http://www.thestar.com/NASApp/cs/Co...72154&t=TS_Home

Low-fat diet 'fails to lower health risks'
No change found in women's diseases
But more research needed, experts say
Feb. 8, 2006. 01:00 AM
ELAINE CAREY
HEALTH REPORTER


Staying on a low-fat diet does not appear to reduce the risk of breast and colorectal cancer or heart disease in older women, a large American study says.

The latest bombshell from the landmark Women's Health Initiative study, released in three papers in the Journal of the American Medical Association yesterday, left health experts scrambling to try and explain the confounding results.

The new study followed almost 50,000 American women aged 50 to 79 for eight years to test the impact of a diet low in fat and high in fruits, vegetables and grains. In the end, those assigned to the low-fat diet had the same rates of breast cancer, colon cancer and heart attack and stroke as those who ate whatever they pleased, the study found.

The findings "are a bit surprising and a bit more disappointing," said Dr. Andrea Eisen, head of preventive oncology at Sunnybrook & Women's Health Sciences Centre. "Generally, people have been given advice to cut back on fat and there's a big campaign to eat more fruit and vegetables and I'm not sure it is totally justified," she said.

"These studies are revolutionary," Dr. Jules Hirsch, who has spent a lifetime studying the effects of diets on weight and health, told The New York Times. "They should put a stop to this era of thinking that we have all the information we need to change the whole national diet and make everybody healthy."

However, Ross Prentice, a co-author of the study, qualified the findings, saying that the 20,000 women in the low-fat diet group had a 9 per cent lower rate of breast cancer compared with women in the control group who continued to eat what they wanted, but that was not enough to be statistically significant.

"The bottom line is that changing to a low-fat diet may reduce breast cancer risk, especially among women who have a relatively high-fat diet to begin with," Prentice said, "but we don't view our data as strong enough at this time to make a broad recommendation that all women initiate a low-fat diet for that purpose."

In women who cut the most fat there were signs of less breast cancer, and in women who ate small amounts of the worst kind of fats, signs of less heart disease, the researchers said, adding longer follow-up may lead to more definitive results. The women also didn't reduce their fat intake as much as the diet demanded and most remained overweight, a major risk factor.

A low-fat diet had no significant impact on the incidence of stroke, heart attack, cardiovascular disease or coronary artery disease, indicating people have to do more than eat more healthfully for a number of years to avoid disease, said an accompanying editorial.

"To reduce the risk of cardiovascular disease, individuals should maintain a desirable body weight, be physically active, avoid tobacco exposure and eat a diet consistent with national guidelines," it said.

The low-fat group reduced their fat intake by an average of only 2.9 per cent and didn't distinguish between so-called "good" and "bad" fats.

"I think you can safely say that very small changes are going to lead to very small changes in cardiovascular disease," said Dr. Grant Pierce, chair of the scientific research group of the Heart & Stroke Foundation of Canada.

"We may be knocking the icing off the cake but we've still got a very big cake."

Women in the low-fat group aimed to reduce their fat intake to 20 per cent of their diet and to increase their consumption of fruits and vegetables to at least five servings a day and grains to six servings a day.

While they did increase their fruit and vegetable consumption by one serving a day and grains by about a half serving, "that's not a whole lot, is it?" Pierce asked. "I think you have to take that into consideration."

The study showed a trend toward higher rates of cardiovascular disease in subjects who ate higher amounts of trans fats, and a trend toward lower rates of disease in those with a higher vegetable intake, he said.

"The trends are there as we would expect, but maybe it's just a matter that you can't tinker with the diet, you need to make some real changes," Pierce said.

In interviews with more than 50 specialists conducted by ABC News, questions were raised about the study's shortcomings. The experts said:

The study was too short to detect a reduction in breast and colon cancer from dietary fat.

The amount of fat reduction was too small and was unlikely to produce meaningful benefits.

The researchers simply looked at fat intake in general and did not distinguish between healthy fats like olive oil and unhealthy fats like trans fats.

The study also suggests that dietary intervention has to take place at an early age to avoid disease developing, Pierce said.

"We know cardiovascular disease is already starting in children as young as 10 years old," he said. "If we modify their diet then, I would suspect it would have a major impact on cardiovascular disease but we really haven't done the studies yet."

