CERCH – Center for Environmental Research and Children's Health

The Age, Diet and Genetic Effects in Sperm Study (AGES)

The Age and Genetic Effects in Sperm Study, or AGES, investigates how universal factors of diet quality and normal aging might be related to increased DNA or genetic damage in sperm, or to a decline in sperm quality.

Two healthy sperm and one with sex chromosome aneuploidy YX (on left). X appears as yellow, Y as green and chromosome 21 is red. (Image: Andy Wyrobek/Lawrence Berkeley National Laboratory)

What the AGES Study investigates:

• Whether increase in age, and/or poorer diet quality are related to poorer semen or sperm quality.
• Whether better diet reduces sperm damage incurred by age.

Why study the effects of age and diet on sperm?

• Understanding the impact of age and diet, which are  factors experienced by everyone, on male reproductive health is a key step toward understanding the effects of more specific environmental exposures.
• The impact of paternal age and diet on male fertility and the health of offspring are much less clearly understood than are the effects of maternal age and diet on maternal fertility.

Findings from the AGES Study: (Go to Findings)

Exposures/Factors Studied:

• Age
• Dietary nutrients (zinc, folate, tocopherol, antioxidants)

Health Outcomes Studied:

• Genetic damage in sperm, chromosomally-defective sperm
• Semen quality (amount and motility of sperm, etc.)

Location:

• Lawrence Livermore National Laboratory (LLNL), Livermore, California.
  • Relatively homogeneous workforce
  • Site of the semen analysis laboratory

Study Participants:

• Healthy Subjects:
  • 97 men currently employed or retired from LLNL
  • Recruited between October 1997 and July 1998 from advertisements posted at the LLNL, e-mail listings, and in newsletters
  • 15-20 men in each decade of life from 20-80; additional men above age 70 were also enrolled
  • 91% Caucasian, 55% had more than 16 years of education
• Screening criteria
  • Screening conducted over the telephone
  • Healthy nonsmokers, no vasectomy, no current infertility history
  • No prior history of undescended testicle, varicocele, prostate or testicular cancer, radiotherapy or chemotherapy, previous semen analysis with zero sperm count (azoospermia) or fever in last 3 months.

Data Collection:

• Eligible men were mailed a questionnaire and semen collection containers.
• The men provided a semen sample, which they collected via masturbation after several days of abstinence that they delivered to a drop box at LLNL.
• Questionnaire covered topics including lifestyle habits (e.g. food, alcohol, cigarette and caffeine consumption), medical history, reproductive history (e.g. fatherhood history), and sociodemographic characteristics (age, race, education).
• Diet quality was evaluated by evaluation of reported intake of various foods, as well as by measurement of nutrients in seminal fluid in the laboratory.
• Sperm quality and genetic integrity/makeup were measured through laboratory methods.

Research Team:

• Brenda Eskenazi, PhD
• Andrew Wyrobek, PhD, Life Sciences Division, Lawrence Berkeley National Laboratory
• Rosana Hernandez Weldon, PhD
• Caihong Xing, Life Sciences Division, Lawrence Berkeley National Laboratory and National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention
• Guilan Li, National Institute of Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention
• Francesco Marchetti, PhD, Life Sciences Division, Lawrence Berkeley National Laboratory
• Thomas Schmid, Life Sciences Division, Lawrence Berkeley National Laboratory
• Suramya Waidyanatha, University of North Carolina, Chapel Hill