There are many substances that people use regularly as part of their lifestyle. Some are legal, some are illegal, depending on where you live. I’m going to be addressing common substances from the standpoint of optimal fertility, based on the mind-body health perspective that I’m applying throughout this program. I’m not addressing here the legal, political, social, or any other ramifications of any of these substances. 

I see lots of discussions on forums about whether it’s ok to drink coffee or alcohol while TTC. How much is too much? Will it affect your fertility? I’m going to delve in a bit to research studies and what they can tell us. I will also extrapolate from these studies to discuss what this means in the context of our egg nurturing program.

If you’re in a hurry and just want the my short list of recommendations in this arena, then scroll to the bottom and read the last section, “My personal recommendations.” If you want to take a journey into the research and learn about how I view data and draw my conclusion, then settle in and we’ll take this little trip together.

About my perspectives

Before diving into the research, I’d like to share a bit about my personal experiences and potential biases. People often want to know details of my story to find out what exactly I did that might have allowed me to have successful fertility so late in the game. I encourage everyone to realize that we are all unique and what I did won’t be what works necessarily works for someone else. However, I also am happy to share these details so that you understand where I’m coming from. 

When I was engaged in my own egg nurturing program, I did not take in any caffeine. I rarely drank alcohol (maybe half a drink once in a blue moon). I have never smoked. I didn’t use any drugs. This isn’t because I was trying so hard to be “perfect”. It was what I saw as part of a generally healthy lifestyle that was agreeable to me. I’ve never liked the taste of coffee, and I avoid caffeine so that I can be fully aware of my needs for sleep. I had my fun drinking alcohol back in the day, but without any raging parties in my life, I really had no inclination to drink. In general, I still avoid alcohol because I feel it brings me down physically. So in this sense, my lifestyle was already quite “clean” and I really didn’t have to give anything up to achieve this state. 

Based on my own experiences, I feel quite strongly that one can have a full, rich, satisfying life without any of these substances. I’m not morally opposed to other people using substances. However, I think there are many health benefits to clean living, and I believe that one can come to feel very satisfied without their morning coffee and their evening glasses of wine. The things people are gaining from these substances can be achieved in other ways that are healthier in the long run. 

So as you read what I’ve written, you might sense a bias that I don’t think any of these substances are important to have in your life. Let me be completely honest. Yes, this is my bias. I think you can be super happy and fulfilled without any of these things. I think that in general you will be healthier without them. 

I don’t however believe YOU MUST give up all these things for the sake of your fertility. I don’t know what the maximum amount is that you can have without affecting your fertility. We will be exploring what the research tells us, but as always, not everything has been thoroughly tested so there’s room for interpretation. And then, like everything in this program, it’s going to be your choice to decide what’s right for you. 

I will share with you what I’m seeing in the current research. And I will share how I interpret this in the context of our egg nurturing program. With this knowledge, I hope that you will feel empowered to make the best choices for yourself, based on your unique makeup.

For me it was a no brainer to avoid these elements. There was no downside because I really wasn’t attached to any of them. For some people, for a variety of reasons, there is stronger attachment and removing these substances can also have some negative impact. I want you think about these issues in terms of your whole system of mind-body wellness. If you decide that it best serves you to make changes, consider what will be the most effective way to do this with the goal of optimizing your overall health and wellbeing.

My approach to the research

I want to share a bit about how I'm approaching research on these topics. As I’m looking at research about the impact of various substances on health and fertility, I’m looking for relatively recent studies. I prefer to read the original study rather than an article referencing the study. I’m looking for research published in journals that aren’t obviously biased. (Not, for example, “Journal of the coffee lovers of America” or “Journal of all things natural and holistic”). I like it when I can find a meta-analysis, because it’s looking systematically at many studies on a topic. I’m looking for any evidence that suggests this substance could be a problem for health and fertility. Because I'm assuming that most women in this program want to play it relatively safe and err in the direction of optimizing fertility, once I see enough credible evidence that there is significant reason to be concerned about this substance, I draw my conclusion and move on. 

I’m not trying to become an expert in all the research available, understanding all the mechanisms by which something might impact fertility. So my survey of the literature is not meant to be comprehensive and my explanation won’t be extremely detailed in terms of the scientific mechanisms. If I had a research team at my disposal, I would love to delve into all that detail. To be expedient, I’m limiting myself to just addressing what I feel is most important for our purposes.  

Caffeine

Every time I poke around into the research on coffee and caffeine, I discover a mixture of conclusions. Caffeine constricts blood flow, it improves blood flow. It reduces heart disease, it raises blood pressure. On and on. It can be quite confusing.

My guess is that one of the causes of confusion is that coffee probably has some elements that are healthful (like antioxidants) and others that are more harmful (like caffeine). There may be other complex issues related to the way coffee is prepared. 

