HEALTH NEWS
“Live healthy...Live well”
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by Larry Kline
email: livehealthy-livewell@cox.net
TWO NEW BENEFITS OF
ALCOHOL FOR WOMEN – BONE HEATH -a study from Oregon State University,
published in Menopause, included
women in early menopause who were daily alcohol drinkers. When they stopped drinking for two weeks,
they showed increases in blood markers of bone turnover. (Having a high bone
turnover contributes to osteoporosis, since more bone is lost than reformed.)
When the women resumed drinking, the markers returned to their prior levels
within 24 hours. The findings support
the hypothesis that moderate dietary alcohol consumption may slow bone loss in
postmenopausal women. Previous studies
have observed a positive relationship between moderate alcohol intake and bone
mineral density - though excess amounts can harm bones.
JOINT
HEALTH –a study published in BMJ
collected data on the drinking habits of 34,000 women and then followed up with
them seven years later. Those who drank
more than three alcoholic beverages a week had half the risk of developing
rheumatoid arthritis over the study period compared to women who never
drank. Rheumatoid arthritis is a chronic
inflammatory disease that affects joints and is more common in women. Some (but not all) previous studies have
linked alcohol to reduced risk of rheumatoid arthritis, as well as to less
severe symptoms in people with the disease.
It is too
early to recommend that women start drinking to avoid either bone loss or
rheumatoid arthritis, but these studies add to the evidence that moderate
amounts of alcohol may have health benefits beyond the heart. Excess alcohol
has adverse effects, and even a moderate intake may increase the risk of breast
cancer. Most physicians recommend women
to limit alcohol to one drink a day. University of California Berkeley Wellness
Letter, 01/13.
CONSIDER EATING
LESS RED MEAT – Researchers believe they have found a new link between the
consumption of red meat and heart disease – the carnitine link. Heart disease, cancer, diabetes, stroke have
all been tied to red meat in recent years.
Yet Americans still eat more red meat (beef, pork, lamb, and veal) than
poultry and seafood combined.
LIVE LONGER
In 2012,
scientists at the Harvard School of Public Health published data on more than
120,000 participants in the Health Professionals Follow-Up Study and the
Nurses’ Health Study. After 28 years,
those who ate the most red meat (roughly two servings a day) had a 30 percent
higher risk of dying than those who ate the least (about half a serving a day).
It is
estimated that 8 percent of deaths in women and almost 10 percent in men could
be prevented if people consumed less than half a serving per day of red
meat. (In this study, a serving was
three ounces of cooked steak, hamburger, pork chop, or other unprocessed meat,
but only one ounce of sausage, ham, or other processed meat and half an ounce
of bacon.)
In 2009,
the NIH-AARP Diet and Health Study reported results on half a million
people. After 10 years, those who ate
the most red meat (about 5 ounces a day) were 30 percent more likely to die
than those who ate the least (about two-thirds of an ounce a day).
PROTECT YOUR HEART
Many
recommendations for limiting red meat intake are based on its saturated fat and
cholesterol content. Red meat is one of
the largest sources of saturated fat in the average American’s diet. We know that saturated fat can raise LDL (bad
cholesterol).
In the
84,000 women studied in the Nurses’ Health Study for 26 years, those who ate
the most red meat (at least two servings a day) had a 29 percent higher risk of
heart disease than those who ate the least (half a serving a day).
Sticking with
lean meat may not eliminate that risk.
There are probably a combination of half a dozen different compounds and
nutrients that lead to the ill-health effects of meat, among which are heme
iron, nitrite, salt, and compounds that are created when meats are cooked at
high temperatures.
In April,
2013, the Cleveland Clinic published a study that named a new compound in meat
that increases health risk: carnitine. The researchers believe that carnitine
ingestion leads to accelerated atherosclerosis, or hardening of the arteries. But carnitine, a nutrient that carries fuel
into our cells (the mitochondria), may not cause damage on its own. When animals and humans ingest carnitine,
microbes that live in the intestines digest the carnitine. As a byproduct, the microbes make something
that gets converted into a compound called TMAO.
The
bacteria in our intestines consume carnitine (or choline) which produces TMA
(trimethylamine) which gets converted to TMAO (trimethylamine-N-oxide) in the
liver. Carnitine is found largely in red
meat.
Your
everyday diet can affect how much TMAO microbes make. In one study, scientists fed a large dose of
carnitine to omnivores (who reported eating beef, pork, lamb, or other meat
almost every day) and to long-term vegans. The omnivores had a rise in blood levels of
TMAO, but the vegans had virtually none.
When the omnivores consumed oral antibiotics to eliminate the gut
bacteria, they made no TMAO either.
Three weeks after stopping the antibiotics, they once again had TMAO,
confirming gut microbes’ role in producing TMAO.
Further
research from the Cleveland Clinic examined 2,600 people who had gone to the
Clinic for a cardiac catheterization – a procedure that enables doctors to see
if the arteries feeding the heart muscle are clogged.
They
found that increased blood carnitine levels in patients strongly predicted
increased risks for cardiovascular disease and major adverse events like heart
attack, stroke, and death, but this was only true in subjects who also had high
TMAO levels.
Those who
had higher blood levels of TMAO were about 50 percent more likely to have a
heart attack, stroke, or other cardiovascular event over the next three
years. TMAO was a strong and independent
predictor of future heart attack, stroke, and death.
