Preserving Male Reproductive Health With Diet

Image Credit: Julia Mariani / Flickr. This image has been modified.

Preserving Male Reproductive Health With Diet

In 1992, a controversial paper was published suggesting sperm counts have been dropping around the world over the last 50 years. However, this remains a matter of debate. It’s notoriously difficult to determine sperm counts in the general population for obvious reasons. If you just go ask men for samples, less than 1 in 3 tend to agree to participate.

Finally though, a study of tens of thousands of men studied over a 17-year period was published. It indeed found a significant decline in sperm concentration, about a 30 percent drop, as well as a drop in the percentage of normal looking sperms. Most sperms looked normal in the 90’s, but more recently that has dropped to less than half. This may constitute a serious public health warning.

Semen quality may actually be related to life expectancy. In a study of more than 40,000 men visiting a sperm lab during a 40-year period, they found a decrease in mortality was associated with an increase in semen quality, suggesting that semen quality may therefore be a fundamental biomarker of overall male health. Even when defective sperm are capable of fertilizing an egg, creating a child with abnormal sperm may have serious implications for that child’s future health.

What role may diet play? I profiled a first-of-its-kind Harvard study suggesting that a small increase in saturated fat intake was associated with a substantially lower sperm count, but not all fat was bad. Higher intakes of omega-3’s were associated with a more favorable sperm shape. This may help explain why researchers at UCLA were able to improve sperm vitality, movement, and shape by giving men about 18 walnuts a day for 12 weeks. Walnuts have more than just omega 3’s, though. They also contain other important micronutrients. In a study of men aged 22 through 80, older men who ate diets containing lots of antioxidants and nutrients, such as vitamin C, had the genetic integrity of sperm of much younger men.

The antioxidants we eat not only end up in our semen, but are concentrated there. The amount of vitamin C ends up nearly ten times more concentrated in men’s testicles than the rest of their bodies. Why? Because sperm are highly susceptible to damage induced by free radicals, and accumulating evidence suggests that this oxidative stress plays an important role in male infertility. So, more fruits and vegetables and perhaps less meat and dairy, but the Harvard data were considered preliminary. They studied fewer than 100 men, but it was the best we had… until now.

A much larger follow-up study, highlighted in my video, The Role of Diet in Declining Sperm Counts, found that the higher the saturated fat intake the lower the sperm count, up to a 65 percent reduction. These findings are of potentially great public interest because changes in diet over the past decades may be part of the explanation for the recently reported high frequency of subnormal human sperm counts. In any case, the current findings suggest that adapting dietary intake toward eating less saturated fat may be beneficial for both general and reproductive health.

Why is high dietary intake of saturated fat associated with reduced semen quality? What’s the connection? Sex steroid hormones in meat, eggs, and dairy may help explain the link between saturated fat intake and declining sperm counts. That’s the subject of my video, Dairy Estrogen and Male Fertility.

More on male infertility in my videos Fukushima and Radioactivity in Seafood and Male Fertility and Diet.

Diet also has a role to play in sexual dysfunction:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live year-in-review presentations Uprooting the Leading Causes of Death, More Than an Apple a Day, From Table to Able, and Food as Medicine.


Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.

15 responses to “Preserving Male Reproductive Health With Diet

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  1. The image of “sperm kites” is just too funny! The images that go with the articles and the splash image at the front of the videos are so creative they just pull you in. Hats off to Dr. Greger and his creative team.

  2. Genetic Entropy shows that sperm counts will continue to drop, and cancer rates will continue to climb. Nutrition and exercise can help slow this process down, but the 2nd Law of Thermodynamics will, in all likelihood, continue.

      1. Thank you, let me know what you find (I believe genetics were conclusively discovered in the 50’s? so a paper from ’44 may be of limited use in the analysis)

        1. Matthew: This is actually a book Shrodinger wrote based on a series of lectures he had given. As for its relevance, Wikipedia says,
          “Both James D. Watson,[2] and independently, Francis Crick, co-discoverers of the structure of DNA, credited Schrödinger’s book with presenting an early theoretical description of how the storage of genetic information would work, and each respectively acknowledged the book as a source of inspiration for their initial researches.”

    1. I have a T-shirt that says “will do physics for food”, so I think I am qualified to speak on this, well that and I have 30 years of experience do thermodynamic cycle design and simulations of jet and rocket engines. I might be just babbling on issues of nutrition here, but with regard to thermodynamics, I think I am on much firmer ground.

      The second law of thermodynamics is one of the most misunderstood, misused and abused physical principles. It *only* applies to closed systems. If the system being examined is in any way connected to an outside system, then a “mandatory” increase in entropy does not exist. In practice the only truly closed system is the Universe in its entirety (at least as far as we know). Everything else is an open system that exchanges mass and energy with other portions of the Universe. The Earth for example receives energy from the sun and rejects energy in the form of long wave radiation to the rest of the universe. As such local processes in the Earth system can have a local decrease in entropy at the expense of increasing entropy of it surroundings.

      A key example of these entropy reducing processes are what what we call “living beings”. The hallmark of whether something is alive is whether it can swim uphill against entropy as it were and maintain a lower internal entropy state. Living beings do this by using the low entropy state of its food and air, and in the case of plants, sunlight that it takes in to provide chemical energy to expand and maintain the high order/low entropy state of its tissues. In doing so it increases the entropy of the wastes it excretes. And in fact something is dead when it can no longer maintain low internal entropy. When that happens it rapidly becomes food for other living things looking to borrow its low entropy tissues so that they can maintain their own internal order.

      This ability of living creatures to reduce entropy is just as applicable to maintaining the high degree of order in its genes as well as reproductive cells like sperm. So there is nothing in thermodynamics that requires that genes or sperm quality following some inevitable downhill slide into chaos and disorder. And there is absolutely nothing about the 2nd law of thermodynamics that requires populations as a whole to see increasing cancer or decreasing fertility.

      1. > So there is nothing in thermodynamics that requires that genes or sperm quality following some inevitable downhill slide into chaos and disorder.

        The 2nd Law of Thermodynamics suggests genomes to be degrading as is readily witnessed by scientific observation. As the end result of the universe is “heat death”, the end result of all organisms is extinction. No amount of broccoli and kale can stop genomic degeneration, but they function very well to slow it down.

        1. Don’t know that I have ever quite seen the heat death of the universe used explain why cancer and fertility rates are changing.

    2. More like the “law of epigenetics”? Populations tend to pass on epigenetic changes to their offspring…changes derived from the foods they eat? Crap food in…crap genetics out….

      Current mass food experiments going to end in worse than what we already have?

      1. This is absolutely true. Epigenetic effects of toxic foods are causing genomic degeneration to occur at faster than normal rates

  3. So embarassing, I went for my checkup and I can’t hear a thing. The Dr. said he needs a unine sample, a stool sample and a sperm sample. “Say again, Doc?” My wife pipes up, “He wants your shorts, RhombO.”

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