You can find a lot of opinions on proteins: some say you need animal proteins, others plant-based proteins are better, others say very little proteins are needed.
I tried to summarize all this information and investigated their effect specifically on fertility.
An extensive study called the Nurses’ study showed that high intake of proteins causes ovulatory infertility. In fact, it is more likely with highest intake of animal proteins. On the other hand, with a diet based on mostly plant-based proteins, there is no ovulatory infertility. It seems that one serving a day of meat/chicken/turkey increases the chances of ovulatory infertility. Fish and eggs make no difference ,whereas beans, peas, peanuts, tofu or soybeans appear to give good protection against ovulatory infertility. Also, the intake of animal proteins instead of carbohydrates can increase the risk of infertility of a 20%.
In summary, we need to eat more plant-based proteins than from animals and our fertility will be protected.
Beyond reproduction, proteins are important for heart health and also for weight loss. We just need to eat the right proteins and the right quantities. In fact, too many proteins can negatively affect our health. Processed meat is the worst and you want to avoid that as much as possible. Colon cancer and premenopausal breast cancer showed to be related to animal protein consumption.
When we eat too many proteins, especially if of animal origin, our kidneys have to work extra to filter out and excrete unused nitrogen, a product of protein digestion.
The recommendation is to choose nuts as a source of healthy proteins: 1 ounce of peanuts, walnuts, almonds or pistachios gives you as much protein as a glass of whole milk. It is true there are more fats in nuts, but since they are unsaturated, they help reduce LDL cholesterol and boost HDL cholesterol. When consumed most days of the week, nuts showed to considerably decrease the risk of heart disease. They are also protective against type 2 diabetes and gallstones.
Beans are another wonderful source of protein. If you are not used to eat beans, I recommend to always soak them at least 12 hours and add seaweed during soaking and cooking to get the gas out.
If you like fish, go for small size to avoid ingesting too many heavy metals. Remember that the bigger the fish the bigger quantity of mercury. All our seas are polluted!!
Salmon is another option since it showed to have low levels of mercury and high levels of omega-3 fatty acids.
Remember not to exaggerate with the quantity of protein per meal. 10% of your total meal is enough.
In general, open up to new options and stick as much as possible to plant-based food. If you are a bit lost and don’t know how to start to introduce new protein sources, just reach out to me and I will be more than happy to give you some tips and recipes.