|
Levels of folate in men's diets is linked to chromosomal abnormalities in their sperm
March 20, 2008Folate (and folic acid) is a vitamin B
Researchers have found an association between a vitamin found in leafy green vegetables, fruit and pulses [1] and levels of chromosomal abnormalities in men's sperm. Men who consumed high levels of folate (a water-soluble B vitamin that occurs naturally in food) and folic acid (the synthetic form of the vitamin) tended to have lower levels of abnormal sperm where a chromosome had been lost or gained (known as aneuploidy).
Writing in Europe's leading reproductive medicine journal, Human Reproduction, today (Thursday 20 March), the authors say estimates suggest that between 1-4% of sperm in a healthy man have some type of aneuploidy, but there are large variations among individuals, the mechanisms are poorly understood and little is known about the effects of men's diet on their sperm. [2]
In the first study of its kind to investigate the relationship between sperm aneuploidy and paternal diet, they analysed sperm samples from 89 healthy, non-smoking men and questioned them about their daily total intake (from diet and from vitamin supplements) of zinc, folate, vitamin C, vitamin E and beta-carotene.
One of the principal investigators of the study, Brenda Eskenazi, Professor of Maternal and Child Health and Epidemiology and Director of the Center for Children's Environmental Health at the School of Public Health, University of California, Berkeley, USA, said: "We found a statistically significant association between high folate intake and lower sperm aneuploidy: there was increasing benefit with increasing intake, and men in the upper 25th percentile who had the highest intake of folate between 722-1150 micrograms, had 20-30% lower frequencies of several types of aneuploidy compared with men with a lower intake.
"However, this study cannot prove that high folate intake caused the lower sperm aneuploidy levels, only that there is an association. This is the first study of its kind and the results indicate the need for further research, especially a randomised controlled trial, on this topic."
The researchers found no consistent associations between intakes of zinc and the other vitamins and sperm aneuploidy.
Prof Eskenazi said: "While the importance of maternal diet on reproduction, especially folate intake, is well known, the results of our study suggest the importance of studying paternal nutrition when considering male-mediated developmental consequences. In previous studies, we and others have shown that paternal micronutrient intake may contribute to successful conceptions by improving the quality of the sperm. This study is the first to suggest that paternal diet may play a role after conception in the development of healthy offspring." [3]
The current recommended daily intake (RDA) for men aged over 19 is 400 micrograms, and the authors say that if other studies confirm their findings of the link between folate intake and aneuploidy, then a possible intervention would be to increase the RDA for men considering becoming fathers for at least three months before trying to conceive in order to reduce the risk of chromosomal abnormalities in their children.
Ms Suzanne Young, a researcher in Prof Eskenazi's group and the study co-ordinator, said: "Increasing folate intake can be as simple as taking a vitamin supplement with at least 400 micrograms of folate or eating breakfast cereal fortified with 100% of the RDA for folic acid. In addition, green leafy vegetables, such as spinach, can have up to 100 micrograms of folate per serving."
Disentangling the effects of folate from other micronutrients (e.g. the other vitamins) can be difficult, but the authors think they have succeeded in doing this by looking at several different nutrients in statistical analyses. Ms Young said: "The results of the different analyses were different, which gave us some confidence that we could look at the effect of these micronutrients separately. The definitive way to answer this question would be with a randomised control trial with folate supplementation."
###
[1] Pulses include foods such as beans, chickpeas and lentils.
[2] The association of folate, zinc and antioxidant intake with sperm aneuploidy in healthy non-smoking men. Human Reproduction journal. Doi:10.1093/humrep/den036
[3] Sperm aneuploidy can have a number of consequences ranging from failure to conceive, miscarriages or children born with conditions such as Down's syndrome, Turner's syndrome and Klinefelter's syndrome.
European Society for Human Reproduction and Embryology
In the first study of its kind to investigate the relationship between sperm aneuploidy and paternal diet, they analysed sperm samples from 89 healthy, non-smoking men and questioned them about their daily total intake (from diet and from vitamin supplements) of zinc, folate, vitamin C, vitamin E and beta-carotene.
One of the principal investigators of the study, Brenda Eskenazi, Professor of Maternal and Child Health and Epidemiology and Director of the Center for Children's Environmental Health at the School of Public Health, University of California, Berkeley, USA, said: "We found a statistically significant association between high folate intake and lower sperm aneuploidy: there was increasing benefit with increasing intake, and men in the upper 25th percentile who had the highest intake of folate between 722-1150 micrograms, had 20-30% lower frequencies of several types of aneuploidy compared with men with a lower intake.
