High Dietary Fat Reduces Sperm Quality
High Dietary Fat Reduces Sperm Quality
From Medscape Medical News
Nancy A. Melville
October 29, 2010 (Denver, Colorado) — A high intake of saturated and monounsaturated fat is associated with significantly low sperm concentration, whereas a high intake of healthier polyunsaturated fatty acids is associated with improved sperm motility and morphology, according to research presented here at the American Society for Reproductive Medicine 66th Annual Meeting.
Researchers evaluating the semen quality and dietary fat intake of 91 men attending the Massachusetts General Hospital Fertility Center, in Boston, found that men with the highest intake of saturated fat had as much as 41% fewer sperm than those with the lowest intake, and those with the highest levels of monounsaturated fat had 46% fewer sperm than those with the lowest intake.
Higher intake of omega-6 polyunsaturated fats was, however, associated with greater sperm motility (P = .02), and higher intake of omega-3 polyunsaturated fats trended toward a more favorable sperm morphology (P = .04).
"We were able to demonstrate significant relationships between dietary fat intake and semen quality parameters," said lead author Jill A. Attaman, MD, an instructor in obstetrics, gynecology, and reproductive biology at Harvard Medical School in Boston, Massachusetts.
"High intake of polyunsaturated fats [was] correlated with improved sperm characteristics."
Participants in the study ranged in age from 18 to 55 years, had a mean age of 36 years, and were generally overweight, with body mass indexes ranging from 26 to 27 kg/m2.
Their fat intake was measured with a previously validated food frequency questionnaire, and semen quality was analyzed manually and with computer-aided semen analysis. The levels of fatty acid in sperm and seminal plasma in a subgroup of men (n = 21) were measured with gas chromatography.
The association between fat intake and semen quality parameters was made with linear regression while adjusting for total energy intake, age, abstinence time, body mass index, smoking status, and intakes of caffeine and alcohol.
The results showed that saturated fatty acid levels in sperm were inversely related to sperm concentration (r = −0.53); however, saturated fat intake was unrelated to sperm levels.
Dr. Attaman said the findings correlate with a previous smaller study in Spain demonstrating that intake of processed meat, known to be high in saturated fat, was associated with poor semen quality, and research in general is increasingly looking at the role of nutrition in sperm quality.
"Little is known about how diet may affect male fertility potential, but emerging literature does support the hypothesis that specific nutrition components can affect semen quality parameters."
She noted that fatty acids play key roles in the body, particularly in sperm.
"Fatty acids are not only important stores of compact energy in the body, but they are also important components of cell membranes," Dr. Attaman explained. "The long-chain fatty acids, particularly polyunsaturated fatty acids, are direct precursors for biosynthesis and also give rise to prostaglandin and leukotrienes.
"Levels of fatty acids in the sperm are markers of sperm maturation, in general, with the amount of DHA increasing as the sperm matures and the total amount of fatty acids decreasing."
Although the findings are intriguing, the fact that the research is a correlation study means there are still many questions about the true effect of fat intake on sperm, said Keith Jarvi, MD, a professor in the Department of Surgery at the University of Toronto, Ontario, Canada.
"This is a correlation study, meaning that the type and quantity of fat intake is associated with the sperm quality and quantity, but it is unknown if the fat intake is causing the changes in sperm quality, or if men with different fat intakes also have some other differences, such as different exercise habits, other food intake habits, etc," he said.
"It is interesting, but a very early finding. We cannot now state that men with infertility should alter their diets by changing their intake of fat," Dr. Jarvi cautioned.
The study was supported by grants ES09718 and ES00002. Dr. Attaman and Dr. Jarvi have disclosed no relevant financial relationships.
American Society for Reproductive Medicine 66th Annual Meeting: Abstract O-168. Presented October 26, 2010.
From Medscape Medical News
Nancy A. Melville
October 29, 2010 (Denver, Colorado) — A high intake of saturated and monounsaturated fat is associated with significantly low sperm concentration, whereas a high intake of healthier polyunsaturated fatty acids is associated with improved sperm motility and morphology, according to research presented here at the American Society for Reproductive Medicine 66th Annual Meeting.
Researchers evaluating the semen quality and dietary fat intake of 91 men attending the Massachusetts General Hospital Fertility Center, in Boston, found that men with the highest intake of saturated fat had as much as 41% fewer sperm than those with the lowest intake, and those with the highest levels of monounsaturated fat had 46% fewer sperm than those with the lowest intake.
Higher intake of omega-6 polyunsaturated fats was, however, associated with greater sperm motility (P = .02), and higher intake of omega-3 polyunsaturated fats trended toward a more favorable sperm morphology (P = .04).
"We were able to demonstrate significant relationships between dietary fat intake and semen quality parameters," said lead author Jill A. Attaman, MD, an instructor in obstetrics, gynecology, and reproductive biology at Harvard Medical School in Boston, Massachusetts.
"High intake of polyunsaturated fats [was] correlated with improved sperm characteristics."
Participants in the study ranged in age from 18 to 55 years, had a mean age of 36 years, and were generally overweight, with body mass indexes ranging from 26 to 27 kg/m2.
Their fat intake was measured with a previously validated food frequency questionnaire, and semen quality was analyzed manually and with computer-aided semen analysis. The levels of fatty acid in sperm and seminal plasma in a subgroup of men (n = 21) were measured with gas chromatography.
The association between fat intake and semen quality parameters was made with linear regression while adjusting for total energy intake, age, abstinence time, body mass index, smoking status, and intakes of caffeine and alcohol.
The results showed that saturated fatty acid levels in sperm were inversely related to sperm concentration (r = −0.53); however, saturated fat intake was unrelated to sperm levels.
Dr. Attaman said the findings correlate with a previous smaller study in Spain demonstrating that intake of processed meat, known to be high in saturated fat, was associated with poor semen quality, and research in general is increasingly looking at the role of nutrition in sperm quality.
"Little is known about how diet may affect male fertility potential, but emerging literature does support the hypothesis that specific nutrition components can affect semen quality parameters."
She noted that fatty acids play key roles in the body, particularly in sperm.
"Fatty acids are not only important stores of compact energy in the body, but they are also important components of cell membranes," Dr. Attaman explained. "The long-chain fatty acids, particularly polyunsaturated fatty acids, are direct precursors for biosynthesis and also give rise to prostaglandin and leukotrienes.
"Levels of fatty acids in the sperm are markers of sperm maturation, in general, with the amount of DHA increasing as the sperm matures and the total amount of fatty acids decreasing."
Although the findings are intriguing, the fact that the research is a correlation study means there are still many questions about the true effect of fat intake on sperm, said Keith Jarvi, MD, a professor in the Department of Surgery at the University of Toronto, Ontario, Canada.
"This is a correlation study, meaning that the type and quantity of fat intake is associated with the sperm quality and quantity, but it is unknown if the fat intake is causing the changes in sperm quality, or if men with different fat intakes also have some other differences, such as different exercise habits, other food intake habits, etc," he said.
"It is interesting, but a very early finding. We cannot now state that men with infertility should alter their diets by changing their intake of fat," Dr. Jarvi cautioned.
The study was supported by grants ES09718 and ES00002. Dr. Attaman and Dr. Jarvi have disclosed no relevant financial relationships.
American Society for Reproductive Medicine 66th Annual Meeting: Abstract O-168. Presented October 26, 2010.
