August 28, 2011

Despite what your mother told you, fidgeting is a good thing

Most people would agree that "exercise" as part of healthy living means physical activity for the purpose of body conditioning-- jogging, pilates, lifting weights, and so forth. But physical activity for any purpose counts as exercise. Pacing while on the phone, doing your laundry or other chores, even nervously standing up and sitting down in a waiting room... it all counts, and it's all beneficial to your health.

Some even contend that these little daily activities are just as important as "regular exercise" for preventing chronic illness. As little as two weeks of inactivity has been found to cause adverse metabolic changes related to Type 2 diabetes in previously healthy individuals.

For similar reasons, increasing patient mobility is slowly becoming integrated into hospital care, especially for the critically ill in intensive care, who are more likely to be bedridden. A recent study found that patients who chose to walk around during a hospital stay, rather than sit still, were able to go home about a day-and-a-half sooner.

Despite what your mother told you, fidgeting (what physiologists call "spontaneous physical activity") is a good thing. It's been known for years that fidgeting can burn calories; a 1986 study looking at human metabolism found that fidgeting accounted for 100-800 kcal per day in their 177 subjects. However, not until recently have researchers understood how vital "spontaneous physical activity" could be to overall health. A 2008 review notes,
Spontaneous physical activity... can contribute significantly to interindividual differences in total daily energy expenditure. Cross-sectionally, spontaneous physical activity is inversely related to body weight; however, more importantly, spontaneous physical activity is inversely associated with weight gain in prospective studies.... Although spontaneous physical activity is a biologically driven behavior, interventions to increase nonexercise activity within the workplace and school hold promise in increasing daily energy expenditure for the average sedentary American.
Get up, move around!

August 8, 2011

Fish or fish oil for omega-3 goodness?

Yesterday I was asked to weigh in on a simple question that happens to have a complicated answer-- the best kind! The question: If you're trying to get the health benefits of increased dietary omega-3 fatty acids, is fish oil supplementation as good as eating oily fish?

Considering that several of the studies that support omega-3 benefits were done using fish oil supplementation, I suspect that the quick answer is "fish and fish oil are similar." At least as far as we can currently tell.

But the real answer depends on a number of things:

1. The ratio of omega-3 to other omega family fatty acids.

Because of the mechanism of fish's omega-3 benefits, it's necessary for omega-3 molecules to greatly outnumber competing omega molecules. (Omega-6 fatty acids are necessary, but are common in the Western diet.) Some supplements expressly include these competing fatty acids, which may decrease the potential for the omega-3 to do any good. Farmed fish may also be lower in omega-3 than their wild counterparts. (The overall ratio of omega-3 to other fats in your diet is also very important.)

2. Content of toxins such as heavy metals, PCBs, and other chemicals that may negate the long-term good stuff associated with omega-3.

Ocean waters contain some level of these contaminants, and so therefore do fish. The higher up the food chain the fish is and the older it is, the more they have tended to accumulate these toxins. For example, a tiny, short-lived, plankton-eating sardine will be safer to eat than a huge, long-lived, carnivorous tuna.

Supplement makers put their fish oils through a chemical purification process that reduces these contaminants, but they may also concentrate the fish oil, which would also concentrate any toxins present. An unconcentrated, well-purified supplement would probably have fewer toxins than carnivorous fish from the ocean.

3. What kind of processing the oil has undergone.

For fish, this is not of great concern except for cooking. Suffice it to say, deep frying your fish in peanut oil or being lavish with the butter may not produce the health benefits you want from fish. Eating raw fish would not alter the oil content, but comes with concerns of food-borne illness.

For supplements, processing is more industrial. Oil may be chemically cleaned, distilled, converted and re-converted. This processing should leave the oil safe to ingest and the omega-3 content intact, but only if done correctly. As fish oil gains in popularity as a supplement, some companies will no doubt be tempted to cut corners, to the detriment of consumers. Doing a little brand research may be helpful.

4. What else you are eating.

One of the benefits of reaching for whole foods rather than a supplement is that whole foods come with other nutrients. Fish is low in saturated fat and contains a large percentage of protein, which helps you feel satisfied after a meal. For example, 3 oz of cooked mackerel comes with 22 g of protein and nearly 2 g of minerals. Plus, if you are eating a piece of fish, you may be replacing something else on your menu that is not as nutritious.