Why walnuts are a fertility superfood for men
Including some specific foods in your diet may help to boost male fertility. Andrew Cate argues the case for walnuts.
Nuts are high in fibre, low in saturated fats, high in beneficial unsaturated fats and very high in antioxidants.
Walnuts in particular have the highest concentration of polyunsaturated fatty acids and are a great vegetarian source of omega-6 and omega-3 fats.
Walnuts contain significantly higher amounts of polyphenols (a type of antioxidant) compared to an equivalent serving of other types of nuts- including Brazil, pistachio, pecan, peanut, almond, macadamia, cashew and hazelnuts.
Walnuts and fertility
A study published in Biology of Reproduction examined 117 healthy men, half of whom were asked to eat 75 grams of walnuts a day, as well as their usual diet
Semen and blood samples were collected before and after the 12 week intervention. The men who consumed walnuts saw significant improvement in sperm vitality, motility and morphology compared to the men who did not consume walnuts or other tree nuts.
They also found that circulating blood levels of omega-3 and omega-6 fats- were higher in the walnut eaters after the 3 month study.
A handful of walnuts a day
The fertility study mentioned above chose the daily amount of 75 grams of walnuts because previous research has shown this amount can be expected to alter blood fat levels but not trigger weight gain.
A serving of 75 grams of shelled, whole walnuts is approximately one large handful, or 18- 20 nuts.
- At breakfast - Add walnuts to porridge or muesli. They can also be included in smoothies, but leave them in the milk for a few minutes before blending so they soften.
- As a snack - Walnuts are the ideal snack food. Serve on their own, or combine with low fat natural yoghurt and berries.
- At lunch - Try a Waldorf salad (walnuts, apple, lemon juice, a little light mayonnaise, celery and lettuce) with steamed chicken or fish.
- For dinner - Use walnuts instead of pine nuts in a pesto, and serve over salmon with baked sweet potato and Asian greens.
- Smart storage - Shelled walnuts are available in large packs, which are best kept in the refrigerator for nutritional quality and maximum shelf life.
References available on request