Plants vs. lipids. A look at ketogenic and vegan diets.
WORDS ANNA M. ADORA
Based on the data released by the Philippine Statistics Authority, seven out of 10 of the leading causes of death in our country are related to the diet and lifestyle choices we make. This data is consistent with the leading causes of death in other countries, which may signify a new phase of epidemiologic transition medical anthropologists call the age of inactivity and obesity. Rather than looking for a magic pill or trying fad diets, perhaps we should address the root cause and recognize the solution which has been right under our noses: a whole-food, plant-based diet.
Ischemic heart disease is the leading cause of death worldwide and it is caused by cholesterol plaques that accumulate within our arteries, a process called atherosclerosis. This is an insidious process, occurring over decades, as the cholesterol plaque gradually reduces the space that blood can flow within the vessel. The restriction of the blood supply to the heart muscles may cause chest pain especially during moments of exertion, and much worse, if a plaque ruptures a clot can form within the artery causing a heart attack.
This is the reason cholesterol-lowering drugs (mostly statins) are among the best-selling drugs. However, according to a study published in Comparative Biochemistry and Physiology, a diet consisting of leafy vegetables, fruits and nuts reduced LDL (low-density lipoprotein) cholesterol by more than 30%, which is the same effect when taking some statins, and without acquiring the side effects of taking the said medication.
A diet high in fiber (whole grains, legumes, fruits, vegetables, nuts and flaxseed) lowers our LDL and triglyceride levels and a diet high in saturated fat and cholesterol which are both found in meat, poultry, fish, eggs and dairy, have the opposite effect. Eating unhealthy food not only causes an anatomic obstruction in our arteries, but also affects their movement. Inflamed arteries are stiffer and are unable to relax normally. Meat can contain endotoxins which can cause inflammation, regardless of how the meat was prepared.
In a recent systematic literature review, evidence showed that a meat-based or Western-like diet is linked to higher inflammation and a vegetable-and-fruit-based diet is linked to lower inflammation. In another study where 604 people were asked to follow a whole-food, plant-based diet, their C reactive protein (CRP), a marker for inflammation and cardiovascular disease risk, lowered significantly in three weeks. Population studies of communities with low rates of heart disease are all centered on a plant-based diet high in grains and vegetables.
A plant-based diet can also reduce the risk for type 2 diabetes, another disease entity with an overwhelming health impact. In an Adventist population study, the odds of having diabetes was highest in non-vegetarians and lowest in vegans, even after being adjusted for body weight. In a meta-analysis released just last year, processed meat increased the risk for diabetes by 37% per each daily serving, followed by sugar-sweetened beverages (21%) and red meat (17%) while whole grains decreased the risk for diabetes by 13%.
A large-scale case-cohort study of diabetes study published in Diabetes Care found that replacing carbohydrates with protein increased the risk for type 2 diabetes, with the link between protein and diabetes exclusive to protein coming from animals. People who ate the highest amount of protein (109 g/day) had a 22% increase risk for developing diabetes. There is much more evidence linking meat intake to type 2 diabetes mellitus which is why it is not surprising that in the latest guidelines for the management of diabetes, a plant-based diet is now being recommended by the American Association of Clinical Endocrinologists.
If reduction of risk for heart disease and diabetes is not convincing enough, a plant-based diet can also reduce the risk of developing some types of cancer. In 2015, the International Agency for Research on Cancer (IARC) gave processed meat a Group 1 classification meaning that there is sufficient evidence to state that processed meat definitely causes cancer. Other carcinogens that belong to this group are smoking and alcohol. Red meat has been given a group 2A classification, meaning it probably causes cancer.
Processed meat is defined as any meat that has been cured, smoked, salted, fermented or has added preservatives. This includes food such as chicken nuggets, cold cuts, bacon, hot dogs, sausages, pepperoni and ham. The chemicals that are contained in these types of food have been proven to cause cancer, chemicals such as nitrate salts, heme iron, heterocyclic amines, polyaromatic hydrocarbons and N-glycolylneuraminic acid to name a few.
On the other end of the spectrum, a study in the Journal of the American College of Nutrition has stated that fruits and vegetables reduce the risk of esophageal cancer by 64%-67%, lung cancer by 26%-29%, colorectal cancer by 18%, and breast cancer by 11%. For these reasons, a plant-based diet is also recommended by another major health organization, the American Institute for Cancer Research.
But what about protein?
A popular misconception is that people on plant-based diets don’t get enough protein, when in fact, plants contain protein (all kinds of beans, broccoli, mushrooms, nuts, seeds, oats, spinach, avocado, just to name a few) and the healthier type of protein too.
A study published in JAMA Internal Medicine in 2016, which included 131,342 participants, plant protein was associated with a lower all-cause mortality, high animal protein intake was associated with a higher cardiovascular mortality and replacement of animal protein with plant protein can reduce mortality. Instead of worrying about the lack of protein, one should worry about excess protein, especially when it comes from an animal source.
Excess protein is either metabolized by the kidneys, liver, or stored as excess fat. Excess animal protein have been associated with obesity, diabetes, heart disease, high blood pressure, high cholesterol, kidney stones, gout, cancer and premature death.
Many people who decide to avoid meat and dairy make the mistake of consuming processed or unhealthy food that are “accidentally vegan”—potato chips, Oreos, vegetarian cup noodles. An unhealthy plant-based pattern may still increase the risk for the aforementioned illnesses. All of the studies mentioned have been based on a whole-food (“unprocessed”), plant-based diet.
Aside from affecting one’s physical health, a plant-based diet has a large impact on animals and our environment. Animals are bombarded with chemicals and antibiotics, live in the worst conditions and slaughtered as children. The animal agriculture industry is the largest contributor to greenhouse gas emissions. The food, land and water that is used to produce the meat and dairy that we consume leads to deforestation, destruction of wildlife and contributes to world hunger. By eating plant-based we show more compassion to ourselves, animals, and the world we live in.
Anna M. Adora is a vegan cardiologist.