With files from Star Wire Services

this is the third thread started on this topic.

the other two are:
http://forum.lowcarber.org/showthread.php?t=284807
http://forum.lowcarber.org/showthread.php?t=284852

Even going high carb is very safe, it just really depends on the type of carbs. Going upto 80% carbs can effective too. Okinawa elders get 80% of the daily food intake from carbs, mainly from sweet potatoes and they have the lowest disease rates in the world and highest number of people living into their hundreds. They have 80% fewer heart disease, breast and prostate cancer is virtually not existant and same with other diseases that westerners get. But the young okinawans showing the same problems as westerners as they change their eating habbits.

one thing I don't share with a lot of people here is carbs are evil. They are not not bad and niether is fat. Excess calories and hi GI foods are the problem.

This study was a waste of time and poorely done.

Really? What makes it "poorly done"?

The first of these is a non-functioning thread, the second is page 1 of this very same thread.

Notice that instead of "experts" admitting that low-fat diets may not make you healthy this study may actually flame the low-fat fire. Now they can say that cutting your fats by a little bit doesn't have much of an effect -- in order to get the benefits they say you will have to cut the fat by a lot. They will just say that the study didn't hit the sweet spot where they cut the fat and sodium or whatever by just the right amount.

My favorite too is when they say that you have to get kids on that low fat dogma ASAP, because they "hope" that might show some benefit.

Excuse me, but I am not putting my kids on your experimental high grain diet on your hope. My kids are going to eat a balanced diet, avoid high carbs, avoid trans fats, and eat moderate amounts of everything.

The other part I find annoying is that they talk about "bad fats", but in the details they finally admit that it is Transfats that are the problem. They can't show any issue with Saturated Fats.

Last time I checked, it was Atkins who was pushing the reduction of trans fats and the high GI diet what was increasing them in your body.

Of course if they admit that you can eat fat, and saturated fat, then people might question their agenda based science.....

I was watching Fox and Friends this morning and they had there pet doctor on. Dr Many Alverez(sp?). The guy danced around and did the good fat, bad fat tripe and then said that even though this study showed no benefit to going low-fat you still should not go out and eat a big mac. Sometimes you have to wonder how Doctors get away with being so ignorant.

The other doctor that Fox has on the payroll is no better. I forget his name but he is usually on the Sunday morning show. One day I was watching he got a question about Atkins and said that he tried to discourage his patients from going on it but if they did he would prescribe a statin just in case, even if there lipids were normal. What a moron.

http://www.theglobeandmail.com/serv...alth/columnists

LESLIE BECK

Since the 1970s, reducing our fat intake has been the cornerstone of dietary advice. A high-fat diet has been linked to a greater risk of heart disease, stroke, certain cancers and obesity. But according to three reports published in today's issue of the Journal of the American Medical Association, a low-fat diet does not protect postmenopausal women from breast and colon cancers, or even heart disease.

These new findings add to what may seem like a steady stream in the news of nutrition flip-flops. One day we're told that something is good for us; the next day, it's not. For health conscious Canadians trying to adopt a healthy diet, these flip-flops can be frustrating.

But just because this one study didn't find an overall protective effect, there's no reason to swap a low-fat menu for one that's high in fat. These study findings do uncover some encouraging trends and suggest there's more to the low-fat story than could be told from this particular research.

The Women's Health Initiative Dietary Modification Trial, the largest long-term trial ever conducted, followed 48,835 postmenopausal U.S. women, ages 50 to 79, for eight years. Researchers assigned 40 per cent of the women to a low-fat diet (20 per cent of calories from fat) and an increased amount of fruits and vegetables (at least five servings per day) and grains (six or more servings per day). The remaining women were assigned to the comparison group and were asked to not make any changes to their diets.

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At the beginning of the study, all the women got roughly 38 per cent of their calories from fat, and ate 3.5 servings of fruits and vegetables, and 4.5 servings of grains each day.

During the study, women in the low-fat group managed to reduce their fat intake to 24 per cent of calories -- 70 per cent of the targeted reduction in fat. Intake of fruit and vegetables was modestly increased to five servings per day; intake of grains remained unchanged.

After eight years of follow-up, there was no overall difference in risk of breast cancer, colon cancer, heart disease or stroke between women in the low-fat group and the comparison group. There were, however, signs that a woman's risk of disease could be modified by dietary change.

Women in the low-fat group were 9-per-cent less likely to develop breast cancer than their peers in the comparison group, although this finding was not deemed statistically significant (it could have been due to chance). A 9-per-cent reduction in breast cancer risk means that out of 10,000 women, 42 following the low-fat diet and 45 following their normal diets developed breast cancer each year.

