Saturday, September 24, 2011
How Our Genes Respond to the Foods We Eat
Interesting and important research coming from Berit Johansen,Ingerid Arbo, Hans-Richard Brattbakk et al., from the Norwegian University of Science and Technology:
Feed Your Genes: How Our Genes Respond to the Foods We Eat
If you could ask your genes to say what kinds of foods are best for your health, they would have a simple answer: one-third protein, one-third fat and one-third carbohydrates. That's what recent genetic research from the Norwegian University of Science and Technology (NTNU) shows is the best recipe to limit your risk of most lifestyle-related diseases.
NTNU researchers Ingerid Arbo and Hans-Richard Brattbakk have fed slightly overweight people different diets, and studied the effect of this on gene expression.
"We have found that a diet with 65% carbohydrates, which often is what the average Norwegian eats in some meals, causes a number of classes of genes to work overtime," ... "This affects not only the genes that cause inflammation in the body, which was what we originally wanted to study, but also genes associated with development of cardiovascular disease, some cancers, dementia, and type 2 diabetes -- all the major lifestyle-related diseases," she says.
"Both low-carb and high-carb diets are wrong," says Johansen. "But a low-carb diet is closer to the right diet. A healthy diet shouldn't be made up of more than one-third carbohydrates (up to 40 per cent of calories) in each meal, otherwise we stimulate our genes to initiate the activity that creates inflammation in the body." This is not the kind of inflammation that you would experience as pain or an illness, but instead it is as if you are battling a chronic light flu-like condition. Your skin is slightly redder, your body stores more water, you feel warmer, and you're not on top mentally. Scientists call this metabolic inflammation.
It was not only inflammatory genes that were putting in overtime, as it would turn out. Some clusters of genes that stood out as overactive are linked to the most common lifestyle diseases.
"Genes that are involved in type 2 diabetes, cardiovascular disease, Alzheimer's disease and some forms of cancer respond to diet, and are up-regulated, or activated, by a carbohydrate-rich diet," says Johansen.
"We're not saying that you can prevent or delay the onset of Alzheimer's if you eat right, but it seems sensible to reduce the carbohydrates in our diets," she suggests.
The immune system operates as if it is the body's surveillance authority and police. When we consume too many carbohydrates and the body is triggered to react, the immune system mobilizes its strength, as if the body were being invaded by bacteria or viruses.
"Genes respond immediately to what they have to work with. It is likely that insulin controls this arms race," Johansen says. "But it's not as simple as the regulation of blood sugar, as many believe. The key lies in insulin's secondary role in a number of other mechanisms. A healthy diet is about eating specific kinds of foods so that that we minimize the body's need to secrete insulin. The secretion of insulin is a defense mechanism in response to too much glucose in the blood, and whether that glucose comes from sugar or from non-sweet carbohydrates such as starches (potatoes, white bread, rice, etc.), doesn't really matter."
Johansen has some encouraging words, however, for those of us who have been eating a high carbohydrate diet. "It took just six days to change the gene expression of each of the volunteers," she says, "so it's easy to get started. But if you want to reduce your likelihood of lifestyle disease, this new diet will have to be a permanent change."
The best is to cut down on potatoes, rice and pasta, and to allow ourselves some of the good stuff that has long been in the doghouse in the refrigerator.
"Instead of light products, we should eat real mayonnaise and sour cream," Johansen says, "and have real cream in your sauce, and eat oily fish.
Johansen's research also shows that some genes are not up-regulated, but rather the opposite -- they calm down rather than speed up.
"It was interesting to see the reduction in genetic activity, but we were really happy to see which genes were involved. One set of genes is linked to cardiovascular disease. They were down-regulated in response to a balanced diet, as opposed to a carbohydrate-rich diet," she says. Another gene that was significantly differently expressed by the diets that were tested was one that is commonly called "the youth gene" in the international research literature.
"We haven't actually stumbled on the fountain of youth here," Johansen laughs, "but we should take these results seriously. The important thing for us is, little by little, we are uncovering the mechanisms of disease progression for many of our major lifestyle-related disorders."
(I wish to express my thanks to chili_in_a_can from McDougall's vegan forum for publishing the article link)
Contact: Berit Johansen, Department of Biology, NTNU
TEL. +47 73 59 86 91 E-MAIL: berit.johansen at bio dot ntnu dot no
More articles on this topic:
What should we eat to stay healthy?
Best diet: One-third protein, carbs, fat
- Stan (Heretic)
- Buckhorn/Lakefield, Ontario, Canada
- (hires pic) I am a physicist, sensor design consultant (website) and embedded software engineer (picture of my lab). This blog is meant to collect essays, articles and debates on optimal human nutrition, science and other topics. This board is for like-minded people who know (or will know) each other and share certain common values. I welcome all heresies and opposing views, and discourage conformity of any kind. I sincerely welcome all people who are creative and like doing things, are self-reliant, have individualistic mindset and do not like wasting too much time on socializing, sport or mainstream entertainment. I am currently interested in the socio-anthropological theory (link) of evolutionary regression in developed countries.