A very recent study conducted in Brazil found evidence that people who drank more than three cups of coffee per day had less risk of clogged arteries. Here’s a layman’s version of the article and here's the original article.

It’s not hard to google search and find small individual studies that point to some sign that coffee has health benefits. One study of 27 people showed improved blood flow immediately following coffee consumption: General article, Original study.

However, a treatment center that specializes in vein issues claims that excess caffeine is harmful to veins and blood circulation: website page.

And here is an interesting study looking at how caffeine affects blood flow to the brain. This study found on average a 27% decrease in blood flow to the brain for people who drank coffee, when comparing their brain scans after abstaining from caffeine to their brain scans after having their usual amount of caffeine. The numbers were similar for those classified as low users (<200 mg/day; average 45mg/day), moderate (200-600mg/day; average 405 mg/day) or high users (>600mg/day; average 950 mg/day). You can see the differences in the MRI brain scans below. The top row shows brain scans after abstaining and the bottom row shows brain scans after having the usual amount of caffeine. Green, yellow and red indicate higher levels of blood flow, whereas blues and purples indicate lower levels of blood flow.

This is a helpful video showing how caffeine interferes with our ability to perceive how much sleep we need. At 0:56 you’ll see a brain scan after 4 cups of coffee showing signs of decrease in blood flow to the brain. 

This article walks through a handful of health concerns related to caffeine, including the process of caffeine activating the fight-or-flight (sympathetic) response of the nervous system.

If you really want to geek out and dive into the science of how caffeine affects blood flow, this is a very extensive and thoughtful article about caffeine and vascular function. The main points I draw from this article are: It’s complicated, and more research is needed to tease apart whether caffeine is actually helpful or harmful to vascular functioning. 

The study that got my attention the most was this fairly recent meta-analysis of the effects of caffeine on fertility outcomes. (They looked across over 300 research articles, reducing the number down to 47 studies after eliminating those that didn’t meet criteria for inclusion.)  They found no relationship between caffeine and how long it took to get pregnant, chances of getting pregnant, or success with medical fertility interventions. However, there was a statistically significant increase in miscarriage rates with caffeine use. They identified three groups based on caffeine usage: no caffeine use, 100mg/day, 300 mg/day, 600 mg day. Miscarriage rates were  slightly increased for 100mg/day (8%), more for 300mg/day (37%), and at 600mg/day the risk was more than double that of those who had no caffeine. 

So for those who are drinking one 8oz cup of coffee a day (approx. 100 mg), that 8% increase in miscarriage risk may or may not seem high to you. What is significant to me though is that there is something going on with caffeine that appears to be impacting miscarriage rates, even at lower amounts of caffeine intake. Perhaps something about caffeine is impact mitochondria and hence egg quality? The research is just not far along enough to tell us what the mechanism might be. 

Acknowledging that there are many conflicting findings about caffeine’s impact on health, here are the things that appear fairly certain that raise concern:

• Caffeine consumption reduces blood flow to the brain, even among those averaging the equivalent of one cup of coffee per day.
• Caffeine activates the sympathetic nervous system (fight-or-flight response), while I believe most people generally need to bring more activation to the parasymptathetic system, to allow them to rest and restore. 
• Caffeine intake appears to increase risk of miscarriage, even at dosages as low as 100mg/day (approximately two 8-oz cups of coffee).
• Caffeine blocks natural ability to detect the need for sleep.

For me, these are enough reasons to conclude that it’s reasonable to avoid caffeine while TTC. If removing caffeine causes significant distress, then that should be factored in as well. In general, I would encourage women who are TTC to prioritize cutting back and eventually eliminating caffeine if they want to optimize their health for fertility. Most fertility authorities I come across, however, suggest that 1-2 cups of coffee a day should be okay. So consider the data, your priorities, and your unique needs to determine what seems suitable for your egg nurturing program.

Caffeine levels

An average 8 oz cup of coffee has 95 mg of caffeine. Here’s a chart that shows caffeine levels of various caffeinated beverages. Note that a Starbucks coffee can have as much as 475 mg of caffeine. 

Marijuana

Interestingly, I seldom see anyone asking on forums if it’s okay to use marijuana while TTC, or how much is ok. However, my guess is that marijuana use in general is common enough that marijuana use while TTC might be more common than people are likely to admit. One can imagine that legal issues deter people from asking these questions publicly too. 

A fertility center in Tucson offers a number of compelling reasons to avoid marijuana use while TTC and while pregnant.

https://www.ivftucson.com/marijuana-affect-fertility/

A San Diego fertility center claims, “Smoking marijuana, even infrequently, can dramatically affect sperm and egg quality, which can have a dramatic impact on fertility.”

