Is obesity genetic, or is lifestyle is a bigger factor? Over thousands of years, human genetics haven’t changed much; yet over the past couple of decades there’s been an exponential increase in obesity and its related problems like metabolic syndrome, a group of risk factors that leads to heart disease and diabetes.¹ So, even though it may seem that some people are hard wired to be overweight, the sudden increase in obesity indicates that something more than genetics is playing out.

As it turns out, our genetics can be steered toward obesity, but it is guided by something called our epigenetics, certain behavioral or environmental influences that tell our genes what to do. And guess what? Our epigenetics are heavily influenced by our nutritional intake, including what we eat too much of and what we don’t get enough of.

Let me explain. Everybody is born with a unique set of genes, your hardwired DNA. (That’s called our genome.) Your genes lie there and wait to see if they will be turned on or not as directed by tagging systems that sit on top of genes, called the epigenome. Our genes and epigenetics have been compared to a computer and its software.² Our genes are the hard drive; the epigenetics are the software telling the hard drive what to do.

The chemical “tags” of the epigenome are called methyl groups and they come from foods. There are other influences from our diet and the environment that profoundly affect our epigenetic tagging too. But the point is, our epigenetic molecular tagging system is what guides a gene’s expression, meaning whether a gene will be turned on or kept silent, and that system is heavily influenced by nutrition and other factors.

This was a huge discovery out of something called “The Genome Project,” and I find that most people still don’t know about it. The reason it is important is because it means we have far more power over our genes than we ever realized.

Methyl groups, our chemical tags, seem to have many positive effects; they are highly protective against several types of cancer for example.^3-7 In mice, they also have an impact on weight. Groundbreaking studies in mice that carry an overeating gene called the Agouti gene found that mice who were supplemented with the methyl group-containing nutrients — vitamin B12, folic acid, choline, and betaine — gave birth to babies that stayed lean, were healthier, and lived longer. In mice that didn’t get supplementation, the Agouti gene was turned on in their offspring, and they became obese, insulin resistant, more prone to cancer, and had shorter life spans.⁸

The big surprise was that the epigenome for obesity or anti-obesity effects were passed down, continuing on in every successive generation. Researchers noted that the Agouti gene itself didn’t change; it was just whether it was expressed or not due to “DNA methylation.”

But will increased intake of methyl donors lead to weight loss in humans? There is one way methyl donors may enhance it, but significant weight loss is not likely. Methyl donating nutrients enhance detoxification capabilities of the body. If they help eliminate metabolically disruptive pesticides and heavy metals, it could improve metabolic rate and enhance weight loss. However, I have seen many people increase their intake of methyl donor nutrients and it does not translate to much weight loss.

In another attempt to ascertain more information on the interactions of our diet and our genes, Australian researchers looked at the effects of a high blood sugar environment on human cells in vitro (such as would occur after eating sweets) and found that it had negative effects on the cell lines for up to two weeks afterward.⁹

These researchers also looked at the effects of high blood sugar in mice and found that it led the mice to have a predisposition toward obesity, diabetes, heart disease, cancer and shorter life spans; and again the effects were carried down to their offspring.⁹

These studies show us two dietary habits — eating sugar and inadequate intake of methyl donor nutrients — that in mice and human cells in a test tube steered the genes toward weight gain and the health problems that come from it, like diabetes and cancer. These findings indicate that both lifestyle and genes contribute to obesity, but the lifestyle is what triggers the genes to head in that direction.

Methyl donor nutrients are contained in fruits, vegetables, beans, legumes and meats. So, if you want to improve your epigenetics based on the studies I’ve discussed, you would increase your intake of these foods and stop eating sugar. From my experience, these two steps alone will not provide a complete weight loss answer for many people, but they would certainly jump start it for most people. But in the end, is this really anything that we didn’t already know?

In the future, further discoveries from genetic research may provide some real breakthroughs for weight loss. In the meantime, at LMI we have had tremendous success helping our patients lose weight and keep it off, first and foremost, by working to down-regulate insulin resistance with a carb-modified low-sugar diet and blood sugar supporting nutrients.

Secondly, we make sure that we thoroughly evaluate and support thyroid hormone function. And finally, we look at all the factors like stress hormones, intestinal health, and environmental toxicity that could negatively affect insulin resistance and thyroid function, since they are two primary influences on metabolism. We then take measures to correct or address them as necessary to further support and optimize metabolism.

Since most of these measures end up affecting methyl donors, in a way they are epigenetically supporting weight management. We just look at it as a thorough whole-body, metabolic approach to health.

References

1. Rochea, HM. et al. Proceedings of the Nutrition Society. (2005), 64:371-377.
2. http://www.pbs.org/wgbh/nova/sciencenow/3411/02.html.
3. Gastroenterology (doi:10.1053/j.gastro.2005.03.002)
4. Park SP. et al. In Vitro Cellular & Developmental Biology. Aug. 2008. 44(7):268-272.
5. Arkadianos et al. Nutrition Journal. 2007 6:29 (doi:10.1186/1475-2891-6-29).
6. Dobosy, JR et al. Prostate. 2008 Aug 1;68(11):1187-95
7. http://jn.nutrition.org/cgi/content/full/132/8/2333S.
8. Waterland, R.A. et al. (2008). International Journal of Obesity. (doi: 10.1038/ijo.2008.100).
9. http://www.bakeridi.edu.au/research/human_epigenetics/

[Ed. Note: James LaValle is the founding Director of the LaValle Metabolic Institute, one of the largest integrative medicine practices in the country.  Dr. LaValle is the author of The Metabolic Code Diet: Unleashing the Power of Your Metabolism for Lasting Weight Loss and Vitality To learn more, click here.]

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