, instead of a measured therapeutic dosage which is the general way that medicine is administered.

The risk of lung cancer , and the development of emphysema should be lower than for smoking - but it's a dose response, and I would believe that smoking the same quantity of joints and cigarettes would be more-or-less equal on that.

THC has long-term negative effects on memory and mental health, however research also shows that it could slow the development of Alzheimer's. But take note that the research shows the dose required for the protective effect against Alzheimer's is very small, and taking a higher dose could have the opposite effect - it's one of those things, wait and see where the research goes.