The Two Most Active Ingredients of the Mediterranean Diet

Which Parts of the Mediterranean Diet Extended Life.jpg

Olives and nuts are plant foods, and as such, are packed with antioxidants, raising the antioxidant level of our bloodstream resulting in lower fat oxidation and free radical DNA damage, but what's happening inside people's arteries?

Researchers measured the amount of atherosclerotic plaque in the neck arteries going to the brain in folks who for years were eating added nuts, added extra virgin olive oil or neither to their daily diets. In the control group, the plaque got worse, which is what happens when one continues to eat an artery-clogging diet, but there were no significant changes in the added extra virgin olive oil group, and the plaque in the added nut group appeared to get better. The nuts appeared to induce a regression of the disease, or at least a significant delay in the progression. The nut group was still suffering strokes, but only half as many, perhaps because the reduction in plaque height within the arteries on extra nuts was indicating a stabilization of the plaque, rendering them less likely to rupture. You can see these results in my video Which Parts of the Mediterranean Diet Extended Life?

Adding nuts to our diet may also improve endothelial function, boosting the ability of our arteries to dilate naturally by about 30 percent. If you look at the baseline adherence to Mediterranean diet principles and control for things like smoking and exercise, there were only two factors significantly associated with reduced heart attack and stroke risk: more vegetables and more nuts. No significant association with the olive oil, wine, fish or cutting back on soda and cookies. Among the individual components, only increased consumption of vegetables and nuts were related to reduced cardiovascular events.

On the one hand, cutting stroke risk in half just by eating a handful of nuts a day is pretty amazing, but those in the added nut group didn't appear to live any longer overall. This is in contrast to other studies that suggested that frequent nut consumption may extend life. For example, the Harvard health professionals studies, involving a whopping three million person-years of follow-up over decades, found nut consumption associated with fewer deaths from cancer, heart disease, respiratory disease and most importantly fewer deaths overall. This was confirmed by all the other big major prospective studies in a recent review.

So what's going on here with the study showing no longevity benefit from nuts? Did they just not wait long enough? Just because people were randomized to the nut group didn't mean they actually ate more nuts, and those randomized to the other groups didn't necessarily stay away.

If you re-analyze the data comparing the death rates of those who actually ate more nuts to those who actually didn't, nut consumption was indeed associated with significantly reduced risk of death. If you do the same kind of post hoc analysis with olive oil, even with the extra virgin, there is no benefit in terms of living longer. This is consistent with how Ancel Keys, the so-called Father of the Mediterranean diet, viewed olive oil. He thought of its benefit more as a way of just replacing animal fats; anything to get people to eat less lard and butter.

What is the best kind of nut? The greatest benefits were attributed to walnuts, particularly for preventing cancer deaths. Those eating more than three servings of walnuts a week appeared to cut their risk of dying from cancer in half.

Now it's just a matter of communicating the research to the public. All the major cancer groups emphasize a more plant-based diet, remarkably consistent with the World Health Organization guidelines for healthy eating. The far-reaching positive effects of a plant-based diet--including walnuts--may be the most critical message for the public.

Here are some of my previous videos on the Mediterranean diet:

Think the effects of adding a few nuts to one's daily diet are too good to believe? Check out my video Four Nuts Once a Month. For more on Walnuts and Artery Function check out the video, and for more on nuts and cancer prevention, see Which Nut Fights Cancer Better?

Nuts May Help Prevent Death and so may beans; see Increased Lifespan from Beans. What about Fruits and Longevity: How Many Minutes per Mouthful?

More on protecting ourselves from "brain attacks" in Preventing Strokes with Diet.

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:

Image Credit: garlandcannon / Flickr. This image has been modified.

Original Link

The Two Most Active Ingredients of the Mediterranean Diet

Which Parts of the Mediterranean Diet Extended Life.jpg

Olives and nuts are plant foods, and as such, are packed with antioxidants, raising the antioxidant level of our bloodstream resulting in lower fat oxidation and free radical DNA damage, but what's happening inside people's arteries?

