The moderate viewpoint always seems to be most truthful, from my experiences. This is especially true in nutrition. I have read articles by MDs stating that nutrition isn't a big issue and there's no evidence showing that fruits and vegetables lead to long life. I have also read alternative health providers stating that eating a raw vegan diet will stave away every ailment known to man.
I find this polarized view to be quite vexing - and part of the reason that I'm interested in the intersection of genetics and nutrition. There is definitely no questioning that people benefit from increasing their consumption of nutrient dense foods - getting back to nature is definitely a good thing in a secure food environment; choosing minimally processed foods increases the amounts of vitamins, mineral, antioxidants and phytonutrients that you'll get. It's not all about genetics; people don't become obese due to some genetic defect alone - there needs to be a calorically rich environment.
While I find that MD who said fruits/veggies aren't that big of a deal to be misguided, the polar viewpoint is just as worrisome. There's this almost religious idea among alternative health followers that nutrition is a cure-all; this concept that nature designed food for humans fit to fulfill all his/her needs and prevent every disease is a worrisome one to me - everyone is genetically distinct, has different metabolic rates, different stomachs/intestines, and presumably, different nutrient needs. Seeing as evolution most likely didn't act on the diseases that affect older individuals, there's really very little concrete evidence to state nutrition is going to cure cancer or altogether stop osteoporosis. Don't get me wrong, it plays a part, especially in preventable disease, but it's no miracle worker - and that's why we need medicine. A lot of medicine is just a bioactive component of food that has been modified to interact with our bodies in some way; According to the World Resources Institute, 25% of prescriptions in the U.S. today are derived from a plant.
I want to run through two examples quickly of over-hyped nutrition : olive oil and green tea. Both are antioxidant rich foods that people regularly consume that can be beneficial for your health.
Olive Oil: Olive Oil is a major part of the Mediterranean diet, whose followers tend to have lower rates of chronic disease. A major study (1) was published in BMC Cancer that tried to find a molecular mechanism as to how olive oil consumption might play a role in staving off breast cancer. Quick low down on breast cancer; there are 3 kinds: ER positive, HER2 positive, or Triple Negative. The study I mentioned looked at Olive Oil's role in HER2 positive breast cancer. They found that extra virgin olive oil secoiridoids and lignans, two polyphenolic components of EVOO (hey rachael ray!), were able to modulate the HER2 protein tyrosine kinase activity - secoiridoids inhibited the phosphorylation of 1248 tyrosine, the main autophosphorylation site. Basically, a binding of a ligand to HER2 receptors sends a signaling cascade that leads to cell proliferation and ultimately to beta catenin aggregation in the cytosol, a hallmark of many cancers. These polyphenols were able to inhibit that normal ligands binding and prevent the active state from being achieved, preventing the signaling cascade. Higher levels of apoptosis were seen for HER2 + breast cells when exposed to lignans and secoiridoids.
^^All of that sounds great right? It's truly wonderful information for anyone who is involved in drug development. Understanding how the stereochemistry of these polyphenolic elements interact with HER2 proteins can give a lot of insight in pharmacological therapy. However, from a nutrition perspective, it's hard to draw a whole lot out of this. As the study's author points out in a WebMD interview (2), secoiridoids exhibit reduced activity after digestion. The study looked at direct application of these extracts onto a cell line - quite different than the polyphenols suspended in oil, eaten with other foods, probably cooked, digested, needing to be absorbed and then make their way to membrane. It's hard to say how effective the lignan component would be. There's varied effects of cooking on lignans; in one study (3), lignans in rye/sesame degraded at 100 degrees Celsius. Lignans in EVOO dont' have the protection of seeds and I imagine would degrade much more rapidly at cooking temperatures. None of this is reason to not eat olive oil, but a simple google search of 'cancer killing foods and olive oil' will cite these results as if olive oil is a miracle cure. Sure, we don't have lifelong studies to look at but HER2 + breast cancers are largely an issue of genetic susceptibility. Nature didn't design EVOO polyphenols to cure breast cancer.
Green Tea: Go to google: type in 'burn more calories and green tea'. If you're a scientist, this is a great way to get your blood pumping before going for a workout *cue frustration*. There is nothing about green tea that is going to make your body burn an absurd amount of calories. From an evolutionary perspective, this would make green tea extremely toxic - anything that burns up energy with no life-sustaining benefit would be a toxin for sure - our concept of green tea's benefits are largely in helping control modern disease (blood glucose control, LDL metabolism, etc - not of concern for reproduction). Nature didn't design green tea to fight obesity. From a historical perspective, all of the Chinese population that drinks several cups a day would have been extremely stressed by their tea consumption and, if you follow the internet myths, would've lead to about 35,000 extra calories burnt/yr, or weight loss of about 10lbs. Seem ridiculous yet?
Always keep in mind that nutrition is toxicology - dosage matters. The extracts used in studies generally overconcentrate an individual polyphenol that one would normally consume in a few cups of green tea. Green tea has been shown to benefit a number of conditions and I don't doubt these much. UofMaryland's website (4) talks about it's potential role in heart disease/cholesterol and a number of cancers - the cancer benefits are just implications (and almost always done in a cell line)- I can see regular consumption of tea, over long periods of time, playing a role in oxidative stress but if you have cancer already, I wouldn't expect green tea to be your Superman/Wonderwoman. But back to the issue of weight loss: The most studied bioactive phenolic compound in green tea is known as EGCG ( epigallocatechin-3-gallate). EGCG was shown to be an inhibitor of Fatty Acid Synthase (FAS) in chicken livers - I find it interesting that this research was initially reported and used by cancer researchers, not intended to be picked up on by the weight loss industry (5). FAS is overexpressed in human carcinomas (tumors from epithelial cells) - one study (6) in 2008 actually looked at using EGCG as a potential cancer treatment because it inhibits FAS but does not stimulate carnitine palmitoyltransferase-1- CPT1 lies on the mitochondrial membrane and is essential for shuttling fatty acids into the mitochondria for oxidation- AKA FAS was inhibited but fatty acid oxidation didn't increase. While this study was an animal model, the animals subjected to treatment did not lose weight - in this sense, animals are much easier to control to see the pure effects of green tea; humans are more genetically variable, have different eating/activity patterns than a lab-bred mouse in a cage. A 2010 meta-analysis (7) in the American Journal of Clinical Nutrition sums up the my thoughts on green tea quite nicely: "The administration of GTCs with caffeine is associated with statistically significant reductions in BMI, body weight, and WC; however, the clinical significance of these reductions is modest at best. Current data do not suggest that GTCs alone positively alter anthropometric measurements." Keep in mind that significant means statistically significant - so yes, it does help, but the amount of weight lost is not clinically significant. I stumbled onto a PhD dissertation (Maastricht University, Rick Hursel- can't link and the published info is in Dutch, google if you're interested in the citation) from the Netherlands (fun fact: they write a book as their dissertation) that had an entire chapter on this topic and found that "Dosage of catechins in the treatment or in the placebo, did not have any significant effect on the outcome of the studies that were included" - this dissertation reviewed the data in a similar meta-analysis fashion and worked to parse out the effects of caffeine +catechin mixtures vs just catechins.
Let's also not forget that antioxidants have the potential to become pro-oxidants - they're just playing toss with some electrons. Watson came out recently with a warning to stay away from high dose antioxidants because they might actually damage DNA. It's one thing to get some green tea antioxidant benefits by drinking a cup of two a day- especially for reducing LDL cholesterol levels (8) - it's another to take a mega dose of EGCG (generally about 10-15% of the phenol content of tea overall-AKA you're getting more EGCG in these supplements than you would via drinking tea). The body relies on oxidation as means of a signaling - large does of Vitamin C and E have been shown to impair performance in exercise (9). More isn't always better - there's a homeostatic range for most aspects of physiology and it seems this would apply to antioxidants as well. The potential for an extra thermogenic boost isn't worth the cost of these supplement and the long term risks of large antioxidant dosage supplementation. Spend that extra 6$ on some vegetables.
UPDATE: I forgot to mention that another detrimental aspect of large doses of ECGC supplementation is the reduced bioavailability of iron. It's been known that pre/post-prandial tea/coffee consumption can inhibit the binding of iron (10,11)). The interaction between ECGC and non-heme iron (11, 12)) creates a bio-unavailable complex. It's frightening to me that a lot of these health sites that promote EGCG's 'benefits' also promote vegetarianism and increased activity levels - both leading to physiological states that require more iron.
Back to my original point - nutrition is awesome. eating a lot of fruits/vegetables/plants and some animal products across a lifetime, while meeting your calorie needs, and staying active will probably benefit you with a long life - hitting the genetic lottery would've helped too. Drink your green tea and eat some olive oil - it'll do you good. but only some good. not a miracle.
1. http://www.ncbi.nlm.nih.gov/pubmed/19082476
2. http://www.webmd.com/breast-cancer/news/20081218/extra-virgin-olive-oil-evoo-vs-breast-cancer
3. http://www.ncbi.nlm.nih.gov/pubmed/23411317
4. http://umm.edu/health/medical/altmed/herb/green-tea
5. http://www.sciencedirect.com/science/article/pii/S0006291X01959236
6. http://www.ncbi.nlm.nih.gov/pubmed/19189648
7.http://www.ncbi.nlm.nih.gov/pubmed/19906797
8. http://www.ncbi.nlm.nih.gov/pubmed/22027055
9. http://www.hindawi.com/journals/oximed/2012/707941/
10. http://gut.bmj.com/content/16/3/193.abstract
11. http://www.tandfonline.com/doi/abs/10.1080/10408690091189194#.UiNxFbypY7A
12. http://jn.nutrition.org/content/138/9/1647.short
13. http://ajcn.nutrition.org/content/73/3/607.short
I find this polarized view to be quite vexing - and part of the reason that I'm interested in the intersection of genetics and nutrition. There is definitely no questioning that people benefit from increasing their consumption of nutrient dense foods - getting back to nature is definitely a good thing in a secure food environment; choosing minimally processed foods increases the amounts of vitamins, mineral, antioxidants and phytonutrients that you'll get. It's not all about genetics; people don't become obese due to some genetic defect alone - there needs to be a calorically rich environment.
While I find that MD who said fruits/veggies aren't that big of a deal to be misguided, the polar viewpoint is just as worrisome. There's this almost religious idea among alternative health followers that nutrition is a cure-all; this concept that nature designed food for humans fit to fulfill all his/her needs and prevent every disease is a worrisome one to me - everyone is genetically distinct, has different metabolic rates, different stomachs/intestines, and presumably, different nutrient needs. Seeing as evolution most likely didn't act on the diseases that affect older individuals, there's really very little concrete evidence to state nutrition is going to cure cancer or altogether stop osteoporosis. Don't get me wrong, it plays a part, especially in preventable disease, but it's no miracle worker - and that's why we need medicine. A lot of medicine is just a bioactive component of food that has been modified to interact with our bodies in some way; According to the World Resources Institute, 25% of prescriptions in the U.S. today are derived from a plant.
I want to run through two examples quickly of over-hyped nutrition : olive oil and green tea. Both are antioxidant rich foods that people regularly consume that can be beneficial for your health.
Olive Oil: Olive Oil is a major part of the Mediterranean diet, whose followers tend to have lower rates of chronic disease. A major study (1) was published in BMC Cancer that tried to find a molecular mechanism as to how olive oil consumption might play a role in staving off breast cancer. Quick low down on breast cancer; there are 3 kinds: ER positive, HER2 positive, or Triple Negative. The study I mentioned looked at Olive Oil's role in HER2 positive breast cancer. They found that extra virgin olive oil secoiridoids and lignans, two polyphenolic components of EVOO (hey rachael ray!), were able to modulate the HER2 protein tyrosine kinase activity - secoiridoids inhibited the phosphorylation of 1248 tyrosine, the main autophosphorylation site. Basically, a binding of a ligand to HER2 receptors sends a signaling cascade that leads to cell proliferation and ultimately to beta catenin aggregation in the cytosol, a hallmark of many cancers. These polyphenols were able to inhibit that normal ligands binding and prevent the active state from being achieved, preventing the signaling cascade. Higher levels of apoptosis were seen for HER2 + breast cells when exposed to lignans and secoiridoids.
^^All of that sounds great right? It's truly wonderful information for anyone who is involved in drug development. Understanding how the stereochemistry of these polyphenolic elements interact with HER2 proteins can give a lot of insight in pharmacological therapy. However, from a nutrition perspective, it's hard to draw a whole lot out of this. As the study's author points out in a WebMD interview (2), secoiridoids exhibit reduced activity after digestion. The study looked at direct application of these extracts onto a cell line - quite different than the polyphenols suspended in oil, eaten with other foods, probably cooked, digested, needing to be absorbed and then make their way to membrane. It's hard to say how effective the lignan component would be. There's varied effects of cooking on lignans; in one study (3), lignans in rye/sesame degraded at 100 degrees Celsius. Lignans in EVOO dont' have the protection of seeds and I imagine would degrade much more rapidly at cooking temperatures. None of this is reason to not eat olive oil, but a simple google search of 'cancer killing foods and olive oil' will cite these results as if olive oil is a miracle cure. Sure, we don't have lifelong studies to look at but HER2 + breast cancers are largely an issue of genetic susceptibility. Nature didn't design EVOO polyphenols to cure breast cancer.
Green Tea: Go to google: type in 'burn more calories and green tea'. If you're a scientist, this is a great way to get your blood pumping before going for a workout *cue frustration*. There is nothing about green tea that is going to make your body burn an absurd amount of calories. From an evolutionary perspective, this would make green tea extremely toxic - anything that burns up energy with no life-sustaining benefit would be a toxin for sure - our concept of green tea's benefits are largely in helping control modern disease (blood glucose control, LDL metabolism, etc - not of concern for reproduction). Nature didn't design green tea to fight obesity. From a historical perspective, all of the Chinese population that drinks several cups a day would have been extremely stressed by their tea consumption and, if you follow the internet myths, would've lead to about 35,000 extra calories burnt/yr, or weight loss of about 10lbs. Seem ridiculous yet?
Always keep in mind that nutrition is toxicology - dosage matters. The extracts used in studies generally overconcentrate an individual polyphenol that one would normally consume in a few cups of green tea. Green tea has been shown to benefit a number of conditions and I don't doubt these much. UofMaryland's website (4) talks about it's potential role in heart disease/cholesterol and a number of cancers - the cancer benefits are just implications (and almost always done in a cell line)- I can see regular consumption of tea, over long periods of time, playing a role in oxidative stress but if you have cancer already, I wouldn't expect green tea to be your Superman/Wonderwoman. But back to the issue of weight loss: The most studied bioactive phenolic compound in green tea is known as EGCG ( epigallocatechin-3-gallate). EGCG was shown to be an inhibitor of Fatty Acid Synthase (FAS) in chicken livers - I find it interesting that this research was initially reported and used by cancer researchers, not intended to be picked up on by the weight loss industry (5). FAS is overexpressed in human carcinomas (tumors from epithelial cells) - one study (6) in 2008 actually looked at using EGCG as a potential cancer treatment because it inhibits FAS but does not stimulate carnitine palmitoyltransferase-1- CPT1 lies on the mitochondrial membrane and is essential for shuttling fatty acids into the mitochondria for oxidation- AKA FAS was inhibited but fatty acid oxidation didn't increase. While this study was an animal model, the animals subjected to treatment did not lose weight - in this sense, animals are much easier to control to see the pure effects of green tea; humans are more genetically variable, have different eating/activity patterns than a lab-bred mouse in a cage. A 2010 meta-analysis (7) in the American Journal of Clinical Nutrition sums up the my thoughts on green tea quite nicely: "The administration of GTCs with caffeine is associated with statistically significant reductions in BMI, body weight, and WC; however, the clinical significance of these reductions is modest at best. Current data do not suggest that GTCs alone positively alter anthropometric measurements." Keep in mind that significant means statistically significant - so yes, it does help, but the amount of weight lost is not clinically significant. I stumbled onto a PhD dissertation (Maastricht University, Rick Hursel- can't link and the published info is in Dutch, google if you're interested in the citation) from the Netherlands (fun fact: they write a book as their dissertation) that had an entire chapter on this topic and found that "Dosage of catechins in the treatment or in the placebo, did not have any significant effect on the outcome of the studies that were included" - this dissertation reviewed the data in a similar meta-analysis fashion and worked to parse out the effects of caffeine +catechin mixtures vs just catechins.
Let's also not forget that antioxidants have the potential to become pro-oxidants - they're just playing toss with some electrons. Watson came out recently with a warning to stay away from high dose antioxidants because they might actually damage DNA. It's one thing to get some green tea antioxidant benefits by drinking a cup of two a day- especially for reducing LDL cholesterol levels (8) - it's another to take a mega dose of EGCG (generally about 10-15% of the phenol content of tea overall-AKA you're getting more EGCG in these supplements than you would via drinking tea). The body relies on oxidation as means of a signaling - large does of Vitamin C and E have been shown to impair performance in exercise (9). More isn't always better - there's a homeostatic range for most aspects of physiology and it seems this would apply to antioxidants as well. The potential for an extra thermogenic boost isn't worth the cost of these supplement and the long term risks of large antioxidant dosage supplementation. Spend that extra 6$ on some vegetables.
UPDATE: I forgot to mention that another detrimental aspect of large doses of ECGC supplementation is the reduced bioavailability of iron. It's been known that pre/post-prandial tea/coffee consumption can inhibit the binding of iron (10,11)). The interaction between ECGC and non-heme iron (11, 12)) creates a bio-unavailable complex. It's frightening to me that a lot of these health sites that promote EGCG's 'benefits' also promote vegetarianism and increased activity levels - both leading to physiological states that require more iron.
Back to my original point - nutrition is awesome. eating a lot of fruits/vegetables/plants and some animal products across a lifetime, while meeting your calorie needs, and staying active will probably benefit you with a long life - hitting the genetic lottery would've helped too. Drink your green tea and eat some olive oil - it'll do you good. but only some good. not a miracle.
1. http://www.ncbi.nlm.nih.gov/pubmed/19082476
2. http://www.webmd.com/breast-cancer/news/20081218/extra-virgin-olive-oil-evoo-vs-breast-cancer
3. http://www.ncbi.nlm.nih.gov/pubmed/23411317
4. http://umm.edu/health/medical/altmed/herb/green-tea
5. http://www.sciencedirect.com/science/article/pii/S0006291X01959236
6. http://www.ncbi.nlm.nih.gov/pubmed/19189648
7.http://www.ncbi.nlm.nih.gov/pubmed/19906797
8. http://www.ncbi.nlm.nih.gov/pubmed/22027055
9. http://www.hindawi.com/journals/oximed/2012/707941/
10. http://gut.bmj.com/content/16/3/193.abstract
11. http://www.tandfonline.com/doi/abs/10.1080/10408690091189194#.UiNxFbypY7A
12. http://jn.nutrition.org/content/138/9/1647.short
13. http://ajcn.nutrition.org/content/73/3/607.short
Hi Kevin! Just a hint, in the last line would be better say "..eat some EXTRA virgin olive oil..". I am sure that you know the difference in terms of quality and quantity of the different compounds.
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