Consider the Evidence When You Make Life-or-Death Decisions

In the 1940s and ’50s, the American Medical Association was not only saying that “smoking in moderation” wasn’t a problem, but that, on balance, it may even be beneficial. After all, most physicians themselves smoked, so how bad could it be? With such a position taken by one of the country’s leading medical groups, where could you turn if you just wanted the facts?

According to one tobacco company ad, “science advances new data that may completely change your idea of cigarettes!” And what might those new data tell us? “She was too tired for fun…and then she smoked a Camel.” (You can see the unbelievable ads in my video Evidence-Based Eating, starting at 0:29). In another ad, baseball legend Babe Ruth told us, “Now! Medical science offers proof positive!” that the brand he was hawking is the safest to smoke of all the leading cigarettes—well, he told us, that is, when he still could talk, before he died of throat cancer.

Now, some of the science-based evidence did leak out, causing a dip from an average of 11 or so cigarettes a day per person down to 10, as you can see at 0:50 in my video, but those who got scared of possible health risks from smoking could always choose “[t]he cigarette that takes the FEAR out of smoking!” Even better, why not choose the cigarette that “gives you the greatest health protection?”

Had a SmokingFacts.org website existed during the time of these outrageous ads making such outrageous claims—a site that delivered the science directly to the people, bypassing commercially corruptible institutional filters—it would have featured a study of Seventh-day Adventists in California in 1958 that showed that nonsmokers may have at least 90 percent less lung cancer than smokers. With so much money and personal habit at stake, there will always be “dissenters.” Given the seriousness of these diseases and the sum total of evidence, though, we shouldn’t wait to put preventive measures in place.

If you’re a smoker in the 1950s in the know and privy to the science-based realities of smoking, you realize the best available balance of evidence suggests your smoking habit is probably not good for you. So, what do you do? Do you change your smoking habits, or do you wait? If you wait until your physician tells you—between puffs—to quit, you could have cancer by then. If you wait until the powers that be officially recognize it, like the Surgeon General did in the subsequent decade, you could be dead by then.

It took more than 7,000 studies and the deaths of countless smokers before the first Surgeon General report against smoking was finally released in the 1960s. Wouldn’t you think that after the first 6,000 studies or so, they could have given people a heads up? One wonders how many people are suffering needlessly right now from dietary diseases.

Let’s fast-forward 55 years to a new Adventist study out of California warning Americans about the risks of something else they may be putting in their mouths: “Vegetarian diets are associated with lower all-cause mortality.” It’s not just one study either. According to a recent review, a total sum of evidence suggests that mortality from all causes put together, including many of our dreaded diseases were significantly lower in those eating more plant-based diets. As well, “[c]ompared with omnivores, the incidence of cancer and type 2 diabetes was also significantly lower in vegetarians.”

So, instead of someone going along with America’s smoking habits in the 1950s, imagine you or someone you know is going along with America’s eating habits today. With access to the science, you realize the best available balance of evidence suggests your eating habits are probably not good for you. So, what do you do? Do you change your eating habits, or do you wait? If you wait until your doctor tells you—between bites—to change your diet, it could be too late.

Just like most doctors smoked back then and didn’t tell their patients to change, despite the overwhelming evidence published for decades, most doctors today continue to eat foods that are contributing to our epidemics of dietary disease.


For more on this topic, check out my series of videos on parallels to smoking and the tobacco industry’s tactics, including:

In health,
Michael Greger, M.D.

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

How to Lower Your Sodium Intake

Reduction of salt consumption by just 15 percent could save the lives of millions. If we cut our salt intake by half a teaspoon a day, which is achievable simply by avoiding salty foods and not adding salt to our food, we might prevent 22 percent of stroke deaths and 16 percent of fatal heart attacks—potentially helping more than if we were able to successfully treat people with blood pressure pills. As I discuss in my video Salt of the Earth: Sodium and Plant-Based Diets, an intervention in our kitchens may be more powerful than interventions in our pharmacies. One little dietary tweak could help more than billions of dollars worth of drugs.

What would that mean in the United States? Tens of thousands of lives saved every year. On a public-health scale, this simple step “could be as beneficial as interventions aimed at smoking cessation, weight reduction, and the use of drug therapy for people with hypertension or hypercholesterolemia,” that is, giving people medications to lower blood pressure and cholesterol. And, that’s not even getting people down to the target. 

A study I profile in my video shows 3.8 grams per day as the recommended upper limit of salt intake for African-Americans, those with hypertension, and adults over 40. For all other adults the maximum is 5.8 daily grams, an upper limit that is exceeded by most Americans over the age of 3. Processed foods have so much added salt that even if we avoid the saltiest foods and don’t add our own salt, salt levels would go down yet still exceed the recommended upper limit. Even that change, however, might save up to nearly a hundred thousand American lives every year.

“Given that approximately 75% of dietary salt comes from processed foods, the individual approach is probably impractical.” So what is our best course of action? We need to get food companies to stop killing so many people. The good news is “several U.S. manufacturers are reducing the salt content of certain foods,” but the bad news is that “other manufacturers are increasing the salt levels in their products. For example, the addition of salt to poultry, meats, and fish appears to be occurring on a massive scale.”

The number-one source of sodium for kids and teens is pizza and, for adults over 51, bread. Between the ages of 20 and 50, however, the greatest contribution of sodium to the diet is not canned soups, pretzels, or potato chips, but chicken, due to all the salt and other additives that are injected into the meat.

