Mediterranean vs. processed foods: how diet changes sperm count

A new study in Nutrients has shown a simple thing: the closer a man's diet is to the Mediterranean, and the less ultra-processed foods (UPF) it contains, the better the key sperm metrics - concentration, total count, progressive motility, viability and morphology. The link remained even after accounting for age and BMI, but the UPF addiction - from sugary drinks to snacks - went into the negative by the same metrics.

The study included 358 men (mean age 34.6 years) who came to the reproductive center for sperm analysis. Adherence to the Mediterranean diet was assessed using the 14-point MEDAS questionnaire (low ≤5, average 6-9, high ≥10), the proportion of UPF was assessed using a 24-hour food survey with NOVA classification. Spermograms were performed according to the WHO-2021 criteria, hormones were additionally measured (FSH, LH, testosterone, SHBG, etc.).

Background of the study

Male infertility accounts for half of all couples’ infertility cases; in a significant proportion of men, the cause remains “idiopathic,” i.e., without obvious organic pathology. In practice, sperm quality—concentration, total count, progressive motility, viability, and morphology—is sensitive to lifestyle factors: body weight, smoking, heat stress, sleep, and, increasingly, research shows, diet. The biological logic is straightforward: spermatogenesis is vulnerable to oxidative stress and systemic inflammation, and is also dependent on micronutrient status (zinc, folate, vitamin D), fat quality (omega-3, monounsaturated), glycemic load, and metabolic health.

Against this background, two dietary “poles” are particularly interesting. The Mediterranean diet (vegetables, fruits, legumes, whole grains, fish, nuts, olive oil, moderate red meat) provides a rich array of antioxidants and anti-inflammatory nutrients, improves the lipid profile and insulin resistance - all of which potentially support sperm maturation and Leydig/Sertoli cell function. In contrast, a diet high in ultra-processed foods (UPF) - sugary drinks, snacks, confectionery, processed meats, “fast” breakfasts - is associated with excess energy density, micronutrient deficiencies, higher glycemic load and chronic low-grade inflammation. Of additional concern are food additives and potential exposure to endocrine disruptors from packaging, which could theoretically affect the hypothalamic-pituitary-gonadal axis.

Despite the growing number of studies, until recently the data were fragmented: more often individual products or nutrients were analyzed, rarely whole dietary patterns; even less often were both the “positive” pattern (adherence to the Mediterranean diet) and the “negative” indicator (UPF share according to the NOVA classification) taken into account simultaneously. The clinically important question of modifiability also remained: do sperm parameters “respond” to nutrition in the same way in men with intact and already impaired testicular function (for example, with elevated FSH)?

This is precisely the gap that the study fills: in one sample of men, it compares adherence to the Mediterranean diet, the proportion of UPF, and a complete spermogram according to WHO-2021, adding hormonal markers (FSH/LH/androgens) and checking whether the strength of the associations changes depending on the FSH level. This design allows for a more accurate assessment of where nutrition acts as a real lever for improving reproductive performance, and where it is only a supporting factor against the background of an already pronounced deficiency in spermatogenesis.

Key figures

• With medium and high adherence to the Mediterranean diet, the risk of “low total sperm count” was 69% and 75% lower, respectively (multivariate model).
• As the proportion of calories from UPF increased, the risk of low total sperm count increased: by approximately +249% (medium-low intake) and +349% (medium-high intake).
• UPF categories were formed by quartiles: from Q1 = 0.5-10.8% to Q4 = 42.6-96.6% of calories from UPF. The higher the quartile, the worse the sperm parameters.

How might food work? The authors discuss two themes. The first is the “pluses” of the Mediterranean plate (fish, whole grains, legumes, vegetables, fruits, olive oil): antioxidants and anti-inflammatory nutrients support spermatogenesis and possibly “tune” the hypothalamic-pituitary-gonadal axis. The second is the “minuses” of UPF: calories without nutrients, additives, and excess sugar/trans fats are associated with systemic inflammation and worse reproductive outcomes. The study did indeed find that higher MEDAS was associated with lower FSH and LH, while UPF and hormones did not correlate, but they reliably pulled sperm counts down.

An important detail about the "biological threshold"

• In men with FSH < 8 IU/L (i.e. without obvious signs of primary testicular failure), diet and UPF were particularly clearly “mirrored” in sperm quality.
• When FSH ≥ 8 IU/L, the effect of nutrition was attenuated: the Mediterranean diet was still associated with better progressive motility and normal morphology, but the effect was more modest.
  The conclusion is simple: when testicular tissue is intact, nutrition is a powerful lever; when severe damage occurs, it is only a supportive factor.

What does this mean in practice?

• Put together the “Mediterranean Five” for every day: fish 2-3 times a week, olive oil as the main fat, whole grains, legumes, vegetables/fruits “half a plate”. It’s not just about the heart – it’s better for sperm too.
• Limit UPF: sugary drinks, candy/baked goods, chips/snacks, processed meats, “fast” breakfasts. The lower the proportion of calories from UPF, the higher the chance of seeing a plus in the spermogram.
• Watch your weight and exercise: The model takes into account BMI, but weight and activity remain “background factors” that enhance the effect of the diet. (And yes, quitting smoking is a must.)

How the study was designed

• Design: Cross-sectional observation of 358 men attending a reproductive center.
• Nutrition: MEDAS (14 items) + UPF proportion from NOVA from 24-hour survey.
• Spermogram: WHO-2021; hormones: FSH, LH, TT, SHBG, bio-T, fT.
• Analytics: correlations and multivariate models, where age and BMI were controlled; separately - stratification by the level of FSH 8 IU/L.

Restrictions

• The data are cross-sectional - they show association, not causation. Prospective and interventional studies are needed.
• The 24-hour food survey is subject to error and may distort the actual UPF share.
• This is a single center and men who self-reported testing; generalizability is limited. However, the result is robust in multivariate models.

Why does men's health need all this right now?

Male infertility accounts for half of couples' infertility cases, and there are few modifiable factors. This work adds weight to the recommendations to "eat Mediterranean and cut out UPF": not only for the sake of waist and blood pressure, but also for the sake of sperm quality. Especially if the hormonal background (FSH) still allows "intervention" by lifestyle.

Source: Petre GC et al. Role of Mediterranean Diet and Ultra-Processed Foods on Sperm Parameters: Data from a Cross-Sectional Study. Nutrients. 2025;17(13):2066. https://doi.org/10.3390/nu17132066