Researchers measured the amount of atherosclerotic plaque in the neck arteries going to the brain in folks who for years were eating added nuts, added extra virgin olive oil or neither to their daily diets. In the control group, the plaque got worse, which is what happens when one continues to eat an artery-clogging diet, but there were no significant changes in the added extra virgin olive oil group, and the plaque in the added nut group appeared to get better. The nuts appeared to induce a regression of the disease, or at least a significant delay in the progression. The nut group was still suffering strokes, but only half as many, perhaps because the reduction in plaque height within the arteries on extra nuts was indicating a stabilization of the plaque, rendering them less likely to rupture. You can see these results in my video Which Parts of the Mediterranean Diet Extended Life?

Adding nuts to our diet may also improve endothelial function, boosting the ability of our arteries to dilate naturally by about 30 percent. If you look at the baseline adherence to Mediterranean diet principles and control for things like smoking and exercise, there were only two factors significantly associated with reduced heart attack and stroke risk: more vegetables and more nuts. No significant association with the olive oil, wine, fish or cutting back on soda and cookies. Among the individual components, only increased consumption of vegetables and nuts were related to reduced cardiovascular events.

On the one hand, cutting stroke risk in half just by eating a handful of nuts a day is pretty amazing, but those in the added nut group didn't appear to live any longer overall. This is in contrast to other studies that suggested that frequent nut consumption may extend life. For example, the Harvard health professionals studies, involving a whopping three million person-years of follow-up over decades, found nut consumption associated with fewer deaths from cancer, heart disease, respiratory disease and most importantly fewer deaths overall. This was confirmed by all the other big major prospective studies in a recent review.

So what's going on here with the study showing no longevity benefit from nuts? Did they just not wait long enough? Just because people were randomized to the nut group didn't mean they actually ate more nuts, and those randomized to the other groups didn't necessarily stay away.

If you re-analyze the data comparing the death rates of those who actually ate more nuts to those who actually didn't, nut consumption was indeed associated with significantly reduced risk of death. If you do the same kind of post hoc analysis with olive oil, even with the extra virgin, there is no benefit in terms of living longer. This is consistent with how Ancel Keys, the so-called Father of the Mediterranean diet, viewed olive oil. He thought of its benefit more as a way of just replacing animal fats; anything to get people to eat less lard and butter.

What is the best kind of nut? The greatest benefits were attributed to walnuts, particularly for preventing cancer deaths. Those eating more than three servings of walnuts a week appeared to cut their risk of dying from cancer in half.

Now it's just a matter of communicating the research to the public. All the major cancer groups emphasize a more plant-based diet, remarkably consistent with the World Health Organization guidelines for healthy eating. The far-reaching positive effects of a plant-based diet--including walnuts--may be the most critical message for the public.

Here are some of my previous videos on the Mediterranean diet:

Think the effects of adding a few nuts to one's daily diet are too good to believe? Check out my video Four Nuts Once a Month. For more on Walnuts and Artery Function check out the video, and for more on nuts and cancer prevention, see Which Nut Fights Cancer Better?

Nuts May Help Prevent Death and so may beans; see Increased Lifespan from Beans. What about Fruits and Longevity: How Many Minutes per Mouthful?

More on protecting ourselves from "brain attacks" in Preventing Strokes with Diet.

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:

Image Credit: garlandcannon / Flickr. This image has been modified.

Original Link

How to Mitigate and Prevent Crohn’s Disease with Diet

NF-Sept20 Preventing Crohn's Disease With Diet.jpeg

Crohn's disease is an autoimmune disorder that affects more than a million Americans. It is an inflammatory bowel disease in which the body attacks the intestines. There is currently no known cure for Crohn's disease; current research focuses on controlling symptoms. There is no definitive medical or surgical therapy. The best we have is a plant-based diet, which has afforded the best relapse prevention to date.

Researchers got the idea to try a plant-based diet because diets rich in animal protein and animal fat have been found to cause a decrease in beneficial bacteria in the intestine. So, researchers designed a semi-vegetarian diet to counter that, and 100 percent of subjects stayed in remission the first year and 92 percent the second year. These results are far better than those obtained by current drugs, including new "biological agents" that can cost $40,000 a year, and can cause progressive multifocal leukoencephalopathy, a disabling and deadly brain disease. And a healthy diet appears to work better.

