SciBlogs

Archive July 2009

Vitamins and Exercise Darcy Cowan Jul 31

No Comments

I think it’s safe to say that in recent years the push to “Become Healthier” has become much stronger than it was previously. Statistics like 1/4 of New Zealand adults are obese and New Zealand being the “3rd Fattest” country in the world are used to promote a lifestyle that is aimed at making us healthier. Many of us have taken this message to heart (pun intended) and attempted to shape up but sometimes it’s not clear exactly what is healthy. The primary action people are urged to take is exercise and it’s a good one. There are many recognised benefits to regular exercise including reducing risk of Type II diabetes and possibly even reversing the condition.

Another item that is also touted as a general health promoter is antioxidants. Here’s where things start to get tricky, in order to reap the benefits of excersise there has to be some way that the fact that you are exerting yourself is communicated to the cells of your body. A promising candidate for this signal is ROS, or Reactive Oxygen Species. In other words – Oxidants. This brings up an interesting question, if you are taking antioxidants and exercising in your attempt to be healthy – what happens? A study released early this year suggests that the antioxidants reduce the beneficial effects of excersise in the body.

Researchers looked at two markers of insulin sensitivity: Glucose infusion rates and plasma adiponectin levels (high Glucose infusion rate and high adiponectin levels correlates with high insulin sensitivity = no diabetes for you). They found that taking two antioxidants (Vitamins C and E) while engaging in exercise (not literally, friends don’t let friends jog and pill-pop) actually reduced the before and after exercise difference in these markers. This result strengthens the evidence that ROS are involved in signalling changes in cells and that taking antioxidants interferes with this process.

The drawback of this study is that the participant numbers were quite small. The intial group was made up of forty men, 20 that had athletic backgrounds and 20 that didn’t. These where then split into two goups either recieving supplements or not. So the end was 4 groups of ten, not exactly a significant cross-section of the population. Even so the results are compelling and should be investigated further.

I think the moral still holds, beware of taking too many suplements, you don’t always know what the side effects will be.

Posted in Alternative medicine, Medicine, Sciblogs, Science, skepticism Tagged: Alternative medicine, altmed, antioxidants, diabetes, Exercise, health, obesity, Research, Science, study, Vitamin C, vitamin E

Cancer is Depressing Darcy Cowan Jul 10

No Comments

I don’t think the observation that cancer contributes to depression would win any awards for profundity, it’s likely such news would put a crimp in anyone’s day. Indeed, the very fact that the news of cancer itself can influence our emotions  makes it difficult to examine the contributing factors toward depression in those suffering from cancer. Our ability to foresee our own possible demise and react emotionally to it confounds attempts to tease out the strands of cause and effect. Approximately 10% of cancer sufferers are diagnosed with clinical depression and up-to two thirds experience some sort of mood disorder.

In order to separate out the effect of conscious knowledge of the disease from the psychological symptoms researchers have to turn to rats. How do you tell if a rat is depressed? To find out the scientists monitored the rat’s Twitter and Facebook pages for negative statements, no actually the rats are subjected to a swimming test, the longer the rats floated in the water without trying to escape the more depressed the animal is. The researchers found that rats with cancer showed signs of depression but not other behaviours normally associated with sickness, implying the rats were not simply feeling unwell.

Analysis of the rats tumours, blood and brain showed an increase in specific cytokines that have been linked to behavioural changes. In other words the presence of the tumour triggers changes in the brain that influence behaviour. This means that depression could be considered another symptom of cancer and not merely a by-product of knowledge of the cancer. This could have implications for how we treat depression in cancer patients and help them deal with the side-effects, simply knowing that being depressed is not something under their own control might itself be helpful.

Posted in Medicine, Psychological, Sciblogs, Science Tagged: cancer, depression, Medicine, Research, Science