Why Large Amounts of Fruit May Not Be Healthy

fruit The editorial linked below appeared in the American Journal of Clinical Nutrition. It traces the rise in fructose consumption, and the rise in chronic diseases that have come in its wake.

Fructose is a simple sugar found in honey, fruit, table sugar, and high-fructose corn syrup (HFCS). Because of the increase in the consumption of these sweeteners, fructose intake worldwide has quadrupled since the early 1900s.

Over the past three decades, there has been an even greater acceleration in consumption, in part because of the introduction of HFCS. The increase in fructose consumption parallels the rise in obesity, diabetes, hypertension, and kidney disease.

Studies in animals have shown that fructose can induce insulin resistance, elevated triglycerides, abdominal obesity, elevated blood pressure, inflammation, oxidative stress, endothelial dysfunction, microvascular disease, hyperuricemia, glomerular hypertension and renal injury, and fatty liver. The consumption of large amounts of dietary fructose also can rapidly induce insulin resistance.
Sources:

* American Journal of Clinical Nutrition November 2008, 88(5): 1189-1190


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Dr. Mercola Dr. Mercola's Comments:
Fruits contain antioxidants, vitamins and minerals, which is why eating a small amount of them is fine for healthy people. However, I would conservatively estimate that 75 percent of the population needs to restrict fruit intake, and this is directly related to its fructose content.

Fructose, a simple sugar found in fruit, is preferentially metabolized to fat in your liver, and eating large amounts have been linked to negative metabolic and endocrine effects. So if you eat large amounts of fruit, or, worse, drink large amounts of soda or juice, or eat a lot of processed foods (both of which usually contain high-fructose corn syrup), you may be increasing your risk of:

• Insulin resistance
• Impaired glucose tolerance
• High insulin levels
• High triglycerides
• High blood pressure

• Leptin resistance
• Obesity
• Metabolic syndrome
• Oxidative stress

How Fructose Wreaks Havoc in Your Body

Your body absorbs fructose differently than other sugars, and while this doesn’t sound like a very big deal, it causes a cascade of problems.

If you eat glucose, for instance, your production of insulin increases so that sugar in your blood can be taken to cells and used for energy. Eating glucose also increases production of leptin, which regulates your appetite and fat storage, and decreases production of ghrelin, which helps regulate your food intake. The idea is that when you eat glucose, your body knows it should feel less hungry.

With fructose, this is not the case. Eating fructose does not stimulate insulin or leptin production, and it does not suppress ghrelin. This is why fructose may contribute to weight gain, and the host of problems that go along with it.

Fructose also gets converted into triglycerides more efficiently than glucose, which is a big negative since elevated triglycerides are linked to an increased risk of heart disease. Fructose also interferes with the balance of magnesium in your body, which may accelerate bone loss.

The Largest Source of Fructose in the American Diet?

While fruit does contain fructose, eating fruit in moderation is not the problem. The biggest culprit, by far, is the consumption of high-fructose corn syrup, especially in the form of soda, fruit juice and other beverages, as that is now the number one source of calories in the U.S.

Food and beverage manufacturers began switching their sweeteners from sucrose (table sugar) to corn syrup in the 1970s when they discovered that HFCS was not only cheaper to make, it was also much sweeter (processed fructose is nearly 20 times sweeter than table sugar), a switch that has drastically altered the American diet.

As I said, the number one source of calories in the United States is not meat, veggies or even bread -- it’s high-fructose corn syrup from soda.

The fact that most fructose is consumed in a liquid form significantly magnifies its negative metabolic effects. Since this is such a pervasive problem in the United States, we could make radically outrageous improvements in our health as a culture if we just simply stopped everyone from drinking soda!

So, in order of importance, if you’re trying to reduce the amount of fructose in your diet, which is, by the way, a very wise move, you should focus on eliminating:

1. Soda
2. Fruit juice and other sweetened beverages
3. Processed foods that contain HFCS

Should You Also Eliminate Fruit?

