Up to 80 percent of male infertility cases are related to oxidative stress. All those little daily assaults on the cells—both from normal wear and tear and toxins (tobacco, trauma, weight gain, etc.)—take their toll on the reproductive system along with the rest of the body. Antioxidants help prevent and repair this microdamage, like tiny garbage trucks picking up all the cellular trash. Based on this and the fact that supplements have improved fertility in clinical studies, I believe most male fertility experts should (and do) recommend supplements.
The largest research review ever completed on dietary supplements for male infertility involved men/couples undergoing ART. The researchers looked at pregnancy rates and live births and concluded that oral antioxidant supplements could improve the chances of conception during fertility treatment. They didn’t recommend specific supplements, though. Why not? So many different supplements help reduce oxidative stress and improve fertility that they weren’t able to single out any specific ones. I would argue, however, that if you look at benefit versus risk, there are some standouts (and some I would avoid).
WHAT WORKS
Note: You should take these supplements for 3 to 6 months before deciding if they’re working. It takes that long to make an impact.
1. Multinutrient fertility supplement one or two pills a day, or simply one or two multivitamins per day
This is one of the only conditions in the book where taking two multivitamins or multinutrient fertility supplements a day makes some sense. You want to be replete with nutrients to help the fertility process. And since you’re generally only taking these for a short time—not years and years—the benefit outweighs the risk.
ProXeed (manufactured by Sigma-Tau) is popular with physicians because there’s some preliminary research showing men who take it have increased pregnancy rates with their partners. It contains several nutritional compounds that have also been shown to be beneficial for fertility (most are discussed in this section). It’s a little pricier to buy this versus just buying the individual ingredients, but there is good quality control and research supporting it.
2. (tie) CoQ10 200 to 300 milligrams aday
This fat-soluble antioxidant improves energy production and reduces oxidative stress, and since the male reproductive tract is susceptible to oxidative stress, it makes sense that it could be beneficial. In addition, levels of CoQ10 in the seminal fluid correlate with sperm count and motility. In one study, men with idiopathic (no known reason) reduced sperm motility who took 200 milligrams of CoQ10 per day for 6 months saw increased motility. Another study of 212 infertile men taking 300 milligrams over 26 weeks found significant improvements in multiple parameters, including sperm density, motility, and acrosome reaction (the ability of sperm to meet the egg).
2. (tie) Vitamin C (ascorbic acid) 500 to 1,000 milligrams a day
Seminal fluid is high in vitamin C, and there is a relationship between higher vitamin C levels in the fluid and a lower risk of male infertility and improved male sperm quality. In addition, smoking and environmental toxins can dramatically lower vitamin C levels and damage sperm cells. Smokers, ex-smokers, and people exposed to toxins (such as lead) seem to respond well to vitamin C in terms of improving their overall antioxidant status, especially vitamin C levels. Studies have shown that consuming 500 to 1,000 milligrams daily of vitamin C in combination with other common antioxidants improves fertility in men. It is unknown if taking vitamin C by itself is as beneficial as taking the combination supplements (see #1), but the upside outweighs the downside.
Taking more than 1,000 milligrams of C per day decreases absorption, increases side effects, and may be detrimental to fertility, so don’t overdo it. In fact, it could be argued that 500 milligrams per day improves fertility almost as well as 1,000 milligrams per day. A study by this super-smart guy named Moyad showed people at risk of kidney stones should choose buffered vitamin C or calcium ascorbate.
3. (tie) NAC (N-acetylcysteine) 600 milligrams a day
The liver produces a compound called glutathione, an antioxidant that’s found in very high concentrations in the body. Taking too much acetaminophen greatly reduces stores of glutathione, which leads to the formation of high concentrations of free radicals in liver cells, oxidative stress, liver injury, and in some cases failure (especially in combination with alcohol). In the emergency room, doctors will give you NAC for an overdose of acetaminophen; it increases the production of glutathione to protect the liver from going into failure. Since glutathione is the primary anti-oxidant in the body, increasing levels of it protects against oxidative stress—and remember, up to 80 percent of male infertility cases are related to oxidative stress. You could just take glutathione supplements— and many people do—but they are poorly absorbed in the gastrointestinal tract. Instead, you’re better off taking NAC. One study showed taking 600 milligrams of NAC daily improved semen measurements, but more research is needed, especially for pregnancy and live birth rates. (NAC in combination with whey protein can boost glutathione levels as well.)
3. (tie) L-carnitine 2,000 to 3,000 milligrams a day
In every cell of your body, L-carnitine transports fatty acids from one area of the cell (cytosol) to another (mitochondria) as part of the energy production process. Multiple clinical trials have demonstrated the ability of L-carnitine (or other forms of carnitine) to improve sperm characteristics and, potentially, pregnancy rates. Several randomized trials have found that L-carnitine improves sperm count, motility, and normal shape of sperm better than a placebo in men with idiopathic (no known cause) infertility.
Most trials have used an average of 2,000 to 3,000 milligrams per day (with or without food) or in the form of acetyl-L-carnitine without significant side effects. This is already a large dose and going beyond it can cause gastrointestinal problems, abnormal body odor, and neurologic concerns (such as peripheral neuropathy or nerve damage). The reason I ranked it number three instead of at the top is that these dosages just aren’t practical for daily use. Plus, a few independent US studies from researchers I know and admire did not show the same dramatic results the previous studies did. There are several minimally different forms of L-carnitine, so take whichever you like (price does not connote effectiveness). There haven’t been enough studies yet to really identify adverse events or serious drug interactions with L-carnitine, so talk with your doctor.
LIFESTYLE CHANGES
Heart healthy = sperm healthy. Most heart-unhealthy behaviors negatively impact almost all areas of male health, including fertility, therefore heart health is tantamount to male fertility.
Lose weight. Besides being heart unhealthy, obesity in men can increase estrogen levels, lower testosterone levels, and negatively impact fertility hormones. It can also reduce levels of a crucial compound involved in sperm support and production (inhibin B) and can increase testicular temperature, which can result in reduced sperm counts and motility and altered sperm shape.
Kick the habit. Smoking and tobacco use in general dramatically lowers sperm and seminal fluid nutrient levels and reduces the testicular production of sperm. Oh, and smoking can kill you in many other ways and cause chronic obstructive pulmonary disease, which dramatically reduces your ability to breathe.
Limit alcohol. In excess (more than a drink or two a day), alcohol can increase the risk of sperm damage in some people and alter hormone levels that may make it more difficult to get your partner pregnant.
Boost your omega-3 intake. While the research is still out on supplement sources of omega-3 fatty acids, dietary sources may improve fertility. Salmon, tuna, sardines, and whitefish are a few marine sources; plant sources include flax-seed, chia seeds, plant oils (like canola), and walnuts.
Mind your Fs and Vs. Fruit and vegetables (even a few servings a day) can raise antioxidant and nutrient levels in the blood and sperm by a large amount.
Cool your package. A lower scrotal temperature may be associated with an increase in sperm quantity and quality, so you might want to switch to boxers from briefs, avoid spending too much time in hot tubs or saunas, and keep your laptop on your desk instead of in your lap. I think the impact is minimal, but it may provide a small advantage.
