I read recently in Nature that a child is more likely to be autistic if the father is older at time of conception. The risks increase starting at the age of 25. The risk for older fathers can be up to 2%. Older fathers are more likely to have an autistic child because as men age, they are more likely to have accumulated “spontaneous” genetic mutations in their sperm cells. Sperm cells reproduce and divide every 15 days so that over time small changes in the genes may gradually accumulate. By contrast, women’s eggs do not continue to divide, so there is no increased risk of autism for an older woman than for a younger woman giving birth.
No one can truly account for the “spontaneous” mutations and where they come from. Men who are between the ages of 25 and 35 are considered young. Their skin, organ, and other cells keep dividing with very few mutations. So why should sperm cells accumulate mutations which may cause some autism?
Maybe we should look for an answer in something that is known to target sperm cells. This is a toxin that comes from the seed of the cotton plant called gossypol. As we will see below, gossypol causes major problems with DNA but is found in our food. Why? The cotton gin separates the cotton fiber from the seed. The fiber becomes our clothing. Cottonseed remains. Cottonseed contains valuable protein, so farmers feed it to animals instead of disposing of it. The only problem is that cottonseed is loaded with multiple poisons, one of which is gossypol. When too much cottonseed is fed to animals, they bleed to death or die due to failing hearts and lungs. Scientists have spent many research years determining how much cottonseed can be safely fed to farm animals such as pigs and chickens. Even in non-lethal amounts, cottonseed toxins accumulate in the animals. This means that the cottonseed toxins, including gossypol, are still in the animal products and human beings then eat these toxins daily as they eat beef, pork, chicken and dairy products.
The cottonseed toxin gossypol does a double whammy on sperm . Gossypol prevents the assembly of microtubules, a necessary process in the development of sperm. Too much gossypol fed to male animals leads to infertility . They can’t produce sperm.
But gossypol has another effect. Gossypol causes breaks in DNA and can cause exchange of genetic material between chromosomes. Both of these effects are genetic mutations. Gossypol is called “genotoxic” because it is toxic to DNA.
But these effects do not prevent the presence of gossypol containing cottonseed in animal feed. The gossypol is then present in the meat that people eat. Human beings are therefore eating a toxic chemical which can cause toxic effects on DNA.
I do not know of any other “genotoxic” chemical that is regularly found in our food. Gossypol, however, is found at about 4 parts per million in a piece of chicken . While this may not seem like a large quantity, remember that for most people this toxic chemical is coming in every day and some will find its way into sperm producing cells.
We cannot know without further research whether gossypol is responsible for “spontaneous” mutations in men’s sperm as they age. But before writing off an increased risk of autism to older fathers to “spontaneous” mutations as an effect of simple aging, may be scientists should look further. Maybe they should ask whether something in our food could cause these “spontaneous” genetic mutations. Gossypol could account for some of these mutations, and should be further investigated. The only reason cottonseed can be fed to animals is that people do not know that these toxins are there .
There are many other cottonseed toxins that pose several other major health risks including heart disease and Alzheimer’s. These risks are detailed in an upcoming book by Dr. Bruce Semon about Cottonseed, Alzheimer’s and Your Brain. Look for it in January 2013. For more information on how you can contribute to research on the relationship between cottonseed and a myriad of health problems, click here.
O’Roak, B. J., Vives, L. Girirajan, S., Karakoc, E., Krumm, N., Coe, B. P., Levy, R., Ko, A., Lee, C., Smith, J. D., Turner, E. H., Stanaway, I. B., Vernot, B., Malig, M., Baker, C., Reilly, B., Akey, J. M., Borenstein, E., Rieder, M. J., Nickerson, D. A., Bernier, R., Shendure, J., Eichler, E. E., Sporadic autism exomes reveal a highly interconnected protein network of de novo mutations. Nature. 2012, Apr. 4; 485(7397):246-50
Medrano, F. J., Andreu, J. M. Binding of gossyol to purified tubulin and inhibition of its assembly into microtubules. Eur. J. Biochem 1986;158(1):63-9.
Nordenskjold, M. and B. Lambert Gossypol induces DNA strand breaks in human fibroblasts and sister chromatid exchanges in human lymphocytes in vitro. Journal of Medical Genetics, 1984, 21, 129-132
