When it comes to fertility, we talk a lot about antioxidants and how important they are. Even beyond the fertility conversation, terms like “superfood,” “antioxidant-rich,” and “oxidative stress” have become part of our understanding of health and wellness. But what exactly is an antioxidant? And how do antioxidants benefit fertility, pregnancy and overall health?
What are antioxidants?
In its most basic definition, an antioxidant is a compound that inhibits the production of free radicals and oxidation. Antioxidants can be vitamins (like Vitamins C and E), nutrients (like L-Carnitine and Zinc) and even hormones (like Melatonin). They act like bodyguards, protecting your cells, including DNA and mitochondria (the energy-makers inside your cells). We have systems in place all over the body stationing antioxidants to protect the body’s tissues from the damage of oxidative stress. Some antioxidants can be made by the body, while others come from your diet. However, when the body uses them up too quickly or doesn't have enough to handle the load of reactive oxygen species (ROS—molecules the body produces naturally, but which also enter the body through air pollution, food and drink and infection) in your body, the result is oxidative stress.
What is oxidative stress?
Your body produces ROS as a natural part of your biology and metabolism, but they also enter the body in the air we breathe (from air pollution or smoking), from our food and drink choices (alcohol and fried foods) and from infections. Obesity and chronic stress are also associated with increased ROS in the body. ROS molecules (which include hydrogen peroxide, superoxide and hydroxyl free radicals) are highly reactive and in high amounts cause oxidative stress leading to significant cellular damage. Conversely, in very small amounts, ROS can play a special role in cell signalling. To keep ROS levels in check, the body uses antioxidants; molecules that can transform or neutralize ROS.
Oxidative stress contributes to aging, chronic disease and infertility or subfertility. You need to have proper cell division and DNA replication to make good quality sperm and eggs and to make a healthy embryo. Oxidative stress can damage cell membranes, DNA and mitochondria, leading to cellular dysfunction and accelerated cell death. Bottom line? Oxidative damage can affect the function and health of your reproductive organs and cells.
How can antioxidants improve fertility?
Antioxidants have been shown to improve egg and sperm quality by protecting cells, mitochondria and DNA from oxidative stress. As we age, we naturally have more oxidative stress and less cellular energy production. This is what can tank egg and sperm quality as we approach the age of 40.
How do antioxidants impact fertility for males and people with sperm?
Even though sperm doesn’t contribute many of its own mitochondria to the embryo (compared to the egg), ROS and oxidative damage still affects sperm quality, including its structure and motility. Oxidative stress can also cause breaks and mutations in DNA, resulting in increased sperm DNA fragmentation. This could lead to issues in fertilization and also impact the viability of any resulting embryo. Antioxidants such as Vitamin E, NAC and L-Carnitine are commonly used to improve sperm quality and decrease DNA fragmentation.
How do antioxidants impact fertility for females and people with eggs?
Aging, and the resulting oxidative damage, leads to more abnormalities in DNA, and having damaged mitochondria leads to lower energy production in the ovaries. By decreasing our load of ROS and improving antioxidant support, it's possible to slow cellular aging. Certain hormonal disorders are also associated with increased oxidative stress and subfertility, like polycystic ovary syndrome (PCOS), endometriosis and low ovarian reserve. Antioxidants can help improve egg quality, especially as we age and in conditions associated with increased oxidative stress ( endometriosis, type 2 diabetes and obesity), leading to better embryo quality.
How can you get more antioxidants?
From your diet
There are many different foods and beverages that are high in antioxidants, but that doesn’t mean that all of them are great for your fertility. Espresso and red wine are both sources of antioxidants but their caffeine and alcohol content, respectively, are not especially fertility friendly.
The best dietary sources of antioxidants:
- Whole fruits (not juiced or jammed) including blueberries, strawberries, black currants, goji berries, cranberries and olives.
- Vegetables like purple cauliflower, broccoli, kale, artichokes, red beets and red cabbage.
- Nuts and seeds like chestnuts, walnuts, pecans and sunflower seeds.
- Dried herbs and spices like dill, peppermint, oregano, thyme, sage, rosemary, allspice, cinnamon, clove and ginger.
From your prenatal supplement
The main purpose of a prenatal is to provide the minimum amount of nutrients necessary for your body’s functioning and for the development of an embryo and fetus. This includes critical Folic Acid that ensures the proper development of your baby’s spinal cord and brain. A good-quality prenatal can contain much more though, and if you’re experiencing infertility, subfertility or if you’re in your mid-thirties and beyond, you would likely benefit from a prenatal that includes key antioxidants.
Many vitamins and minerals in a prenatal have antioxidant properties, including Vitamin C which also assists in making carnitine (another antioxidant that also helps in cell energy production), and is a co-factor for immune responses. Vitamin E is an antioxidant that prevents your lipids and cholesterol from being oxidized, protecting your blood vessels from damage and preventing the buildup of plaques.
Antioxidant ingredients to look for in a prenatal:
Coenzyme Q10 (CoQ10): CoQ10 is an antioxidant most famous for its role in producing cell energy. Studies have shown that CoQ10 can improve egg and embryo quality, restoring mitochondrial function and reducing DNA abnormalities in women over the age of 38.
L-Carnitine: Carnitine is a nutrient that works with CoQ10 to deliver fatty acids (fuel) into mitochondria to be made into cellular ATP energy. Supplementing with carnitine can improve the growth and maturation of ovarian follicles and in those with PCOS, it’s been shown to improve ovulation pregnancy rates.
N-acetyl cysteine (NAC): NAC is an antioxidant itself, but it also increases the levels of other antioxidants in the body. In women with PCOS (where there’s often issues with slow to no follicle growth), NAC supplementation has been shown to improve insulin sensitivity, and improve IVF outcomes, increasing the likelihood of ovulation by three to nine times.
Resveratrol: Studies have found that supplementing with resveratrol, can help slow ovarian aging by activating a protein called sirtuin 1 (SIRT1) which protects your mitochondria, regulates cell division and improves DNA repair.
Can you get too many antioxidants?
ROS are required by the body in small amounts, and reproductively we need them for proper egg maturation and ovulation, as well as for the interaction between the sperm and egg to occur. That doesn’t mean we should completely avoid all antioxidants. There are many benefits to taking antioxidants, but they shouldn’t be over-consumed either.
That said, the role of antioxidant supplementation in fertility is an important consideration that could drastically change the outcome when trying to conceive, especially as we age. There is an important balance between ROS and the antioxidants that control them, but over the age of about 35 we accumulate greater amounts of ROS, which in turn affects egg quality. If you’re trying to conceive in your thirties, forties and beyond, including antioxidants in your diet or your prenatal may help preserve the function of the ovaries and egg quality.