Why Drinking Diet Soda Makes You Crave Sugar

Recommendations on limiting sugar consumption vary around the world, with guidelines ranging from “[l]imit sweet desserts to one every other day” to “[k]eep sugar consumption to 4 or less occasions per day.” In the United States, the American Heart Association is leading the charge, “proposing dramatic reductions in the consumption of soft drinks and other sweetened products” and recommending fewer than about 5 percent of calories a day from added sugars, which may not even allow for a single can of soda.

Why is the American Heart Association so concerned about sugar? “Overconsumption of added sugars has long been associated with an increased risk of cardiovascular disease,” meaning heart disease and strokes. We used to think added sugars were just a marker for an unhealthy diet. At fast-food restaurants, for example, people may be more likely to order a cheeseburger with their super-sized soda than a salad. However, the new thinking is that the added sugars in processed foods and drinks may be independent risk factors in and of themselves. Indeed, worse than just empty calories, they may be actively disease-promoting calories, which I discuss in my video Does Diet Soda Increase Stroke Risk as Much as Regular Soda?.

At 1:14 in my video, you can see a chart of how much added sugar the American public is consuming. The data show that only about 1 percent meet the American Heart Association recommendation to keep added sugar intake down to 5 or 6 percent of daily caloric intake. Most people are up around 15 percent, which is where cardiovascular disease risk starts to take off. There is a doubling of risk at about 25 percent of calories and a quadrupling of risk for those getting one-third of their daily caloric intake from added sugar.

Two hundred years ago, we ate an estimated 7 pounds of sugar annually. Today, we may consume dozens of pounds of sugar a year. We’re hardwired to like sweet foods because we evolved surrounded by fruit, not Froot Loops, but this adaptation is “terribly misused and abused” today, “hijacked” by the food industry for our pleasure and their profits. “Why are we consuming so much sugar despite knowing too much can harm us?” Yes, it may have an addictive quality and there’s the hardwiring, but the processed food industry isn’t helping. Seventy five percent of packaged foods and beverages in the United States contain added sweeteners, mostly coming from sugar-sweetened beverages like soda, which are thought responsible for more than a 100,000 deaths worldwide and millions of years of healthy life lost. Given this, can we just switch to diet sodas? By choosing diet drinks, can’t we get that sweet taste we crave without any of the downsides? Unfortunately, studies indicate that “[r]outine consumption of diet soft drinks is linked to increases in the same risks that many seek to avoid by using artificial sweeteners—namely type 2 diabetes, metabolic syndrome heart disease, and stroke.” At 3:15 in my video, you can see data showing the increased risks of cardiovascular disease associated with regular soft drinks and also diet soda. They aren’t that dissimilar.

“In other words, the belief that artificially sweetened diet beverages reduce long-term health risks is not supported by scientific evidence, and instead, scientific data indicate that diet soft drink consumption may contribute to the very health risks people have been seeking to avoid.” But, why? It makes sense that drinking all that sugar in a regular soft drink might increase stroke risk, due to the extra inflammation and triglycerides, but why does a can of diet soda appear to increase stroke risk the same amount? It’s possible that the caramel coloring in brown sodas like colas plays a role, but another possibility is that “artificial sweeteners may increase the desire for sugar-sweetened, energy-dense beverages/foods.”

The problem with artificial sweeteners “is that a disconnect ultimately develops between the amount of sweetness the brain tastes and how much glucose [blood sugar] ends up coming to the brain.” The brain feels cheated and “figures you have to eat more and more and more sweetness in order to get any calories out of it.” So, “[a]s a consequence, at the end of the day, your brain says, ‘OK, at some point I need some glucose [blood sugar] here.’ And then you eat an entire cake, because nobody can hold out in the end.”

If people are given Sprite, Sprite Zero (a zero-calorie soda), or unsweetened, carbonated, lemon-lime water, but aren’t told which drink they’re getting or what the study is about, when they’re later offered a choice of M&M’s, spring water, or sugar-free gum, who do you think picks the M&M’s? Those who drank the artificially sweetened soda were nearly three times more likely to take the candy than those who consumed either the sugar-sweetened or unsweetened drinks. So, it wasn’t a matter of sweet versus non-sweet or calories versus no-calories. There’s something about non-caloric sweeteners that somehow tricks the brain.

The researchers did another study in which everyone was given Oreos and were then asked how satisfied the cookies made them feel. Once again, those who drank the artificially sweetened Sprite Zero reported feeling less satisfied than those who drank the regular Sprite or the sparkling water. “These results are consistent with recent [brain imaging] studies demonstrating that regular consumption of [artificial sweeteners] can alter the neural pathways responsible for the hedonic [or pleasure] response to food.”

