Fruits That Fight Cancer

What if organic fruit and vegetable growers could prove that their produce is 10 to 15 percent more effective in combating cancer than conventional fruits and vegetables?  Customers would flock to their doors offering to pay triple (up from the usual double) prices for such healthful foods.

Unfortunately for organic farmers, they can’t demonstrate any such healthy advantages in their produce. In fact, they’ve been unable to document any consistent, significant health difference in organic produce.

Instead, it’s researchers at the U.S. Department of Agriculture’s Beltsville research center who have been able to increase the healthfulness of already-healthful strawberries—by growing them at higher concentrations of CO₂.

That’s right. More carbon dioxide in the air improves strawberries’ ability to cleanse our cells of the potentially carcinogenic free radicals produced by living and breathing.

Researchers already knew that strawberries are good sources of natural antioxidants. “Strawberries have shown a remarkably high scavenging activity toward chemically generated radicals,” they note. They theorized that adding more CO₂ might improve the strawberries’ health-protecting powers because giving fruits more CO₂ is like giving a human athlete more oxygen: it enhances performance.

Shiow Wang, James Bunce, and John Maas, all with the USDA’s Beltsville Agricultural Research Center, grew and harvested strawberries for two years in open-top clear-acrylic chambers. Two of the chambers had no added CO₂, two had an added 300 parts per million CO₂ above ambient air levels, and two had 600 ppm more CO2 than is currently in the air.

They found that the concentrations of nine different healthful flavinoids doubled in the 600 ppm CO₂ chambers! 

The researchers also found that the high-CO₂ strawberries had higher concentrations of beneficial ascorbic acid and glutathione. Ascorbic acid levels increased by 10 percent in the 300 ppm added-CO₂ chambers and 13 percent at in the 600 ppm added-CO₂ chambers. Glutathione concentrations increased by 3 and 171 percent respectively.

Increasing CO₂ levels for the plants also substantially increased their absorbance activity against such potentially harmful free radicals as peroxyl, hydrogen peroxide, superoxide and singlet oxygen.

Summing up, the USDA researchers said, “Strawberry fruit contain flavonoids with potent antioxidant properties, and under CO₂ enrichment conditions, increased their ascorbic acid, glutathione, phenolic acid, flavonol, and anthocyanin concentrations.”  They further noted further that “plants grown under CO₂ enrichment conditions also had higher oxygen radical absorbance activity.”

I note this good-news strawberry experiment not because I think strawberry growers will soon start marketing CO₂ enriched strawberries. (Actually, at triple prices, they might.)

The point I really want to make is that CO₂ is not a pollutant, as too many global warming activists have made it seem. Instead, CO₂ is the lifeblood of plant life all over the planet.

Nor is human-released CO₂ associated with higher temperatures on the earth. Humans put only about 6 to 7 billion tons of CO₂ into the atmosphere each year, while natural CO₂ emissions from the land, oceans and volcanoes total more than 200 billion tons per year. The atmosphere itself contains some 750 billion tons of carbon dioxide, in dynamic equilibrium with about 37 trillion tons of inorganic carbon dissolved in the oceans.

If every molecule of CO₂ ever emitted from every factory, car, power mower, and barbecue in human history were still in the atmosphere, it still wouldn’t account for the change in the earth’s CO₂ since 1950.

Moreover, recent studies of the Antarctic by the Scripps Institute of Oceanography show that after the last three Ice Ages, CO₂ concentrations increased naturally—200 to 800 years after the warm-up began! If there’s a linkage, higher atmospheric CO₂ is the result of increased warming, not the cause. That’s the opposite of what the global warming advocates have told us.