Humans native to more extreme latitudes have DNA built for warmth. Their cells produce more heat, scientists say due to non-shivering cold induced thermogenesis in the Brown Adipose Tissue (ie – allowing your body to be exposed to cooler temperatures can speed up your metabolism and get you to burn fat, if your genetics are from a northern latitude).
People native to the far north evolved to produce more heat in their body’s cells than people from lower latitudes in order to maintain their body temperature at ~98.6°F. The researchers suggest this change is a climate-driven effect of where your ancestors lived. Your DNA has evolved and changed for your genetic line to thrive in a specific climate that had specific seasonal changes in temperature and food selection. Research has come out that shows the many genetic lines tying us back to our ancestors location and that our DNA, though plastic (changeable), has fixation patterns in it linking us to this ancestral genetic type.
Douglas Wallace and Eduardo Ruiz-Pesini of the University of California at Irvine provided substantial evidence from 1,125 people ranging from Africa to Europe and Arctic Siberia. They found that the mitochondrial DNA of those people living in more northern latitudes had increased production of heat through non-shivering cold-induced thermogenesis, increased fat metabolism, decreased insulin resistance, and increased life expectancy when compared with tropical residents.
“Our observations support the hypothesis that certain (mitochondrial DNA) variants permitted humans to adapt to colder climates,” the researchers concluded. The variants continue to produce differences in energy production and affect health, they said. DNA provides the blueprint for the development of the body, combining information from the separate DNA of each parent. However, mitochondrial DNA directing the energy production in cells is inherited only from the mother, unlike the DNA that provides the body’s primary set of instructions for operation. This maternal link to mitochondrial DNA is key to understanding the effect of pre-natal nutrition, stress, and subsequent epigenetic passing of disease from mother, grandmother, or great-grandmother to progeny.
Knowing that we have this genetic predisposition for burning fat and increasing our body temperature in the cold, this presents a huge problem when this person moves to a warm climate where they are genetically not built to live in. For instance, arctic and sub-arctic native peoples had variants that programmed them to produce more heat, but put out less energy. Their bodies were thus more efficient at keeping them warm. Previous studies have shown that indigenous populations around the North and South Poles tend to have a higher resting metabolism. Tropical and sub-tropical natives made more efficient use of energy, producing little heat.
The authors say the variants are evidence of natural selection at work--that genes evolved in response to environmental stresses. But this adaptive response might not be beneficial when people native to one climate relocate to another climate, the authors say. "Given that mitochondrial DNA lineages are functionally different, it follows that the same variants that are advantageous in one climatic and dietary environment might be maladaptive when these individuals are placed in a different environment," they write.
Natives of cold regions are used to stoking their bodies with heat-producing high-calorie meals. That dietary habit might not serve them well if they move to a warmer region, and may play a role in causing disease, the authors say.
"Ancient regionally beneficial mitochondrial DNA variants could be contributing to modern bioenergetics disorders such as obesity, diabetes, hypertension, cardiovascular disease, and neurodegenerative diseases as people move to new regions and adopt new lifestyles," they write.
This study lends credence to our philosophy and that of Metabolic Typing® with over 25 years of research and clinical findings suggesting this to be a contributing reason for obesity, diabetes, and other diseases. People differ in how their bodies metabolize nutrients. What constitutes a healthy diet for one high latitude ancestry may produce pathology in a different low latitude ancestry person. Forces of natural selection, genetic mutation, and survival of the fittest assured that the indigenous people of a certain geographical and climatic region became perfectly adapted to the foods in their environment. This same scenario played itself out throughout the planet.
The author's statement, "...the same variants that are advantageous in one climatic and dietary environment might be maladaptive when these individuals are placed in a different environment," echoes the research of metabolic typing pioneer George Watson, Ph.D. Watson spent some 30 years objectifying indicators of what he termed Fast Oxidizers and Slow Oxidizers. Watson found that Fast Oxidizers metabolized carbohydrates too quickly and as a result tended toward an acid blood pH and thereby thrived on a diet high in proteins and fats and low in carbohydrates. Slow Oxidizers with an alkaline blood pH required a diet high in carbohydrates and low in proteins and fats in order to acidify the blood. Watson further showed that the right diet for the Metabolic Type® resolved health issues but that when the diets were transposed, pathologies worsened.