"However, this study cannot prove that high folate intake caused the lower sperm aneuploidy levels, only that there is an association. This is the first study of its kind and the results indicate the need for further research, especially a randomised controlled trial, on this topic."
The researchers found no consistent associations between intakes of zinc and the other vitamins and sperm aneuploidy.
Prof Eskenazi said: "While the importance of maternal diet on reproduction, especially folate intake, is well known, the results of our study suggest the importance of studying paternal nutrition when considering male-mediated developmental consequences. In previous studies, we and others have shown that paternal micronutrient intake may contribute to successful conceptions by improving the quality of the sperm. This study is the first to suggest that paternal diet may play a role after conception in the development of healthy offspring." [3]
The current recommended daily intake (RDA) for men aged over 19 is 400 micrograms, and the authors say that if other studies confirm their findings of the link between folate intake and aneuploidy, then a possible intervention would be to increase the RDA for men considering becoming fathers for at least three months before trying to conceive in order to reduce the risk of chromosomal abnormalities in their children.
Ms Suzanne Young, a researcher in Prof Eskenazi's group and the study co-ordinator, said: "Increasing folate intake can be as simple as taking a vitamin supplement with at least 400 micrograms of folate or eating breakfast cereal fortified with 100% of the RDA for folic acid. In addition, green leafy vegetables, such as spinach, can have up to 100 micrograms of folate per serving."
Disentangling the effects of folate from other micronutrients (e.g. the other vitamins) can be difficult, but the authors think they have succeeded in doing this by looking at several different nutrients in statistical analyses. Ms Young said: "The results of the different analyses were different, which gave us some confidence that we could look at the effect of these micronutrients separately. The definitive way to answer this question would be with a randomised control trial with folate supplementation."
###
[1] Pulses include foods such as beans, chickpeas and lentils.
[2] The association of folate, zinc and antioxidant intake with sperm aneuploidy in healthy non-smoking men. Human Reproduction journal. Doi:10.1093/humrep/den036
[3] Sperm aneuploidy can have a number of consequences ranging from failure to conceive, miscarriages or children born with conditions such as Down's syndrome, Turner's syndrome and Klinefelter's syndrome.
European Society for Human Reproduction and Embryology
Folate News and Current Folate Events RSSNARSAD Researchers Identify Specific Genes and Family Traits Linked to Schizophrenia, Bipolar Disorder and Depression
New findings from research supported by NARSAD, the world's leading charity dedicated to mental health research, and conducted by Harvard-affiliated scientists are providing important clues into how genes work to impair various aspects of attention, memory and perception -- the behaviors associated with many psychiatric illnesses, such as schizophrenia, bipolar disorder and depression.
Study links dietary folate intake to genetic abnormalities in sperm
Healthy men who report lower levels of the nutrient folate in their diets have higher rates of chromosomal abnormalities in their sperm, according to a new study by researchers at the University of California, Berkeley, and the Lawrence Berkeley National Laboratory.
Certain vitamin supplements may increase lung cancer risk, especially in smokers
Vitamin supplements do not protect against lung cancer, according to a study of more than 77,000 vitamin users. In fact, some supplements may even increase the risk of developing it.
Regular, long-term aspirin use reduces risk of colorectal cancer
The use of regular, long-term aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) reduces the risk associated with colorectal cancer, according to a study published in Gastroenterology, the official journal of the American Gastroenterological Association (AGA) Institute.
Low vitamin E levels associated with physical decline in elderly
Researchers at Yale School of Medicine have found that a low concentration of vitamin E in the blood is linked with physical decline in older persons.
Vitamin B12 function may be diminished by excessive folate
In a study of adults aged 20 and over, researchers at Tufts University showed that homocysteine and methylmalonic acid are at much higher levels in individuals who have a combination of vitamin B12 deficiency and high blood folate levels than in individuals who are also vitamin B12 deficient but have normal folate levels.
Scientists question folic acid fortification
Scientists at the Institute of Food Research have highlighted possible consequences of fortifying flour with folic acid due to new evidence of how it is absorbed by the body.
New report shows how our diet must change to cut cancer risk
A new report published this week by the World Cancer Research Fund (WCRF) will show how much our diet needs to change if we are to reduce the risk of cancer.
Gold nanorods shed light on new approach to fighting cancer
Researchers have shown how tiny "nanorods" of gold can be triggered by a laser beam to blast holes in the membranes of tumor cells, setting in motion a complex biochemical mechanism that leads to a tumor cell's self-destruction.
Impact of elevated homocysteine levels on vision under study
Homocysteine, an amino acid believed to contribute to heart attack, stroke and dementia, likely also is a player in retinal damage and vision loss, researchers say.
More Folate News Articles
| © 2008 BrightSurf.com |