There is a lot of information out there about the best foods to help us lose weight, prevent cancer, fight inflammation – the list goes on. In fact, for everything about our health we try and improve, there’s someone out there with a new theory on how to do it. But what does the science say?
Welcome to the Nutrition Facts Podcast. I’m your host Dr. Michael Greger. And I’m here to give you the evidence-based approach to take the mystery out of the best way to live a healthier, longer life.
It’s time for the nutrition facts grab bag, where we look at the latest science on a whole variety of topics. First up, we find out if cooking meals at home leads to improved health outcomes? And how do TV dinners compare nutritionally to TV-chef recipes?
Modern Americans are described as “eating breakfast in their cars, lunch at their desks and chicken from a bucket.” Within the last few decades, Americans are eating out more and more, and cooking fewer meals at home. And, “food prepared at home tends to be healthier,” less saturated fat, cholesterol, and sodium, more fiber.”
And so, the “benefits to preparing healthful food at home may include chronic disease prevention.” But, even during the recession, folks were found “resistant to dietary change,” and kept going out to eat, or bringing it home. “Almost half of all fast-food eaten by children is eaten at home.” So, just because they’re technically eating at home doesn’t mean they’re eating healthy.
“Even when food is prepared at home,” it still may not mean much, as most dinners were found to incorporate “processed commercial foods.” Microwaving a frozen pizza ain’t exactly home cooking. One of the problems is many people no longer know how to cook. For example, one study reported that “25% of the men had absolutely no cooking skills” whatsoever.
“It is encouraging to see the new wave of interest in cooking, in numerous TV shows.” But, what are they actually cooking? A study in the UK compared the nutritional “content of meals created by television chefs with ready meals,” like TV dinners, “to compare both with nutrition guidelines set forth by the World Health Organization.” They looked at a hundred of each, and not a single one complied with the nutrition standards. And, the TV chef recipes were even “less healthy” than the TV dinners.
Many people just don’t know how to make healthy food taste good. This is not a new problem. As an editorial in the Journal of the American Medical Association bemoaned back in 1913: In the United States, “vegetables are frequently boiled in a way that deprives them of their characteristic odor and their toothsomeness. ‘Villainous and idiotic’ are the only adjectives that can describe our methods of cooking vegetables” in the United States.
Is there any research showing that cooking meals at home actually improves health outcomes? Do people who cook live longer? We didn’t know, until now. Researchers in Taiwan found that those “who cook their own food are healthier, and do, indeed, appear to live longer.
“In a 10-year study, they found that those who cooked most frequently “had only 59% of the mortality risk.” And, this took into account the exercise people got grocery shopping, and “physical function and chewing ability.” So, why did they live longer? Well, those that cooked ate more nutritious foods” as evidenced by their higher consumption of vegetables.”
The effect on mortality was much more evident in women than in men, though. Turns out that “men were, with doubtful justification, more positive about the nutritive value of convenience foods.” So, their idea of cooking was like microwaving a Pop-Tart®, whereas “women who cook actually make better food choices.”
As one author noted, last century, “we began the long process of turning over to the food industry many of the decisions about what we eat. Today, our staggering rates of obesity and diabetes are testimony to the faith we put in corporations to feed us well. But the food industry is a business, not a parent; it doesn’t care what we eat as long as we’re willing to pay for it. Home cooking these days has far more than sentimental value; it’s a survival skill.”
In our next story we discover how genetic differences in caffeine metabolism may explain the Jekyll and Hyde effects of coffee.
Three-quarters of American adults drink coffee, about half of which on a daily basis. That comes out to a million tons of coffee every year. Might there be “grounds for concern”? Population studies have found that coffee drinkers tend to have lower risk of Parkinson’s, less prostate cancer (especially the women), less liver cancer, less diabetes, liver cirrhosis, depression among women, and a reduction in mortality overall, such that coffee drinkers tend to live longer than non-coffee drinkers, with mortality bottoming out at about four cups a day. But these are all just associations. You don’t know if it’s cause and effect until you put it to the test.