Here are a few more links exploring fertility and marijuana…  

• https://www.livefertile.com/blog/marijuana-your-fertility
• https://www.verywellmind.com/can-marijuana-cause-infertility-22305
• https://modernfertility.com/blog/cannabis/

What concerns me most in reading through these accounts is that it appears that marijuana might impact hormone balance (lowering LH and FSH) in a way that delays or suppresses ovulation. It appears these effects may apply even with occasional use. That is enough argument for me to conclude that marijuana is best left out of any program for optimal fertility. 

Aside from cases where people are using marijuana for pain management and other medical uses, it’s my impression that most people who use marijuana beyond the teens and early adulthood are using it to treat anxiety. I’ve also observed that when people learn better ways of coping with anxiety, their need for marijuana decreases. 

I’m reminded of a therapy client I worked with many years ago. She was a college student who was very engaged in the therapy process, eager to learn ways to better decrease her anxiety. After several months of weekly sessions, she came in one day and announced that she wanted to share about something that had changed in her that was really significant to her….”I quit smoking pot.”  I must have held my jaw up to keep it from falling on the ground, because this was the first I had heard that she was using any drugs at all. Apparently she had been smoking daily, several times a day, to cope with anxiety throughout the months we’d been working together. Once she started learning better ways of taking care of her emotions, she discovered she no longer need marijuana and gradually tapered off over a period of weeks. She was so proud of herself and didn’t miss the habit at all.

If you’re using marijuana (in any form), I encourage looking at what purpose it is serving for you and looking for ways to meet these needs that don’t have potential negative effects on your fertility.  

Alcohol

In this 2017 review of literature on the impact of alcohol on reproductive health, there are references to several interesting studies. I delved into each of the studies referenced there that seemed relevant for our purposes and am elaborating on them here.

This study of 221 couples undergoing Assisted Reproductive Technology, compared outcomes for women who drank more than others (“one more drink per day”). Those who drank more retrieved fewer eggs, had lower pregnancy rates and had higher miscarriage rates. (I actually couldn't access the full study, and the way the summary was written up was a little confusing to me, so I'm just sharing the general results here.)

A large study published in 2011 followed 2,545 couples undergoing 4,729 cycles of IVF. This study looked at the relationship between alcohol consumption and various outcomes of IVF.  

There was a trend toward greater miscarriage rates (16% more) among those who drank 4 or more drinks per week compared to those who drank less than 4 drinks per week. However this trend was not statistically significant.

When looking at fertilization rates, those who drank four or more drinks per week were 48% more likely to have failed fertilization compared with those who drank less. The study also looked at results broken down by type of drink. In the case of red wine, those who drank 1-7 drinks per week were 51% more likely to have failed fertilization, compared with those who drank less than one drink per week. 

Among those who had eggs that successfully fertilized, there was an 18% greater likelihood of implantation failure for those who drank one to seven drinks per week compared to those who drank less than one drink per week.

What stands out to me about these results is that it appears that having just one to seven drinks per week might impact chances of fertilization and implantation.  

As small study conducted in Poland examined quality of embryos during IVF for 54 women. Those who reported drinking less alcohol were more likely to have higher quality embryos than those who drank more. Embryo quality was rated as Class A, B, C, or D, with Class A being the highest quality.  

Here is a table showing the results:

You can see the trend toward higher quality embryos for those who drank less alcohol. 

Contrasting these studies that show alcohol having a negative impact on fertility, there was a recent Danish study (2016) that concluded that moderate drinking has no effect on fertility. This study analyzed data from 6120 women collected over nine years. These were women who were trying to conceive but not receiving fertility treatment. They followed each the women for up to one year to see if they got pregnant during that year. They did not assess whether the pregnancy was successful of not (which to me is a major oversight for our purposes); they only recorded whether pregnancy was achieved. 69% of the women achieved pregnancy.

The graph below shows the likelihood of getting pregnant at various levels of alcohol consumption as compared to the likelihood of getting pregnant for those who drank no alcohol. So you’ll see at 0 drinks per week, the “fecundability ratio” is 1.0, meaning the rate of pregnancy is the same (because it’s the same group being compared to itself). As you move along toward the right, you see the bold blue line wavering then dropping steadily downward after about 8 drinks per week, indicating that the likelihood of getting pregnant drops with an increase in alcohol consumption. (The dotted lines above and below represent the “confidence interval”, showing that there’s a 95% chance of the outcome falling into this range; the solid line is the average result.) This gradual drop in pregnancy rates was not large enough to be “statistically significant” until alcohol consumption was at a rate of 14 drinks per week or more. The study then reported this conclusion: “In summary, our study showed that consumption of 14 or more servings of alcohol a week was slightly associated with reduced fecundability, but consumption of lower amounts seemed to have no discernible effect on fertility.”

I’ve come across many articles referencing this article that are sharing this research as evidence that there are no fertility risks from “moderate drinking” (less than 14 drinks per week). I invite you to draw your own conclusions. 

