By Dr. Mercola
Tomatoes, which are actually a fruit and not a vegetable,
contain a number of valuable nutrients, and according to recent
research, organically-grown tomatoes are even more
nutritious than their conventionally-grown counterparts.
One of the most well-known nutrients in tomatoes is lycopene
— the compound that gives tomato its deep red color.
Lycopene is a vital anti-oxidant that has been shown to have
potent
anti-cancerous activity. This compound is not naturally
produced in your body, so it must be supplied via your diet.
Other fruits and vegetables also contain lycopene, but none
has the high concentration of lycopene that the tomato boasts.
Interestingly, when cooked, the bioavailability of lycopene
increases rather than decreases, as is the case with
many other raw foods, as heat has a tendency to destroy valuable
nutrients.
That said, you’re best off avoiding canned tomatoes and
tomato sauces as can liners tend to contain potent estrogen
mimics such as bisphenol A (BPA), which is also a toxic
endocrine disrupting chemical. Your best bet is to make your own
organic tomato sauce from scratch, or buy organic sauce sold in
glass jars.
Organic Tomatoes have 139 Percent Higher Phenolic Content, Study
Shows
It seems perfectly sensible that food grown in healthier soil
with natural fertilizers and no synthetic agricultural chemicals
would be more nutritious. This is common knowledge among
farmers, yet this age-old, common sense wisdom is greatly
suppressed in the United States in order to protect the
large-scale industrial farming model.
According to a recent study published in the journal PLOS
One,1
growing tomatoes according to organic standards results in
dramatically elevated phenols content, compared to tomatoes
grown conventionally, using agricultural chemicals.
The researchers compared total phenol content in organic and
conventional tomatoes grown in nearby plots in Brazil. This
allowed for a more accurate comparison of the tomatoes, as both
varieties were grown in similar soil- and climate conditions
that might otherwise affect nutrient content.
According to the authors:
“This study was conducted with the objective of
testing the hypothesis that tomato fruits from organic
farming accumulate more nutritional compounds, such as
phenolics and vitamin C as a consequence of the stressing
conditions associated with farming system.”
The organic tomatoes were found to contain 55 percent more
vitamin C, and 139 percent more total phenolic content at the
stage of commercial maturity, compared to the
conventionally-grown tomatoes. According to the authors:
“[T]his seems consistent with the more than two times
higher activity of phenylalanine ammonia lyase (PAL) we
observed throughout fruit development in fruits from organic
farming.
Taken together, our observations suggest that tomato
fruits from organic farming experienced stressing conditions
that resulted in oxidative stress and the accumulation of
higher concentrations of soluble solids as sugars and other
compounds contributing to fruit nutritional quality such as
vitamin C and phenolic compounds.”
Today’s Vegetables Aren’t as Nutritious as They Used to Be...
There was a trade-off, and that was size. The
conventional tomatoes were significantly larger. However, while
many unaware consumers equate size with quality, this simply
isn’t the case. At least in the case of organic tomatoes, you
get more even though it’s in a smaller “package.”
This does tend to hold true for other organic produce as well
though. According to research published in 2009, American
produce, while larger than ever before, contains fewer
nutrients and tastes worse than it did in your grandparents'
days.
In fact, the average vegetable found in today's supermarket is
anywhere from 5 percent to 40 percent lower in minerals such as
magnesium, iron, calcium and zinc than those harvested just 50
years ago. As the featured study suggests, jumbo-sized produce
contains more "dry matter" than anything else, which dilutes
mineral concentrations.
Other Studies Have Also Shown Organic Fruits and Veggies Are
More Nutritious
Previous research has also shown there can be a nutritional
difference between organic- and conventionally-grown vegetables.
For example, a 2003 study in the Journal of Agricultural
Food Chemistry2
found that organic foods are better for fighting cancer. And in
2005, scientists found that, compared to rats that ate
conventional diets, organically fed rats experienced various
health benefits. Rats that ate organic or minimally fertilized
diets had:
- Improved immune system status
- Better sleeping habits
- Less weight and were slimmer than rats fed other diets
- Higher vitamin E content in their blood (for organically
fed rats)
Other studies assessing the nutritional composition and
difference between organic and conventional produce include:
- A 2010 study conducted by PloS ONE3
(partially funded by the USDA), which found organic
strawberries to be more nutrient-rich than non-organic
strawberries
- In 2009, the American Association for the Advancement of
Science featured a presentation on soil health and its
impact on food quality.4,
5 Conclusion: Healthy soil leads to higher levels
of nutrients in crops
- Even the Centers for Disease Control and Prevention
conducted their own behavioral study that found higher risk
of ADHD in children with higher levels of organophospates
(pesticides)6
But perhaps one of the best studies out there on the benefits
of organic versus conventionally-grown foods is the 2007 Quality
Low Input Food Project7
-- a $25-million study into organic food, and the
largest of its kind. The researchers grew fruit and vegetables,
and raised cattle, on adjacent organic and non-organic sites,
and discovered that:
- Organic fruit and vegetables contain up to 40 percent
more antioxidants
- Organic produce had higher levels of beneficial minerals
like iron and zinc
- Milk from organic herds contained up to 90 percent more
antioxidants
The results were so impressive they stated that eating
organic foods can even help to increase the nutrient intake of
people who don’t eat the recommended five servings of fruits and
vegetables a day. Besides the potential for improved nutrition,
other reasons for choosing organic, and ideally locally-grown
food include better food quality, better taste and, in the case
of local food: increased freshness since the food has not
traveled over thousands of miles.
Another Important Boon of Organic = Reduced Toxic Load
Many “health” experts insist there is little difference
between organic and conventionally raised produce, but their
arguments are flimsy at best. For example, a 2012 meta-analysis
by Stanford University8
received widespread media coverage, and with few exceptions,
conventional media outlets used it to cast doubt on the value of
an organic diet. You had to be a reader of alternative media to
get the real scoop on this study...
In a nutshell, the meta-analysis, which looked at 240 reports
comparing organically and conventionally grown food (including
17 human studies), found that organic foods ARE safer, and
probably healthier than conventional foods — if you are of
the conviction that ingesting fewer toxins is healthier and
safer for you. Interestingly, the Stanford study also
found that organic foods tend to have higher levels of phenols,
specifically.
While I believe organic foods grown in healthy soils can be
more nutritious than their conventional counterparts grown in
depleted soils with synthetic chemicals, a major
benefit of organically grown foods really is the reduction
in your toxic load. Agricultural chemicals, such as
synthetic fertilizers, herbicides and pesticides, can cause a
wide variety of health problems, including:
- Neurotoxicity
- Disruption of your endocrine system
- Cancer
- Immune system suppression
- Male infertility and miscarriages in women
The Health Benefits of Tomatoes
Tomatoes are rich in flavonoids and other phytochemicals that
have anticarcinogenic properties. They’re also an excellent
source of lutein, zeaxanthin, vitamin C, which is most
concentrated in the jelly-like substance that surrounds the
seeds, as well as vitamins A, E and B-complex vitamins,
potassium, manganese and phosphorus. Other lesser known
phytonutrients found in tomatoes include:
- Flavonols: rutin, kaempferol, quercetin
- Flavonones: naringenin, chalconaringenin
- Hydroxycinnamic acids: caffeic acid, ferulic acid,
coumaric acid
- Glycosides: esculeoside A
- Fatty acid derivatives: 9-oxo-octadecadienoic acid
Getting back to lycopene — a carotenoid antioxidant that
gives fruits and vegetables like tomatoes and watermelon a pink
or red color — this is one nutrient you’ll want to be sure
you're getting enough of.
Lycopene's antioxidant activity has long been suggested to be
more powerful than other carotenoids such as beta-carotene, and
recent research revealed it may significantly reduce your
stroke risk (while other antioxidants did not). The 2012
analysis9
followed over 1,000 men in their mid-40s to mid-50s for more
than 12 years.
After controlling for other stroke risk factors, such as
older age and diabetes, they found that men with the highest
blood levels of lycopene were 55 percent less likely to have a
stroke than those with the lowest. Other antioxidants, including
alpha carotene, beta-carotene, alpha tocopherol (vitamin E) and
retinol (vitamin A), showed no such benefit.