For example, coffee really does seem to protect the liver. Take people with chronic hepatitis, and have them drink coffee, or not, for a month, then switch them back. And, the coffee really did seem to help. Similarly, randomize Parkinson’s patients to get two cups of coffee’s worth of caffeine, and get a significant improvement in movement symptoms within three weeks. Runners randomized to drink coffee shaved about six seconds off their mile. Weightlifters randomized to coffee can squat more weight, about 600 pounds more worth of reps. And, not just athletic performance. A cup of coffee’s worth of caffeine can significantly improve IELT, which stands for “intra-vaginal ejaculation latency time,” from two minutes all the way up to five.
Unfortunately, those effectively randomized at birth to genetically just have a higher predilection to drink coffee do not appear to be protected from diabetes, or depression, or Alzheimer’s, or obesity, or metabolic syndrome. So, it seems the protective associations may just be due to “confounding factors,” like, maybe those who drink coffee just happen to exercise more, or something. And, the same with prostate cancer, no apparent cause-and-effect relationship, and even the mortality benefit seemed to disappear.
Even if a study did show coffee drinking could extend lifespan by reducing inflammation, or improving lung function or insulin sensitivity, that would mean on average. There is “interindividual variability after consumption of major plant-food compounds,” meaning people may respond differently. For example, how crazy is this? “In some rare individuals, heavy use of caffeine apparently provokes sleepiness.” That’s an extreme example. Most of the time, it’s just that “some individuals may benefit more than others from the health effects of different foods.” For example, because of differences in gut bacteria, only a minority of Westerners may derive extra benefit from soy, as I’ve described before. The most common difference in caffeine effects is that while most people metabolize caffeine rapidly, certain gene variants in liver detox enzymes make some people slow metabolizers. Might that make a difference?
Well, habitual coffee consumption of at least three cups a day has been “associated with uncontrolled blood pressure” among older individuals diagnosed with hypertension, suggesting that “moderating coffee intake” may be a good idea for some people. But, even if it was cause-and-effect, that would be on average. What would happen if you split people up by how fast they metabolize caffeine? Compared to coffee abstainers, those who have impaired caffeine metabolism genes have an elevated risk of becoming hypertensive at one to three cups a day, and especially at four or more. Okay, but check this out. For the rapid metabolizers, not only was there no excess risk at one to three cups, heavy coffee drinkers were protected, meaning apparently the more coffee they drank, the lower their risk. How do we explain that?
“Coffee is a complex ‘blend’ of a vast number of different compounds.” There are protective polyphenol antioxidants that are beneficial. Coffee beans are, after all, beans; well, actually, seeds, but seeds are really healthy too! On the other hand, there’s the caffeine, which can spike adrenaline levels in the blood, but only if you’re a slow metabolizer. Rapid metabolizers can clear caffeine so fast that there’s no increase in adrenaline even at four or more cups a day. And so, then you just have the beneficial polyphenols that actually lower your blood pressure hence the benefit overall. “Thus, there seems to be a Jekyll and Hyde aspect to coffee, whose overall action on the cardiovascular system appears to be regulated by” that gene for the enzyme that metabolizes caffeine.
“The important question,” though is, “Does it give women larger breasts?” W-w-hat?! Young women who drink a lot of coffee and are rapid caffeine metabolizers have about a half-a-baseball-sized larger breast volume, which may be a bad thing, “as breast volume is associated with breast cancer risk.” But no, the important question is, “What about heart attack risk?” In slow metabolizers, daily coffee consumption appeared to double the odds of a heart attack, or even quadruple the odds at four cups a day, whereas in the rapid caffeine metabolizers, daily coffee consumption was protective, cutting the odds of heart attack by more than half or at least until you get up to four or more cups a day. “The protective effects observed among rapid metabolizers suggest that the efficient elimination of caffeine might have unmasked the protective effects of other phytochemicals in coffee.”
We think it may be the adrenaline again, since if you’re a slow metabolizer of adrenaline, high coffee consumption may put you at risk as well.
So, is coffee “friend or foe”? “These studies suggest the possibility that slow caffeine metabolizers who consume caffeinated coffee may have an increased risk of cardiovascular disease, whereas fast caffeine metabolizers may be protected from this risk by the antioxidants and other beneficial compounds present.”
Finally today –we learn how the biggest barrier to reducing toxic pesticides in cannabis is, not surprisingly, the cannabis industry itself.
California was the first state to legalize medical marijuana. When labs started reporting they were finding high levels of “pesticide residues,” the LA city government “covertly acquired and then tested” three samples from dispensaries, and found that two of the three samples did have “exceedingly high levels” of a pesticide up to a thousand times the legal limit.
