According to new research from the University of Warwick, eating a plant-based diet can lower blood pressure even if only small amounts of meat and dairy are consumed.
A team from Warwick Medical School published online Journal of Hypertension Today (July 25), they argue that any effort to increase plant-based foods in your diet and limit animal products will benefit your blood pressure and reduce your risk of heart attack, stroke and cardiovascular disease. They conducted a systematic review of previous studies from controlled clinical trials to compare seven plant-based diets, some of which included small amounts of animal products, with a standardized control diet and its effects on individuals’ blood pressure.
Plant-based diets support high consumption of fruits, vegetables, whole grains, beans, nuts, and seeds, while limiting consumption of most or all animal products (mainly meat and dairy).
High blood pressure is a major risk factor for heart attack, stroke and other cardiovascular diseases worldwide. Lowering blood pressure has important health benefits for both individuals and populations. Unhealthy diets account for more death and disability worldwide than tobacco use, high alcohol consumption, drug use and unsafe sex. Increased consumption of whole grains, vegetables, nuts and seeds, and fruits, as achieved in a plant-based diet, could avoid 1.7, 1.8, 2.5 and 4.9 million deaths worldwide each year, according to previous studies.
Vegetarian and vegan diets with a complete absence of animal products are already known to lower blood pressure compared to omnivorous diets. However, their feasibility and sustainability are limited. Until now, it is not known whether the complete absence of animal products is necessary in plant-based dietary patterns to achieve significant beneficial effects on blood pressure.
Lead author Joshua Gibbs, a student at the University of Warwick’s School of Life Sciences, said: “We reviewed 41 studies involving 8,416 participants, examining the effects of seven different plant-based diets (including DASH, Mediterranean, vegetarian, vegan, Nordic), high fiber and high in fruits and vegetables) were studied in controlled clinical trials on blood pressure. A systematic review and meta-analysis of these studies found that most of these foods lowered blood pressure. The DASH diet had the greatest effect on lowering blood pressure. 5.53/3.79 mmHg compared to a control diet, and 8.74/6.05 mmHg compared to a ‘normal’ diet.
“The level of blood pressure reduction due to higher consumption of a plant-based diet, even with limited animal products, would result in a 14% reduction in stroke, a 9% reduction in heart attack and a 7% reduction in overall mortality.
“This is a significant finding because it highlights that it is not necessary to completely eliminate animal products to reduce and improve blood pressure. Basically, any change to a plant-based diet is good.”
Senior author Professor Francesco Cappuccio, from Warwick Medical School, said: “Adopting plant-based diets will also contribute to global food sustainability and security. They will contribute to reduced land use due to human activities, global water conservation and significant reductions in global greenhouse gas emissions.
“Research shows the effectiveness of a plant-based diet on blood pressure. However, the translation of this knowledge into actual benefits for humans, i.e. its effectiveness, depends on a variety of factors related to both personal preference and government policy decisions. For example, for an individual, a plant-based diet The ability to adopt will be influenced by socio-economic factors (cost, availability, access), perceived advantages and disadvantages, resistance to change, age, health status, low adherence, taste and acceptance.
“To overcome these barriers, we should develop strategies to influence beliefs about plant-based diets, availability and cost of plant foods, environmental sustainability of food production, science gathering, and multisectoral actions for policy change focused on health outcomes.”
Details of the seven plant-based diets tested (Table 1 of the research paper):
Plant-based foods and main ingredients:
- Healthy Nordic Diet — high in plant foods, fish, eggs and vegetable fats and low in meat products, dairy products, sweets, desserts and alcoholic beverages
- High Fruit and Vegetable Diet – Increased consumption of fruits and vegetables. To further increase the polyphenolic load, some studies included regular dark chocolate content
- Foods High in Fiber — Fiber is found in varying degrees in all plant foods and is most common in whole grains and legumes. For this reason, most high-fiber diets focus on increasing consumption of whole grains and legumes
- Lacto-ovo vegetarian diet — which excludes the consumption of all meat, poultry and fish, but includes the consumption of dairy products and eggs. Key ingredients include fruits, vegetables, whole grains, beans, and nuts and seeds
- DASH Diet – encourages intake of fruits, vegetables, whole grains, nuts and seeds and low-fat dairy products and limits intake of sweets, saturated fat and sodium
- Mediterranean Diet – The main components are daily vegetables, fruits, whole grains, olive oil, weekly lemons, nuts, fish, dairy and eggs, and a limited intake of meat.
- Vegan diet – consists exclusively of plant foods. Does not include any animal meat or other animal products (including dairy and eggs). It focuses on eating mostly low-fat and whole plant foods like fruits, vegetables, whole grains, legumes, and nuts and seeds.