But what about preventing Crohn's disease in the first place? A systematic review of the scientific literature on dietary intake and the risk of developing inflammatory bowel disease found that a high intake of fats and meat was associated with an increased risk of Crohn's disease as well as ulcerative colitis, whereas high fiber and fruit intakes were associated with decreased risk of Crohn's.

These results were supported more recently by the Harvard Nurse's Health Study. Data revealed that long-term intake of dietary fiber, particularly from fruit, was associated with lower risk of Crohn's disease. Women who fell into in the highest long-term fiber consumption group had a 40 percent reduced risk, leading the accompanying editorial to conclude, "advocating for a high-fiber diet may ultimately reduce the incidence of Crohn's disease."

The irony is that the highest fiber group wasn't even eating the official recommended daily minimum of fiber intake. Apparently, even just being less fiber deficient has a wide range of benefits, including a significant reduction in the risk of developing Crohn's disease, but why? The authors suggest it's because "fiber plays a vital role in the maintenance of our intestinal barrier function."

Our skin keeps the outside world outside, and so does the lining of our gut, but in Crohn's disease, this barrier function is impaired. You can see this under an electron microscope as shown in my video Preventing Crohn's Disease With Diet. The tight junctions between the intestinal cells have all sorts of little holes and breaks. The thought is that the increase in prevalence of inflammatory bowel diseases may be that dietary changes lead to the breakdown of our intestinal barrier, potentially allowing the penetration of bacteria into our gut wall, which our body then attacks, triggering the inflammation.

We know fiber acts as a prebiotic in our colon (large intestine), feeding our good bacteria, but what does fiber do in our small intestine where Crohn's often starts? We didn't know, until a landmark study was published. Researchers wanted to find out what could stop Crohn's associated invasive bacteria from tunneling into the gut wall. They found the invasion is inhibited by the presence of certain soluble plant fibers, such as from plantains and broccoli at the kinds of concentrations one might expect after eating them. They wondered if that may explain why plantain-loving populations have lower levels of inflammatory bowel disease. But, the researchers also found that there was something in processed foods that facilitated the invasion of the bacteria. Polysorbate 80 was one of them, found predominantly in ice cream, but also found in Crisco, Cool Whip, condiments, cottage cheese--you just have to read the labels.

What about maltodextrin, which is found in artificial sweeteners like Splenda, snack foods, salad dressings, and fiber supplements? Maltodextrin markedly enhanced the ability of the bacteria to glob onto our intestinal cells, though other additives. Carboxy-methyl cellulose and xanthan gum appeared to have no adverse effects.

This may all help solve the mystery of the increasing prevalence of Crohn's disease in developed nations, where we're eating less fiber-containing whole plant foods and more processed foods. What we need now are interventional studies to see if boosting fiber intake and avoiding these food additives can be effective in preventing and treating Crohn's disease. But until then, what do we tell people? The available evidence points to a diet low in animal fat, with lots of soluble fiber containing plant foods, and avoiding processed fatty foods that contain these emulsifiers. We also want to make sure we're not ingesting traces of dishwashing detergent, which could have the same effect, so make sure to rinse your dishes well. Researchers found that some people wash dishes and then just leave them to dry without rinsing, which is probably not a good idea. We don't currently have studies that show that avoiding polysorbate 80 and rinsing dishes well actually helps. Nevertheless, advice based on 'best available evidence' is better than no advice at all.

Here's a video about using a more plant-based diet to reduce the risk of relapses: Dietary Treatment of Crohn's Disease.

I get a lot of questions about additives like polysorbate 80. I'm glad I was finally able to do a blog about it. Here are some videos on some others:

If you, like me, used to think all fiber was good for was helping with bowel regularity you'll be amazed! See for example, Dr. Burkitt's F-Word Diet.

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--2013: Uprooting the Leading Causes of Death, More Than an Apple a Day, 2014: From Table to Able: Combating Disabling Diseases with Food, 2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet, and my latest, 2016: How Not To Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers.

Image Credit: Graphic Stock

Original Link

Which Nut Suppresses Cancer Cell Growth the Most?

