News of a study from Harvard researchers released today says antioxidants may not ward off strokes and dementia. But more research is needed on whole foods rather than just the antioxidants from the foods. People still want to know the bottom line, can certain 'functional' foods override or "switch off" through epigenetics that inheritable predisposition to what runs in family histories such as strokes or dementia?
The study in today's news was published in the journal of Neurology. Also see the results of other Harvard studies that are pro-foods high in antioxidants and flavonoids. Check out the site and list of studies "Antioxidants: Beyond the Hype - Harvard School of Public Health." But other Harvard studies look at what colorful vegetables can do. See, "ALS Risk Reduced by Eating Brightly Colored Vegetables, Study Suggests."
The antioxidant study in the news today, "Total antioxidant capacity of the diet and major neurologic outcomes in older adults,"was published in the journal of Neurology. In that study, researchers set out to evaluate total antioxidant capacity of the diet, measured by the ferric-reducing antioxidant power (FRAP) assay, in relation to risks of dementia and stroke, as well as key structural brain volumes, in the elderly.
To do the study, scientists prospectively studied 5,395 participants in the Rotterdam Study, aged 55 years and older, who were dementia free and provided dietary information at study baseline; 5,285 individuals were also stroke free at baseline, and 462 were dementia and stroke free at the time of an MRI brain scan 5 years after baseline.
How the dietary data was analyzed
Dietary data were ascertained using a semiquantitative food-frequency questionnaire, and combined with food-specific FRAP measurements from published tables; this information was aggregated across the diet to obtain “dietary FRAP scores.” Multivariable-adjusted Cox proportional hazard models were used to estimate relative risks of dementia and stroke, and multivariable-adjusted linear regression was used to estimate mean differences in structural brain volumes, across tertiles of dietary FRAP scores.
The only issue is whether a study is needed to look at inherited genes that lead to stroke and/or dementia rather than foods. And a study needs to be done on lifestyle and family eating and activity patterns or stress as well as genes.
Study concluded that total antioxidants from the diet does not predict risks of stroke or dementia
The researchers concluded that the total antioxidant capacity of the diet, measured by dietary FRAP scores, does not seem to predict risks of major neurologic diseases. How the study was done focused on antioxidants. In the study on antioxidants and their relation to stroke and/or dementia, the study's results showed that during a median 13.8 years of follow-up, we identified approximately 600 cases each of dementia and stroke.
The conclusions of the study were that no associations were seen between antioxidant consumption and risk of dementia or stroke. In medical terms, the researchers looked at multivariable-adjusted models, and observed no associations between dietary scores and risk of dementia or stroke. The details scientists researched were the FRAP scores and the risk risk of dementia, which were in percentage similar.
Regarding relative risk, scientists found such details as the following: (p trend = 0.3; relative risk = 1.12, 95% confidence interval = 0.91–1.38, comparing the highest vs lowest FRAP tertiles) or risk of stroke (p trend = 0.3; relative risk = 0.91, 95% confidence interval = 0.75–1.11, comparing extreme FRAP tertiles). In plain language, the results were similar across subtypes of these outcomes. Dietary FRAP scores were unrelated to brain tissue volumes as well.
Strokes run in families, say some scientists. See, "Stroke Risk Often Runs in the Family."
Scientists still don't know for sure and for all people with all different family histories of genetic predisposition whether or not antioxidants ward off dementia and strokes or whether it's the entire whole, fresh food that plays a role or even lifestyles, stress, exposure to pollutants or other factors. But what scientists do know is that fruits and vegetables are good for you if you're told food is medicine.
It can be, to a certain extent. Foods are supposed to nourish you. This year the latest diet 'fad' that really works is called functional foods as super foods. Functional foods move beyond 'necessity' to provide additional health benefits that may reduce disease risk, according to some nutritionists.
Now a new study finds there are some things anti-oxidants can't do. Harvard researchers followed more than 5,000 people over 14 years, tracking the food they ate. They found many got their antioxidants through coffee and tea. See, Preventing Stroke & Dementia. If you look at antioxidants as part of foods rather than as separate supplements taken out of foods by processing, you have whole foods that may promote optimal health.
Functional foods with antioxidants
Such foods with antioxidants may be conventional foods, modified foods, medical foods, and foods for special use in specific dosages. But now the latest study shows that antioxidants in coffee and tea may not help prevent stroke and dementia. On the other hand, experts say antioxidants in foods like blueberries, strawberries, tomatoes, bell peppers, corn, and spinach can be beneficial.
There is growing evidence that eating lots of fruits and vegetables and even drinking a very small amount of alcoholic beverages may reduce the risk of stroke. Scientists usually claim that strokes run in families and that the predisposition to get a stroke, usually at a certain age, is inherited. But can you prevent or alter in some way the 'destiny' of having strokes run in families from generation to generation based on eating more vegetables and fruits than your relatives did who had the strokes at similar ages or within a decade? Is there any way to stop the genetic family history from happening with food instead of waiting to breed strokes out of your family by marrying non-stroke-prone mates?
