07/11/2009 05:12 am ET Updated Nov 17, 2011

Do You Have Fat Genes?

We have identified the fat gene! It is not just a gene but it's a gene with a variant. It's called the DRD2 gene. The variant that is heavily associated with obesity, alcoholism and addiction is the A1 allele.


I believe that our ability to look at genes, which is relatively new, is the key to finding cures for many of the diseases that plague us today. At UCLA, Dr. Ernest Noble studied the brains of dead alcoholics. (Sounds like fun, don't you think?) In 1990 he published a ground breaking paper on his findings. He was the first to find the DRD2 gene with the A1 allele to be prevalent in alcoholics. I was privileged to hear him present at the recent Food Addiction/Obesity Conference in Washington.


Dr. Noble said that we all have the DRD2 gene. It is the reward gene in the brain that mediates our dopamine and makes us feel good. People with the A1 allele are dopamine deficient and therefore have a baseline state of feeling sort of lousy. Alcohol, other drugs of abuse, and food (specifically carbohydrates), increase dopamine in the brain and make us feel good, or rewarded. If you have DRD2 with the A1 allele, it will take more of these substances to make you feel good, since you are starting out in a deficient state. These results have been replicated in many labs since Dr. Noble's findings.

There are some clinical trials going on right now where they are giving DRD2 A1 allele obese subjects a substance called bromocriptine. It is a drug that increases dopamine in the brain. At this point there are risks associated with this substance but there is a glimmer of hope on the horizon that we may one day have a cure. When animals were given this substance, they self-limited their intake of alcohol, drugs and/or food.

If you have the DRD2 gene, with the A1 allele variant, you are more likely to be obese and more likely to be addicted to alcohol and/or drugs. This is not your fault. You were born with this and you are simply trying to feel OK. When obese subjects, with this genetic make-up, cut carbs and calories, they experience withdrawal. They feel anxious, depressed and just plain lousy. This often leads them right back to the food.

If you think you have this gene, please share your story. The obesity tends to come on in adulthood and you are likely to have at least one parent who is also obese.

More on this and what we can do about it coming up.

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