Fruit is definitely a source of fructose, and one that can harm your health if you eat it in vast quantities. However, eating small amounts of whole fruits, in accordance to your nutritional type, is fine if you are healthy.

Those who need to be careful about their fruit intake are people with high insulin levels. You can measure your fasting insulin level to find out for sure, but if you have any of the following problems it is highly likely you have insulin resistance syndrome:

• Overweight
• High Cholesterol
• High Blood Pressure
• Diabetes
• Yeast Infections

Some of the best fruits to eat are small berries. They are even better if you can use a high-speed blender like a Vita Mixer, which pulverizes the seeds and releases the stored antioxidants, polyphenolic bioflavonoids, that are stored there. Most people don’t realize that most of the healthy constituents of the fruit are stored in the skin and the seeds.

However, if you’re trying to reach optimal health, I highly suggest you eat fruit in accordance with your nutritional type.

For example, if you’re a protein type, fruits are generally not beneficial for you with the exception of coconut, which has a higher fat content that is beneficial for protein types.

On the other hand, carbohydrate types tend to fare well with fruit and can safely consume moderate amounts. This is an important distinction, and everyone should try to eat primarily the specific fruits t

then again, it's really hard to distinguish whether you are completely "protein type" or a "carbohydrate type" considering there is such a mix of metabolisms out there; so more people are most likely mixed, with more of a protein type, or more of a carbohydrate type. So one is probably required more then the other -- but not to extremities like 90% protein or 90% carbohydrate -- unless they are pretty much a "pure bred" person- this is my understanding of it

ah

informing article; so fructose absorption is affected if you eat too much of it? fruits high in fructose are things like apples and pears, and syrups like honey, i've read.

an example of a person who eats all protein and fat is like.. an eskimo; all carbohydrate is probably south african
it's best to look at what people un-effected by the western diet eat and how they survive without disease, i think - more importantly how they use that food they eat, what tasks they do, and such. no wonder it's so hard to find the right diet in a pampered society.

Is is any surprise that a raw foodist that has a high amount of fat and protein in their diet is going to feel bad eating a lot of fruit?

Also, most of the research around fructose was done with high fructose corn syrup, not with fresh fruit. Fresh fruit has tons of fiber and phytonutrients that offset any kind of (refined) sugar related ill effects.

when i said bad article i meant
1. there is no evidence of nutritional "types"
2. invalid conclusions drawn and mixing up fructose in fruit with hfcs
3. taking studies and falsely concluding that fructose is to blame and ignoring other factors, then extrapolating this to demonize fruit.

etc.

[shockingly bad article from mercola]

All of his articles are shockingly bad. Don't read his garbage anymore.

When I was much younger and still ridding my body of toxins and candida, I was sure I was a 'protein type' for awhile. It was only after I healed further that I realized I was clearly not meant to eat that way. I bet a lot of people get caught in this predicament, craving lots of protein because their bodies aren't assimilating nutrients properly.

Sharrhan:


[www.facebook.com]

I wonder how much fructose our ancestors ate.

Well, since we are descended from a line of frugivorous apes I would say quite a bit, but not in a purified form. Too, wild fruits tend to be lower in fructose than modern cultivars.

In addition we have moved away a bit from such diets-- most people prefer diets with significantly less bulk, by choosing either starches, which are just long chains of glucose, fats, or animal foods.

But it seems pretty clear that the diets with the most overtly therapeutic effects are the very high nutrient density, high fiber ones that are not too high in fat and either seriously limit or eliminate animal foods. The biggest source of calories then must come from either fruit or starches. Starch sources of course must be cooked and tend to have a lower yield of protective phytochemicals.

I have read many papers on the evils of purified fructose, and even some on the evils of too much fruit juice, but none on the evils of too much fruit. The fibers and the phytochemicals in the whole sources especially when the skins and flesh are highly colored must be providing significant protection. Fruit wants to be eaten. We evolved to eat it and disperse the seeds as plants evolved their fruits to become more enticing.

Fructose can jump in the citric acid cycle, it can even be rearranged from a glucose molecule, phosphorylated, and then split into two glyceraldehyde phosphates, which then yield ATP and NADH.

We can do just fine with fructose, the key must be to keep from spiking the plasma with more than what can be metabolized at the time. I doubt it's possible to overdo it as long as we stick with the whole food sources, stay thin or normal weight, and we are also meeting out mineral, EFA, and essential amino acid needs.

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Well, since we are descended from a line of frugivorous apes I would say quite a bit, but not in a purified form. Too, wild fruits tend to be lower in fructose than modern cultivars.

We branched off quite a long time ago however. I'm no scientists but AFAIK humans have been distinct from other primates for a million+ years.

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In addition we have moved away a bit from such diets-- most people prefer diets with significantly less bulk, by choosing either starches, which are just long chains of glucose, fats, or animal foods.

What about tubers? And/or a mix of the above. Most human cultures don't limit themselves to just one or two food groups.

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But it seems pretty clear that the diets with the most overtly therapeutic effects are the very high nutrient density, high fiber ones that are not too high in fat and either seriously limit or eliminate animal foods.

With that in mind have vegans, as a group, every been studied in any significant way. I'm actually quite curious about this. I know there was one tiny study of raw food vegans in Europe somewhere but I'm not aware of any large study of vegans. It would do a lot to dispels people's fears if what you're saying could objectively be proven to be true (in a number of large studies).

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The biggest source of calories then must come from either fruit or starches.

Or tubers or a different source depending on the season.

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Starch sources of course must be cooked and tend to have a lower yield of protective phytochemicals.

Which can be counter-balanced with nutrient rich green vegetables.

Would you say a diet of say bananas, apples, grapes & a romaine salad with an avocado would cover the bases better than say one of quinoa, rice, tubers, assorted nutrient rich veggies (broccoli, kale, chard, collards, etc.) with a few supplements &/or fortified foods & a small amount of an animal product (say backyard eggs)?

I'm a bit skeptical but curious as to your thoughts on the matter since you study this & I don't.

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Fruit wants to be eaten. We evolved to eat it and disperse the seeds as plants evolved their fruits to become more enticing.

That's neither here nor there. Grains & even livestock co-evolved with humanity. I'm not sure how badly sterile apples "want" to be grafted to hardier trees monocropped in huge plantations.

It's an enticing moral argument & one I got caught up in when I first got into raw food. It's beautiful in a way. I'm just not sure how much it applies to the average piece of fruit being eaten by the average person in today's modern industrial world.

Quote

We can do just fine with fructose, the key must be to keep from spiking the plasma with more than what can be metabolized at the time. I doubt it's possible to overdo it as long as we stick with the whole food sources, stay thin or normal weight, and we are also meeting out mineral, EFA, and essential amino acid needs.

But there's a big jump from fine to optimal.

Again, I'm not arguing that fruit is not optimal, just questioning whether it should make up the majority (or even largest minority) of man's diet.

Note : I'm not advocating animal products as I know it's frowned on, just asking pointed questions I am honestly curious as the answers to. Thank you!

edited to correct formating & a few basic typos fixed (there may still be more )



Edited 2 time(s). Last edit at 11/30/2008 03:33AM by communitybuilder.

[We branched off quite a long time ago however. I'm no scientists but AFAIK humans have been distinct from other primates for a million+ years. ]

Yes, but the foods that provide the most protection from diseases of affluence are the ones that those more distant relatives ate. So there is probably some merit in aiming backward, way beyond the paleo.


[What about tubers?]

These are starches.