The new study looked at antioxidants and implied that simply adding more antioxidants to your diet isn't going to stop your predisposition to have strokes. On the other hand, doctors say eating fruits and vegetables is still the best source of antioxidants and that getting plenty of those foods reduces the risk of obesity, heart disease and hypertension. Broccoli, spinach, carrots, berries and apricots are all foods rich in antioxidants.
More antioxidants in your diet may not mean better health, a new study says
In a new study, according to the February 21, 2013 NPR news report, "More Antioxidants In Your Diet May Not Mean Better Health." People who ate more antioxidants overall didn't lower their risk of stroke and dementia in old age. That flies in the face of earlier research that found that the antioxidants in fruits and vegetables reduce stroke and dementia risk. The new study was published online in the journal Neurology.
Check out the news report which contains a quote by Elizabeth Devore, an epidemiologist at Brigham and Women's Hospital who led the new study. The National Public Radio news report is "More Antioxidants In Your Diet May Not Mean Better Health." What scientists did find in 2012 noted that eating a good amount of berries delayed cognitive decline among women in the big, ongoing Nurses Health Study.
Flavonoids, another form of antioxidants and vitamin C studied regarding reduced risk of stroke
Berries have lots of chemicals called flavonoids, which researchers think probably have protective powers much like those of better-known antioxidants like beta-carotene, vitamin C and vitamin E. Another study of more than 5,000 people ages 55 and older in Rotterdam, Netherlands followed for about 14 years found that individuals who ate foods with more vitamin E were less likely to suffer dementia. The study also noted that people who ate foods with more vitamin C were less likely to have a stroke.
Does that mean that whatever you eat doesn't matter because you get what you inherit from your family history as far as stroke or dementia? But on the other hand, the Rotterdam study's statistics were ran through again to check, and that same study still showed that vitamins C and E were doing good things for the brain. But in the new study, the people with the highest levels of antioxidant intake were getting most of those antioxidants from coffee and tea. Is the road to prevention ethnic cuisine?
The latest study also looked at the same people in the previous studies and found that having lots of antioxidants in the diet overall doesn't help with stroke and dementia
After all, the Dutch drink a lot of coffee and tea? What do other groups drink? Coffee and tea cntain a lot of antioxidants, but in the form of flavonoids. Other plant foods contain flavonoids also. And fruits and vegetables have flavonoids without the caffeine of coffee or tea (unless people are drinking decaf).
If you look at other European studies on people, you'll read how drinking a lot of coffee, say five cups a day, does help protect against Alzheimer's. But what about green tea sipped among Asian groups elsewhere? In the latest study on the Dutch, coffee-drinking didn't point to some other benefits, which leads researchers to theorize that the total level of antioxidant intake isn't the whole story.
Then what is the whole story, genetics, that strokes and/or dementia or both run in families? But there has to be some whole foods that help protect people, regardless of their genes because bad genes can be switched off through epigenetics, those little switches that turn on the good genes and turn off the bad genes based on foods, lifestyle, pollution exposure, and stress.
Another study shows reduced risk of stroke in people eating an overall high-antioxidant diet
Another Italian study from 2011 also showed less stroke risk in people who had a high-antioxidant diet overall. But in that case, the people were getting their antioxidants from wine, fruits and vegetables. The Dutch eat participants in the study ate a lot of meat and dairy, and fewer vegetables and fruit. The Dutch in the study weren't vegans.
Now there's a huge USDA database available on the still largely mysterious flavonoids, antioxidants, and other chemical compounds, micronutrients, and phytonutrients in various plant foods high in antioxidants. After all, researchers may look not only at the antioxidant (ORAC) value of foods, but also whether people are eating high on the Glycemic Index (eating foods low or high in sugar), whether people are drinking lots of fructose-laden processed foods, or whether they're consuming caffeine, wine, fermented foods, functional foods, restorative foods, cruciferous vegetables, nuts, or seeds, and what fats people eat--transfats, oils, or solid shortenings such as lard or chicken fat?
Scientists have just started to analyze the relationship between flavonoids and health.
Consumers want researchers to help resolve the confusion over the merits of antioxidants because at this point scientists really aren't sure what micronutrients, phytonutrients or antioxidants and other factors are helping to prevent stroke. Even if artery hardening is part of family history, there's steps to take with what you eat, lifestyle, and what stress and pollution, even environmental plastics and other toxins you're exposed to.
Right now, scientists are looking at nontraditional antioxidant foods. But more research is needed before anyone can say for sure whether dairy, non-dairy, fermented foods, fresh foods, plant foods, whole foods, or your high or low insulin levels are making you age faster. What scientists do know is foods grilled, fried, or barbequed at very high heart and charred creates carcinogenic compounds in the food.
Another new study released on February 21, 2013 shows avocado consumption may be associated with better diet quality, but what about overall health?
