Tuesday, November 8, 2011

Food and Lifestyle are Information for Your Genes

For most of us, when we think of the health and nutritional qualities of food, we think of calories, vitamins, minerals, and macronutrients like protein, carbohydrates, and fats.  Science, however, is demonstrating that food and even lifestyle, are offering far more information to our bodies than energy and nutrients.

Plant genetic material can regulate mammalian genes. For example, a recent study conducted in mice showed that when the animals were fed rice, a small, very specific piece of genetic material called a miRNA found in rice actually prevented the expression of an LDL receptor that works to lower LDL in the liver.  This made LDL levels go up.  Both plants and animals have miRNAs that regulate their own genes, but this study demonstrated that they work across species.   In fact, the researchers originally found the rice RNAs in both human and mouse blood samples.

What does this mean?  Although much more research needs to be conducted to understand which miRNAs from which types of foods can regulate mammalian gene expression, it suggests that the food we eat is affecting our health from multiple levels and vantage points.  I’ve said before that we haven’t even begun to understand all the benefits of eating whole foods and this supports that idea. 

But gene regulation doesn’t only involve food:

Dieting-induced stress affects future eating and can induce binge eating.  In support of stress as a contributing factor to the negative effects of yo-yo dieting (also known as diet cycling), another study in mice measured the stress response in mice that had previously been fed a restricted diet.   Compared to mice fed normal mouse chow, the calorically restricted mice had increased basal levels of the stress hormone corticosterone, exhibited a higher rise in response to stress, and took longer to recover from the stress tests. 

In addition, the diet deprived mice displayed epigenetic changes (i.e., changes in their DNA) for genes involved in regulating stress that were not reversed even when they were allowed to eat a high fat diet.   And during a 10-day period where they were exposed to stress, the dieters consumed a significantly greater amount of high fat food compared to the mice that were allowed to eat normally.

Imagine, after dieting for several weeks, coming home from a stressful day at work and eating too much of a heavy cheese pizza or devouring a pint of Haagen Dazs.  If you’ve been feeling deprived, this study suggests that you’re more likely to do that on a regular basis and that you’ll be more sensitive to stress overall.

Another study that examined yo-yo dieting in mice also showed that mice who alternated between high fat and low fat diets throughout their lives ate 20% more when given the low fat food than the control mice that were always fed the normal, low fat diet. 

This suggests that chronic dieters consistently eat more even when not put under stress.

Remember, ultimately, diets don’t work, not because you’re a failure and you have no willpower.   Any feeling of deprivation will ultimately backfire, which is why, for losing weight, the best alternative is to slowly make changes to your eating habits and lifestyle that provide pleasure and feel right.

And as much as you can, base your eating plan on whole, intact foods rather than processed foods with lots of additives, since the real gold from the food-based ingredients has likely been removed. 

Image courtesy of luigi diamanti

No comments:

Post a Comment