By Vicky Communale
Rapidly melting glaciers, a loss of species diversity, and rising sea levels—the delicate balance of our planet is in chaos. While many deny these and other effects of global warming, or think that the consequences are distant and intangible, these ramifications are much more connected to our personal health than one would think. In that regard, a new study has found a very pressing concern—the effects of global warming will become directly intertwined with our neurological health in the near future.
Through research conducted by a group at Dalhousie University in Canada, it is predicted that in less than 80 years, over 96 percent of the world’s population will not have access to an essential component to brain health—docosahexaenoic acid. This lack of access is tied directly to the increasing water temperatures brought on by global warming.
Docosahexaenoic acid, also known as DHA, is an omega-3 fatty acid that has numerous benefits, including reducing heart disease risk and reducing inflammation. A healthy, functioning brain requires a high level of DHA: studies conducted in the 1990’s found that DHA is vital to the brain development of infants. For formula-fed infants, adding DHA to the formula was shown to improve cognitive and visual development. On the other hand, a lack of DHA has been implicated in numerous neurological disorders. One study, conducted by a group from the New England Medical Center in 2006, found that the brain tissue of people afflicted with Alzheimer’s Disease had significantly lower levels of DHA when compared to healthy human brain tissue. Furthermore, the scientists conducting this study also found that people with high blood levels of this fatty acid were half as likely to develop dementia as those with lower levels.
Given that DHA has been established as a vital component of healthy brain development and function, the depletion of this compound would be massively detrimental to all of us. Additionally, our bodies do not produce much DHA, so we must obtain it through our diet. The most abundant source of DHA is fish, and fish acquire DHA through their consumption of algae. Algae change the proportion of different fatty acids in their cellular membranes in accordance with the surrounding temperature. When water temperatures are cold, algae need to ensure that their cell membranes remain flexible. They do so by increasing their membranes’ proportion of polyunsaturated fatty acids, a group which includes DHA. On the molecular level, this occurs because the multiple double bonds in the fatty acid tails prevent them from packing tightly with each other, thus preventing freezing. With rising temperatures, however, the algae replace the polyunsaturated fatty acids with saturated fatty acids to promote more packing of the fatty acids, countering the heat but consequently reducing the presence of DHA. Therefore, the Dalhousie University group’s study predicted that due to warming environments, from region to region, algal production of DHA will decrease by anywhere from 10 to 58 percent. Because of this, the DHA found in fish will be significantly reduced, and consequently, our access to the compound will likewise be depleted.
While the study predicts that countries with small populations and prominent fishing industries, such as Norway and Chile, will still be able to maintain adequate access to DHA, the same cannot be said for other countries around the world. Countries with rapid population growth, such as China and Indonesia, are predicted to face severe shortages. Landlocked countries will also suffer greatly from the shortage, and the intake of DHA by their populations will fall below recommended levels.
There is some hope that future scientific endeavors may help alleviate the effects of the shortage. Several initiatives are trying to directly farm algae as a source of DHA and others are trying to genetically engineer plants that produce high amounts of DHA, all with the goal of compensating for the damaging effects of a DHA shortage on our neurological health. At this time, however, it is unclear if these endeavors will become a permanent solution to solving this issue. Even if they do, it will only be a band-aid solution to the myriad other problems that arise from global warming.