USDA’s Dietary Guidelines are updated every five years, and most of the changes are based on the report from the Dietary Guidelines Advisory Committee that was released July 15, 2020, followed by a month-long comment period that ended August 13. The final guidelines were released in December (New York Times, December 29, 2020) As expected, food industry lobbyists object to the Committee’s recommendations for limiting:
• sugar added to foods and drinks,
• alcoholic beverages, and
• red and processed meats.
Arguing against limiting these foods is incredible, when more than 70 percent of North Americans are overweight or obese, increasing their risk for heart attacks, diabetes, many types of cancers, and premature death.
Reduce Intake of Added Sugars
Just about every responsible medical organization, such as the American Heart Association and the American Institute for Cancer Research, recommends restriction of sugar-added foods and drinks. “The amount of daily energy that Americans should get from added sugar was reduced from 10 percent (in the 2015 report) to six percent (this year), though the Advisory Committee notes that only around a third of Americans even hit that ten percent mark” (Modern Farmer, July 15, 2020).
A high rise in blood sugar can damage cells throughout your body. Sugared drinks, including fruit juices, cause the highest rises in blood sugar. Almost all processed foods are likely to have added sugars; check the list of ingredients. More than 70 percent of the added sugars in the North American diet are found in five major categories of foods:
• sweetened beverages,
• sweet snacks,
• candy, and
• breakfast cereals and bars.
The Advisory Committee now recommends restricting alcohol intake to one beverage a day for both men and women, instead of the previous recommendation for men of two drinks per day. They said, “emerging evidence suggests the magnitude of risk associated with low volume alcohol consumption may have been underestimated.”
Alcohol is a poison that can only be broken down by enzymes in your liver. A single drink is the amount of alcohol that can be broken down in one hour:
• 12 ounces of beer (5% alcohol content)
• 8 ounces of malt liquor (7% alcohol content)
• 5 ounces of wine (12% alcohol content)
• 1.5 ounces of 80-proof liquor (40% alcohol content, e.g., gin, rum, vodka, whiskey)
Alcohol in any amount increases risk for heart attacks and certain cancers.
Restrict Red Meat and Processed Meats
Meat from mammals and processed meats are associated with increased risk for heart attacks, diabetes and some cancers, including colon cancer. We now have two leading theories to explain these associations: TMAO and Neu5Gc. These two theories are non-contradictory — they may both be risk factors at the same time.
TMAO (TriMethylAmine Oxide): Meat contains choline and carnitine, which pass to your colon where bacteria convert them to a gas called trimethylamine (TMA) that is absorbed into the bloodstream. TMA then passes to the liver where liver enzymes convert TMA to TMAO. TMAO may increase risk of heart attacks by:
• reducing cholesterol clearance from the bloodstream,
• increasing cells that deposit cholesterol in plaques,
• increasing the cytokines that promote inflammation to form plaques, and
• increasing clotting that is the ultimate cause of heart attacks (Cell, March 24, 2016;165(1):111-124).
Neu5Gc is a sugar-protein molecule found in the tissues of almost every mammal except humans (Proc Nat Acad of Sciences, Sept 29, 2003). When you eat mammal meat, the Neu5Gc is absorbed into your bloodstream and your immune system treats this sugar-protein in the same way that it treats germs, so if you eat mammal meat regularly, your immune system will stay active all the time. This is called inflammation. Researchers have identified a gene (CMAH) that produces Neu5Gc (Genome Biol Evol, Jan 1, 2018;10(1):207-219).
The Advisory Committee’s recommendations on alcohol and sugar were not included in the final 2020-2025 USDA Dietary Guidelines (New York Times, December 29, 2020), but I think that you should still follow their advice:
• “Eat more vegetables, fruits, legumes, whole grains, nuts and seeds,” and
• “Eat less red and processed meats, sugar-sweetened foods and drinks, and refined grains,” and less alcohol.
There is little debate on this in the scientific community, but of course there is still resistance from many members of the food industry.