The way I see this research, it is evident that alcohol decreases likelihood of getting pregnant the more one drinks. This applies to women who have no known fertility issues. There is no information about the impact on miscarriage rates. We only know how many women got pregnant, nothing about the health of their pregnancies. We also don’t know anything about how this would look if we were looking at data only for women over age 40. The age range in this study was 18-40, with an average age of 28. 

So personally, the way I would look at this study is quite different from how the media interpreted it. The common interpretation was, “Alcohol consumption has no impact on your fertility if you’re drinking less than 14 drinks per week.” My interpretation is, “Alcohol has some negative impact on the ability of younger women to get pregnant.” I extrapolate from that to conclude that alcohol has some kind of negative impact on fertility. We don’t know exactly what the mechanisms is or how much it takes to impact the fertility of women over 40. 

So even though a study like this might be seen by others as evidence that light to moderate drinking is fine for fertility, I am actually inclined to see it as evidence that someone who wants to be extra cautious and do everything possible to optimize fertility might be better served by avoiding alcohol.

I’m breaking down the details of the research and my thought process so that you can see an example of how it can be worthwhile to read the research yourself and come to your own conclusions. And when you hear other people making recommendations (even your doctors), you can ask them what specific research they have read, and how they are coming to their conclusions. 

After looking at the research that I’ve shared with you here, my conclusion is that those who want to optimize their fertility are going to be better off avoiding alcohol while TTC. I’m guessing that an occasional drink on special occasions isn’t likely to have a significant impact.  

Nicotine

There is extensive research that cigarette smoking is harmful to fertility, so I’m not going to take the time to pull up that research. Vaping is a form of smoking that is considered less harmful than smoking cigarettes. This article by a reproductive endocrinologist states that there isn’t enough research to tell us about the effects of vaping on fertility, but that’s it’s still better to avoid it to be on the safe side as it introduces nicotine and other toxins into the body.

Closing thoughts

There are so many ways that substances interfere with the body’s natural balance. 

Substances throw off your body’s ability to regulate itself naturally. They mask other needs that are calling for attention. They can ultimately impact things like hormone regulation and cell oxygenation which are so important for optimal fertility and egg quality.

If your goal is to optimize natural fertility, I have a hard time seeing a strong rationale for using any substance with regularity. I’m sure there are exceptions though and that will be up to you to evaluate for yourself. 

I’d like to suggest a shift in mindset from what I commonly see regarding use of various substances. 

Rather than asking…

• “Will this harm my fertility or my egg quality?”  
• How much can I have without causing too much damage?  

…I encourage you to ask, 

• What is my attraction to this substance? What is it doing for me?
• Is there something out of balance in my system that leads me to reach for this substance to help me feel better?
• What could I do naturally to help address this need?
• If I had all my basic needs fulfilled, would I still feel strongly about having this substance?
• Is it worth the tradeoffs of risks to my fertility and egg quality to continue including this substance in my lifestyle?
• Is this something I would be willing to give up for the next 3-6 months?

Here are some of the needs/desires that the various substances might be addressing for people, and you can see if any of these apply to you. 

Caffeine

• lack of sleep
• Physiological dependence
• Psychological attachment to rituals
• Sensory pleasures (flavor, sensation)

Alcohol

• Relaxation, avoidance of stress
• Social
• Taste, sensation

Smoking

• Stress management
• Physiological dependence
• Psychological attachment to rituals
• Sensory pleasures

Marijuana

• Anxiety/stress
• Social

I believe that you can explore other ways to meet these needs and discover an even more fulfilling balance to your health, happiness, and overall wellbeing.

My personal recommendations

I’ll summarize my general recommendations from this section:  

• Nicotine – No. Avoid second hand smoke as well.
• Caffeine – Avoid daily caffeine habits. One to two cups per day might be okay, but I really don’t know for sure. 
• Alcohol – Avoid regular use of alcohol. The occasional glass of wine with a meal or during a social activity is probably not going to be a deal breaker. 
• Marijuana – I’m pretty sure this is not a good idea. Explore underlying anxiety issues if you feel a strong attachment to marijuana. 
• Other substances not addressed here – Use the tools I’m using (google search!) and follow a similar line of reasoning when reading sources. I hope I’m sharing enough of my thought process that you can learn how to do the research too.

If it makes you really miserable to quit any of these completely, then perhaps moderation is the better option to avoid the stress of abstinence. However, I would be curious as to why abstinence is so painful and I would be inclined to pursue that inquiry further.  

Allow this process to be about self-discovery rather than white-knuckle discipline and restriction. Revisit module 8 on behavior change and motivation if you want to make changes that might be challenging for you. Let TTC be your motivation to help you find a joyful path toward optimal health and self-care.