CANCER RISK
Limit
consumption of processed meat and red meat, advises the American Cancer
Society. To reduce your cancer risk, eat
no more than 18 ounces per week of red meats and avoid processed meat such as
ham, bacon, salami, hot dogs, and sausages.
A report by the American Institute
for Cancer Research concludes that the risk of colon and rectal cancer
rises by about 20 percent for every serving of red or processed meat eaten per
day. A few studies have found that red
meat eaters have a higher risk of pancreatic, prostate, or esophageal cancer.
N-nitroso
compounds cause cancer in laboratory animals. They are created by the nitrite that is used
to color and preserve processed meats like bacon, sausage, and lunch meats.
N-nitroso
compounds do not show up in the meat itself now that companies must add sodium
ascorbate or sodium erythorbate to keep N-nitroso from forming in meats that
have added nitrite. Instead, the
N-nitroso compounds form in the gut in a reaction that is catalyzed by bacteria. This might explain why processed-meat eaters
have a higher risk of colorectal cancer.
When people were fed increasing doses of unprocessed red meat, levels of
N-nitroso compounds increased. When
those people were fed the same amount of white meat, there was no increase in
the damaging compounds in the gut. Why
the difference in red and white meat?
One possibility is that the iron attached to hemoglobin in blood. Further research fed low red-meat consumers a
supplemental dose of blood sausage, which resulted in an increase in N-nitroso
compounds similar to those found in a high red-meat diet.
The
NIH-AARP study found the risk of colorectal cancer was higher in people who ate
more heme iron, which is found in all meats, but predominately in red meats.
Meat
mutagens: Starting many years ago, scientists found that heterocyclic
amines and polycyclic aromatic hydrocarbons are formed when meats are cooked to
well done at high temperatures. Animal
studies show that both are carcinogenic.
The
300,000 NIH-AARP Diet and Health Study found a 20 percent higher risk of
colorectal cancer among people who consumed the highest levels of two key
heterocyclic amines (HCAs). But they
found no link with the major polycyclic aromatic hydrocarbons (PAHs).
Studies
have shown that the levels of HCAs and PAHs are much lower in meats that are
cooked at lower temperatures and are not well done. Marinating the meat before cooking it, and
pouring off the marinade, also cuts the mutagens.
STROKE
Most
strokes that strike Americans are caused by clogged arteries rather than a
ruptured artery. Researchers followed
more than 125,000 people for more than 22 years. They found the risk of a non-hemorrhagic
stroke rose by 30 percent for every one to two ounces of processed meat, and by
21 percent for every four to six ounces of unprocessed meat eaten per day. A Swedish study on more than 300,000 people
reported that the risk of a non-hemorrhagic stroke was 12 percent higher for
every serving of red meat eaten per day.
The scientists estimated that swapping one serving a day of red meat for
poultry would cut the risk of stroke by 27 percent, that trading a serving a
day for fish or nuts would cut the risk by 17 percent, and that trading a
serving a day for dairy would cut the risk by about 10 percent.
High
blood pressure is the biggest risk factor for stroke. People that consume no more than two servings
of meat a week have significantly lower risk because when you are eating red
meat, you are not eating the healthier protein sources.
DIABETES
Processed
red meats, as well as unprocessed red meats have been linked to a higher risk
of type 2 diabetes. Harvard researchers
tracked more than 200,000 men and women for up to 28 years. The risk of type 2 diabetes increased by 32 percent
for every two ounces of processed meat, and by 12 percent for every three
ounces of unprocessed meat, eaten per day.
The fats
in red meat may also play a role.
Polyunsaturated fatty acids are related to lower risk, and red meat has
very low amounts. In the study, people
ate about a quarter cup of nuts a day (nuts are rich in polyunsaturated fat)
had a 21 percent lower risk of diabetes than those who ate one serving of red
meat.
At a
minimum, red meat will displace healthier fatty acids found in other sources of
protein. Also, the N-nitroso compounds
generated by red meats may be toxic to insulin-making cells in the pancreas.
Carnitine
metabolites could also damage cells that secrete insulin. Nutrition
Action Healthletter, 06/13.
The
team in Japan has come up with a way to get the master body clock to be more
flexible. It is a group of 10,000 brain cells - about the same size as a grain
of rice - which constantly communicate with each other to keep a strict control
over body time. The scientists found that interfering with the vasopressin
receptors, essentially a brain cell's “ears” that allow it to keep in touch
with its “neighbors,” let the clock shift rapidly. Genetically modified mice
which had no vasopressin receptors were able to adjust to the clocks being put
back eight hours within a single day, while normal mice took six days. When the
clocks were put forward eight hours, then it took normal mice eight days to
adapt, but those without vasopressin receptors adjusted in two. Similar results
were then achieved in normal mice using a drug. The results identify
vasopressin signaling as a possible therapeutic target for the management of
circadian rhythm [body clock] misalignment.
However,
vasopressin receptors were also heavily involved in kidney function so any drug
developed would need to be designed carefully to target the body clock without
disrupting the kidneys. The issue here in terms of public health is rotational
shift work. The epidemiological evidence that we have now shows that if a
worker has spent a working life doing rotational shift work, they're at higher
risk of contracting certain forms of cancer, cardiovascular disease or metabolic
syndrome like diabetes. BBC News Health, 10/3/13.