The high blood levels of lycopene were said to be a marker
for intake of tomatoes and tomato-based products, as these are a
particularly concentrated source. It's estimated that 85 percent
of dietary lycopene in North Americans comes from tomato
products such as tomato juice or tomato paste.10
In addition to lowering your risk of stroke, lycopene from
tomatoes (including unsweetened organic tomato sauce) has also
been shown to be helpful in treating
prostate cancer.
Tomatoes Must be Eaten with Fat for Proper Absorption, and Two
Other Caveats
Lycopene is a fat-soluble nutrient, which means eating it
with some dietary fat is essential in order for it to be
properly absorbed. So a slow-cooked tomato sauce that contains
olive oil or another source of healthy fat, such as grass-fed
beef, may be an ideal source.
One caveat: when making your tomato sauce, start out with
fresh tomatoes, as canned tomatoes typically have a lining that
contains bisphenol-A (BPA) which is a potent estrogen mimic that
have been linked to a number of health problems, including
diabetes, heart disease, heightened risk of breast and prostate
cancers, neurological effects, reproductive problems and
obesity.
The current US federal guidelines put the daily upper limit
of “safe” exposure at 50 micrograms of BPA per kilogram of body
weight. According to endocrinologist Dr. Fredrick vom Saal, a
tin can contains around 50 mcg of Bisphenol A (BPA), and when
the cans contain acidic food such as tomatoes, it will leach
more BPA from the liner into the food. According to
Consumer Reports’ testing, just a couple of servings of
canned food can exceed the safety limits for daily BPA exposure
for children.
So, ideally avoid canned foods entirely and stick to fresh
fruits and vegetables, or switch over to brands that use glass
containers instead. One other point: if you eat a lot of
ketchup, you might want to consider choosing an organic version
(as well as one that is unsweetened, as regular ketchup is a
common source of sugar and high fructose corn syrup). Organic
ketchup has been found to contain 57 percent more lycopene than
conventional national brands.11
Cooked Tomatoes May be Better than Raw
Tomatoes differ from many other raw foods in that cooking
them may in fact be better than eating them raw. Research shows
that cooked tomatoes (such as in tomato sauce or tomato paste)
not only increases the lycopene content that can be absorbed by
your body, but also increases the total antioxidant activity. In
one study,12
when tomatoes were heated to just over 190 degrees F (88 degrees
C) for two minutes, 15 minutes and 30 minutes:
- Beneficial trans-lycopene content increased by 54
percent, 171 percent and 164 percent, respectively
- Levels of cis -lycopene (which is a form easily absorbed
by your body) rose by 6, 17 and 35 percent, respectively
- Overall antioxidant levels increased by 28, 34 and 62
percent, respectively
Return to 'the Way Things Were...'
The simplest way back toward health is to focus on whole,
organic foods, grown or raised as nature intended. Meaning, it’s
grown using sustainable farming practices, and without the use
of chemical additives, pesticides and fertilizers. You can even
grow your own. Picking the types of seeds can go a long way in
helping your garden be plentiful and even determines how juicy
or hardy your vegetables are. Heirloom seeds are seeds that have
been carefully cultivated to produce the best plants possible;
they're hardy and bountiful. You can find packages containing 26
of the popular heirloom seeds in my
Heirloom Variety Seed Collection, available in my online
store.
As the featured study attests, fruits and vegetables grown
according to organic standards are typically nutritionally
superior, but even if they weren’t, organic produce
will limit the amount of toxic residues you end up consuming,
which is a major benefit in and of itself.
As for tomatoes, they’re one of the most potent sources of
lycopene, shown to have anti-cancerous activity and the
potential to reduce stroke risk. Just remember to consume your
tomatoes, whether raw or cooked, with some type of fat, such as
olive oil, since lycopene is a fat-soluble nutrient. Also
remember to choose organic varieties, whether whole tomatoes or
tomato paste, ketchup or sauce, and avoid anything that comes in
a can, since the acidity of the tomatoes will increase toxic BPA
release from the liner in the can.
© Copyright 1997-2013 Dr. Joseph Mercola. All Rights Reserved.