Diet and fertility: what the science establishes

There is no miracle food

No food, supplement or “superfood” has been shown to restore fertility. Studies look at overall dietary patterns, over long periods, and show statistical associations — not guaranteed individual effects.

Scepticism is a useful reflex here: the more spectacular a claim, the thinner the evidence behind it.

The best documented associations

Two findings come up repeatedly in the literature:

• high intake of trans fatty acids is associated with lower fertility, in women as well as men,
• a Mediterranean-style diet — vegetables, legumes, fish, olive oil, little processed meat — is associated with better assisted reproduction outcomes in several studies,
• a diet very high in ultra-processed products and added sugars is associated with metabolic disturbances unfavourable to ovulation.

Where diet meets exposures

Diet does not act only through nutrients: it is also a route of exposure to substances studied for their effects on reproduction. Rather than repeating the detail of each one here, the factor pages below document them with their level of evidence.

A reasonable take-away

Cutting back on ultra-processed products, limiting added sugars and diversifying vegetables and good-quality fats are risk-free adjustments, beneficial for general health and consistent with the available fertility data. They are neither a treatment nor a guarantee.