Many fertility professionals suggest a Mediterranean diet [MD] to optimize fertility. And while this is often an improvement over a standard American/Australian diet [SAD], as with any ‘diet’ this may not always the best approach. Let me explain.
We first have to acknowledge that the typical American definition of a Mediterranean diet used by researchers is not at all an accurate reflection of what is traditionally consumed throughout that region. I’ve detailed these issues in a previous blog. Some modern interpretations of the MD is exceedingly low in animal protein, animal fat, and often pushes an unnecessarily high intake of grain-based carbohydrates. Therefore, it must be noted that the Mediterranean region incorporates a great variety of countries, cultures, landscapes (dry, mountainous) and coastal all having their own unique blend of local foods. This leads to interpretations of such a diet being not regionally or historically accurate.
The benefits of the MD are that regardless of region, it prioritizes whole foods over processed foods. This is a very positive shift for most Americans/Australians, who are (on average) getting 58% of their calories from ultra-processed foods. This is a major reason why research studies find improvements in fertility (such as with PCOS and IVF success rates) when switching participants from a SAD to a Mediterranean diet.
Women who follow a low-fat version of the MD — one that’s low in meat but high in grains, legumes, vegetables, fish, and fruit — have a significantly higher incidence of having a short luteal phase (less than 10 days). This observation held true for these women despite similar energy intake, age, and body fat percentage of women with normal cycles.
Why would a short luteal phase matter to fertility? The luteal phase is the time between ovulation and the start of the next menstrual period. In women who are trying to conceive, the luteal phase is the time in which implantation takes place. If the luteal phase is too short — an indication of low progesterone — implantation often cannot occur. This means a short luteal phase can impact your ability to become pregnant or sustain a pregnancy.
As with most diets but especially if you are trying to conceive and maintain a healthy pregnancy, it less about what is included but rater more about what is missing.
Therefore it is essential to ensure you are consuming sufficient protein while increasing your regular intake of fresh fruits and vegetables, while reducing intake of processed foods. You’ll find more on protein required and how much is provided by certain foods in my book.
