Does Smoking Really Protect Against Parkinson’s Disease?

The Centers for Disease Control and Prevention recently celebrated the 50-year anniversary of the landmark 1964 Surgeon General’s report on smoking, considered one of the great public health achievements of our time and the first of 30 other such reports from the Surgeon General on smoking. Internal tobacco industry memos, which you can see in my Is Something in Tobacco Protective Against Parkinson’s Disease? video, document their response. Major criticisms of the report include a “[c]avalier treatment of costs of smoking”: The Surgeon General argued that smoking costs the United States billions, but the tobacco industry noted that “smoking saves the country money by increasing the number of people dying soon after retirement,” so we don’t have to pay for Social Security, Medicare, and the like. In fact, the industry argued, if we were truly patriotic, maybe we should encourage smoking to help balance the budget!

The tobacco industry also criticized the Surgeon General for a “[l]ack of balance regarding benefits of smoking,” asserting that “[o]ne has to search pretty hard to find any concession anywhere in the Report that smoking is not all bad.” This is something the tobacco industry liked to bring up when testifying before Congress, saying that health benefits include “the feeling of well-being, satisfaction, and happiness and everything else.” But beyond just all the happiness the Surgeon General was trying to extinguish, he failed to even mention that smokers appear protected against Parkinson’s disease.

“Quite unexpectedly…[m]ore than 50 studies over the last half century consistently demonstrated reduced prevalence of Parkinson’s disease among smokers compared with never-smokers.” Now there are more than five dozen studies.

But smokers are probably dying before they even have a chance to get Parkinson’s, so is that the explanation? No, that didn’t seem to be it. Researchers found a protective effect at all ages. Maybe it’s because smokers tend to be coffee drinkers, and we know coffee consumption alone appears protective. But, no. The protective effect of smoking remained even after carefully controlling for coffee intake. Well, maybe we inherit some propensity to not smoke and to get Parkinson’s. If only we could clone someone to have the same DNA. We can! They’re called identical twins. And still, the relationship remained, suggesting “a true biologic protective effect of cigarette smoking.”

Not so fast. Maybe finding unusually low rates of Parkinson’s among smokers is an example of reverse causation. That is, maybe smoking doesn’t protect against Parkinson’s—maybe Parkinson’s protects against smoking. Could there be something about a Parkinson’s brain that makes it easier to quit? Or perhaps failure to develop a smoking habit in the first place is an early manifestation of the disease.

To put that to the test, researchers studied children exposed to their parents’ smoke. If they grew up to have less Parkinson’s, that would confirm the protective link—and indeed they did. So, smoking really does seem to be protective against Parkinson’s disease, but who cares? How does that help us? “More than 20 million Americans have died as a result of smoking since the first Surgeon General’s report…” Even if we didn’t care about dying from lung cancer and emphysema, even if we only cared about our brain, we still wouldn’t smoke because smoking is a significant risk factor for having a stroke, as well.


Is there a way we could get the benefits of smoking without the risks through our diet? I discuss this in my Peppers and Parkinson’s: The Benefits of Smoking Without the Risks? video.

Other Parkinson’s videos include Preventing Parkinson’s Disease with Diet and Treating Parkinson’s Disease with Diet.

Diet may play a role in other movement disorders. For example:

Surprised about the potential benefits of coffee? See:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Get Our 2019 Recipe Calendar

It’s Giving Tuesday

Today is #GivingTuesday, kicking off the charitable season with a celebration of giving and philanthropy. To commemorate it this year, we’ve created a limited edition 2019 NutritionFacts.org Staff Recipe Calendar. If your annual wall calendar doesn’t specify when National Kale Day is (first Wednesday of October, duh) then you have the wrong calendar! This year’s recipes include Purple Sweet Potato Burgers (Kristina, Social Media Director), Almond Berry Crunch Bars (Steven, Global Volunteer Director), Curried Chickpea Wraps from my How Not to Die Cookbook, and more…directly from the kitchens of our staff members! The first 200 people to donate $100 or more to keep my 501c3 nonprofit NutritionFacts.org alive and thriving will get a calendar in time for the new year. Don’t wait—we ran out within a few days last year.

 

Gift Cards Available

Shopping for someone else but not sure what to give them? How about the gift of science promotion with a DrGreger.org gift card (100% of proceeds go to NutritionFacts.org). Cards are available in three designs and come in denominations of $10, $25, $50, and $100. You can send them via e-mail or print them out and give them as a physical gift. Check them out here.

 

Federal Employee CFC

CFC ApprovedAre you a federal worker? You can also show some love for evidence-based nutrition by giving to NutritionFacts.org through the CFC workplace giving program. Look for our designation number: 26461.