NF-Dec22 Which Nut Fights Cancer Better?.jpg

People who eat nuts in their adolescence may have a better chance of fighting off breast cancer later in life, according to data from the Harvard Nurse's Study. A follow-up study involving the daughters of the nurses corroborated the findings. Those eating more peanut butter, nuts, beans, lentils, soybeans, or corn were found to have just a fraction of the risk for fibrocystic breast disease, which places one at higher risk of cancer. The protective effects were found to be strongest for those most at risk, such as those with a family history of breast cancer.

Another study out of the British Journal of Cancer found that even two handfuls of nuts a week may protect against pancreatic cancer, one of our most fatal malignancies.

Nuts are described as "nutritionally precious," which may explain some of the mechanisms by which nut components induce cancer cell death and inhibit cancer growth and spread in vitro. But which nuts work the best? In my video #1 Anticancer Vegetable, we learned that two classes of vegetables--the broccoli family vegetables and the garlic family vegetables--most effectively suppressed breast cancer cell growth. In Which Fruit Fights Cancer Better?, cranberries and lemons took the title.

What about nuts? In terms of antioxidant content, walnuts and pecans steal the show. Twenty-five walnuts have the antioxidant equivalent of eight grams of vitamin C (the vitamin C found in a hundred oranges).

But how do they do against cancer? In the video, Which Nut Fights Cancer Better?, you can see a graph of human cancer cell proliferation versus increasing concentrations of the ten most common nuts eaten in the United States. If you drip water on these cancer cells as a control, nothing happens. Hazelnuts, pistachios and Brazil nuts don't do much better. Pine nuts, cashews and macadamias start pulling away from the pack. Almonds appear twice as protective, halving cancer cell growth at only half the dose as pine nuts, cashews, and macadamias. Walnuts, pecans, and peanuts come out as the clear winners, causing a dramatic drop in cancer proliferation at just tiny doses.

More nuttiness:

-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 Uprooting the Leading Causes of Death, More Than an Apple a Day, From Table to Able, and Food as Medicine.

Image Credit: Mariya Chorna / Flickr

Original Link

Salmon May Be the Greatest Source of Dietary Pollutants

NF-Aug6 Pollutants in Salmon and Our Own Fat.jpg

In my video Diabetes and Dioxins, I explored a nationwide study that found a strong dose-response relationship between industrial toxins and diabetes. Since then, Harvard researchers have reported a link between persistent pollutants like hexachlorobenzene and diabetes in their Nurse's Health Study (See Food Sources of Perfluerochemicals). This is supported by an analysis they did of six other studies published since 2006 that showed the same thing. The Harvard researchers conclude that "past accumulation and continued exposure to these persistent pollutants may be a potent risk factor for developing diabetes."

Where is hexachlorobenzene found? In a U.S. supermarket survey, salmon and sardines were most heavily tainted with hexachlorobenzene, with salmon "the most contaminated food of all." Farmed salmon specifically is perhaps the greatest source of dietary pollutants, averaging nearly ten times the PCB load of wild-caught salmon.

Wait, isn't there a flaw in this argument? Since many of these chemicals were banned in the 70's, the levels inside people have been going down, whereas the rates of diabetes have been shooting straight up. Therefore, how could pollutant exposure be causing diabetes? This puzzle may be explained by our epidemic of obesity. The nationwide study found that the association between these toxins and diabetes was much stronger among obese subjects than among lean subjects. As people get fatter, the retention and toxicity of pollutants related to the risk of diabetes may increase.

So we're not just exposed by eating the fat of other animals; our own fat can be a continuous source of internal exposure because these persistent pollutants are slowly but continuously released from our fat stores into our circulation.

They don't call them "persistent pollutants" for nothing. These chemicals have such a long half-life that people consuming regular (even just monthly) meals of farmed salmon might end up retaining these chemicals in their bodies for 50 to 75 years.

Hexachlorobenzene in fish has been tied to diabetes; what about the mercury? A 1995 study highlighted in my video, Pollutants in Salmon and Our Own Fat, out of Japan found that diabetics do seem to have higher mercury levels in their body. Mercury alone does not seem to increase diabetes risk, though. It may be the simultaneous exposure to both dioxins and mercury that increases risk, so the safety limits for dioxins and mercury individually may underestimate the risk when they're consumed together in seafood.

So while the pharmaceutical industry works on coming up with drugs to help mediate the impact of these pollutants, a better strategy might be to not get so polluted in the first place.