This is one of the reasons that, in general, animal foods contain higher amounts of sodium than plant foods. Given the sources of sodium, complying with recommendations for salt reduction would in part “require large deviations from current eating behaviors.” More specifically, we’re talking about a sharp increase in vegetables, fruits, beans, and whole grains, and lower intakes of meats and refined grain products. Indeed, “[a]s might be expected, reducing the allowed amount of sodium led to a precipitous drop” in meat consumption for men and women of all ages. It’s no wonder why there’s so much industry pressure to confuse people about sodium.

The U.S. Dietary Guidelines recommend getting under 2,300 milligrams of sodium a day, while the American Heart Association recommends no more than 1,500 mg/day. How do vegetarians do compared with nonvegetarians? Well, nonvegetarians get nearly 3,500 mg/day, the equivalent of about a teaspoon and a half of table salt. Vegetarians did better, but, at around 3,000 mg/day, came in at double the American Heart Association limit.

In Europe, it looks like vegetarians do even better, slipping under the U.S. Dietary Guidelines’ 2,300 mg cut-off, but it appears the only dietary group that nails the American Heart Association recommendation are vegans—that is, those eating the most plant-based of diets.


This is part of my extended series on sodium, which includes:

If you’re already cutting out processed foods and still not reaching your blood pressure goals, 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:

What About Canned Fruit?

Food cans used to be soldered with lead compounds—so much so that people living off of canned food may have died from lead poisoning. Thankfully, this is no longer a problem in the United States. Lead contamination was one of the first priorities of the Food and Drug Administration back in 1906, before it was even called the FDA. Newspapers now have online archives going back a century so we can read about landmark historical events like “FDA Proposes Lead-Soldered Cans Be Banned” from way back yonder in…1993. So even though it was a priority in 1906, the ban didn’t actually go into effect until 1995. Evidently it was complicated because lead solder was “grandfathered” in as a “prior-sanctioned” substance.

Now that the lead is gone, though, are canned foods healthy? It depends primarily on what’s in the can. If it’s SPAM or another processed meat product, for instance, I’d probably pass.

What about canned fruit? We know fruits and vegetables in general may help protect us from dying of cardiovascular disease, and, when it comes to preventing strokes, fruit may be even more protective. But whether food processing affects this association was unknown, as I discuss in my video Is Canned Fruit as Healthy? One study found that unprocessed produce, mostly apples and oranges, appeared superior to processed produce. But that study focused mainly orange and apple juice. It’s no surprise whole fruit is better than fruit juice.

What about whole fruit when it is in a can? Dietary guidelines encourage eating all fruit whether it’s fresh, frozen, or canned, but few studies have examined the health benefits of canned fruit…until now. Canned fruit did not seem to enable people to live longer. In fact, moving from fresh or dried fruit to canned fruit might even shorten one’s life. Therefore, perhaps dietary guidelines should stress fresh, frozen, and dried fruit rather than canned.

Why the difference? While there’s no longer lead in cans these days, there is bisphenol A (BPA), the plastics chemical used in the lining of most cans. BPA can leach into the food and might counterbalance some of the fruits’ benefits. Recently, for example, blood levels of this chemical were associated with thickening of the artery linings going up to the brains of young adults. Canned fruit is often packed in syrup, as well, and all that added sugar and the canning process itself may diminish some nutrients, potentially wiping out 20 to 40 percent of the phenolic phytonutrients and about half of the vitamin C.

Maybe one of the reasons citrus appears particularly protective against stroke is its vitamin C content. It appears the more vitamin C in our diet and in our bloodstream, the lower the risk of stroke. And the way to get vitamin C into the bloodstream is to eat a lot of healthy foods, like citrus and tropical fruits, broccoli, and bell peppers. “Therefore, the observed effect of vitamin C on stroke reduction may simply be a proxy for specific foods (eg, fruits and vegetables) that causally lower stroke” risk. How could the researchers tell? Instead of food, they gave people vitamin C pills to see if they worked—and they didn’t.

This might be because citrus fruit have all sorts of other compounds associated with lower stroke risk, proving that the whole is greater than the sum of its parts. You can’t capture Mother Nature in a pill. It’s like the apocryphal beta-carotene story. Dozens of studies showed that people who ate more beta-carotene-rich foods, like greens and sweet potatoes, and therefore had more beta-carotene circulating in their system, had lower cancer risk. What about beta-carotene supplements instead of whole foods? Researchers tried giving beta-carotene pills to people. Not only did they not work, they may have even caused more cancer. I assumed the National Cancer Institute researcher who did this study would conclude the obvious: produce, not pills. But, no. Instead, the researcher questioned whether he should have tried lower dose pills, alpha-carotene pills, pills with other phytochemicals, or maybe multiple combinations. After all, he said, “[i]t is likely that neither the public nor the scientific community will be satisfied with recommendations concerned solely with foods…”


Check out my other videos on the can-lining chemical BPA, including:

Is fresh fruit really that healthy? See:

Is it possible to get too much of a good thing? See How Much Fruit Is Too Much?.

Now that there’s no more lead in the cans, are there any other ways we’re exposed to the toxic heavy metal? I did a whole series on lead, which you can watch. See also:

I close with yet another screed against reductionism. For more on that, see my videos Why Is Nutrition So Commercialized? and Reductionism and the Deficiency Mentality.

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: