Tuesday, February 23, 2010

The obesity epidemic

Terming the gradual increase in the number of overweight people as the Obesity Epidemic is more an emotional phrase than an accurate one say Canadian academics in an editorial in the European Journal of Public Health. An epidemic usually refers to a disease that has a sudden onset with a temporary high prevalence in a population. Although over half of western populations are overweight, it has hardly been a sudden onset.

Is excess body fat a disease?

The other aspect to calling obesity an epidemic is that it then becomes a disease. Is obesity really a disease or just a mis-management of energy in and energy out in a society with abundant food and energy saving devices? Labeling obesity as a disease can help generate research funding to find a “cure” for the disease. It also suggests that people had little say in becoming overweight because, well, it’s a disease, and diseases are something that you catch, possibly from another person!

Disaster on the horizon?

In my view, the use of the terms “disease” and “epidemic” helps cement the idea that a disaster is pending and many people are about to die, and, without a skerrick of justification, people can say that “our children will be the first generation to have a shorter life span than their parents.” Rest assured, that claim has been pure fabrication to generate headlines. Right now, average life spans continue to increase, with no hint of dropping.

The good news

The authors point out that while overweight has increased, high blood pressure and heart disease have been on the decline. They say that: “further, since the early 1980s, coronary heart disease mortality rates have halved and life expectancy has increased steadily in several developed countries.”

In Australia, high blood pressure has halved in adults dropping from 40% in 1980 to 18% in adults aged 25 to 64 years at the beginning of this century. Coronary heart disease death rates have fallen rapidly since the 1970s. In the decade 1996 to 2005 the heart disease death rate dropped by 42% due to a reduction in the number of heart attacks and a better survival rate.

However, the authors do add that the increase in obesity may well have slowed down these favourable trends, and that it is very unlikely that heart disease rates will ever return to those of the 1970s.

Not for a moment are the authors downplaying the health consequences of being overweight as it is associated with a number of chronic disabilities such as diabetes and osteoarthritis, and the fact that such people are unlikely to be enjoying life to the fullest.

What does it all mean?

The authors do warn that classifying obesity as a disease rather than a risk factor does not help us understand obesity as a public health problem. For example, you cannot guess somebody’s weight if you only look at a series of tests such as blood cholesterol or blood pressure. In NI 36 I mentioned that that about half of overweight people are metabolically fit and around one quarter of lean people are quite unhealthy. There is no specific cut off weight that determines whether you are going to be unhealthy or healthy in the future.

Although the authors didn’t state it in blunt language, if they think that labeling obesity as a disease is more about creating fear in the public in the potential hope that researchers will attract government attention and possibly funding for research, then I can only agree.

Reference: European Journal of Public Health 2009; 19 (6): 568-571

Juice Plus revisited

You may recall that in an earlier blog I asked about this fruit and vegetable extract supplement. To refresh your memory I said: “Juice Plus has been around for some time. Nutrition professionals are not that excited by it, as it is very difficult to get much dehydrated vegetable or fruit into a tablet. There is research to show that the tablets do increase antioxidant levels in the blood. You would have to eat at least 10 tablets to get even close to a single serve of a vegetable and even then, many nutrients will be lost through processing.”

Since then, there has been a short article in the American Journal of Medicine late last year. A 51 year old woman with endometrial cancer began to take Juice Plus as a supplement. It is very common for people with cancer to start taking what is perceived as natural supplements in the hope that this will reverse the cancer or halt its progression. In this case, the Juice Plus began to adversely affect her liver function. Stopping the Juice Plus returned the liver to normal after four weeks.

The authors from the University of Texas said it was important that doctors know of all the supplements being taken by patients and, conversely, that patients were open about what they took in addition to any prescribed medication. That way they can be alerted to potential side-effects of the supplement. Natural does not always equal safe or healthy.

Tuesday, February 9, 2010

Comfort Foods

Down in the dumps? Life not too flash? Or simply just want to enjoy a feel good food? What would be your comfort food? No doubt many would turn to chocolate, bit I’m certain there are other choices too. Camembert on thick fruit toast, creamy pumpkin soup, mushroom and egg on a wholemeal bun, super premium ice cream with chocolate coated almonds. I best stop there before I give away too many personal secrets. So what’s yours?

Psychology link

There is often a psychological component to a food you like (and those you dislike). Chocolate pudding could bring back memories of Sunday lunch at Grandmas, or fish and chips might have been the Friday night special when you were a kid and you were allowed to stay up and watch the late movie.

Brian Wansink’s research group at Cornell University in the US have taken an interest in comfort foods (see __Mindless Eating__, Bantam Books 2006) and found men and women were different. Golleee! Yep, the ladies preferred sweet foods and the blokes generally went for savoury comfort foods, except when they were offered super-premium ice cream with chocolate coated almonds. Everyone loves their ice cream.

Boys vs girls

The guys said they preferred pasta, pizza and soup because they felt spoiled or pampered and being the focus of attention when given these foods. Comfort foods did their magic especially when they were prepared “just like mama used to make”, and lost some of their comforting effect when they deviated from expectation in look and taste.

The women didn’t rate such savoury foods as highly because they generally reminded them of the time spent in preparing the dishes. For the women, cake and chocolate were preferred because they required no effort, no prep, no cleaning, just pop out and buy your favourite.

The mood made a difference too. A happy mood often led to more healthier choices, such as a pizza instead of a bag of potato chips/crisps.

Change begets change

Anyway, that has been our common understanding of comfort foods. When life throws out a challenge we tend to towards familiar foods that make us feel good. Stacy Wood who is a professor of marketing at the University of South Carolina has put her spin on comfort foods. She found that when people were subjected to a changing environment (eg move house, go on a trip, traumatic event) they chose different, unfamiliar foods, not the stabilizing comfort foods. Paradoxically, people predicted that if they had to move town they would much prefer comfort foods over foods they had never experienced before. So, what they predicted would happen was different to what they eventually did.

What does it all mean?

It all depends on the circumstances. If you have scored some winners at work and then choose a pizza or ice cream, there is synergistic effect of boosting your mood. If you have moved to a different address, some distance from your previous home, along with the hassle of packing, it makes sense that many people will check out new supermarkets and restaurants and experiment with new foods in a new place. What I think Stacy Wood is trying to demonstrate is humans adapt in different ways and an upheaval in life doesn’t send everyone in search of a comfort food.

Ever travelled to a very different country? Did you decide to eat like the locals or did you ask the concierge if they knew if Pizza Hut had a franchise close by? The answer to that question might give you an insight into your relationship with comfort foods.

Reference: Journal of Consumer research 2010; 36: doi 10.1086/644749

Why does a mushroom have that shape?

I bet you haven’t, for one moment, thought about the shape of a mushroom. Why does it look like it does? Because it is a clever example of natural engineering according to the boffins at Miami University. The gills on the underside are designed to carry the maximum number of spores, about 20 times more than would fit on a flat surface.

“Spores are catapulted from the gill surface, travel a short distance horizontally, then fall vertically to be swept away by air currents. The spores then go off to start new mushroom colonies,” explains Professor Nicholas Money. (Yes. Real name. I bet he is called “Thief” behind his back. You know, Nick Money. I don’t think it is funny either).

Nick and his colleagues have placed mushrooms in wind tunnels and found that the leading edge of the mushroom causes a rapid slowing of air movement close to the underside, allowing spores to successfully leave the gills and drop into fasting moving air to be dispersed. If the air movement wasn’t slowed near the gills there is a good chance that the spores will be blown back into the gill structure and not travel anywhere. That’s a clever mushroom.