 
 
 

Get a Dr. Ornish Bookplate!

My dear friend and colleague, Dean Ornish, has a new book coming out that’s available right now for preorder. His 40 years of revolutionary scientific research proving that comprehensive lifestyle changes can often reverse some of our deadliest diseases essentially launched the entire field of lifestyle medicine, now the most exciting movement in medicine today. He asked me how I got so many preorders for my books and I told him you just have to put yourself out there. And look, he took my advice! Be one of the first 2,500 people to preorder UnDo It! and you’ll receive your very own personalized bookplate signed by Dr. Dean Ornish and Anne Ornish. (Actually, one of the first 2,499 since I just ordered mine!)

 

New Look Coming Soon

A brand new video experience is coming to NutritionFacts.org. In the next couple of weeks, we will be launching a stylin’ new video interface for enhanced viewing, an option for continuously playing videos, subtitle selection for our multilingual users, floating video player on scroll, and the all-new Theater Mode. I’m excited to see it myself!

 

 

Q&As Temporarily on Hold

Every month for the last two years, I have done live Q&As on Facebook and YouTube. I love this opportunity to answer all your burning questions directly, but right now I’m in the final stretch of finishing my next tome and every minute counts. So I need to put the Q&As on hold until April, but once How Not to Diet is finally out (fingers crossed for December 2019!) I hope you’ll agree that it was worth it.

Until I get back to it, you can dive into my past live chats right here on NutritionFacts.org. And remember I have an audio podcast to keep you company at http://nutritionfacts.org/audio.

 

This year, as every year, I give thanks to you and everyone who has supported me and my work to spread the power and hope of evidence-based nutrition,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Should Plant-Based Women Supplement with DHA During Pregnancy?

A systematic review of randomized controlled trials of DHA supplementation of pregnant and breastfeeding women failed to find any clear and consistent short- or long-term benefit for psychomotor, mental, visual, or physical development. Perhaps DHA supplementation during pregnancy has no effect because the body wisely protects the growth of the baby’s brain by drawing off of maternal stores of DHA, upregulating maternal DHA synthesis, and preferentially shuttling it to the fetus. But what if moms don’t start out with large maternal stores? In other words, maybe DHA failed to help women who were already getting enough, but perhaps women with very low intakes would benefit from DHA supplementation. My video Should Vegan Women Supplement with DHA During Pregnancy? explores the evidence available to date.

It’s interesting to note that, by 1978, researchers already were suggesting a plant-based diet as the diet of choice in the treatment of our number-one killer, heart disease, but babies breastfed by vegan moms had significantly less DHA in their bloodstreams, presumably because the moms had significantly less DHA in their breast milk.

The question is whether these differences are of any consequence. The growth and development of vegan and vegetarian born children are normal as long as they’re getting their B12, and “[t]here is no evidence that neural or intellectual functions are impaired.” In fact, the two studies we have on kids in vegetarian communities showed they had higher IQs, though that may be because their parents tended to be better educated. However, even though the kids seemed fine, that doesn’t rule out the possibility that there may be some “subtle differences…in visual or neural functioning.”

It would be interesting to compare the function of babies getting vegan breast milk levels versus general population levels. In one of the studies I profile in my video, it shows that vegans hit a level of 14, vegetarians 30, and omnivores 37. Another study compared 0 to 32, 64, and 96, and, though 32 worked better than 0, more than 32 didn’t add anything. This could explain why the general population at 37 doesn’t benefit from additional DHA supplementation. But what about down at 14? Most studies at that level show no advantage over 0, though one study found a benefit supplementing at as low as 5, but that doesn’t help us.

Just because babies breastfed by vegan moms have significantly lower DHA levels in the blood, that doesn’t necessarily mean they have lower levels in their brain, which is where it counts. What we need is a randomized, controlled trial in non-fish-eaters of DHA supplementation. Until then, it’s going to remain uncertain. So, what should pregnant and breastfeeding women who avoid fish do in the meanwhile? Low intake of DHA doesn’t “necessarily equate with fetal DHA inadequacy,” but new data suggest that some infants may not be getting enough and could benefit from their moms supplementing. Given this, I recommend pregnant and breastfeeding women on plant-based diets to follow the consensus guidelines to get about 200mg of preformed DHA from an uncontaminated source, like algae oil, which is probably the best combination for all women given the state of our world to minimize exposure to toxic pollutants such as dioxins, PCBs, and mercury. 


To gain a better understanding of why algae oil is better than purified fish oil, I encourage you to watch my video Should Pregnant and Breastfeeding Women Take DHA.

I’ve discussed concerns about pollutants in seafood during pregnancy in a number of my videos:

Finally, for more on taking long-chain omega-3s to protect your heart, see: 

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: