Fruits and Vegetables offer modest cancer prevention?

Article that went up on Science Daily today in which a study of 400k people only found "weak" links between consumption of fruits and vegetables and cancer.

http://www.scienceda...00406162941.htm

An analysis of dietary data from more than 400,000 men and women found only a weak association between high fruit and vegetable intake and reduced overall cancer risk, according to a study published online April 6, 2010 in the Journal of the National Cancer Institute.

The authors found a small inverse association between high intake of fruits and vegetables and reduced overall cancer risk. Vegetable consumption also afforded a modest benefit but was restricted to women. Heavy drinkers who ate many fruits and vegetables had a somewhat reduced risk, but only for cancers caused by smoking and alcohol.

I guess modest is better than nothing at all eh?

I think fruits and vegetables provide protection against an array of different diseases, cancer being just one. Hopefully no one takes this as an excuse to skip those fruits and vegetables

Click HERE to rent this advertising spot for NUTRITION to support LongeCity (this will replace the google ad above).

I was going to make a thread about this but here is better:

Plants and plant compounds are not essential or magic
http://www.paleonu.c...l-or-magic.html

Show me a randomized intervention that shows the benefits of fruits and vegetables. Such trials have been done and they have not shown a benefit. Same as the trials to limit fat consumption.

It's "lets see what (olive oil, resveratrol, blueberries antioxidantss - insert name of magic chemical here) does in a test tube or in mice. Look, one of our many experiments shows something! Humans must have evolved to be dependent on this substance to optimize their health.

Look, I don't read everything but I read a lot. I am not interested in dying early. The minute I see plausible evidence of some magic supplement working or an essential plant that is not commmon to all humans, I'll be the first one to promote it.

Analogical reasoning (wolves eat leaves, therefore,,... ) is not enough. We need a plausible biochemical explanation combined with robust epidemiological evidence (rare) or real proof from an intervention.

To overcome the inherent implausibility of a particular compound or plant being essential or uniquely beneficial to health, there must be a high standard of proof.

Similar to the level of proof there that there is extraterrestrial intelligence. It's implausible, so good evidence is needed. If we believe, as I do, that the key to health is avoiding neolithic agents of disease and that the common element of all healthy populations is animal products, how can it be that any plant that was not universally available is essential to health? It is not impossible, but in the scientific sense it is highly implausible if you accept my other premises.

I am not really that interested in what is possible - more so in what is very likely to be true.

Part of this is philosophical as well, applying the 80/20 rule to health. I think the idea that one should micromanage dietary constituents based on speculative reasoning about magic special compounds is not only wrong, it is a big waste of time. There are many other things to occupy your time with.

Counting, measuring, weighing and titrating food and and researching supplements and special foods? I have zero interest in that, as I'd rather practice my guitar or read a good book.

Dr. Harris is a very intelligent critical thinking scientist. So I have been musing about this post of his for some time. Look at the last line I highlighted, is this where our different approaches clash?

these promising studies are always refuted, it seems. We need much more funding for research into cancer prevention and research into synthetic compounds/medicines that will really prevent cancer, not just finding stuff in nature and hoping for the best, as you said, base merely on animal studies.

I do think Dr. Harris is being a bit too skeptical in not considering some supplements that show potential promise; supplements that have all been discussed here, some in great length of course.

...how can it be that any plant that was not universally available is essential to health?

How is health defined? Yes you can probably live, and even be semi "healthy" while not eating certain obscure foods, but aren't we interested in those foods which give the maximal health benefits? Penicillin isn't a natural thing humans have been ingesting, nor was it universally available in the stone age, but it sure can make us healthier.

I'm not biased against paleo myself since it offers many benefits, but it seems Dr. Harris isn't reading enough:

I have a bias against the idea of supplements and "magic food". I have seen little good (human) evidence for beneficial plants. Plants are tolerated and it is adaptive for us to be able to use them for nourishment when food on the hoof or with fins or wings is in short supply.