Indeed, “[t]he only way really to prevent this problem—to break the addiction—is to go completely cold turkey and go off all sweeteners—artificial as well as fructose [table sugar and high fructose corn syrup]. Eventually, the brain resets itself and you don’t crave it as much.”

We’ve always assumed the “[c]onsumption of both sugar and artificial sweeteners may be changing our palates or taste preferences over time, increasing our desire for sweet foods. Unfortunately, the data on this [were] lacking”…until now. Twenty people agreed to cut out all added sugars and artificial sweeteners for two weeks. Afterwards, 95 percent “found that sweet foods and drinks tasted sweeter or too sweet” and “said moving forward they would use less or even no sugar.” What’s more, most stopped craving sugar within the first week—after only six days. This suggests a two-week sugar challenge, or even a one-week challenge, may “help to reset taste preferences and make consuming less or no sugar easier.” Perhaps we should be recommending it to our patients. “Eating fewer processed foods and choosing more real, whole, and plant-based foods make it easy to consume less sugar.”


Speaking of stroke, did you see my Chocolate and Stroke Risk video?

For more on added sugars, see:

You may also be interested in my videos on artificial and low-calorie sweeteners:

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:

The Foods With the Highest Aspirin Content

The results of a recent aspirin meta-analyses suggesting a reduction of cancer mortality by about one-third in subjects taking daily low-dose aspirin “can justly be called astounding.” Yet the protection from “Western” cancers enjoyed by those eating more traditional plant-centered diets, such as the Japanese, “is even more dramatic.” I examine this in my video Plants with Aspirin Aspirations.

Before the Westernization of their diets, animal products made up only about 5 percent or less of the Japanese diet. At 0:37 in my video, you can see the difference in cancer mortality of U.S. men and women compared with Japanese men and women. “[A]ge-adjusted death rates from cancers of the colon, prostate, breast, and ovary were on the order of 5–10-fold lower in Japan than in the US at that time; mortality from pancreatic cancer, leukemias, and lymphomas was 3–4-fold lower in Japan. But this phenomenon was by no means isolated to Japan; Western cancers were likewise comparatively rare in other societies where “people ate plant-based diets.”

“The cancer protection afforded by lifelong consumption of a plant-based diet, in conjunction with leanness and insulin sensitivity (which tend to be promoted by low-fat plant-based diets)…may be very substantial indeed.” Therefore, a “lifestyle protocol for minimizing cancer risk” may include a whole-food plant-based diet.

If part of this cancer protection arises out of the aspirin phytonutrients in plants, are there any plants in particular that are packed with salicylates? Though salicylic acid, the main active ingredient in aspirin, is “ubiquitously present in fruits and vegetables,” the highest concentrations are found in herbs and spices.

Red chili powder, paprika, and turmeric contain a lot of salicylates, but cumin is about 1 percent aspirin by weight. Eating a teaspoon of cumin is like taking a baby aspirin. (See the table at 1:54 in my video for details on other herbs and spices, and their salicylate content.) “Consequently, populations that incorporate substantial amounts of spices in foods may have markedly higher daily intakes of salicylates. Indeed, it has been suggested that the low incidence of colorectal cancer among Indian populations may be ascribed in part to high exposure to dietary salicylates throughout life from spice consumption.”

“The population of rural India, with an incidence of colorectal cancer which is one of the lowest in the world, has a diet that could be extremely rich in salicylic acid. It contains substantial amounts of fruits, vegetables, and cereals flavored with large quantities of herbs and spices.” Some have proposed it’s the curcumin in the spice turmeric (which I discuss in detail in my video Turmeric Curcumin and Colon Cancer), but it may be the salicylic acid in cumin—and the spicier the better.

A spicy vegetable vindaloo may have four times the salicylates of a milder Madras-style veggie dish. As you can see from the chart at 2:55 in my video, after just one meal, we get an aspirin spike in our bloodstream like we just took an aspirin. So, eating flavor-filled vegetarian meals, with herbs and spices, may be more chemoprotective—that is, more protective against cancer—than regular, blander vegetarian meals.

We may also want to eat organic produce. “Because salicylic acid is a defense hormone of plants, the concentration…is increased when plants become stressed,” like when they are bitten by bugs (unlike pesticide-laden plants). Indeed, soups made from organic vegetables were found to have nearly six times more salicylic acid than soups prepared from conventionally grown ingredients.