Interestingly, the researchers did find that the low-fat diet was associated with a 15-per-cent reduction in circulating levels of estradiol, the form of estrogen that increases the risk of breast cancer.

Significant results were seen among women in the low-fat diet group who had the highest intakes of fat at the beginning of the study. Women in these categories were 15- to 22-per-cent less likely to be diagnosed with breast cancer, compared to women following their normal diets.

It appears that adopting a low-fat diet may help guard against breast cancer, especially among women who have a relatively high fat intake to begin with.

The study found no evidence that a low-fat diet, initiated in midlife, protected from any form of colorectal cancer during the eight year period. Since colon cancer can take many years to develop, it's possible that the study wasn't long enough to see the impact of a low-fat diet on cancer risk. In fact, women in the low-fat group were less likely to report polyps found during colorectal examinations with their doctors. (Certain types of polyps are precursors to colorectal cancer.) The reduction in polyps suggests that protection from colorectal cancer could occur over a longer period.

Following a low-fat diet also didn't lower the overall risk of cardiovascular disease, including heart attack and stroke. The study targeted a reduction in total dietary fat; it did not distinguish between good fats (polyunsaturated fats found in fish, nuts and vegetable oils), and the bad fats (saturated fats found in animal foods and trans fats used in baked goods and deep-fried foods). What's more, the majority of participants were overweight or obese, a risk factor for heart disease (and postmenopausal breast cancer) but the study did not address weight.

Our thinking about dietary fat and heart disease has evolved considerably since this study began in 1993. Substantial evidence now shows that saturated and trans fats increase total and LDL (bad) cholesterol levels. Mounting evidence also suggests that certain polyunsaturated fats help reduce the risk of heart disease. In 2002, national dietary guidelines moved from recommending less than 30 per cent of calories from fat to 25 to 35 per cent of calories. The revised guidelines also recommend intake levels for specific types of dietary fats.

Participants in the low-fat diet group reduced their intake of saturated fat, but they also reduced their intake of heart healthy fats. Consumption of polyunsaturated fats -- and fruits and vegetables -- was lower than current guidelines recommend. When the researchers analyzed data from women in the low-fat group who had consumed the least saturated and trans fats, they did find a lower risk of heart disease. These women were 19-per-cent less likely to develop heart disease, compared to their peers in the normal diet group. Women consuming lower levels of saturated and trans fats also had greater reductions of LDL cholesterol in the blood.

These new findings about a low-fat diet may not be the news everyone was hoping for. The study had limitations that may have influenced the results -- women in the intervention group didn't meet the 20-per-cent-fat calorie target, they didn't markedly boost their fruit and vegetable intake, and the study might not have been long enough to notice a reduced risk of cancer. Whether a lower fat intake, a higher intake of fruits and vegetables, a longer study period, or making dietary changes before the age of 50 would have reduced overall cancer or heart disease risk remains unanswered.

But I do think these findings indicate our current dietary guidelines are on track: Keep saturated and trans fats to no more than 10 per cent of calories; get most of your fats from fish, nuts, seeds and vegetable oils; and eat five to 10 daily servings of fruits and vegetables. It seems to me these new findings aren't a dietary flip-flop. Rather, they support our current body of knowledge and help guide future studies.

Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV's Canada AM every Wednesday. Visit her website at lesliebeck.com.

Interestingly - there's no mention of grains in this sentence. What happened to the grains so prevalent in our "current dietary guidelines" ???

Funny how this Canadian dietician conveniently left them out when mentioning how this study somehow proves "current dietary guidelines are on track."

As grains are grass seeds, they may be hidden in the "fish, nuts, seeds and vegetable oils"

The more I look at that last sentence in the Globe article, the more it looks to me as if the dietician is advocating something akin to a Paleo style diet...which is (to me) a radical departure from "current dietary guidelines".

Odd how she would say those things, and yet still stick to the idea that one should follow "guidelines".

PS - on edit....there's no mention of dairy either, which is rather interesting.

Dr. Eades nails it again. Good read.

45 out of 1000 is 4.5%. 42 out of 1000 is 4.2%. That is a 0.3% reduction, not the 9% reduction that they are claiming. That is why it is insignificant. Their words and calculation methods do not match and they deliberately do this to mislead people.

I think that they were calculating it by the prevelance rate in the population. Not everyone in the population gets cancer. There are rates or norms about how many typically get cancer (I dont know what the current rate is). I think the 9% is the diviation from that rate, not how many people actually get cancer. I think what they are doing is a calculation of a calcualtion.