New analysis based on WHEL study titled "Starch Intake May Influence Risk for Breast Cancer Recurrence" presented at the 2011 CTRC-AACR San Antonio Breast Cancer Symposium, held Dec. 6-10, 2011.
Quotes:
“The results show that it’s not just overall carbohydrates, but particularly starch,” said Jennifer A. Emond, M.S., a public health doctoral student at the University of California, San Diego. “Women who increased their starch intake over one year were at a much likelier risk for recurring.”
Researchers conducted a subset analysis of 2,651 women who participated in the Women’s Healthy Eating and Living (WHEL) Dietary Intervention Trial, a plant-based intervention trial that enrolled about 3,088 survivors of breast cancer. WHEL researchers studied breast cancer recurrence and followed the participants for an average of seven years.
...
The change in starch intake was “independent of dietary changes that happened in the intervention arm,” Emond said. “It is independent of more global changes in diet quality.”
I have to comment on the following quote: . “The WHEL dietary trial, even though it focused on fruits and vegetables, fiber and fat, didn’t really have a specific carbohydrate goal,” Emond said.
Time and time again studies focus on some secondary issues such as which particular vegetable or fruit selection affects some outcome while at the same time ignoring a major issue of macronutrient ratios! Such analyses often come as afterthoughts and end up using incomplete or partial data, just because the study proponents didn't bother to measure a major variable. Now they seem surprized finding an "elephant" in their lab! The biggest kicker is that vegetables - the one "healthy" diet aspect that they WHEL study authors did focused to the detriment of other more real issues, turned out to be irrelevant as far as cancer was concerned! (see the study I discuss further down)
Even though the results suffer from the fact that the original study methodology wasn't properly focused on the issue that mattered, the results are consistent with other studies. For example this one:
"Carbohydrates and the Risk of Breast Cancer among Mexican Women"
Isabelle Romieu, Eduardo Lazcano-Ponce, Luisa Maria Sanchez-Zamorano, Walter Willett and Mauricio Hernandez-Avila
The study showed a very strong breast cancer promoting effect of carbohydrate consumption: for every additional 1% of carbohydrate calories consumed above 52%, the relative risk of breast cancer was incrementally increasing by about 10%!
Consistent also with the Italian data:
"Dietary glycemic index, glycemic load, and the risk of breast cancer in an Italian prospective cohort study", Sabina Sieri et al.
The study showed that a 56% higher glycaemic load (from 96g/d to 150g/d) produced 2.53 times higher relative risk of breast cancer among Italian women.
------
The following paper (also based on the same WHEL study as the headline study!) demonstrated that a low fat high vegetable diet was useless for fighting cancer!
"Influence of a Diet Very High in Vegetables, Fruit, and Fiber and Low in Fat on Prognosis Following Treatment for Breast Cancer." John P. Pierce, PhD; Loki Natarajan, PhD; Bette J. Caan, et al. The Women's Healthy Eating and Living (WHEL) Randomized Trial. JAMA. 2007;298:289-298.
Quote:
Among survivors of early stage breast cancer, adoption of a diet that was very high in vegetables, fruit, and fiber and low in fat did not reduce additional breast cancer events or mortality during a 7.3-year follow-up period.
-----------------------
Similar pattern with the ovarian cancer:
"Nutrient dietary patterns and the risk of breast and ovarian cancers." Edefonti V, et al., Int J Cancer. 2008 Feb 1;122(3):609-13.
... Cases were 2,569 breast cancers and 1,031 ovarian cancers hospitalized in 4 Italian areas between 1991 and 1999. Controls were 3,413 women from the same hospital network. Dietary habits were investigated through a validated food-frequency questionnaire. ... The animal products pattern and the unsaturated fats pattern were inversely associated with breast cancer (OR = 0.74, 95% CI: 0.61-0.91 and OR = 0.83, 95% CI: 0.68-1.00, respectively, for the highest consumption quartile), whereas the starch-rich pattern was directly associated with it (OR = 1.34, 95% CI: 1.10-1.65). The vitamins and fiber pattern was inversely associated with ovarian cancer (OR = 0.77, 95% CI: 0.61-0.98), whereas the starch-rich pattern was directly associated with it (OR = 1.85, 95% CI: 1.37-2.48). In conclusion, the starch-rich pattern is potentially an unfavorable indicator of risk for both breast and ovarian cancers, while the animal products and the vitamins and fiber patterns may be associated with a reduced risk of breast and ovarian cancers, respectively.
---------------------------
[side issue: carbs and HDL putting it here as a reminder for myself to write some more on it]
"Carbohydrate intake and HDL in a multiethnic population." Am J Clin Nutr. 2007 Jan;85(1):225-30.
"Previous research has identified ethnic differences in cholesterol and other blood fat levels that couldn't be explained by genes, obesity, lifestyle factors or diet, Merchant and his team note, but these analyses usually looked at dietary fat, not carbohydrate consumption"-----------------------
Another Italian study, similar pattern:
"Intake of macronutrients and risk of breast cancer."
Franceschi S, Favero A, Decarli A, Negri E, La Vecchia C, Ferraroni M, Russo A, Salvini S, Amadori D, Conti E, Montella M, Giacosa A.
Lancet. 1996 May 18;347(9012):1351-6.
... FINDINGS: The risk of breast cancer decreased with increasing total fat intake (trend p ? 0.01) whereas the risk increased with increasing intake of available carbohydrates (trend p=0.002). The odds ratios for women in the highest compared with the lowest quintile of energy-adjusted intake were 0.81 for total fat and 1.30 for available carbohydrates. Starch was the chief contributor to the positive association with available carbohydrates. ... Conversely, the intakes of saturated fatty acids, protein, and fibre were not significantly associated with breast-cancer risk. ...
---------
Update (25-12-2011)
I am slapping this paper here quickly for the reference although it is not strictly on-topic (thanks Kiran)
Mean life span of CR sucrose-fed rats was significantly greater than all other groups [including starch fed CR]
| Feed | Corn starch | Sugar |
|---|---|---|
100% cal | 720 | 659 |
60% cal | 726 | 890 |
The rats diet consisted of 14% protein, 10% fat, and 66% sucrose or cornstarch. The numbers are the average lifespans of rats in days (standard deviation is about +/-20days). 100% cal means an ad-libidum diet. 60% cal = calorie-restriction diet.
(this study needs a discussion)
.
9 comments :
What is the mechanism driving this relationship I wonder. Is it the higher blood glucose, the higher insulin, the spikes or something particularly damaging about starch itself?
Lately I've been trying to untangle the relationship between diet and blood glucose/insulin and disease risk but it's not as simple as I first thought.
Inquiry, please contact me.
One cannot be 100% sure, the studies show some correlation but do not tell us about the actual mechanism.
The previous article in my blog indicates that excessive insulin is the direct risk factor for arterial plaque. Since arterial plaque and diabetes correlate, diabetes correlates with cancer risk and since insulin is primarily driven by carbohydrate intake then it is plausible that all 3 modern "civilisation" diseases may have a common cause - excessive glycemic load of the common diets.
I have to digress here: I found it is often misunderstood: the concept of the glycemic load. For example, many people find diets based on green vegetables and fruit helpful even though they are very high in carbohydrates in terms of percentage. However, such diets are low in the TOTAL amount of absorbed carbohydrates - they deliver low glycemic load and thus produce low insulin response! Just like other low carb diets such as Atkins, or Optimal.
My other lingering suspicion regarding the primary cancer culprit is wheat. Not only because all whet products deliver very high glycemic load but because of wheat germ agglutins (WGA). WGA acts as vitamin D3 receptor blockers, and also as insulin mimicker, pro-inflammatory etc.
See this:
Wheat and lactose
and
Wheat Germ Agglutinin; how little is enough?
There is a very well documented strong correlation between low vitamin D3 status and cancer.
I don't buy this study, as much as I'd like to: http://stuartbuck.blogspot.com/2011/12/starch-consumption-raises-risk-of.html
True, this is marginal but it does show a direction of the trend. That's why I quoted a few of other studies where the correlation between carbohydrates and cancer was better measurable. In spite of that, I assume that the study's finding is statistically significant (P less than 0.05) otherwise they probably wouldn't be presenting the findings on a conference, although I may be wrong. One cannot really trust fully the academics' integrity.
Stan the Man, always a great read. Good to know you are on this. I will pass your blog to many women who can use this info now. Thank you, Andre
Hi Andre,
You are very welcome. I must link your blog and Dr. Rosedale's. India needs you more than the West. They seem too be really badly hit with diabetes and heart disease. Bad diet? Any interesting research from there?
Regards,
Happy Winter Solstice,
Stan (Heretic)
On a related note, this study is intersting.
Mean life span of CR sucrose-fed rats was significantly greater than all other groups [including starch fed CR]
Interesting indeed! Thanks for the link.
Looks like in caloric-restricted (smaller doses), replacing corn starch with sugar is significantly healthier for the rats while in higher doses the reverse is true.
I wonder if this has something to do with the fact that the glycemic index (that is insulin triggering capability) of starch is higher than sugarÉ
The results can be explained perhaps by some kind of insulin and/or fructose threshold effect.
High starch and high sugar trigger high insulin. Sugar in additon releases fructose which may overloads the liver (harmful like ethanol), when in high doeses. In low doses the fructose does not matter while the insulin plays the main role in determining the lifespan. I think, the lower the insulin, the longer the lifespan (as long of course as the level is sufficient for metabolising glucose). This is highly speculative of course.
Stan
P.S.
I am very interested in longevity issue!
Post a Comment