I'm proud to post this guest blog from a German nutrition student who interned with me last year. During her time with me she researched and wrote about evening primrose oil and fertility.
By: Andrea Kienle (Student of Bachelor of Science in Nutrition, University of Applied Science Fulda)
A balanced diet should accompany us at every stage of our lives. But there is a time in which we are more aware of the importance of balance: during pregnancy. During this time, many women change their eating habits, give up alcohol and take prenatal supplements folic acid and iron. But what if you plan to get pregnant and want to prepare for a healthy pregnancy? These days, many women move their plan to start a family later – and realize that it is more difficult to get pregnant. If you are in this situation, you probably want to improve everything you can for conception. Many food supplements offer to enhance fertility, but what does the scientific side look like? Do the products keep their promises? One commonly used supplement is Evening Primrose Oil (EPO). This supplement is advertised to increase and enhance the quality of cervical mucus and thereby help the sperm get to the egg.
So, let´s take a closer look at the composition of EPO. The botanical name for EPO is Oenothera biennis L. and the supplement industry uses the seeds. It`s health-promoting effects are attributed to its composition of gamma-linoleic acids and phytosterols (Montserrat-de la Paz et al. 2014). Plant-based gamma-linoleic acids are omega-6 fatty acids with anti-inflammatory properties (Horrobin 1981). Phytosterols may reduce cholesterol. Nevertheless, the evidence doesn´t show that EPO helps improve fertility. So far, there have been no studies that look for improvements in the cervical mucus. You may ask yourself what role does the cervical mucus play for conception? During most of the month, the cervical mucus prevents conception by preventing sperm from reaching the uterus. Right before ovulation it changes consistency to allow the sperm to reach the egg. Thus, the cervical mucus is a practical sign of ovulation, which women use to recognize ovulation (Owen 2013).
Certainly, women have used EPO and gotten pregnant. But, we have no evidence that EPO made this happen any faster than it would have without it. To recommend a supplement, we need randomized controlled trials where the effectiveness of medications is compared to placebo. And of course, we can´t forget that supplement companies aim to make money. The National Health Statistics Reports show that Americans spent 12.8 billion dollars in 2012 for natural product supplements. This market gets bigger and bigger every year in today´s food culture (Nahin et al. 2016), and if a product sounds too good to be true, it probably is.
So, what are the best recommendations for conception?
One study from 2007 speaks about a “fertility diet” which may influence fertility positively in otherwise healthy women. But what does the term “fertility diet” mean (Chavarro et al. 2007)?
One part of this diet is replacing animal sources of protein like red meat, chicken and turkey with vegetable sources of protein. Even one serving of meat per day can increase the risk of developing ovulatory infertility by more than 30 % of women (Chavarro et al. 2008).
Vegetable sources of protein, Source: USDA 2017
Legumes: Tofu (fried) 3oz. (85g) = 16 g
Lentils (cooked) 1 cup (198g) = 18g
Peanuts (unsalted) 1 cup (131g) = 25,5g
Nuts: Cashew (unsalted) 1oz. (28g) = 4g
Almonds (unsalted) 1oz. (28g) = 6g
Walnuts (unsalted) 1oz. (28g) = 7g
Cereals: Whole wheat bread: 1 slice (32g) = 4g
Oats (dry) = 1/3 cup (28g) = 4g
Quinoa (cooked): 1 cup (185g) = 8g
Furthermore, to improve fertility, trans fatty acids such as in some French fries, croissants, and granola bars should be strictly removed from the diet. Simply put, the risk of ovulatory infertility increases with the amount of trans fats in your diet up to over 70 % (Chavarro et al. 2007a). Spice up your salad with cold pressed olive oil or flax seed oil to get lots of healthful fats.
Sources of mono- and polyunsaturated fatty acids
Monounsaturated fatty acids: Olive oil
Polyunsaturated fatty acids: Flax seed oil, walnut oil
Mono- and polyunsaturated fatty acids: Avocado
For fertility, high-fat dairy foods are preferable, as low-fat dairy foods may increase the risk of an ovulatory infertility whereas high-fat dairy products may decrease it (Chavarro et al. 2007b).
What else can you do to improve fertility?
Combine a “fertility-friendly” diet with weight management and regular physical activity to reduce your risk of ovulatory disorder infertility more than 60 % (Chavarro et al. 2007). It’s also important to take a multivitamin supplement with B vitamins, in particularly folic acid 3 to 6 times per week (Chavarro et al. 2008).
My personal recommendation is: instead of spending lots of money for a supplement with cheap promises, invest this money in a private consultation with a Registered Dietitian Nutritionist. Here, you can get a detailed look at your personal needs and receive evidence-based recommendations.
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