A recent research study was published that has discovered there are seasonal variations in the activity of our DNA. This may sound absolutely obvious to those that feel different during each season have always had a favourite season in which they feel their best. We now have the scientific evidence that backs this up. The research team reviewed annual gene expression patterns from ethnically and geographically diverse populations and compared data from both northern and southern hemispheres as well as groups at the ecuador and those closer to the poles. The trends were astonishing. The populations studied in the northern hemispheres exhibited gene expression trends consistent with the seasons in the same way as to their counterparts in the southern hemisphere during their identical season. Similarly, gene expression at the equator exhibited its own unique pattern, relevant to their unique seasonal changes and this was vastly different from the trend observed closer to the north pole.
The research team were able to identify one hundred and forty-seven genes that showed common seasonality in blood circulation. The total number of white blood cells (lymphocytes, monocytes, basophils, eosinophils, neutrophils) and platelets in the peripheral circulation were present in different quantities and ratios to during the different seasons . It was also observed that the average volume and mass of hemoglobin within the red blood cells changed with the seasons. This observation is consistent with a previous study that showed seasonal red blood cell and platelet gene expression.
In the United Kingdom, the increase in white blood cells was observed in the winter months and closer to the ecuador in Gambia, it was during their rainy season (June through October). In both cases, it is when infectious diseases are more prominent. This would be consistent with the times of the year when common airborne pathogens are most prominent; think cold and flu season. Our first line of immune defense is carried out in part by our white blood cells.
In addition, it was observed that seasonal environments have an impact on autoimmune disease pathologies. The circulating level of C-reactive protein, a common marker for inflammation, was found to be increased during winter months. Gene expression in fat tissue was observed to have seasonal fluctuations in over twelve hundred different genes. Think of how we instinctually put on a little extra weight in preparation for the cold of the winter months and then slim down for the heat of the summer. In total, the research team was able to identify 4,027 genes to be seasonally expressed.
In both the United Kingdom and southern Australia, fall and autumn were observed to be a distinct transition between the seasonal fluctuations of gene expression. Whereas at the equator, seasonal gene expression was closely linked to their rainy season. Closer to the north pole the fluctuations were more connected with the change in daylight hours with distinct difference between summer solstice and winter solstice.
In Chinese medicine theory, the idea of seasonal fluctuations is well outlined. One of the diagnostic tools that we as Chinese medicine practitioners utilize is the palpation of the radial pulse. We feel for variations in the pulse presentation, noting its quality and character to help us refine our diagnosis. We have to discern what is balance and what is pathology for the individual while at the same time taking into account that there is a specific type of radial pulse presentation for each of the seasons. In the spring the pulse should have a slight wiry characteristic, during the summer the pulse becomes full and can appear to be overflowing, towards the end of the summer the pulse gets more slippery as the warmth of the summer decreases. In the autumn the pulse has a floating characteristic as the temperature becomes cooler when the pulse finally descends into the deeper levels, signifying that the warmth is kept deeper in our core to protect the internal organs during the cold months of winter and the immune system must protect the body at the surface during this time. Perhaps what we are feeling in the pulse throughout its seasonal variations are the very changes that this study was able to observe.
There is certainly a trend in modern functional medicine that considers seasonal fluctuations in dosing of vitamins, supplements and for interpretation of diagnostic testing. It is recognized that the human body will exhibit different patterns of deficiency or excess depending on the time of year. It will therefore require different dosages of supplementation and the response rate from the body in its utilization of supplements or medicine may also fluctuate.
Observing the seasons, tailoring treatment to the individual and the geographical location may seem like an obvious statement, however with the use of the internet for information exchange and standardized research based dosing guidelines, individualized treatment strategies are not as common as they should be. Research such as the paper outlined above, are excellent reminders to continue to take into account the individual, their unique situation in life and of course the environment they live in.