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Every month there is more evidence of the importance of the human microbiome or microbiota - the community of microbes that live in and on us. Trillions of microbes! When we eat food, we eat all the microbes that are in the food, and this has effects on the microbes living in the gut (intestines).

How many microbes do we eat daily? An interesting study was published in 2014 that tried to answer this question. The researchers found that the average American adult ingests between 1 million to over 1 billion microbes every day! It depended on food choices.

Another study just published looked at more than 9000 foods in the US health and dietary database (from 74,466 persons). The researchers estimated the number of live microbes present in all the foods. From that they estimated that the intakes of foods with live microbes were pretty low (about 85 grams/day for children and 127 grams/day for adults). Their results were similar to the earlier 2014 study mentioned above.

They found that around 20% of children and 26% of adults consumed foods with high levels of live microorganisms in their diet. Also, American children and adults have steadily increased their consumption of foods with live microbes over an 18 year period of time - but it still didn't meet guidelines.

The researchers found that fruits, vegetables, and fermented dairy foods were the main sources of microbes, as well as 3 important nutrients which Americans generally do not get enough of: calcium, fiber, and potassium. They also mention that fruits and vegetables have more diverse microbes than fermented dairy foods (yogurts have mainly lactic acid bacteria).

Bottom line: Eating a diet rich in fruits, vegetables, and live fermented foods (e.g., yogurt, kefir, fermented pickles, and kimchi) are good ways to increase the number and variety of microbes in your diet. This study did not mention organic foods, but some studies have found more beneficial bacteria in organic produce (e.g., apples).

From Medical Xpress: Quantifying the live microbes on your plate

Many have hypothesized that bacteria and other "friendly" live microorganisms consumed through the diet can play an important role in health. Reduction in dietary microbe consumption has likely contributed to an "impoverished" gut microbiota, which may lead to improper immune system development and an increase in chronic diseases, among other negative health outcomes. ...continue reading "The Foods We Eat Contain Live Microbes"

Recently the CDC (Centers for Disease Control and Prevention) released the  depressing news that very few Americans are eating recommended amounts of fruits and vegetables. Many studies show that eating several servings each day of fruits and vegetables has all sorts of health benefits (e.g., live longer, lower inflammation, lower risk of diabetes and some cancers).

The CDC reported in the Jan. 7, 2022 CDC weekly report that surveys of 294,566 adults in 2019 found that only 12.3% of American adults met fruit intake recommendations, and 10.0% of adults met vegetable intake recommendations.

What are the daily recommendations for fruits and vegetables? According to the CDC, current Dietary Guidelines for Americans advise eating more fruits and vegetables as part of a healthy dietary pattern. This means adults should consume 1.5 to 2 cups of fruit and 2 to 3 cups vegetables daily. (Note: A serving is usually about 1/2 cup of fruits or vegetables.)

Why should you follow these guidelines? The CDC states: "A healthy diet supports healthy immune function and helps to prevent obesity, type 2 diabetes, cardiovascular diseases, and some cancers." Also, having "some of these conditions can predispose persons to more severe illness and death from COVID-19."

Another reason, and one that they don't mention is research finding that eating more fruits and vegetables daily (as part of a healthy diet such as the Mediterranean diet) also improves the gut microbiome. What you eat feeds gut microbes - so you want to feed beneficial microbes associated with health, and not those microbes associated with chronic inflammation and some chronic diseases (e.g. heart disease, diabetes, some cancers).

CDC weekly report, Jan. 7, 2022: Adults Meeting Fruit and Vegetable Intake Recommendations — United States, 2019

A recent study found that eating higher levels of foods with flavonoids (e.g. berries, apples, and tea) may lower the risk of later development of Alzheimer's disease and other age-related dementias.

Since currently there are no effective drugs that prevent or actual medical treatments for dementia, it is great that what a person eats (the dietary pattern) long-term may be protective. Something we can do to lower our risk for Alzheimer's disease and other dementias!

Tufts University researchers followed 2801 persons (50 years and older) for 20 years and found that those with the lowest intake of flavonoid rich foods (especially 3 flavonoid classes: flavonols, anthocyanins, and flavonoid polymers) had a 20 to 40% higher chance of developing Alzheimer's disease and other dementias, when compared to those eating the most flavonoid rich foods. [Note: The lowest intake group averaged  about 1 1/2 apples, but no berries or tea per month.]

Flavonoids are naturally occurring bioactive pigments, of which there are 7 types, that are found in plant-based foods. Some good sources of different types of flavonoids include berries & red wine (anthocyanin rich), onions & apples, pears (flavonol rich), citrus fruits and juices, teas, dark chocolate, parsley, celery,and soy products.

Eating a variety of fruits and vegetables appears to be best for health benefits. There is no one super-food. Other studies also find that the Mediterranean diet, which emphasizes fruits and vegetables (thus flavonoid rich), may reduce the risk of cognitive decline and dementia, including Alzheimer's disease.

Why are flavonoid containing foods protective, specifically "neuroprotective"? Studies suggest that they do the following: antioxidant effects, protect neurons from neurotoxins and combat neuroinflammation, and favorable changes in brain blood flow,

Excerpts from Science Daily: More berries, apples and tea may have protective benefits against Alzheimer's

Older adults who consumed small amounts of flavonoid-rich foods, such as berries, apples and tea, were two to four times more likely to develop Alzheimer's disease and related dementias over 20 years compared with people whose intake was higher, according to a new study led by scientists at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University.  ...continue reading "Eating More Fruits and Berries Lowers Risk of Dementia"

Wondering which fruits and vegetables have the most pesticide residues? The annual Dirty Dozen List of produce with the most pesticide residues has once again been published by the Environmental Working Group (EWG). They suggest that these fruits and vegetables are good candidates for buying organic.

Why organic? Because while almost 70 % of the produce sampled by the Federal Government had pesticide residues, some have more than others. For example: about one-third of the strawberries sampled contained 10 or more pesticides. Yikes! The following article also discusses some recent reproductive research and  pesticides on food, as well as EWG's "Clean Fifteen" list of fruits and vegetables with the least pesticide residues. (See more PESTICIDE posts.) From Environmental Health News:

Report calls out worst produce for pesticides—strawberries, spinach top list

Just when you thought it couldn't get any harder to eat healthy. Turns out those nutrient packed foods we're all told to eat—such as strawberries and spinach— are also consistently tainted with potentially harmful pesticides. Both foods top the "Dirty Dozen" list released today by the Environmental Working Group (EWG), which analyzed federal data on pesticides in produce.

EWG, which examined tests done over the past few years by the U.S. Department of Agriculture, reports almost 70 percent of the produce sampled by the feds had pesticide residues. Some were worse than others: "More than 98 percent of samples of strawberries, spinach, peaches, nectarines, cherries and apples tested positive for residue of at least one pesticide," according to the report.  ...continue reading "Fruits, Vegetables, and Pesticide Residues"

New research looked at people who "aged successfully" over a 10 year period compared with those who were "suboptimal agers" or had died. The successful agers were less likely to smoke, and have higher intakes of fiber from fruits, breads, and cereals (primarily from rolled oats and whole grain breads), but not from vegetables. Successful aging was defined as including an absence of disability, depressive symptoms, cognitive impairment, respiratory symptoms, and chronic diseases including cancer, coronary artery disease, and stroke. Fiber intake was more important for successful aging than glycemic index, glycemic load, carbohydrate intake, or sugar intake. From Medical Xpress:

Dietary fiber intake tied to successful aging, research reveals

A new paper—published in The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences by scientists from The Westmead Institute for Medical Research—reports that eating the right amount of fiber from breads, cereals, and fruits can help us avoid disease and disability into old age

Using data compiled from the Blue Mountains Eye Study, a benchmark population-based study that examined a cohort of more than 1,600 adults aged 49 years and older for long-term sensory loss risk factors and systemic diseases, the researchers explored the relationship between carbohydrate nutrition and healthy aging.

They found that out of all the factors they examined—which included a person's total carbohydrate intake, total fiber intake, glycemic index, glycemic load, and sugar intake—it was the fiber that made the biggest difference to what the researchers termed "successful aging." Successful aging was defined as including an absence of disability, depressive symptoms, cognitive impairment, respiratory symptoms, and chronic diseases including cancer, coronary artery disease, and stroke.

"Out of all the variables that we looked at, fiber intake—which is a type of carbohydrate that the body can't digest—had the strongest influence," she said. "Essentially, we found that those who had the highest intake of fiber or total fiber actually had an almost 80 percent greater likelihood of living a long and healthy life over a 10-year follow-up. That is, they were less likely to suffer from hypertension, diabetes, dementia, depression, and functional disability."

While it might have been expected that the level of sugar intake would make the biggest impact on successful aging, Gopinath pointed out that the particular group they examined were older adults whose intake of carbonated and sugary drinks was quite low.

This study backs up similar recent findings by the researchers, which highlight the importance of the overall diet and healthy aging. In another study published last year in The Journals of Gerontology, Westmead Institute researchers found that, in general, adults who closely adhered to recommended national dietary guidelines reached old age with an absence of chronic diseases and disability, and had good functional and mental health status.