Saturated fats are one of the greatest enemies of healthy diet. The craving for high-energy, salty or sweet foods has swayed people away from healthier foods, leading to a global obesity pandemic. And if the health risks of obesity aren't enough to deter people away from unhealthy foods, another data might do the trick: the saturated fats present in these high-fat diets are responsible for lower sperm quality. The findings of a study carried out by Harvard University corroborate a long-held view among health specialists: high-fat diets, such as junk food, could be contributing to male infertility.
Researchers from the Harvard Medical School gathered information from 99 men over almost four years. Participants answered questions about their diets and provided sperm samples. They were then distributed across three groups according to the amount of fat intake. One of the patterns that emerged was that men with the highest amount of fat in their diets produced significantly lower sperm count (43%) and concentration (38%) than those who consumed the least amount of fat. Saturated fats accounted for most of the differences - 35% for sperm count and 36% for sperm concentration.
Omega-3 fatty acids, on the other hand, seemed to promote semen quality. Those who consumed the highest amount of this polyunsaturated fatty acid produced 2% more sperm than those who least consumed it. Omega-3 polyunsaturated fatty acids are considered healthy fats beneficial to brain health and other organs.
The researchers highlighted the significance of the strong correlations, but infertility specialist also cautioned that more research was vital to confirm the findings of this small study. Although the authors of the study claimed that the effects of obesity itself on sperm quality were statistically isolated, it cannot be entirely known that this prevents data corruption and erroneous associations - 71% of the 99 men were already overweight or obese.
At the time of publication on the journal Human Reproduction in March 2012, this was the largest study ever done about the potential influence of fatty foods on semen quality. Results suggest that high-fat diets (among other factors) could be strongly contributing to the decline of semen quality in males living in Western cultures, where junk food is particularly popular.
This study suggests another plausible causal candidate (saturated fats) to support a growing amount of evidence for the negative effects of the urban lifestyle on male fertility. An unhealthy lifestyle and diet contribute equally to poor human health. However, it is difficult to determine a clear cause and effect relationship given that the exact mechanisms tend to work intertwined with many factors.