We don’t buy everything the American Heart Association (AHA) says about diet and cardiovascular disease (CVD).
But – aside from an unscientific, broad-brush swipe at saturated fats – we applaud their new statement on the ability of lifestyle changes to lower high blood triglyceride levels and the risk of cardiovascular disease (CVD).
Rather than announcing new research, the new statement stresses the proven but under-recognized implications of what we already know about the impacts of lifestyle on triglyceride levels.
Here’s the key sentence from the AHA’s press release: “Diet and lifestyle changes that include substituting healthy fats for unhealthy saturated and trans fats, engaging in regular physical activity and losing excess weight can reduce triglycerides – a blood fat – by 20 percent to 50 percent.” (AHA 2011)
AHA’s heart-diet advice: A mixed bag
It’s important to note the human fallibility of “official” bodies like the AHA, even as we report on their latest scientific statement.
For example, the AHA’s prior scientific statement – which exonerated high omega-6 fat intake as a heart risk – distorted the evidence pretty badly.
(To read what other researchers found when they scrutinized the studies underlying the AHA’s omega-6 statement, see “Heart Group's Omega-6 Advice Takes a Huge Hit”.)
Having high levels of triglyceride-type fats in the blood is a proven risk factor for cardiovascular disease (CVD).
In fact, the link between high triglyceride levels and CVD is clearer than the sometimes real but generally oversimplified or exaggerated links between total blood cholesterol levels and CVD.
Unlike the AHA’s sadly inaccurate omega-6 statement, this one seems to be a sound reflection of the evidence.
As the full statement makes clear, by “healthy fats”, they mean polyunsaturated fats … especially the omega-3 fatty acids (EPA and DHA) that abound in oily fish like salmon, tuna, and sardines.
We take issue with the implication that saturated fats are inherently unhealthful, or that unsaturated fats are always healthful.
Saturated fats and cholesterol from foods are not unhealthful when consumed in moderation as part of a balanced whole-foods diet.
Instead, the extremely excessive omega-6 fat intake typical of American diets clearly is dangerous … see our sidebar, “AHA’s cardio advice: A mixed bag”, below, visit the “Omega-3 / Omega-6 Balance” section of our news archive, and see “Cholesterol Fiasco Undermines Accepted Theory”.
AHA statement advises fishy whole-food diets
In short, the AHA urges Americans to be physically active and adopt nutritious, whole-food diets:
Get more exercise.
Reduce intake of sugar and refined starches.
Eat more vegetables and high-fiber whole grains.
Enjoy more fatty fish because their omega-3s lower blood triglyceride levels.
Eat more fruits – especially ones lower in fructose such as cantaloupe, grapefruit, strawberries, peaches, and bananas.
Cut back on sugars, excess intake of which is proven to raise triglyceride levels and lead to “fatty liver” … a key driver of insulin resistance and resulting heart and diabetes.
While this list has become official U.S. policy – see “Eating More Fish Advised in U.S. Diet Guidelines” – people may be more motivated to follow it if they know it drastically reduces a major risk factor for heart disease.
New focus on triglycerides
Statement co-chair Neil J. Stone, M.D., put these blood fats in perspective:
“Triglycerides are an important barometer of metabolic health. When the clinician sees an elevated triglyceride level, there needs to be an important conversation about risk factors and the need to eat less, eat smarter, and to move more on a daily basis to improve triglycerides and the metabolic profile.” (AHA 2011)
And, as the AHA statement notes, high triglyceride levels are “… not a target for drug therapy because there has not been adequate study to show that drug therapy to lower triglycerides to this level [100 mg/dL] is helpful.”
(This quote reflects a regrettable bias toward drug therapies over lifestyle-based disease prevention and amelioration … a slant that’s sadly typical of mainstream, pharma-focused and funded medicine.)
Accordingly, the AHA statement advises that instead of taking marginally effective drugs, “Many people can reduce their triglycerides as well as other metabolic risk factors such as blood sugar and blood pressure with diet, weight loss and increased physical activity.”
Nearly one in three American adults has high triglyceride levels (i.e., above 150 mg/dL).
Triglyceride levels have continued to rise in adults aged 20-49 … an ongoing uptick that’s been paralleled by rising rates of obesity and diabetes in that age range … and increasingly among adolescents as well.
In the AHA statement, “elevated triglycerides” remains defined as it has been, at 150 mg/dL or higher … but it sets a new “optimal” level of 100 mg/dL.
Omega-3s praised, sugars panned
The AHA statement recommends these specific dietary targets for people with high triglycerides (AHA 2011):
Eat more vegetables, high-fiber whole grains, and fruits lower in fructose.
Eat more “healthier” unsaturated fats, especially omega-3 fatty acids found primarily in fatty fish like salmon, sablefish, sardines, anchovies, and tuna.
Limit added sugar to less than 5 to 10 percent of calories consumed – about 100 calories per day for women and 150 calories per day for men.
Limit fructose -- from processed foods and naturally occurring -- to less than 50 to 100 grams per day.
Limit saturated fat to less than 7 percent of total calories.
Limit trans fat to less than 1 percent of total calories.
Curb alcohol consumption, especially if triglyceride levels are greater than 500 mg/dL.
Again, we take issue with insinuations that saturated fats are inherently unhealthful, and that unsaturated fats – specifically, omega-6 fatty acids – are always healthful.
The new statement complements recent AHA scientific statements on childhood and adolescent obesity and dietary sugar intake.
In the 2009 AHA statement on sugar, their expert panel wrote, “High intakes of dietary sugars in the setting of a worldwide pandemic of obesity and cardiovascular disease have heightened concerns about the adverse effects of excessive consumption of sugars.” (Johnson RK et al. 2009)
Most of the added sugar consumed by Americans comes from sweetened beverages. The AHA now recommends drinking no more than 36 ounces of sugar-sweetened beverages per week, based on a 2000-calorie-per-day diet.
The AHA statement encourages people with triglyceride levels at or above 150 mg/dL to engage in physical activities of at least moderate intensity (such as brisk walking) for at least 150 minutes per week, saying “… these activities may contribute an additional 20-30 percent triglyceride-lowering effect.” (AHA 2011)
American Heart Association (AHA). Dietary, lifestyle changes can significantly reduce triglycerides. American Heart Association Rapid Access Journal Report. April 18, 2011. Accessed at http://www.newsroom.heart.org/index.php?s=43&item=1315
Daniels SR et al. Overweight in children and adolescents: pathophysiology, consequences, prevention, and treatment. Circulation. 2005;111:1999 –2012.
Johnson RK et al. Dietary sugars intake and cardiovascular health: a scientific statement from the American Heart Association. Circulation. 2009;120: 1011–1020.
Miller M et al. Triglycerides and Cardiovascular Disease: A Scientific Statement From the American Heart Association. Circulation. 2011 Apr 18. [Epub ahead of print]