[Would you say a diet of say bananas, apples, grapes & a romaine salad with an avocado would cover the bases better than say one of quinoa, rice, tubers, assorted nutrient rich veggies (broccoli, kale, chard, collards, etc.) with a few supplements &/or fortified foods & a small amount of an animal product (say backyard eggs)? ]

I would say best would be broccoli, kale, chard, collards, romaine, avocado, a handful of nuts and seeds, whole-food cooked starches (all whole grains, grain-like foods, roots, tubers, and beans) sparingly, and fruit to fill up. Eggs only if the chickens are treated like princesses, the males are not killed, and all are left to live out their natural lifespans unbothered even after their productivity declines. Of course this is probably not feasible most cases, certainly not where I live, so I skip them.

We can't say much about optimal, but one thing I am pretty sure of is this: optimum servings of fruits and vegetables for CVD health is somewhere between 20 and 55. How are you going to get there? You can't do it from vegetables alone.



Edited 1 time(s). Last edit at 11/30/2008 04:18AM by arugula.

Oops, too late to edit again, that second to last sentence should read "optimum servings of fruits and non-starchy vegetables for CVD health."

But the Okinawan centenarians who do around 13 or so rather than 20-55 and eat lots of sweet potato and rice and a bit of fish instead of fruit are not doing to shabbily. They are definitely in the very low fat (10-13% of calories) very low fish (5%) category however.

whats an AFAIK human? .... im confused

i stopped mercola's emails awhile back .. the stuff hes been saying just doesnt jive with me these days



Edited 1 time(s). Last edit at 11/30/2008 05:13AM by Jgunn.

Quote

We can't say much about optimal, but one thing I am pretty sure of is this: optimum servings of fruits and vegetables for CVD health is somewhere between 20 and 55. How are you going to get there? You can't do it from vegetables alone.

CVD? Cardiovascular?

22 to 55 servings a day? That sounds excessive. Who's telling us this? Why not just eat a few super-concentrated veggies, a few fruits & skip the mountains of bananas and grapes & whatnot that the Dough Graham advocates claim we must eat (and must practice stretching our stomachs to accommodate).

Also, is eating 55 fruits a day (or is that bites of fruit) for an American or European (95% of our posters I'd say) or anyone living outside of the tropics ecologically practical?

We're not going to have 13cent bananas forever.

O & BTW Jgunn AFAIK = as far as I know

ohhhhhhhh !!! ROFL !! im sucha dork

[22 to 55 servings a day? That sounds excessive. Who's telling us this?]

David Jenkins, the guy who coined the term "glycemic index." He's probably one of the foremost experts on type II diabetes in the world.

[ Why not just eat a few super-concentrated veggies, a few fruits & skip the mountains of bananas and grapes & whatnot that the Dough Graham advocates claim we must eat (and must practice stretching our stomachs to accommodate). ]

Nope, not the same. The key is the very high fiber content, yes you do have to eat a lot to reach it, it's easier if you split it into many smaller meals in a day. You can't match the therapeutic benefits with fiber supplements. It has to be from real food. If 55 is daunting then try 20, maybe 6-8 pieces of fruit, 10 cups of romaine and 2 cups of other nonstarchy vegetables, some cooked, that's about how I do it. I think it is better to incorporate more veggies, even if some of them are lightly steamed, so I don't completely agree with Graham. But I do suspect that he is right about many things.

[Also, is eating 55 fruits a day (or is that bites of fruit) for an American or European (95% of our posters I'd say) or anyone living outside of the tropics ecologically practical? ] Peaches, pears and apples are not tropical fruits. There are lots of fruits that are not tropical.

The diet he tested was about 40% sweet fruit, 22% nuts/seeds, the rest from nonstarchy vegetables that could theoretically be eaten raw but were probably cooked in most cases. Total fat was about 27%.

All things considered, plant foods are more ecologically practical than animal foods. Miles traveled is not the sole means of damage assessment. But, if distance and processing are equal, higher fat diets are usually lower impact than lower fat diets, the energy in transport is small compared to the energy in the food. If your starches are local you can use a little energy to cook them without much guilt. Sweet potato, regular potato, and winter squash are all pretty good starch sources.

peaches pears and apples have double the fructose of their glucose. just saying.

i think, arugula, that when you say and others say that fruit is "meant" for human beings (in large consumptions), that you don't have much proof just saying we diverged from "frugivorous" apes, considering even apes aren't completely fruit eaters and have a HUUUGE range of food (chimps do) that they eat, somewhere over 150 different species of plants, and bugs and even other monkeys. Even if the percentage is small for the meat and bugs, it's STILL a percentage..they also eat dirt n feces for B12 - which makes a huge difference in B12 levels (i said this in a different post regarding B12, it was in an article) in captive chimps vs. wild ones. And gorillas eat mostly leaves. But anyway, the point is that people have been evolving separately for thousands and thousands of years (just look at the color of our skin); all of us are simply not the same on the inside. Everyone's genes are some kind of mix and we've all adapted differently, therefor one diet can not be typical for ALL human beings. It all depends on your genetic make up (for example, the highest percentage of people with intolerance to milk are the asians, that's *probably* because they've been drinking it for the least amount of time in history; next i think are the africans.)

So it's all crazy, but I think it's important to look at the evolution of common man, and not just go straight from monkey > to human.

i do think that fructose in fruit is DEFINITELY not comparable to high fructose corn syrup or sucrose by any means.. that's just whack

they should do different studies for that -- all the studies I find do tend to group fruit under "sugar" associated with bad sugars rather then it being complex and natural..pshh hope more of the distinguishing factors are taken into consideration in the future..or i hope i find one )

Arugula, you rock! I love that you make sense. Please keep posting! I always read what you post. Thanks so much.

[i think, arugula, that when you say and others say that fruit is "meant" for human beings (in large consumptions), that you don't have much proof ]

Oh, yes, this is something that pretty much all evolutionary biologists agree on, and it doesn't hold just for humans, but many animals as well. We disperse the seeds for the plants.

[just saying we diverged from "frugivorous" apes, considering even apes aren't completely fruit eaters and have a HUUUGE range of food (chimps do) that they eat, somewhere over 150 different species of plants, and bugs and even other monkeys. Even if the percentage is small for the meat and bugs, it's STILL a percentage..]

We did descend from a frugivorous line. That is not to say they are 100% frugivorous, but that most of their calories come from fruit.

[But anyway, the point is that people have been evolving separately for thousands and thousands of years (just look at the color of our skin); all of us are simply not the same on the inside. Everyone's genes are some kind of mix and we've all adapted differently, therefor one diet can not be typical for ALL human beings. It all depends on your genetic make up]

But there are no studies showing that some people do not benefit from high fiber diets, so your point is pretty moot at the present time, and I strongly suspect forever. There is only one highly significant well-documented difference in digestion that arose in those tens of thousands of years and that is degree of lactose intolerance.

I don't argue pure veganism from an evolutionary standpoint, or even a health standpoint. I support pure veganism for ethical and environmental reasons. Just want to make that clear.

arugula Wrote:
-------------------------------------------------------
> All things considered, plant foods are more
> ecologically practical than animal foods.

I dunno. It seems to be that a permaculture style farm would do best to have animals & plants. I'm not sure I would have the heart to kill anything but chickens, for example, speed up composting considerable, and create a useful byproduct (though I can't stand eggs myself, my GF & cats like them). Animals could be used to plow. Goats could transform unfarmable land into milk. Certainly living solely on fruit (maybe 1-10% would make sense in winter, up to 50% in the summer).

I don't know, I don't live very ecologically. In the winter I get 60-90% of my food from California (not sure where my quinoa is from or my tomato paste).

I doubt living ecologically in New Jersey or New England would involve much fruit this time of year.

Grapes, pears, and apples are all in season now in the northeast.

