Levine et al. updated a sperm count analysis in Human Reproduction Update in 2023. Sperm counts in Western countries kept falling through 2018, with no sign of a plateau. Across that same 50-year window, from roughly 1970 to 2020, the male diet changed more than in any previous half century. Yet most male fertility diet plans still start with a supplement bottle. The data points somewhere less marketable: a way of eating that looks closer to 1970 than to a pill organizer.
The food supply changed alongside the sperm count decline
Ultra-processed food went from a small slice of the American diet in the 1960s to 57.9 percent of adult calories by the 2010s, according to an analysis of NHANES data published in BMJ Open in 2016 (MartÃnez Steele et al.). Sperm counts started their documented decline in the same window. This is not proof that ultra-processed food caused the decline. Population trends cannot prove cause. But when a reproductive health metric and a dietary shift track each other for five decades, the rational move is to look at the pattern, not reach for a single nutrient.
What the diet studies compare
Nutritional epidemiology does not study foods in isolation well. It sorts diets into patterns. One pattern keeps showing up: red and processed meat, refined grains, sweets, and sugary drinks. Another keeps showing up on the other side: fish, vegetables, legumes, nuts, fruit, and whole grains.
A 2012 study of young men in Rochester, New York (Gaskins et al., Human Reproduction) found that a Western dietary pattern was associated with lower progressive sperm motility. A 2017 systematic review of observational studies by Salas-Huetos and colleagues found the same direction across many cohorts. Diets high in processed meat, trans fats, and sugary foods tracked with worse semen parameters. Diets high in fish, vegetables, legumes, and whole grains tracked with better ones. A 2017 Greek study of men attending a fertility clinic (Karayiannis et al., Human Reproduction) found higher Mediterranean diet adherence was associated with higher sperm concentration and total count.
The FAZST trial and the problem with nutrient pills
One randomized trial did the most damage to the micronutrient obsession. The Folic Acid and Zinc Supplementation Trial, published in JAMA in 2020 (Schisterman et al.), randomized 2,370 couples and gave men daily folic acid and zinc supplements or a placebo for six months. The supplements did not improve semen quality, pregnancy rates, or live birth rates compared with placebo. These were two of the most common supplements sold for male fertility, tested in a real population, with a real control group.
That does not mean zinc and folate are irrelevant. It means the isolated pill did not reproduce what the food sources do. Oysters, pumpkin seeds, lentils, and leafy greens carry zinc and folate alongside fiber and polyphenols. The food matrix is not a pill. The observational studies support food-based intake. The randomized trial undercuts the supplement-first shortcut.
Processed meat and the soy distraction
In the 2017 systematic review, diets heavy in processed meat and trans fats tracked with worse semen parameters. Fish intake in the same body of research tracked with better ones. Meanwhile, the feared foods usually are not the ones showing up in the data. A meta-analysis of clinical studies published in Fertility and Sterility in 2010 (Hamilton-Reeves et al.) found no meaningful effect of soy protein or isoflavones on male reproductive hormones. The soy panic consumes attention. Deli meat, trans fats, and sugary drinks do not. The literature suggests the worry has been aimed at the wrong shelf.
What that looks like on a plate
If someone asked me to translate the research into a week of eating, I would not hand them a supplement schedule. I would describe substitutions that move a diet from a Western pattern toward a Mediterranean one.
- Fish twice a week instead of processed red meat. Sardines, salmon, or mackerel give long-chain omega-3 fats and coenzyme Q10.
- Beans and lentils replace some meat.
- Cooked tomatoes with olive oil provide lycopene in a form the body absorbs more readily than raw tomatoes.
- Leafy greens and citrus provide folate.
- Nuts and seeds replace chips.
- Cut sugary drinks first, because they load consistently onto the Western pattern in these studies.
Zinc-rich foods like oysters, pumpkin seeds, and beef show up in observational research. The FAZST result suggests the benefit is in the whole food, not in a pill repackaging of the nutrient.
Where the evidence stops
Most of this is association, not causation. Men who eat a Mediterranean-style diet also tend to smoke less, exercise more, and sleep better. The studies adjust for some of that but not all of it. A food frequency questionnaire does not capture everything, and a diet score is a blunt tool.
The supplement trial is the strongest piece because it was a randomized controlled trial. It showed the supplement route did not improve semen quality or live birth for the tested nutrients. That is not proof that switching from processed meat to sardines will change semen quality. It is proof that the pill-first approach is weak. The food pattern remains the more defensible place to focus, and it is also the intervention with fewer downsides.
If you are dealing with a fertility issue or planning to change your diet for a medical reason, talk to a doctor or a registered dietitian. Individual cases vary, and none of this is a prescription.
This content is for educational purposes only and is not medical advice. Oakman products are designed for physical comfort and cooling. They make no claims about fertility, sperm quality, or hormone levels. Consult a healthcare professional for personalized advice.
Frequently asked questions
what does the research say about supplements for male fertility
The strongest evidence comes from a 2020 randomized trial that gave men zinc and folic acid or a placebo for six months. It found no improvement in semen quality, pregnancy rates, or live birth rates. That does not mean zinc and folate are useless from food, but it does not support the pill-first approach.
which foods are linked to lower sperm count
Observational studies have found that diets heavy in processed meat, trans fats, refined grains, and sugary drinks are associated with worse semen parameters. Fish, vegetables, legumes, nuts, and whole grains show up on the other side. These are associations, not proof of cause.
does soy actually lower testosterone or sperm count
A 2010 meta-analysis of clinical studies found no meaningful effect of soy protein or isoflavones on male reproductive hormones. The soy concern gets a lot of attention, but the research points to processed meat and trans fats as the more consistent dietary concerns.
does the mediterranean diet actually help sperm count
Higher Mediterranean diet adherence has been linked to higher sperm concentration and total count in clinic-based studies. That finding is observational, not a guarantee that changing your diet will change a diagnosed problem. If you have a low sperm count, a doctor or registered dietitian can help you sort out what applies to your situation.