Unfortunately, because we've so contaminated our world, we can't escape exposure completely. You have to eat something. Some foods are more contaminated than others, though. Exposure to these pollutants comes primarily from the consumption of animal fat, with the highest levels found in fatty fish like salmon. Farmed Atlantic salmon may be the single largest source of these pollutants, and that's the kind of salmon we most commonly find in supermarkets and restaurants.

We hear about advisories warning pregnant women to avoid the consumption of food containing elevated levels of pollutants and mercury, but as a public health journal article points out, since these toxins bio-accumulate in the body for many years "restricting the exposure to these pollutants only during pregnancy would not protect the fetus or future generations against the harmful effects of these hazardous chemicals."

For the existing links between seafood and diabetes risk, see Fish and Diabetes and I explored this concept of our own body fat as a reservoir for disease-causing pollutants in Diabetes and Dioxins.

More on hexachlorobenzene in my video Food Sources of Perfluorochemicals.

Our body has a tougher time getting rid of some toxins than others:

The best way to detox is to stop toxing in the first place.

-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 Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: Sharon Mollerus / Flickr

Original Link

Treating Asthma With Plants vs. Pills

NF-July7 Treating Asthma with Plants vs. Supplements.jpg

In my video Treating Asthma With Fruits and Vegetables, I highlighted a landmark study on manipulating antioxidant intake in asthma. The study found that just a few extra fruits and vegetables a day can powerfully reduce asthma exacerbation rates. If the antioxidants in the plants are ameliorating asthma, then why can't we take antioxidant pills instead? Because antioxidant pills don't appear to work.

Studies using antioxidant supplements on respiratory or allergic diseases have mostly shown no beneficial effects. This discrepancy between data relating to fruit and vegetable intake compared with those using antioxidant supplements may indicate the importance of the whole food, rather than individual components. For example, in the Harvard Nurse's Health Study, women who got the most vitamin E from their diet appeared to be at half the risk for asthma, (which may help explain why nut consumption is associated with significantly lower rates of wheezing), but vitamin E supplements did not appear to help.

Men who eat a lot of apples appear to have superior lung function, as do kids who eat fresh fruit every day, as measured by FEV1 (basically how much air you can forcibly blow out in one second). The more fruit, salad, and green vegetables kids ate, the greater their lung function appeared.

Researchers are "cautious about concluding which nutrient might be responsible." There's vitamin C in fruits, salads, and green vegetables, but there are lots of other antioxidants, such as "vitamin P," a term used to describe polyphenol phytonutrients found in grapes, flax seeds, beans, berries, broccoli, apples, citrus, herbs, tea, and soy. Polyphenol phytonutrients can directly bind to allergenic proteins and render them hypoallergenic, allowing them to slip under our body's radar. If this first line of defense fails, polyphenols can also inhibit the activation of the allergic response and prevent the ensuing inflammation, and so may not only work for prevention, but for treatment as well.

Most of the available evidence is weak, though, in terms of using supplements containing isolated phytonutrients to treat allergic diseases. We could just give people fruits and vegetables to eat, but then we couldn't perform a double-blind study to see if they work better than placebo. Some researchers decided to use pills containing plant food extracts. Plant extracts are kind of a middle ground. They are better than isolated plant chemicals, but are not as complete as whole foods. Still, since we can put whole foods in a capsule, we can compare the extracts to fake sugar pills that look and feel the same to see if they have an effect.

The first trial involved giving people extracts of apple skins. I've talked about the Japan's big cedar allergy problem before (See Alkylphenol Endocrine Disruptors and Allergies), so apple extract pills were given every day for a few months starting right before pollen season started. The results were pretty disappointing. They found maybe a little less sneezing, but the extract didn't seem to help their stuffy noses or itchy eyes.

What about a tomato extract? A randomized, double-blind, placebo-controlled eight-week trial was performed on perennial allergic rhinitis, this time not for seasonal pollen, but for year-round allergies to things like dust-mites. There are lots of drugs out there, but you may have to take them every day year-round, so how about some tomato pills instead? After oral administration of tomato extract for eight weeks, there was a significant improvement of total nasal symptom scores, combined sneezing, runny nose and nasal obstruction, with no apparent adverse effects.

Would whole tomatoes work even better? If only researchers would design an experiment directly comparing phytonutrient supplements to actual fruits and vegetables head-to-head against asthma, but such a study had never been done... until now. The same amazing study, highlighted in my video, Treating Asthma with Plants vs. Supplements?, that compared the seven-fruit-and-vegetables-a-day diet to the three-fruit-and-vegetables-a-day diet, after completion of its first phase, commenced a parallel, randomized, controlled supplementation trial with capsules of tomato extract, which boosted the power of five tomatoes in one little pill, and the study subjects were given three pills a day.

Who did better, the group that ate seven servings of actual fruits and vegetables a day, or the group that ate three servings a day but also took 15 supposed serving equivalents in pill form? The pills didn't help at all. Improvements in lung function and asthma control were evident only after increased fruit and vegetable intake, which suggests that whole-food interventions are most effective. Both the supplements and increased fruit and vegetable intake were effective methods for increasing carotenoid concentrations in the bloodstream, but who cares? Clinical improvements--getting better from disease--were evident only as a result of an increase in plant, not pill, consumption. The results provide further evidence that whole-food approaches should be used to achieve maximum efficacy of antioxidant interventions.

And if this is what a few more plants can do, what might a whole diet composed of plants accomplish? See Treating Asthma and Eczema with Plant-Based Diets.

I also dealt with preventing asthma in the first place: Preventing Asthma With Fruits and Vegetables.

The theme of whole foods being more efficacious than supplements seems to come up over and over again. See for example:

More on "vitamin P" in How to Slow Brain Aging by Two Years.

The anti-inflammatory effects of nuts may explain the Harvard Nurse's Health Study finding: Fighting Inflammation in a Nut Shell.

-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 Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: Mike Mozart / Flickr

Original Link

Slowing Cognitive Decline with Berries

NF-Apr21 How to Slow Brain Aging by Two Years.jpg

A plant-based diet is thought to have played a significant role in human evolution and the consumption of whole plant foods and even just extracts have repeatedly been associated with a decreased risk of aging related diseases. And by healthy aging I'm not talking preventing wrinkles, what about protecting our brain? "Two of the most dreaded consequences of dementia with aging are problems moving around and difficulty remembering things. Dementia robs older adults of their independence, control, and identity."

Fruits and vegetables help reduce the risk of other chronic diseases, so might they work for brain diseases as well?

There has been a proliferation of recent interest in plant polyphenols as agents in the treatment of dementia. There are 4,000 different kinds of polyphenols found ubiquitously in foods of plant origin, but berries are packed with them, possessing powerful antioxidant and anti-inflammatory properties. There's a subset of polyphenols called anthocyanidins, which are found in blue and purple pigmented fruits and berries. These polyphenols are uniquely and specifically capable of "both crossing the blood-brain barrier and localizing in brain regions involved in learning and memory." And that's precisely where we need them.

The brain takes up less than 2% of body weight but may burn up to 50% of the body's fuel, creating a potential firestorm of free radicals. Maybe these brain-seeking phytonutrients in berries could fight oxidation and inflammation, and even increase blood flow? This raised a thought-provoking idea. Maybe a "nutritional intervention with blueberries may be effective in forestalling or even reversing the neurological changes associated with aging?" It would be a decade before the first human trial was conducted, but it worked! "Blueberry supplementation improves memory in older adults," suggesting that "consistent supplementation with blueberries may offer an approach to forestall or mitigate brain degeneration with age."

What other blue or purple foods can we try? Concord grape juice was also tested and had a similar benefit, suggesting that supplementation with purple grape juice may enhance cognitive function for older adults with early memory decline. Why use juice and not whole concord grapes? Because then you couldn't design a placebo that looked and tasted exactly the same to rule out the very real and powerful placebo effect. And also because the study was funded by the Welch's grape juice company.

This effect was confirmed in a follow-up study, showing for the first time an increase in neural activation in parts of the brain associated with memory using functional MRI scans. But this brain scan study was tiny: just four people in each group. And same problem in the blueberry study: it had only nine people in it.

Why haven't large population-based studies been done? Because we haven't had good databases on where these phytonutrients are found. We know how much vitamin C is in a blueberry, but not how much anthocyanidin--until now. The Harvard Nurses' Health Study, highlighted in my video, How to Slow Brain Aging by Two Years, followed the cognitive function of more than 16,000 women for years, and found that "long-term consumption of berries was related to significantly slower rates of cognitive decline, even after careful consideration of confounding socioeconomic status" (that is, even after taking into account the fact that rich people eat more berries). The Harvard Nurses' Health Study was the first population-based evidence that greater intakes of blueberries and strawberries were highly associated with slower rates of cognitive decline, and not just by a little bit. "The magnitude of associations were equivalent to the cognitive differences that one might observe in women up to two and a half years apart in age." In other words, women with higher intake of berries appeared to have delayed cognitive aging by as much as two and a half years.

Why shouldn't we just take some anthocyanidin supplement? Because there hasn't been a single study that found any kind of cognitive benefit by just giving single phytonutrients. In fact, the opposite is true. "Whole blueberries appear to be more effective than individual components, showing that the whole is greater than the sum of its parts." These findings have potentially substantial public health implications, as increasing berry intake represents a fairly simple dietary modification to test in older adults for maintaining our brain function.

What other ways could we improve our memory and cognitive function?

What other near-miraculous properties of berries are there?

I add them to my morning smoothie: A Better Breakfast.

-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 Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: Angelo Desantis / Flickr

Original Link

How Grapefruit Affects Prescription Drugs

NF-Aug5 How Grapefruit Affects Prescription Drugs.jpg

Does grapefruit in particular help people lose weight?

If someone eats half of a grapefruit three times a day before each meal for a couple months, they may lose about two pounds -- but that's no more than if they ate three apples or pears a day. In one study, the grapefruit eaters not only saw their weight go down, but their waist got slimmer, and their body fat melted away. If, however, we repeat the experiment and instead ask people to drink a half cup of water before each meal, we get the same result. So this belief that grapefruit has some special fat-burning quality appears to be just a long-held myth.

The researchers reported that grapefruit consumers had a drop in weight, a significant drop in cholesterol, and a significant drop in blood pressure. They concluded that consumption of grapefruit daily for six weeks does not significantly decrease body weight, cholesterol, or blood pressure, though. That made me do a little double take, but again, it's because the grapefruit didn't do any better than placebo.

Other studies have found a legitimate cholesterol-lowering benefit of grapefruit, and even a little dip in triglycerides, especially eating red as opposed to white . For example, one study showed a decrease in cholesterol, but only from one life-threatening cholesterol level to another life-threatening cholesterol level. To prevent heart disease, we really have to get down to a total cholesterol of around 150, which is the average cholesterol of those eating diets composed exclusively of plant foods, not just grapefruits (See, for example, One in a Thousand: Ending the Heart Disease Epidemic).

Even though grapefruits alone don't do much, the researchers suggest that people might be more likely to stick with them than cholesterol lowering drugs, noting that most people with heart disease stop taking their statin drugs within a couple years because of the adverse side effects (see Statin Muscle Toxicity). While grapefruits alone don't have any side effects, ironically, combining grapefruits and drugs can make drug side effects even worse.

If we eat lots of fruits and vegetables, we hopefully won't need a lot of drugs (Say No to Drugs by Saying Yes to More Plants), but certain phytochemicals in plants can affect the metabolism of drugs in the body. Grapefruit is the poster child, described as a "pharmacologist's nightmare." Natural phytochemicals in grapefruit suppress the enzymes that help clear more than half of commonly prescribed drugs, and less drug clearance means higher drug levels in the body. This may actually be good if we want a better caffeine buzz from our morning coffee, or our doctors want to help us save thousands of dollars by boosting the effects of expensive drugs instead of just peeing them away.

But higher drug levels may mean higher risk of side effects. Women taking the Pill are normally at a higher risk of blood clots, but even more so, perhaps, if they have been consuming grapefruit. Taking the Pill with grapefruit juice may increase blood drug concentrations by 137 percent.

If suppressing our drug clearance enzymes with grapefruit juice elevates levels of ingested estrogen, what might it be doing to our own estrogen levels? A study associating grapefruit consumption with breast cancer freaked out the medical community, but subsequent studies on even larger groups of women found no evidence of a link. The Harvard Nurses' Study even found a decreased risk of the scariest breast cancer type, so it doesn't look like we have to worry about grapefruit affecting our natural chemistry.