I remember Duke having a list of his healthy lifestyle strategy.

One of them being Cancer Prevention. I would like to know what his strategies look like.

Did they count the "carb junk" like apples, potatoes, and juices; not to mention the canned / overcooked paste that might have started out as a part of a plant but went through more chemical changes than horse dung? That would definitely water down the results...

Also, the vast majority of diet-related health problems come from eating too much of the bad foods, not from not eating enough of the good.

Edited by Alex Libman, 11 April 2010 - 01:29 AM.

So not a big fan of CR eh?

Counting, measuring, weighing and titrating food and and researching supplements and special foods? I have zero interest in that, as I'd rather practice my guitar or read a good book.

Please post any data you have seen indicating that apples or unprocessed potatoes are junk and part of the 'bad foods' group.

Did they count the "carb junk" like apples, potatoes, and juices; not to mention the canned / overcooked paste that might have started out as a part of a plant but went through more chemical changes than horse dung? That would definitely water down the results...

Also, the vast majority of diet-related health problems come from eating too much of the bad foods, not from not eating enough of the good.

Please post any data you have seen indicating that apples or unprocessed potatoes are junk and part of the 'bad foods' group.

Potatoes will be the easy part. I guess it shouldn't be too difficult to show that they're neutral (or even detrimental) as per epidemiology, coupled with crappy nutrient/kcal ratio. But I curiously want to see the data on apples.

Edited by kismet, 11 April 2010 - 12:29 PM.

I didn't say all "junk carbs" were necessarily bad (unless of course you're trying to lose weight, or are a vegan trying to optimize your protein percentage), simply inferior compared to the alternatives. Compare the amounts of most common micronutrients found in one large apple or potato (say 200 grams), with the equivalent weight of spinach for example. The first two are probably the most commonly consumed whole plant foods in the Western World, and their nutritional value is often further decreased through peeling, overcooking / frying (potatoes), etc. The micronutrient density of what a study would count as "a serving of vegetables" can vary drastically! Of course variety is essential and apples / potatoes have some unique qualities and should not be excluded from the diet entirely, but there is substantial value in optimizing your food choices by their overall nutritional value.

Edited by Alex Libman, 11 April 2010 - 01:20 PM.

I just cannot get my mind around this fear of whole plant food carbohydrates. Yes absolutely, gram for gram spinach packs a much more potent nutritional punch, but to me (a vegan who is not trying to lose weight) potatoes seem like a healthy way of getting needed calories. One would have to eat about 5-6x the weight in spinach to get similar calories. Like you said, it shouldn't really be an either or question. Plus, spinach and potato taste great together! From worlds healthiest foods.

...Potatoes are a very popular food source. Unfortunately, most people eat potatoes in the form of greasy French fries or potato chips, and even baked potatoes are typically loaded down with fats such as butter, sour cream, melted cheese and bacon bits. Such treatment can make even baked potatoes a potential contributor to a heart attack. But take away the extra fat and deep frying, and a baked potato is an exceptionally healthful low calorie, high fiber food that offers significant protection against cardiovascular disease and cancer.

Our food ranking system qualified potatoes as a very good source of vitamin C, a good source of vitamin B6, copper, potassium, manganese, and dietary fiber.

Potatoes also contain a variety of phytonutrients that have antioxidant activity. Among these important health-promoting compounds are carotenoids, flavonoids, and caffeic acid, as well as unique tuber storage proteins, such as patatin, which exhibit activity against free radicals.