We should also choose whole foods. Whole-grain breads, which are high in salicylic acid, contain about 100 times more phytochemicals than white bread: 800 phytochemicals compared to 8.

“Interest in the potential beneficial effects of dietary salicylates has arisen, in part, because of the extensive literature on the disease-preventative effects of Aspirin™. However, it should not be forgotten that plant products found to contain salicylic acid are generally rich sources of other phenolic acids…[and many] also have a marked anti-inflammatory and redox-related bioactivity [that is, antioxidant activity] in mammalian cells. Their potential protective effects should not be overlooked. In this context, the importance of dietary salicylic acid should not perhaps be over emphasised…Indeed, some believe that ‘salicylic acid deficiency’ has important public health implications and that it should be classed as an essential vitamin, namely ‘Vitamin S’.”

What they’re saying is that we should all eat a lot of plants.


If you missed the first two videos in this series, see Should We All Take Aspirin to Prevent Heart Disease? and Should We All Take Aspirin to Prevent Cancer?.

The drug-like anti-inflammatory power of certain plant foods may make them a risky proposition during pregnancy. See Caution: Anti-Inflammatory Foods in the Third Trimester.

Herbs and spices not only have some of the most anti-inflammatory properties, but they also are well-rounded protectants. 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 presentations:

How to Get the Benefits of Aspirin Without the Risks

For people without a personal history of cardiovascular disease, aspirin’s risks may outweigh its benefits, but aspirin may have additional benefits. “We have long recognized the preventative role of daily aspirin for patients with atherosclerotic [heart] disease; however, it now appears that we can hatch 2 birds from 1 egg. Daily low-dose aspirin may help prevent certain forms of cancer, as well, as I discuss in my video Should We All Take Aspirin to Prevent Cancer? In an analysis of eight different studies involving more than 25,000 people, “the authors found a 20 percent decrease in risk of death from cancer among those randomized to daily aspirin…” The researchers wrote, “[T]he search for the most efficacious and safe treatments for malignant disease remains an enormous and burdensome challenge. If only we could just stop cancer in its tracks—prevent it before it strikes. Perhaps we can.” Indeed, perhaps we can with salicylic acid, the plant phytonutrient that’s marketed as aspirin.

How does aspirin affect cancer? The Nobel Prize for Medicine was awarded to the team who discovered how aspirin works. Enzymes named COX (cyclooxygenase) take the pro-inflammatory, omega-6, fatty-acid arachidonic acid our body makes or we get directly in our diet (primarily from eating chicken and eggs), and turns it into inflammatory mediators, such as thromboxane, which produces thrombosis (clots), and prostaglandins, which cause inflammation. Aspirin suppresses these COX enzymes. Less thromboxane means fewer clots, and less prostaglandin means less pain, swelling, and fever. However, prostaglandins can also dilate the lymphatic vessels inside tumors, allowing cancer cells to spread. So, one way cancer tries to kill us is by boosting COX activity.

We think one way aspirin can prevent cancer is by counteracting the tumor’s attempts to pry open the lymphatic bars on its cage and spread throughout the body. Indeed, reduction in mortality due to some cancers occurred within two to three years after aspirin was started. That seems too quick to be accounted for by an effect only on tumor formation . Cancer can take decades to develop, so the only way aspirin could work that fast is by suppressing the growth and spread of tumors that already exist. Aspirin appeared to cut the risk of metastases in half, particularly for adenocarcinomas, like colon cancer.

Given this, should we all take a daily baby aspirin? Previous risk-benefit analyses did not consider the effects of aspirin on cancer, instead just balancing cardiovascular benefits with bleeding risks, but these new cancer findings may change things.

If daily aspirin use were only associated with a reduction of colon cancer risk, then the benefits might not outweigh the harms for the general population, but we now have evidence that it works against other cancers, too. “[E]ven a 10% reduction in overall cancer incidence…could tip the balance” in favor of benefits over risks.

How does the cancer benefit compare? We know that using aspirin in healthy people just for cardiovascular protection is kind of a wash, but, by contrast, the cancer prevention rates might save twice as many lives, so the benefits may outweigh the risks. If we put it all together—heart attacks, strokes, cancer, and bleeding—aspirin comes out as protective overall, potentially extending our lifespan. There is a higher risk of major bleeding even on low-dose aspirin, but there are fewer heart attacks, clotting strokes, and cancers. So, overall, aspirin may be beneficial.