Yeah but a diet of 50%+ grapes, pears & apples would rot my teeth (seedless grapes alone hurt my teeth & make me feel jittery). Not to mention be rather boring.

How about in February. I can see still having apples but I don't think the grapes & pears would last that long. Maybe if I made wine with the grapes but I think most raw foodists are anti-alcohol, even in moderation.

communitybuilder,

Eating all raw foods and eating all raw vegan is not a diet that works for everybody. If eating that much fruit doesn't work for you, that's OK. It does work for me and others here. Most people in this world would find eating only raw fruits and vegetables quite boring. And of course, these people reap the benefits (or the consequences) of their choices.

Dried fruit, community builder. You'd be so bored with your vittles you'd want to die, but you wouldn't die from your vittles : ) My problem with Doc Mercola, to whose anti-fructose tirades I have always responded contrarily on his message boards, is that he seems to use fructose as a stealthy and subtle means of pushing a "meatist" agenda. Like, don't eat fruit; it will make you fat because no primates eat just fruit, but DO eat steak tartare because you have incisors for a reason. Anthropological cherry-picking, ahoy!

I agree with Bryan. Totally

Bryan Wrote:
-------------------------------------------------------
> communitybuilder,
>
> Eating all raw foods and eating all raw vegan is
> not a diet that works for everybody. If eating
> that much fruit doesn't work for you, that's OK.
> It does work for me and others here. Most people
> in this world would find eating only raw fruits
> and vegetables quite boring. And of course, these
> people reap the benefits (or the consequences) of
> their choices.

Of course. Everyone reaps what they sew.


Tamukha Wrote:
-------------------------------------------------------
> Dried fruit, community builder. You'd be so bored
> with your vittles you'd want to die, but you
> wouldn't die from your vittles : ) My problem
> with Doc Mercola, to whose anti-fructose tirades I
> have always responded contrarily on his message
> boards, is that he seems to use fructose as a
> stealthy and subtle means of pushing a "meatist"
> agenda. Like, don't eat fruit; it will make you
> fat because no primates eat just fruit, but DO eat
> steak tartare because you have incisors for a
> reason. Anthropological cherry-picking, ahoy!

Everyone's got an agenda baby.

I make no secret of my vegan agenda, or why it motivates me. The question here I think is starch vs. fruit.

I'll take fruit for the most part, because I want the fiber, the carotenoids, resveratrol, anthocyanins, quercetin, hesperidin, tangeritin, kaempferol, myricetin, apigenin, phenolics, and limonene, to name a few, these are only a handful of the known compounds that provide benefits. Yeah you can get some carotenoids from colored sweet potatoes and squash, and you can get some (usually not as much per calorie) fiber from whole grains, but if you want the rest of them, and a lot more, eat fruit.

You're pretty convincing arugula.

Grain really doesn't taste that great either. I have to admit. I had a bowl of quinoa tonight & it was just so bland I could barely shove it down.

What do you think of food combining, BTW?

I really think the "dangers" of too much fat are a bit overblown though. I've been eating 300-400 grams of fat a day for nearly half a decade now (I feel addicted) and while I'm not feeling at my finest I still can run up the stairs & cruise thru traffic with not too much of a problem.

Grains are very tasty with some fat and vegetables.

I don't think food combining is necessary, but some people feel better with it. I'd rather mix up my foods, they taste better to me that way.

You are still young. The differences in lifestyle start to show around 35-ish.

400g per day is really high, I would estimate your actual intake to be about half that most days. That would still be 60% in a 3000 kcal/day diet. But if you are eating lots of f+v on top of that, and most of your fat is raw and monounsaturated, well it might be ok, I don't really know. I lean towards lower, I feel safer with it.

I don't follow any food combining either.

I respect anyone who does, but for myself found it to be far too much of a hassel. I don't seem to have any digestive problems as long as I chew my food properly and don't binge excessively on a meal.

300-400 grams of fat is a lot! Wow. I would certainly not be able to do that much myself.