Potatoes' Phytochemicals Rival Those in Broccoli

Potatoes' reputation as a high-carb, white starch has removed them from the meals of many a weight-conscious eater, but this stereotype is due for a significant overhaul. A new analytical method developed by Agricultural Research Service plant geneticist Roy Navarre has identified 60 different kinds of phytochemicals and vitamins in the skins and flesh of 100 wild and commercially grown potatoes. Analysis of Red and Norkotah potatoes revealed that these spuds' phenolic content rivals that of broccoli, spinach and Brussels sprouts, and includes flavonoids with protective activity against cardiovascular disease, respiratory problems and certain cancers. Navarre's team also identified potatoes with high levels of vitamin C, folic acid, quercetin and kukoamines. These last compounds, which have blood pressure lowering potential, have only been found in one other plant, Lycium chinense (a.k.a., wolfberry/gogi berry). How much kukoamine is needed for a blood pressure lowering effect in humans must be assessed before it can be determined whether an average portion of potatoes delivers enough to impact cardiovascular health. Still, potatoes' phytochemical profiles show it's time to shed their starch-only image; spuds-baked, steamed or healthy sautéed but not fried-deserve a place in your healthy way of eating."Phytochemical Profilers Investigate Potato Benefits,"Agricultural Research, September 2007

Blood-Pressure Lowering Potential

UK scientists at the Institute for Food Research have identified blood pressure-lowering compounds called kukoamines in potatoes. Previously only found in Lycium chinense, an exotic herbal plant whose bark is used to make an infusion in Chinese herbal medicine, kukoamines were found in potatoes using a new type of research called metabolomics.

Until now, when analyzing a plant's composition, scientists had to know what they were seeking and could typically look for 30 or so known compounds. Now, metabolomic techniques enable researchers to find the unexpected by analyzing the 100s or even 1000s of small molecules produced by an organism.

"Potatoes have been cultivated for thousands of years, and we thought traditional crops were pretty well understood," said IFR food scientist Dr Fred Mellon, "but this surprise finding shows that even the most familiar of foods might conceal a hoard of health-promoting chemicals." Another good reason to center your diet around the World's Healthiest Foods!

In addition to potatoes, researchers looked at tomatoes since they belong to the same plant family-Solanaceae-as Lycium chinense. Metabolomic assays also detected kukoamine compounds in tomatoes.

The IFR scientists found higher levels of kukoamines and related compounds than some of the other compounds in potatoes that have a long history of scientific investigation. However, because they were previously only noted in Lycium chinense, kukoamines have been little studied. Researchers are now determining their stability during cooking and dose response (how much of these compounds are needed to impact health)....


Potato, baked, with skin
1.00 cup
122.00 grams
132.98 calories
Nutrient Amount DV
(%) Nutrient
Density World's Healthiest
Foods Rating
vitamin C 15.74 mg 26.2 3.6 very good
vitamin B6 (pyridoxine) 0.42 mg 21.0 2.8 good
copper 0.37 mg 18.5 2.5 good
potassium 509.96 mg 14.6 2.0 good
manganese 0.28 mg 14.0 1.9 good
tryptophan 0.04 g 12.5 1.7 good
dietary fiber 2.93 g 11.7 1.6 good

World's Healthiest
Foods Rating Rule
excellent DV>=75% OR Density>=7.6 AND DV>=10%
very good DV>=50% OR Density>=3.4 AND DV>=5%
good DV>=25% OR Density>=1.5 AND DV>=2.5%


http://www.whfoods.c...ritionalprofile

I didn't say all "junk carbs" were necessarily bad (unless of course you're trying to lose weight, or are a vegan trying to optimize your protein percentage), simply inferior compared to the alternatives. Compare the amounts of most common micronutrients found in one large apple or potato (say 200 grams), with the equivalent weight of spinach for example. The first two are probably the most commonly consumed whole plant foods in the Western World, and their nutritional value is often further decreased through peeling, overcooking / frying (potatoes), etc. The micronutrient density of what a study would count as "a serving of vegetables" can vary drastically! Of course variety is essential and apples / potatoes have some unique qualities and should not be excluded from the diet entirely, but there is substantial value in optimizing your food choices by their overall nutritional value.

Edited by Application, 12 April 2010 - 02:04 AM.