It’s important to note that the age categories in that study only went up to 74 years, though. Why? Because the “risk of bleeding on aspirin increases steeply with age,” so the balance may be tipped the other way at 75 years and older. But, in younger folks, these data certainly have the research community buzzing. “The emerging evidence on aspirin’s cancer protection highlights an exciting time for cancer prevention…”

“In light of low-dose aspirin’s ability to reduce mortality from both vascular events and cancer to a very notable degree, it is tempting to recommend this measure…for most healthy adults…However, oral aspirin, even in low doses, has a propensity to damage the gastroduodenal mucosa [linings of our stomachs] and increase risk for gastrointestinal bleeding; this fact may constrain health authorities from recommending aspirin use for subjects deemed to be at low cardiovascular risk”—that is, for the general population. “Recent meta-analyses estimate that a year of low-dose aspirin therapy will induce major gastrointestinal bleeding (requiring hospitalization) in one subject out of 833…”

If only there were a way to get the benefits without the risks.

Those who remember my video Aspirin Levels in Plant Foods already know there is. The aspirin phytonutrient salicylic acid isn’t just found in willow trees, but throughout the plant kingdom, from blackberries and white onions to green apples, green beans, and beyond. This explains why the active ingredient in aspirin is found normally in the bloodstream even in people not taking aspirin. The levels of aspirin in people who eat fruits and vegetables are significantly higher than the levels of those who don’t. If we drink just one fruit smoothie, our levels rise within only 90 minutes. But, one smoothie isn’t going to do it, of course. We need to have regular fruit and vegetable consumption every day. Are these kinds of aspirin levels sufficient to suppress the expression of the inflammatory enzyme implicated in cancer growth and spread, though? Using umbilical cord and foreskin cells—where else would researchers get human tissue?—they found that even those low levels caused by smoothie consumption significantly suppressed the expression of this inflammatory enzyme on a genetic level.

Since this aspirin phytonutrient is made by plants, we might expect plant-eaters to have higher levels. Indeed, not only did researchers find higher blood levels in vegetarians, but there was an overlap between people taking aspirin pills. Some vegetarians had the same level in their blood as people actually taking aspirin. Vegetarians may pee out as much of the active metabolite of aspirin as those who take aspirin do, simply because vegetarians eat so many fruits and vegetables. “Because the anti-inflammatory action of aspirin is probably the result of SA [salicylic acid, the active ingredient in aspirin], and the concentrations of SA seen in vegetarians have been shown to inhibit [that inflammatory enzyme] COX-2 in vitro, it is plausible that dietary salicylates may contribute to the beneficial effects of a vegetarian diet, although it seems unlikely that most [omnivores] will achieve sufficient dietary intake of salicylates to have a therapeutic effect.”

Aspirin can chew away at our gut. With all that salicylic acid flowing through their systems, plant-eaters must have higher ulcer rates, right? No. Both vegetarian women and men appear to have a significantly lower risk of ulcers. So, for the general population, by eating plants instead of taking aspirin, we may not only get the benefits without the risks, we can get the benefits with even more benefits. How is this possible? In plants, the salicylic acid can come naturally pre-packaged with gut-protective nutrients.

For example, nitric oxide from dietary nitrates exerts stomach-protective effects by boosting blood flow and protective mucus production in the lining of the stomach—“effects which demonstrably oppose the pro-ulcerative impact of aspirin and other NSAIDs.”

The researcher notes that while “[d]ark green leafy vegetables…are among the richest dietary sources of nitrate…it may be unrealistic to expect people to eat ample servings of these every day,” so we should just give people pills with their pills, but I say we should just eat our greens. People who’ve had a heart attack should follow their physician’s advice, which probably includes taking aspirin every day, but what about everyone else? I think everyone should take aspirin—but in the form of produce, not a pill.


To see the pros versus cons for people trying to prevent or treat heart attacks and stroke, see my video Should We All Take Aspirin to Prevent Heart Disease?.

Does the COX enzyme sound familiar? I talked about it in my Anti-Inflammatory Life Is a Bowl of Cherries video.

Where does one get “dietary nitrates”? See Vegetables Rate by Nitrate and Veg-Table Dietary Nitrate Scoring Method. I also discuss nitrates in Slowing Our Metabolism with Nitrate-Rich Vegetables and Oxygenating Blood with Nitrate-Rich Vegetables.

Do some plant foods have more aspirin than others? Definitely. In fact, some foods have the same amount as a “baby” aspirin. Check out Plants with Aspirin Aspirations.

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: