I will agree with Tim on that. Cold sweet potatoes are a nice little treat.
I will agree with Tim on that. Cold sweet potatoes are a nice little treat.
It's your friendly neighbourhood blogosphere exile here. I know that you are probably busy with your legions of adoring internet fans ... being an internet superstar is never easy, I'm told, so this may have slipped through the cracks for you.
I just wanted to remind you that it has now been two days since I asked you for a single, solitary, little, measly peer reviewed article on "how much colonic fermentation is optimal for health" on January 22nd.
Surely you wouldn't be advocating for everyone to increase their intake of resistant starch without knowing first what the average intake is, and, more importantly, how that deviates from the optimum.
I'm looking forward to your reply.
Last edited by pklopp; 01-24-2013 at 12:49 PM.
Health properties of resistant starch - Nugent - 2005 - Nutrition Bulletin - Wiley Online Library
Gives an upper limit of 30g:
Average and optimal discussed here:Resistant starch appears to have no adverse impact on gastrointestinal function in well-nourished people and may even promote health in children with diarrhoeal disease (Topping & Clifton 2001). In addition, it appears to be more readily acceptable than other forms of dietary fibre (e.g. wheat bran) at high levels in the human diet (Ferguson et al. 2003). It has been reported that it is not feasible for humans to consume more than 30 g/day of RS due to problems with flatulence, belching, bloating, mild laxative effects and stomach aches (Heijnen et al. 1996); however, it is unlikely that humans would consume such high levels of RS without aggressive supplementation and in some instances RS was supplemented in association with other forms of dietary fibre. No cases of allergic reactions have been reported following supplementation with more traditional forms of RS, such as those made from high amylose maize (Goldring 2004). At present, other new sources of starch being used which are based on other types of starch including tapioca, potato and wheat. At present, there is little information regarding their effects, or those of RS4, in humans; more comprehensive information and studies are needed in vivo.
Several studies have attempted to quantify population dietary intakes of RS. However, a number of different methods of analyses of RS were used in these studies and this makes any real comparisons between countries and/or studies difficult. From population studies, it has been calculated that intakes of non-starch polysaccharides are approximately < 20 g/day (Baghurst et al. 1996). The last national survey of dietary intakes in the UK revealed that intakes of non-starch polysaccharides were approximately 12 g/day for women and 15 g/day for men (Henderson et al. 2003). However, it is believed that approximately 60–80 g of substrate is needed per day to sustain the 1013−1014 organisms found in the human large bowel. It is thought that RS contributes to this ‘carbohydrate gap’ (Topping et al. 2003). RS has been reported to constitute up to 15% of the dry matter of a food product (Champ et al. 2003b).
Worldwide, dietary intakes of RS are believed to vary considerably. It is estimated that intakes of RS in developing countries with high starch consumption rates range from approximately 30 to 40 g/day (Baghurst et al. 2001). Dietary intakes in India and China were recently estimated at 10 and 18 g/day (Platel & Shurpalekar 1994; Muir et al. 1998). Intakes in the EU are thought to lie between 3 and 6 g/day (Dyssler & Hoffmann, 1994). Dietary intakes of RS in the UK are estimated at 2.76 g/day (Tomlin & Read 1990) and are believed to range from 5 to 7 g/day in Australia (Baghurst et al. 2001). In the study of Baghurst et al. (2001) the authors analysed population dietary intakes of RS using Australian National Dietary Survey data for the years 1988 and 1993 and a foods database which they constructed using analytical data from published findings and data presented at a scientific (EURESTA) meeting. The main sources of RS for this cohort were cereals (42%), vegetables (26%) and fruit and fruit juice (22%). There was little evidence of any age- or occupation-related trends in the density of RS in the diet. However, this data must be viewed with caution as it represents only a small amount of data, a number of techniques were used to ascertain the amount of RS in foods, the authors reported inconsistencies in the database and the data refers to Australian dietary intakes. As mentioned earlier, intakes of RS in Australia are likely to be greater than in Europe due to the commercial availability of top-selling breads and cakes that are enriched with RS.
Importance of RS from starch as opposed to inulins, etc...:
So, I stand by my conclusion that a couple potatoes a day would be extremely healthy. The starchy substrate, recommended at 60-80g above, is there as well as a dose of RS a bit higher than a standard western diet. To give further impact, about half of the potatoes should be eaten cooked and cooled and a few pieces eaten raw.RS appears to function as a prebiotic and symbiotic (Brown et al. 1997; Wang et al. 1999). Studies in humans and pigs have revealed that consumption of high-RS diets result in a time-dependent shift in faecal and large-bowel SCFA profiles, suggesting a change in the autochthonous (local) microbial population and that RS could interact with gut bacteria (Topping et al. 2003). It is also worth noting that RS appears to function differently than more well known prebiotics (e.g. fructo-oligosaccharides); when the RS and fructo-oligosaccharides were fed together, the increase in faecal bacteria was greater than the individual increases observed when these two ingredients were fed separately (Brown et al. 1998).
I'm 100% positive this will not satisfy you and look forward to seeing your rebuttal.
So wait, wait... Otzi, clear this up for me if you will. According to your sources above, humans are supposed to get between 60-80 grams of fiber (spread throughout the various types) per day in order to support proper levels of intestinal bacteria (see this line: "However, it is believed that approximately 60–80 g of substrate is needed per day to sustain the 1013−1014 organisms found in the human large bowel"). And yet, humans have been living for generations on far less than 20 just fine? Ok, then do we really NEED that recommended 60-80 grams? Seems like the overzelous recommendation of someone eating a typical CW type of diet that actually probably requires more cut bacteria than someone eating primally. And even for the typical CW eater 60-80 grams of fiber a day is going to keep them on the pot most of the day. Yikes!
Last edited by Drumroll; 01-24-2013 at 04:29 PM.
Potatoes have about 1gm of fiber per oz.
and 26 calories.
60-80 grams of fiber would be 1560-2080 cal/day just from potatoes.
That doesn't sound very healthy.
It sounds genuinely obsessive.
Also... for anyone with not so great kidneys like prone to stones or something, please ignore at least the raw potato advice.
Feel free to eat potatoes but at least boil them.
“You have your way. I have my way. As for the right way, the correct way, and the only way, it does not exist.”
And that's why I'm here eating HFLC Primal/Paleo.
non-starch polysaccharides, from my beloved Wikipedia:it has been calculated that intakes of non-starch polysaccharides are approximately < 20 g/day (Baghurst et al. 1996). The last national survey of dietary intakes in the UK revealed that intakes of non-starch polysaccharides were approximately 12 g/day for women and 15 g/day for men (Henderson et al. 2003). However, it is believed that approximately 60–80 g of substrate is needed per day to sustain the 1013−1014 organisms found in the human large bowel. It is thought that RS contributes to this ‘carbohydrate gap’ (Topping et al. 2003). RS has been reported to constitute up to 15% of the dry matter of a food product (Champ et al. 2003b).
The reason I think there goal is so high (60-80g) is that if you are eating the usual lineup of fiber (grain, fruit etc..) it takes a lot of it to ensure there is a good bit of RS. If you are targeting RS through cooked and cooled potatoes, for instance, you shouldn't need that much dietary fiber (the 'carbohydrate gap')Chemically, dietary fiber consists of non-starch polysaccharides such as arabinoxylans, cellulose, and many other plant components such as resistant starch, resistant dextrins, inulin, lignin, waxes, chitins, pectins, beta-glucans, and oligosaccharides. A novel position has been adopted by the US Department of Agriculture to include functional fibers as isolated fiber sources that may be included in the diet. The term "fiber" is something of a misnomer, since many types of so-called dietary fiber are not actually fibrous.
Also from the Great Font of Knowledge: Dietary fiber - Wikipedia, the free encyclopedia
I've never bothered to figure out the average fiber content of a PB diet. I'd guess it's even less than SAD. That doesn't really concern me. It really seems the RDA is so high just to ensure a minimal amount of RS.
Current recommendations from the United States National Academy of Sciences, Institute of Medicine, suggest that adults should consume 20–35 grams of dietary fiber per day, but the average American's daily intake of dietary fiber is only 12–18 grams.
The AND (Academy of Nutrition and Dietetics, previously ADA) recommends a minimum of 20–35 g/day for a healthy adult depending on calorie intake (e.g., a 2000 Cal/8400 kJ diet should include 25 g of fiber per day). The AND's recommendation for children is that intake should equal age in years plus 5 g/day (e.g., a 4 year old should consume 9 g/day). No guidelines have yet been established for the elderly or very ill. Patients with current constipation, vomiting, and abdominal pain should see a physician. Certain bulking agents are not commonly recommended with the prescription of opioids because the slow transit time mixed with larger stools may lead to severe constipation, pain, or obstruction.
The British Nutrition Foundation has recommended a minimum fiber intake of 18 g/day for healthy adults.
Fiber recommendations in the USA
On average, North Americans consume less than 50% of the dietary fiber levels recommended for good health. In the preferred food choices of today's youth, this value may be as low as 20%, a factor considered by experts as contributing to the obesity levels seen in many developed countries.
Otzi you really can't win this.
Look at it this way, its the same reason I would not bother to claim that ketosis is optimal for all humans. You know why? Cause there are notable exceptions to the claim. The same stands in this case just in the complete reverse.
You can claim that it is not inherently harmful, as you have plenty of evidence for that (well except for the raw potato bit...not a good idea). Or, you may be able to find specific instances and population (imbalance/disease) in which it "could" be a better alternative just like you can with ketosis. But, your not gonna be able to prove that its anything more than that (least I doubt you can).
BTW I have always grabbed a slice of potato as my mom was peeling them as a kid and ate a bit, but I still don't think its a good idea.