One would have to eat about 5-6x the weight in spinach to get similar calories.

yea, i eat a CR diet that is mostly vegan (60-80g of fish, 20g of cheese daily) and it's totally impossible to survive on the "nutrient dense" stuff like spinach, collards, peppers, etc. there just aren't enough calories, period.

im going to try potatoes all this week, in place of oatmeal. it seems like a smart trade-off, i think. sweet potatoes seem way healthier than oats. plus i lose the phytic acid and omega-6's from oats.

i actually don't even eat spinach, because of the oxalate problem. and leaf spinach is not as easy to get around here as collards.

Why water down micronutrient-rich foods with low-micronutrient low-protein junk like potatoes when there are so many nutritionally superior energy dense legumes and grains out there? A healthy vegan diet is a struggle for protein percentages, 20% being the ambitious goal and 30% being a heroic feat (especially if achieved without supplements or too much soy), so calorie-rich potatoes that are only ~8% aren't helping. I'm trying to grow my own food in northern New Hampshire, so potatoes would seem like an obvious choice, but they are so nutritionally inferior that I'd rather get much lower yields of other crops. Beans, beans, and more beans, yaay!

im sitting on a 5 lb. bag of raw lentils, i just didn't get to it this weekend. i have to prepare a batch of lentils like that over the weekend, because i have to be focused on work during the week. i'd like to find a better way to kill the phytic acid in beans, than just soaking them overnight and cooking them. i need to buy a slow cooker with a specific temperature, so i can get it at that perfec 140 degree F level and leave it overnight.

i personally don't find sweet potatoes to be that poor nutritionally. they seem pretty good nutritionally and have a low glycemic impact. i think relatively speaking my diet is better than ~90% of america, so i'm not gonna stress.

You and I must have been brainwashed by entirely different vegan propaganda .

Why would we be shooting for 20% or even 30% protein? If I believed that was the goal, I would be eating animal products. Breast milk being only 6% protein is a meaningful figure since that level of protein is sufficient to sustain humans during their period of highest growth.

Why water down micronutrient-rich foods with low-micronutrient low-protein junk like potatoes when there are so many nutritionally superior energy dense legumes and grains out there? A healthy vegan diet is a struggle for protein percentages, 20% being the ambitious goal and 30% being a heroic feat (especially if achieved without supplements or too much soy), so calorie-rich potatoes that are only ~8% aren't helping. I'm trying to grow my own food in northern New Hampshire, so potatoes would seem like an obvious choice, but they are so nutritionally inferior that I'd rather get much lower yields of other crops. Beans, beans, and more beans, yaay!

You and I must have been brainwashed by entirely different vegan propaganda .

Why would we be shooting for 20% or even 30% protein? If I believed that was the goal, I would be eating animal products. Breast milk being only 6% protein is a meaningful figure since that level of protein is sufficient to sustain humans during their period of highest growth.

Why water down micronutrient-rich foods with low-micronutrient low-protein junk like potatoes when there are so many nutritionally superior energy dense legumes and grains out there? A healthy vegan diet is a struggle for protein percentages, 20% being the ambitious goal and 30% being a heroic feat (especially if achieved without supplements or too much soy), so calorie-rich potatoes that are only ~8% aren't helping. I'm trying to grow my own food in northern New Hampshire, so potatoes would seem like an obvious choice, but they are so nutritionally inferior that I'd rather get much lower yields of other crops. Beans, beans, and more beans, yaay!

Protein needs and rates of utilization rapidly increase through childhood and puberty. There is a reason why protein requirements change from children to adults.

The Efficiency of Dietary Protein Utilization Is Increased during Puberty
"We investigated whether the efficiency of dietary protein utilization for growth increases during the pubertal growth spurt in both nondiabetic and diabetic subjects. We measured leucine oxidation and retention (intake minus oxidation) in orally fed nondiabetic (n = 9) and diabetic (n = 9) human subjects, aged 7–17 yr. Eight subjects were Tanner stage I, and 10 were Tanner stages III–V; groups were not matched for gender. After 3 days of consuming a diet containing approximately 1 g/kg · day protein, subjects drank a commercial liquid nutrition formula, containing L-[1-13C]leucine, every 30 min for a total of 6 h to provide 1 g protein/kg · day. Isotopic enrichment of CO2 was used to calculate the fractional leucine oxidation rate and, together with {alpha}-ketoisocaproate isotopic enrichment, to calculate total leucine oxidation. Leucine oxidation rates decreased with puberty in both nondiabetic subjects (36.0 ± 10.4 vs. 23.9 ± 4.2 µmol/kg fat-free mass (FFM) · h, prepubertal and pubertal, respectively; P < 0.05) and diabetic (33.6 ± 4.9% vs. 27.3 ± 3.4 µmol/kg FFM · h, prepubertal and pubertal, respectively; P < 0.1) subjects. Leucine retention increased with puberty in both nondiabetic (0.27 ± 3.2 vs. 15.7 ± 5.3 µmol/kg FFM · h, prepubertal and pubertal, respectively; P < 0.001) and diabetic (1.9 ± 4.9 vs. 13.2 ± 4.4 µmol/kg FFM · h, prepubertal and pubertal subjects, respectively; P < 0.05) subjects. The data suggest that the pubertal growth spurt is associated with a marked increase in the efficiency of dietary protein utilization for growth."

Skotkonung,

I'm not entirely familiar with the ramifications of leucine oxidation so I may be misreading this study, but looking at the text you abstracted from, I also find the following quote which seems to indicate no more dietary protein is needed during puberty because effiency of utilizing and retention of dietary protein both increase:

Whole body leucine kinetics

Whole body leucine Ra and NOLD were not affected by puberty in the nondiabetic or diabetic subjects (Figs. 1 and 2; raw data in Table 2). Leucine oxidation was about 30% lower in pubertal than prepubertal nondiabetic subjects (P < 0.05). Leucine oxidation was about 20% lower in pubertal than prepubertal diabetic subjects, but did not reach statistical significance (P = 0.066; Fig. 3). Leucine retention was increased markedly by puberty in both nondiabetic (P < 0.001) and diabetic (P < 0.05; Fig. 4) subjects....



....In conclusion, rates of leucine oxidation in the fed state are decreased during puberty in both diabetic and nondiabetic subjects, resulting in increased efficiency of dietary protein utilization for growth. Changes in protein metabolism are probably related to the myriad of hormonal events that occur at puberty, including pubertal increases in insulin and IGF-I. However, apart from direct hormonal effects on protein metabolism, a decrease in energy expenditure in the fed state during puberty may spare dietary protein."

You and I must have been brainwashed by entirely different vegan propaganda .

Why would we be shooting for 20% or even 30% protein? If I believed that was the goal, I would be eating animal products. Breast milk being only 6% protein is a meaningful figure since that level of protein is sufficient to sustain humans during their period of highest growth.

Protein needs and rates of utilization rapidly increase through childhood and puberty. There is a reason why protein requirements change from children to adults.