For those prescribed unnatural chemistries, it may be a good idea to discontinue grapefruit consumption for 72 hours before use of a drug that may interact with it. If you don't want to give up your grapefruit, you can ask your doctor about switching from a grapefruit-affected drug like Lipitor to one of the citrus-proof alternatives (the replacement drug chart can be seen in my video, Tell Your Doctor If You Eat Grapefruit).

Other videos on citrus include:

And another video on the risks associated with taking estrogens: Plant-Based Bioidentical Hormones.

Can't eat grapefruit without sprinkling sugar on top? Try erythritol instead to avoid so many empty calories: Erythritol May Be a Sweet Antioxidant.

-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 Uprooting the Leading Causes of Death and More Than an Apple a Day.

Image Credit: Liz West / Flickr

Original Link

Breast Cancer and Wine

 

 

 

 

 

 

 

 

NF-Mar20 Breast Cancer Risk - Red Wine vs. White Wine.jpg

After diagnosis, women with breast cancer may cut their risk of dying nearly in half by just instituting simple, modest lifestyle changes—5 or more servings of fruits and veggies a day and walking 30 minutes a day, 6 days a week. But what about preventing breast cancer in the first place?

If we follow the advice of the official dietary guidelines for cancer prevention, does it actually reduce our risk of cancer? If we manage our weight, eat more plant foods, less animal foods, less alcohol and breastfeed, based on the largest prospective study on diet and cancer in history, we may significantly lower our risk of breast cancer, endometrial cancer, colorectal cancer, lung cancer, kidney cancer, stomach cancer, oral cancer, liver cancer, esophageal cancer, and all cancers combined.

Of all the recommendations, the “eat mostly foods of plant origin” appeared the most powerful. For example, a study in the UK found that in just one year in Britain there were 14,902 excess cases of cancer caused by something participants were exposed to 10 years earlier. What was that something that ended up causing thousands of cancers?  

Deficient intake of fruit and vegetables.

If that was instead, some chemical spill causing 14,000 cancers, people would be up in arms to ban it—but instead when that killer carcinogen is not eating their “fruit and veg” (as the Brits would say), it hardly gets anyone’s attention.

What if we throw in smoking, too? Researchers created a healthy lifestyle index, defined by four things: 1) exercise;  2) a dietary shift away from the standard American diet high in meat, dairy, fat, and sugar towards a more prudent dietary pattern—for instance more green and yellow vegetables, beans, and fruits;  3) avoidance of tobacco; and 4) avoidance of alcohol. Young women scoring higher on those four things cut their odds of getting breast cancer in half, older women cut their odds of breast cancer by 80%!

We’ve covered how even light drinking can increase breast cancer risk (see my video Breast Cancer and Alcohol: How Much is Safe?), but for women who refuse to eliminate alcohol, which is less carcinogenic: red wine or white? Some studies, outlined in my four minute video, Breast Cancer Risk: Red Wine vs. White Wine, actually suggest less or even no risk from red wine, and we may have just figured out why. Remember how mushrooms were the vegetable best able to suppress the activity of aromatase, the enzyme used by breast tumors to produce its own estrogen? (from my video Vegetables Versus Breast Cancer). Well, if we run the same human placenta experiments with fruit, strawberries get the silver, but grapes get the gold.

For more on the aromatase story, see:

But what kind of grapes? The wimpy green grapes used to make white wine barely worked compared to those used for making red.  Bottom line: “red wine may serve as a nutritional aromatase inhibitor, which may ameliorate the elevated breast cancer risk associated with alcohol intake.” But why accept any elevated risk? Just eat whole grapes! And if you do, choose ones with seeds if you can, as they may work even better. More on grapes in Fat Burning Via Flavonoids and Best Fruit Juice.

Wasn’t there a study that found that fruits and vegetables weren’t protective against cancer, though? See my video on the EPIC Study.

What if you already have breast cancer? Well, Cancer Prevention and Treatment May Be the Same Thing, but I do have a few studies on breast cancer survival and diet:

-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 Uprooting the Leading Causes of Death and More Than an Apple a Day.

Image credit: TonalLuminosity / Flickr

Original Link