High protein diet linked to risk of dying early
A research report from the University of Southern Carolina published in journal Cell Metabolism, suggests protein controls the growth hormone IGF-I, which has been linked to cancer and hence a high-protein diet during middle age could increase your risk of dying early.
According to the researchers, meat and cheese lovers were 74% more likely to die of any cause within the study period, compared to those who consumed less protein. People who ate lots of animal protein were also several times more likely to die of diabetes.
The study tracked 6,318 adults over the age of 50 for almost 20 years and shows that plant-derived proteins are associated with lower mortality. However it also suggests a moderate protein intake could be good for those over the age of 65 to allow for the maintenance of healthy weight and protection from frailty.
Highlights of the study include:
- High protein intake is linked to increased cancer, diabetes, and overall mortality
- High IGF-1 levels increased the relationship between mortality and high protein
- Higher protein consumption may be protective for older adults
- Plant-derived proteins are associated with lower mortality than animal-derived proteins
The study also revealed that plant-based proteins, such as those from beans, did not seem to have the same mortality effects as animal proteins. And because controlling for carbohydrate or fat intake did not affect rates of cancer and death, researchers said the latest findings suggest that animal protein is to blame.
“There’s a misconception that because we all eat, understanding nutrition is simple. But the question is not whether a certain diet allows you to do well for three days, but can it help you survive to be 100?” corresponding author Valter Longo, the Edna M. Jones Professor of Biogerontology at the University of Southern California Davis School of Gerontology and director of the USC Longevity Institute, said in a news release.
“The majority of Americans are eating about twice as much proteins as they should, and it seems that the best change would be to lower the daily intake of all proteins but especially animal-derived proteins,” Longo said. “But don’t get extreme in cutting out protein; you can go from protected to malnourished very quickly.”
“These results suggest that low protein intake during middle age followed by moderate to high protein consumption in old adults may optimize health span and longevity.”
Speaking to Sky News, Longo added: “Almost everyone is going to have a cancer cell or pre-cancer cell in them at some point. The question is: Does it progress?”
“Turns out one of the major factors in determining if it does, is, protein intake.”
Sky News also included an interview with dietician and nutritionist Nicole Berberian who told the news channel the conclusions were based on an observational study, which she said could not establish cause and effect. “This is an observational study, so from that you can never tell whether protein was the cause of the increase in cancer,” she said.
“It could be anything. It could be a lifestyle factor in those people they observed, it could be just a random chance.” She added that the study did not identify what types of proteins those being observed were eating, and said some forms – such as processed meat – had already been linked to cancer.
There is little doubt this latest research will be the source of a lot of debate as dieticians, scientists and health commentators weigh in over this research and often to the confusion of the man in the street.
However and importantly there are other studies that support these latest findings and include human interaction over long periods of time.
Harvard School of Public Health researchers looked at nearly 125 000 female nurses and male health professionals whose diets were followed for more than two decades and reported in 2013 highlighting the risk of high protein consumption. During this period, around 24 000 of the participants died from cardiovascular disease or cancer.
It’s also a well known fact is that the Japanese are the world’s longest-lived people, however lesser known is that there is a Northeast-to-Southwest gradient in longevity, where the longest lived of the Japanese are those that inhabit the southernmost islands, known as the Ryukyu Islands (or Okinawa prefecture). The citizens of Okinawa have the longest life expectancy in Japan (and most likely in the world), mainly because they avoid or delay major age-associated diseases such as cancer, heart disease, stroke, and diabetes.
Gerontologists, Bradley Wilcox, MD, Craig Wilcox, PhD and Makoto Suzuki, MD spent many years investigating Okinawan longevity and co-wrote a book, The Okinawa Program, which recommends that we “eat as low down the food chain as possible.”
Here is what we can learn from the Okinawans’ habits:
Eat healthy foods, mostly plants. The Okinawans eat more veggies than most people (mostly green and yellow ones), as well as whole grains, tofu, fish and other legumes. They eat very little sugar, and very little meat, dairy or eggs.
1) High consumption of vegetables,
2) High consumption of legumes (mostly soy in origin),
3) Moderate consumption of fish products (especially in coastal areas),
4) Low consumption of meat and meat products,
5) Low consumption of dairy products,
6) Moderate alcohol consumption,
7) Low caloric intake,
8) Rich in omega-3 fats,
9) High monounsaturated-to-saturated-fat ratio, and
10) Emphasis on low-GI carbohydrates.
The research shows that Okinawans also eat 30 to 40 percent less kilojoules than people of the Western world, while their flavonoid consumption is up to eight times higher, and their daily exercise programmes are moderate to high. They generally eat to a 80% full rule.The Okinawans call this rule “Hara Hachi Bu” – eat until you are 80% full. Of course, there’s no way to know exactly how full you are, but it’s a helpful guideline. As our brains are 10-20 minutes behind our stomachs, it usually turns out that when you think you’re 80% full, you’re actually full, while when you eat to 100% full, you are usually overfilling yourself. Okinawans end up eating fewer calories than most people. They tend not to gain too much weight as a result, and coupled with their active lifestyles, it keeps them very healthy.The benefits of the local diet were summarised by the authors of the Okinawa program as follows: “The Okinawans have a low risk of arteriosclerosis and stomach cancer, a very low risk of hormone-dependent cancers, such as breast and prostate cancer. They eat three servings of fish a week, on average … plenty of whole grains, vegetables and soy products too, more tofu and more konbu seaweed than anyone else in the world, as well as squid and octopus, which are rich in taurine – that could lower cholesterol and blood pressure.”
You can watch the Sky News video interview on the high protein diet findings by following this link: http://news.sky.com/story/1221039/meat-and-cheese-as-bad-for-you-as-smoking
For more information on the study, click here: http://www.cell.com/cell-metabolism/retrieve/pii/S155041311400062X#Summary Source: Cell Metabolism, Volume 19, Issue 3, 407-417, 4 March 2014
The study was authored by Levine, Jorge, Sebastian, Priya Balasubramanian, Chia-Wei Cheng, Federica Madia, Fontana Mario,Jaime Guevara-Aguirre,Junxiang Wan,Giuseppe Passarino,Brian K. Kennedy,Min Wei,Pinchas Cohen,Eileen M. Crimmins,Valter D. Longo