The Efficiency of Dietary Protein Utilization Is Increased during Puberty
"We investigated whether the efficiency of dietary protein utilization for growth increases during the pubertal growth spurt in both nondiabetic and diabetic subjects. We measured leucine oxidation and retention (intake minus oxidation) in orally fed nondiabetic (n = 9) and diabetic (n = 9) human subjects, aged 7–17 yr. Eight subjects were Tanner stage I, and 10 were Tanner stages III–V; groups were not matched for gender. After 3 days of consuming a diet containing approximately 1 g/kg · day protein, subjects drank a commercial liquid nutrition formula, containing L-[1-13C]leucine, every 30 min for a total of 6 h to provide 1 g protein/kg · day. Isotopic enrichment of CO2 was used to calculate the fractional leucine oxidation rate and, together with {alpha}-ketoisocaproate isotopic enrichment, to calculate total leucine oxidation. Leucine oxidation rates decreased with puberty in both nondiabetic subjects (36.0 ± 10.4 vs. 23.9 ± 4.2 µmol/kg fat-free mass (FFM) · h, prepubertal and pubertal, respectively; P < 0.05) and diabetic (33.6 ± 4.9% vs. 27.3 ± 3.4 µmol/kg FFM · h, prepubertal and pubertal, respectively; P < 0.1) subjects. Leucine retention increased with puberty in both nondiabetic (0.27 ± 3.2 vs. 15.7 ± 5.3 µmol/kg FFM · h, prepubertal and pubertal, respectively; P < 0.001) and diabetic (1.9 ± 4.9 vs. 13.2 ± 4.4 µmol/kg FFM · h, prepubertal and pubertal subjects, respectively; P < 0.05) subjects. The data suggest that the pubertal growth spurt is associated with a marked increase in the efficiency of dietary protein utilization for growth."

You may be correct in your assertion that less protein is required during physical development, but this appears to be related to an enhanced protein metabolism. For this reason, the recommendation of a 6% total calories from protein DV may be (and is likely) inadequate for adults. Adults handle protein less efficiently and calls into question the use of human breast milk as a nutritional standard.

According to US/Canadian Dietary Reference Intake guidelines, women aged 19–70 need to consume 46 grams of protein per day, while men aged 19–70 need to consume 56 grams of protein per day to avoid a deficiency. For men, that's approximately 9% on a 2,500 (11% @ 2,000) calorie diet as minimum baseline (source - PDF). US recommended daily protein dietary allowance, measured as intake per body weight, is 0.8 g/kg (source). That is about 10-12% of total daily calories for most men (2,500 calories). Furthermore, several studies have concluded that active people and athletes may require elevated protein intake. Suggested amounts vary between 1.6 g/kg and 1.8 g/kg.

Beyond the zone: protein needs of active individuals.
"There has been debate among athletes and nutritionists regarding dietary protein needs for centuries. Although contrary to traditional belief, recent scientific information collected on physically active individuals tends to indicate that regular exercise increases daily protein requirements; however, the precise details remain to be worked out. Based on laboratory measures, daily protein requirements are increased by perhaps as much as 100% vs. recommendations for sedentary individuals (1.6-1.8 vs. 0.8 g/kg). Yet even these intakes are much less than those reported by most athletes. This may mean that actual requirements are below what is needed to optimize athletic performance, and so the debate continues. Numerous interacting factors including energy intake, carbohydrate availability, exercise intensity, duration and type, dietary protein quality, training history, gender, age, timing of nutrient intake and the like make this topic extremely complex. Many questions remain to be resolved. At the present time, substantial data indicate that the current recommended protein intake should be adjusted upward for those who are physically active, especially in populations whose needs are elevated for other reasons, e.g., growing individuals, dieters, vegetarians, individuals with muscle disease-induced weakness and the elderly. For these latter groups, specific supplementation may be appropriate, but for most North Americans who consume a varied diet, including complete protein foods (meat, eggs, fish and dairy products), and sufficient energy the increased protein needs induced by a regular exercise program can be met in one's diet."

For me, and I'm sure for others pursuing strength based athleticism, 6% protein would be inadequate. Anything less than 1g/lb LBM and I begin getting symptoms of over training. 6% may be suitable for some individuals with certain lifestyles and physical builds, but should not be touted as a blanket recommendation. Protein needs will vary. Keeping protein levels above the minimum requirement prevents loss of LBM. If the individual does not consume adequate protein in nutrition, then muscle will waste as more vital cellular processes (e.g. respiration enzymes, blood cells) recycle muscle protein for their own requirements.

Edited by Skotkonung, 12 April 2010 - 06:02 PM.

for reduced phytate/lectin in beans, you could get the dehulled ('dal') ones from an indian grocer.