Yeah, but how much ends up inside the consumer? Only about 10 percent or so of the pesticides in tobacco makes it through a filtered cigarette, which was found to be comparable to using cannabis in a water pipe with filters attached. But use a regular bong, and about half the pesticides end up in your lungs. And, a glass pipe is even worse. Because most users don’t attach a carbon filter to their bongs with seven and a half grams of activated charcoal, “in general the portion of pesticide recovery from cannabis would be alarmingly high and is a serious concern.” Although we don’t know “precisely how damaging these chemicals are, the fact they are present in smoke at such high levels should be concerning.” “Considering these results, high pesticide exposure through cannabis smoking is a significant possibility, which may lead to further health complications in cannabis consumers” especially if we’re talking about medical marijuana. Sick, vulnerable people, potentially making things worse.
“The potential of pesticide and chemical residue exposures to cannabis users is substantial and may pose a significant toxicological threat in the absence of adequate regulatory frameworks.” Okay, so what are states doing about it? Colorado recently suffered some “high-profile recalls of marijuana batches” contaminated with “harmful pesticides” that made it into some of the edibles. Evidently, “growers sometimes find themselves overwhelmed by pest issues and resort to nuclear tactics” trying anything to protect their crop. This has created “a public safety threat,” with “intensified toxicity in concentrated products of particular concern.” “Pesticide levels were found to be approximately 10x higher in concentrated cannabis products,” like the oils and waxes sometimes used in edibles or dabbed as concentrates.
“A study of pesticide use on cannabis crops in Oregon” found a similar problem. A survey of samples off store shelves in Washington state found five out of six contaminated, “including with potentially neurotoxic and carcinogenic agents.” “Many samples harbored multiple contaminants, attaining levels” basically off the chart, including “24 distinct pesticide agents,” insecticides, fungicides none of which are approved for use on cannabis. But, it’s not their fault the EPA hasn’t approved any because it’s still a federally illegal crop. In fact, testing labs in California have “become hesitant to publicize their service or list agents for which they could test, as they suspected that such information” might just be used as an instruction manual by unscrupulous growers to seek out even more toxic agents.
Okay, so just regulate it. They’ve tried, but guess what the biggest barrier was they came up against? Surprise, surprise, the cannabis industry, the multi-billion-dollar cannabis industry. Like the tobacco industry before it, “the cannabis industry is attempting to weaken pesticide regulations.” “Reportedly, the Colorado Department of Agriculture initially hoped to limit permissible pesticides to the most nontoxic,” but this proposal was quashed by industry pushback, just like the tobacco industry was able to do.
Big Tobacco “has provided a detailed road map for” King Cannabis: “deny addiction potential, downplay any known adverse health effects, create as large a market as possible as quickly as possible, and protect that market through lobbying and campaign contributions.” “Bolstered by enormous profits,” the tobacco industry was able to get itself “exempted from every major piece of consumer protection legislation.” So that should be a cautionary tale for us now, given that public health advocates have definitely fewer billions to work with.
Big Tobacco may not just be providing the roadmap, but waiting in the wings to own the road. “As a result of lawsuits against the tobacco industry, more than 80 million pages of internal company documents became available.” And what they reveal is “that since at least 1970, despite fervent denials, major multinational tobacco companies” like Philip Morris having been scheming, willing, and prepared to enter the legalized marijuana market to become Big Blunt. “Because of the tobacco industry’s demonstrated ability and willingness to modify its products to increase addictiveness, obfuscate information, deceive the public, and target vulnerable groups to increase demand, the industry also has the power to dramatically change the game.”
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For recipes, check out my “How Not to Die Cookbook.” It’s beautifully designed, with more than 100 recipes for delicious and nutritious meals. And all proceeds I receive from the sales of all my books goes to charity.
NutritionFacts.org is a nonprofit, science-based public service, where you can sign up for free daily updates on the latest in nutrition research via bite-sized videos and articles. Everything on the website is free. There’s no ads, no corporate sponsorship. It’s strictly non-commercial. I’m not selling anything. I just put it up as a public service, as a labor of love, as a tribute to my grandmother – whose own life was saved with evidence-based nutrition. Thanks for listening to Nutrition Facts. I’m your host, Dr. Michael Greger.