Positive health indicators also are associated with avocado consumption in another study, published in the January 13, 2013 issue of the Nutrition Journal. The study is from the government's Centers for Disease Control and Prevention (CDC). New analysis of data from the National Health and Nutrition Examination Survey (NHANES), a program of the Centers for Disease Control and Prevention (CDC), indicates that consuming avocados may be associated with better diet quality and nutrient intake level, lower intake of added sugars, lower body weight, BMI and waist circumferences, higher "good cholesterol" levels and lower metabolic syndrome risk. These results were published in the January 2013 issue of the Nutrition Journal | Vol 12 | 2013 - January.
For a free copy of the abstract or the full study on avocados, visit the Nutrition Journal site. Also, see, the Centers for Disease Control and Prevention site, "About the National Health and Nutrition Examination Survey." Usually specific foods have their own studies on what health benefits they have. In the avocado study, scientists looked at the nutrient intake levels and positive health indicators.
Specifically, the survey data (NHANES 2001-2008, 17,567 U.S. adults ages 19 years and older) revealed that the 347 adults (50% female) who consumed avocados in any amount during a 24-hour dietary recording period had several significantly better nutrient intake levels and more positive health indicators than those who did not consume avocados. Among the avocado consumers, average daily consumption was about one half (70.1 +/- 5.4 g/day) of a medium sized avocado, somewhat higher in male avocado consumers (75.3 +/-6.3 g/day) than females (66.7 +/- 7.3 g/day).
Overall Diet Quality, Energy and Nutrient Intakes
- According to the study, Avocado consumers more closely adhered to the Dietary Guidelines for Americans than those who did not eat avocados, as measured by the Healthy Eating Index (HEI).
- Avocado consumers had significantly higher intakes of certain important nutrients including 36% more dietary fiber, 23% more vitamin E, 13% more magnesium, 16% more potassium and 48% more vitamin K than non-consumers.
- Avocado consumers also had significantly higher intakes of "good" fats (18% more monounsaturated and 12% more polyunsaturated) and total fats (11% more) than non-consumers, although average caloric intake of both groups was the same.
- Avocado consumers and non-consumers had similar intakes of sodium.
Physiological Health Measures
- Avocado consumers had significantly lower BMI values than non-consumers.
- Avocado consumers had significantly smaller waist circumference measures than non-consumers (an average of 4 cm smaller).
- Avocado consumers weighed significantly less than non-consumers (an average of 7.5 pounds less).
- Avocado consumers had significantly higher HDL ("good") cholesterol levels.
Metabolic Syndrome Risk
The study found that Avocado consumers had a 50% lower odds ratio for metabolic syndrome compared to non-consumers. Metabolic syndrome is a name given to a group of risk factors which, when they occur together, increase the risk for coronary artery disease, stroke and type-2 diabetes.
As with most analyses of NHANES data, research findings were based on cross-sectional data from a single 24-hour dietary recall (which may be inaccurate and biased due to misreporting and memory lapses) and cannot provide cause and effect evidence between avocado consumption and improvements in diet quality. "These findings suggest an interesting association between the consumption of avocados and better nutrient intakes and other positive outcomes," said study primary investigator Victor Fulgoni, PhD, according to the February 21, 2013 news release, New study indicates avocado consumption may be associated with better diet quality. "These observations were derived from population survey data, they provide important clues to better understanding the relationships between diet and health, and give direction to future research endeavors."
"To this end, the Hass Avocado Board is funding additional clinical studies to investigate the relationship between fresh avocado consumption and risk factors for cardiovascular disease, avocados' potential positive role in weight management and diabetes, and avocados' ability to enhance nutrient absorption," said Hass Avocado Board Executive Director Emiliano Escobedo, according to the February 21, 2013 news release, "New study indicates avocado consumption may be associated with better diet quality."
You can read the abstract of the study, at the Nutrition Journal site. For additional information or free resources on avocado research, recipes, tips and photos visit the Hass Avocado Board web site at AvocadoCentral.com. For a free copy of the abstract or the full study visit the Nutrition Journal site.
About the Hass Avocado Board
The Hass Avocado Board was established in 2002 to promote the consumption of Hass avocados in the United States. A 12-member board representing domestic producers and importers of Hass avocados directs HAB's promotion, research and information programs under supervision of the United States Department of Agriculture. Hass avocados are grown in California and imported into the US from Mexico, Chile, Peru, Dominican Republic and New Zealand. But the CDC did the nutrition examination survery. See, the Centers for Disease Control and Prevention site, "About the National Health and Nutrition Examination Survey." Accessed on January 31, 2013.
Fulgoni VL, Dreher M and Davenport A. Avocado Consumption is Associated with Better Diet Quality and Nutrient Intake, and Lower Metabolic Syndrome Risk in US Adults: Results from the National Health and Nutrition Examination Survey (NHANES) 2001-2008. Nutrition Journal. 2013; 12:1 (2 January 2013)
United States Department of Agriculture. Healthy Eating Index. Accessed on January 30, 2013.
National Heart Blood and Lung Institute. What is Metabolic Syndrome? Accessed on January 30, 2013.
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