Each of us today carries the genes of our ancestors and the genetic predisposition to thrive on certain foods and decline on other foods. The secret of the right diet for each person depends not on whim, fancy or philosophy but is irrefutably dictated by our genes. Eating right for your Metabolic Type® should be the foundation of any quest for good health.
As time progressed, the threat of famine among early humans decreased, but genes that once helped humans survive starvation remain and bodies are programmed to stockpile fat, even in times of increasing abundance.
If you are not optimizing your diet for your ancestry, then you are playing with genes that may effect your kids, your grand kids, and your great grand kids because you may be genetically coded for one thing and living the opposite. So lets think of a canal with a ball in it, and this ball can roll left and right according to your genes and your diet. If you genes are telling your body to burn fat in the cold and eat like a high latitude person and you are keeping warm and eating like a tropical person, then you are telling your genes to storage calories and swinging the ball to feast side. If you are doing what you are genetically set up to do, then you are are swing the ball to the famine side. Now you want to have healthy kids, but what genes are you passing? The healthy ones or the backwards genes? Researchers are suggesting that the rise in obesity and diabetes may be linked to this genetic problem.
A new theory for the evolution of obesity proposes that as early humans migrated out of Africa and around the globe (dotted lines) and their bodies adapted to survive in different climates, those whom migrated to warm climates ended up with a lower metabolic rate to help remain cool. Think increased metabolism, increased heat and vice versa. That left them more vulnerable to metabolic syndrome, the cluster of symptoms that include high blood sugar and excess fat because there was not a seasonal change to the colder climate.
Now fast forward 70,000 generations and not that much has changed according the Wallace’s work. That is to say, if you hale from a more northern latitude and live in a more temperate or sub-tropical environment that you are slowing your metabolism in order to stay cool. Think of those snowbirds that go to Florida for the winter and are sweating in 70°F weather and their body would naturally burn more fat in the cold winter in the northeast trying to stay warm (if they actually went outside or allowed the house temperature to drop below 68°F.
Most of us live in world with 18 hours of light either from the sun or electric lighting and a constant year-round temperature of 68° F. Some of the latest research suggests that our DNA is made to go through seasonal changes in light and temperature. I would postulate that we are supposed to go through seasonal changes in:
1) Sleep – more sleep in the winter (think about 2-3 hours after sunset and wake at sunrise would be the natural cycle without electricity. That would be 10-12+ hours in the winter and 5-6 hours of sleep in the summer. Increased metabolism requires more sleep to recover, which is why if you change your sleep patterns in the winter you can lose weight.
2) Macrobiotic Dietary changes (protein, fats, and carbs) in nature change with the seasons. How many fruits and vegetables grow in the northeast in the winter? NONE. However, there are a number of fruits that last a long time when kept cold like apples and pears. Then there are numerous potatoes, sweet potatoes, squashes, and pumpkins that last for months, which are great to make into stews and soups.
3) Seasonal changes in Exercise would occur in nature because of migrating animals to follow to hunt or farming practices. This would look like spring and fall increases in cardiovascular activity to follow the migrating animals or the farming tilling the soil or harvesting the crops. This correlates with seasonal spikes in testosterone that increases fat burning and muscle building. Then winter would be laying low trying to keep warm, which I like to use to repair, recover, and stretch to get ready for the next spring season. Summer is my time to try to challenge the body’s metabolism to increase through metabolic conditioning.
4) Cold thermogenesis is key to triggering your nervous system and activates your DNA to burn fat, so go outside in the fall, winter, and spring! Think of jumping into the cold ocean and “getting used to water” which is an increase in your metabolic rate to increase your body temperature in order to prevent hypothermia. So, slow adapt to the cold and your body will increase your metabolic rate and you won’t feel that cold when the temperatures drop. In order to accomplish this your body will be burning fat like crazy.
Wallace, DC. (2005). A mitochondrial paradigm of metabolic and degenerative diseases, aging, and cancer: a dawn for evolutionary medicine. Annual Review of Genetics 39: 359-407
J.R. Speakman. Annu. Rev. Nutr. 2013
Proceedings of the National Academy of Sciences 2002;10.1073/pnas.0136972100